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  Subjects -> AGRICULTURE (Total: 777 journals)
    - AGRICULTURAL ECONOMICS (77 journals)
    - AGRICULTURE (526 journals)
    - CROP PRODUCTION AND SOIL (91 journals)
    - DAIRYING AND DAIRY PRODUCTS (31 journals)
    - POULTRY AND LIVESTOCK (52 journals)

AGRICULTURE (526 journals)

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Journal Cover European Journal of Agronomy
  [SJR: 1.381]   [H-I: 60]   [9 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1161-0301
   Published by Elsevier Homepage  [2969 journals]
  • Preanthesis biomass accumulation of plant and plant organs defines yield
           components in wheat
    • Abstract: Publication date: November 2016
      Source:European Journal of Agronomy, Volume 81
      Author(s): Quan Xie, Sean Mayes, Debbie L. Sparkes
      The preanthesis period in wheat is critical for growth of plant organs including leaves, stems, spikes and roots. However, the roles of the preanthesis biomass accumulation of plant and plant organs in yield determination are only partially elucidated, and the underlying genetic basis remains largely unknown. This study aimed to understand the physiological and genetic relationships between preanthesis biomass accumulation and yield determination. In a mapping population of bread wheat (Triticum aestivum ‘Forno’) and its relative spelt (Triticum spelta ‘Oberkulmer’) contrasting for biomass, the dry weight of above-ground whole shoots and different organs, and leaf area, were analysed at GS39 (full flag leaf emergence) and anthesis. Yield components (thousand grain weight, grains per spike, final shoot biomass and grain weight per spike) and plant height were measured at maturity, followed by identification of quantitative trait loci (QTL) for all above traits. Field experiments were carried out in UK in 2011–2012 and 2012–2013 seasons, each using a randomised complete block design with three replicates. The results showed that there was a significant variation in biomass and its partitioning to organs at different stages. Consistent with the previous findings, stem water soluble carbohydrates and spike dry weight at anthesis contributed to thousand grain weight and grains per spike, respectively. In addition, this study revealed many other traits positively associated with one or more yield components, including biomass and leaf area at GS39, leaf and structural stem growth as well as whole shoot biomass at anthesis, and higher dry matter accumulation and crop (and spike) growth rates between the two stages. Increasing shoot biomass by removing other tillers at GS39 led to higher grain number and grain weight per spike. These results indicate the importance of the preanthesis growth of plant and plant organs for yield determination. Plant height was only weakly correlated with final biomass at maturity so it is possible to produce high-biomass genotypes without increasing plant height. Genetic analysis revealed 193 QTL associated with biomass and biomass-related traits. Frequent QTL coincidences between biomass and yield traits were observed, mainly on chromosomes 2B, 3A, 4A, 4B, 5A, 6A and 7B, indicating pleiotropy or tight gene linkages, consistent with their phenotypic associations. The preanthesis biomass traits associated with yield components and the underlying QTL, would facilitate the trait-based physiological and molecular breeding in wheat.


      PubDate: 2016-08-25T09:35:43Z
       
  • Does the recoupling of dairy and crop production via cooperation between
           farms generate environmental benefits? A case-study approach in Europe
           
    • Abstract: Publication date: Available online 24 August 2016
      Source:European Journal of Agronomy
      Author(s): John T Regan, Silvia Marton, Olivia Barrantes, Eimear Ruane, Marjoleine Hanegraaf, Jérémy Berland, Hein Korevaar, Sylvain Pellerin, Thomas Nesme
      The intensification of agriculture in Europe has contributed significantly to the decline of mixed crop-livestock farms in favour of specialised farms. Specialisation, when accompanied by intensive farming practices, leaves farms poorly equipped to sustainably manage by-products of production, capture beneficial ecological interactions, and adapt in a volatile economic climate. An often proposed solution to overcome these environmental and economic constraints is to recouple crop and livestock production via cooperation between specialised farms. If well-managed, synergies between crop and livestock production beyond farm level have the potential to improve feed and fertiliser autonomy, and pest regulation. However, strategies currently used by farmers to recouple dairy livestock and crop production are poorly documented; there is a need to better assess these strategies using empirical farm data. In this paper, we employed farm surveys to describe, analyse and assess the following strategies: (1) Local exchange of materials among dairy and arable farms; (2) Land renting between dairy and arable farms; (3) Animal exchanges between lowland and mountainous areas; and (4) Industrially mediated transfers of dehydrated fodder. For each strategy, cooperating farm groups were compared to non-cooperating farm groups using indicators of metabolic performance (input autonomy, nutrient cycling and use efficiency), and ecosystem services provision. The results indicate that recoupling of crop and dairy production through farm cooperation gives farmers access to otherwise inaccessible or underutilised local resources such as land, labour, livestock feed or organic nutrients. This in turn leads to additional outlets for by-products (e.g. animal manure). Farmers’ decisions about how to allocate the additional resources accessed via cooperation essentially determine if the farm diversifies, intensifies or expands operations. The key finding is that in three of the four crop-livestock integration strategies assessed, these newly accessed resources facilitated more intensive farming practices (e.g. higher stocking rate or number of milking cows per hectare) on cooperating dairy farms relative to non-cooperating, specialised dairy farms. As a consequence, cooperation was accompanied by limited environmental benefits but helped to improve resource use efficiency per unit of agricultural product produced. This article provides a critical step toward understanding real-world results of crop-livestock cooperation beyond the farm level relative to within-farm crop-livestock integration. As such, it brings practical knowledge of vital importance for policy making to promote sustainable farming.


      PubDate: 2016-08-25T09:35:43Z
       
  • Climate, soil and land-use based land suitability evaluation for oil palm
           production in Ghana
    • Abstract: Publication date: November 2016
      Source:European Journal of Agronomy, Volume 81
      Author(s): Tiemen Rhebergen, Thomas Fairhurst, Shamie Zingore, Myles Fisher, Thomas Oberthür, Anthony Whitbread
      In the past decade, oil palm (Elaeis guineensis Jacq.) has become the world’s most important oil crop. The large demand for palm oil has resulted in a rapid expansion of oil palm cultivation across the globe. Because of the dwindling availability of land in Southeast Asia, most expansion of the industry is expected in Central and South America and sub-Saharan Africa, where land with suitable agro-ecological conditions is available. Using Ghana as a case study, a method for evaluating areas that are both suitable and available for oil palm production is presented. Our assessment used spatial data and GIS techniques, and showed that areas with suitable climatic conditions (annual average water deficit <400mm) is about 20% greater than was previously identified. The observed differences are the result of using different methods to determine suitability, and climate change. A major climatic factor limiting suitability for oil palm production in Ghana is the annual water deficit, with the most suitable areas located in the rainforest and semi-deciduous forest zones with higher rainfall in southern Ghana. Opportunities for large-scale oil palm plantation development is limited, however, because of the lack of availability of large and contiguous tracts of land that are required for commercial plantation oil palm development. A feasible strategy for oil palm expansion is therefore smallholder production, which can make use of smaller parcels of land. Alternatively, oil palm production in Ghana can be increased by yield intensification on land already planted to oil palm. This can also reduce the requirement for further land clearance for new plantations to meet the growing demand for palm oil. Such assessments will be essential for guiding government policy makers and investors considering investments in oil palm development.


      PubDate: 2016-08-25T09:35:43Z
       
  • Intensification of an irrigated rice system in Senegal: Crop rotations,
           climate risks, sowing dates and varietal adaptation options
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): P.A.J. van Oort, A. Balde, M. Diagne, M. Dingkuhn, B. Manneh, B. Muller, A. Sow, S. Stuerz
      Feeding the future world population requires increased crop production. Here, we investigate the intensification option of increasing production by increasing cropping intensity and choice of varieties with different crop duration. We developed a model to generate, compare and visualise opportunities for single/double/triple cropping systems consisting of irrigated rice and optionally a vegetable. The model was applied in a case study in the Senegal River valley. Results showed that with appropriate choice of sowing dates, severe cold sterility in rice can be avoided, also in rice–rice crop rotations. At optimal sowing dates, simulated total long term average potential yields of single, double and triple cropping yields were 10.3, 19.0 and 18.9 t/ha respectively (total of 1,2 and 3 yields). With a hypothetical completely cold tolerant variety, yields could increase to 11.2, 20.2 and 20.9 respectively. Simulated Triple crop yields are hardly any higher than those of a double crop with two medium duration varieties. Delay in sowing due to late availability of resources (machinery, irrigation water allocation within a scheme, credits for pump fuel) is a known problem in the region. Therefore we also simulated how much delay was possible (width of the sowing windows) whilst still allowing for double cropping. We found enough delay was possible to allow for a rice–rice or a rice-vegetable crop. A rice-rice-vegetable triple cropping system would only be possible without delays and with a very short duration vegetable of 2 months. Most promising options to increase production are through shifting the sowing date to facilitate double cropping, adoption of medium duration varieties and breeding for cold tolerant varieties.
      Graphical abstract image

      PubDate: 2016-08-19T09:12:37Z
       
  • Fertilizers, hybrids, and the sustainable intensification of maize systems
           in the rainfed mid-hills of Nepal
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): K.P. Devkota, A.J. McDonald, L. Khadka, A. Khadka, G. Paudel, M. Devkota
      In the rainfed mid-hill region of Nepal, most fields receive 2–3tha−1 of organic compost application every year. Despite efficient recovery and use of organics in the mixed crop-animal systems that predominant in the mid-hills, depleted soil fertility is widely understood to be a significant constraint to crop productivity, with most farmers achieving maize grain yields below 2tha−1. Increased use of fertilizer may arrest and even reverse long-term soil quality degradation, but few farmers in the mid-hills use them at present and existing recommendations are insufficiently responsive to site, varietal, and management factors that influence the productivity and profitability of increased fertilizer use. Moreover, policy makers and development practitioners often hold the perception that returns to fertilizer use in the mid-hills are too low to merit investment. In this study, on-farm experiments were conducted at 16 sites in the Palpa district, Nepal to assess the responsiveness of a maize hybrid (DKC 9081) and an ‘improved’ open-pollinated maize variety (‘OPV’, Manakamana-3) to four nitrogen (N) rates, i.e., 0, 60, 120 and 180kgha−1, with each N rate response evaluated at 30:30 and 60:60kgha−1 rates of phosphorus (P2O5) and potassium (K2O), respectively. With sound agronomy and high rates of fertilizer (180:60:60kgN:P2O5:K2Oha−1), grain yields observed in the field experiments exceeded 8tha−1 with hybrids and 6tha−1 with OPV. Yield levels were lower for OPV than hybrid at every level of applied N, but both genotypes responded linearly to N with partial factor productivity for N (PFPN) ranging from 14 to 19 for OPV versus 26–30 for hybrid, with improved N efficiencies obtained when P and K rates were significantly higher. Averaged across phosphorus (P) and potassium (K) levels, a $ 1 incremental investment in fertilizer increased the gross margin (GM) by $ 1.70ha−1 in OPV and by $ 1.83ha−1 in the hybrid. For the full response of N, requires higher rate of P2O5:K2O and vice-versa and full response to P2O5:K2O does not occur if N is absent. These results suggest that, i) degraded soils in the mid-hills of Nepal respond favorably to macronutrient fertilizers – even at high rates, ii) balanced fertilization is necessary to optimize returns on investments in N but must be weighed against additional costs, iii) OPVs benefit from investments in fertilizer, albeit at a PFPN that is 36–47% lower than for hybrids, and, consequently iv) hybrids are an effective mechanism for achieving a higher return on fertilizer investments, even when modest rates are applied. To extend these findings across years and sites in the mid-hills, crop growth simulations using the CERES-maize model (DSSAT) were conducted for 11 districts with historical weather and representative soils data. Average simulated (hybrid) maize yields with high fertilizer rate (180:60:60kgN:P2O5:K2Oha−1) ranged from 3.9tha−1 to 7.5tha−1 across districts, indicating a high disparity in attainable yield potential. By using these values to estimate district-specific attainable yield targets, recommended N fertilizer rates vary between 65 and 208kgNha−1, highlighting the importance of developing domain-specific recommendations. Simulations also suggest the potential utility of using weather forecasts in tandem with site and planting date information to adjust fertilizer recommendations on a seasonal basis.


      PubDate: 2016-08-14T08:41:20Z
       
  • Dynamic change of mineral nutrient content in different plant organs
           during the grain filling stage in maize grown under contrasting nitrogen
           supply
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Qinwu Chen, Xiaohuan Mu, Fanjun Chen, Lixing Yuan, Guohua Mi
      The introduction of new hybrids and integrated crop-soil management has been causing maize grain yield to increase. However, less attention has been paid on the nutrient concentration of the grain; this aspect is of great importance to supplying calories and nutrients in the diets of both humans and animals worldwide. Increasing the retranslocation of nutrients from vegetative organs to grain can effectively increase the nutrient concentration of grain and general nutrient use efficiency. The present study involved monitoring the dynamic change of macro- and micronutrients in different organs of maize during the grain filling stage. In addition, the mobility of different elements and their contribution to grain nutrient content were evaluated in a 2-year experiment under low (LN, no N supplied) and high N (HN, 180kgNha−1) supply. Under HN supply, the net remobilization efficiency (RE) of the vegetative organs as a whole (calculated as nutrient remobilization amount divided by nutrient content at silking) of N, P, K, Mn, and Zn were 44%, 60%, 13%, 15%, and 25%, respectively. The other nutrients (Mg, Ca, Fe, Cu, and B) showed a net accumulation in the vegetative organs as a whole during the grain filling stage. Among the different organs, N, P, and Zn were remobilized more from the leaves (RE of 44%, 51% and 43%, respectively) and the stalks (including leaf sheaths and tassels) (RE of 48%, 71% and 43%, respectively). K was mainly remobilized from the leaves with RE of 51%. Mg, Ca, Fe, Mn, and Cu were mostly remobilized from the stalks with the RE of 23%, 9%, 10%, 42%, and 28%, respectively. However, most of the remobilized Mg, Ca, Fe, Mn, Cu, and Zn were translocated to the husk and cob, which seemingly served as the buffer sink for these nutrients. The REs of all the nutrients except for P, K, and Zn were vulnerable to variations in conditions annually and were reduced when the grain yield and harvest index were lower in 2014 compared with 2013. Under LN stress, the RE was reduced in P and Zn in 2013, increased in Cu and unchanged in other nutrients. The concentration of these nutrients in the grain was either unchanged (P, K, Ca, Zn, and B) or decreased (N, Mg, Fe, Mn, and Cu). It is concluded that grain N, P, K, Mn, and Zn, but not Mg, Ca, Fe, Cu, and B concentration, can be improved by increasing their remobilization from vegetative organs. However, enhancing the senescence of maize plant via LN stress seems unable to increase grain mineral nutrient concentration. Genetic improvement aiming to increase nutrient remobilization should take into account the organ-specific remobilization pattern of the target nutrient.


      PubDate: 2016-08-09T13:30:50Z
       
  • Ridge-furrow mulching system in semiarid Kenya: A promising solution to
           improve soil water availability and maize productivity
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Fei Mo, Jian-Yong Wang, You-Cai Xiong, Simon N. Nguluu, Feng-Min Li
      In semiarid Kenya, field productivity of maize has been at a low integrity level due to insufficient use of rainwater use. From 2012 to 2013, an innovative ridge-furrow mulching system (RFMs) was tested using local maize (Zea mays L.) hybrid, KCB in KARI-Katumani Farm, Kenya in long and short rainy seasons. Field experiments were conducted in a randomized complete block design with four treatments: 1) RFMs with transparent polyethylene film (RFT), 2) RFMs with black polyethylene film (RFB), 3) RFMs with grass straw mulching (RFS), and 4) RFMs without mulching (CK). Soil moisture & temperature, grain yield, water use and economic benefit were determined and analyzed. The results indicated that both RFT and RFB treatments significantly increased soil water storage amount in the depth of 0–60cm. Grain yield and water use efficiency (WUE) in both treatments were increased by 66.5–349.9% and 72.9–382% respectively, compared with those of CK over two growing seasons. In addition, grain yield and WUE in RFS treatment were only increased by from 4.2–127.1% compared with those of CK. Particularly, two types of plastic films displayed different effects on modifying topsoil temperature. Transparent film mulching significantly increased topsoil temperature by 1.3°C (p <0.05) higher than CK, to facilitate growth and grain formation in long (but cool) growing season. In contrast, black film mulching lowered soil temperature by 0.3°C lower than CK in short (but warm) growing season, which led to better soil thermal balance. Overall, RFMs with film mulching could serve as an effective solution to increase maize productivity, and hence a promising strategy to cope with food security under climate change in semiarid Kenya.


      PubDate: 2016-08-09T13:30:50Z
       
  • Impacts of agricultural land use changes on pesticide use in French
           agriculture
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Nicolas Urruty, Tanguy Deveaud, Hervé Guyomard, Jean Boiffin
      Public policies seeking to regulate pesticide use must be based on a clear identification of the factors influencing such use. Since the agricultural use of pesticides is primarily crop-dependent, agricultural land use change is potentially an important driver of the overall level of pesticide use in a given country. In this paper, we investigate the influence of agricultural land use changes on pesticide use in French agriculture over the period 1989–2013, during which important changes in the Common Agricultural Policy took place. Toward that end, we developed a method allowing the direct effects of agricultural land use changes to be disentangled from other factors affecting the intensity of pesticide use. On the basis of standard protection programs defined by crop protection experts, a fixed pesticide use intensity is estimated for 19 annual and perennial crops representing 90% of French arable land area and the bulk of pesticide use in French agriculture. These coefficients, combined with national agricultural land use statistics, are used to construct an artificial index of pesticide use in France whose variations depend solely on changes in agricultural land use. This index is calculated over the period 1989–2013. Our results indicate that the direct impacts of agricultural land use changes on pesticide use in France have varied depending on the time period considered, reflecting the influence of public regulations, notably the compulsory set-aside policy in force during the 1990s, and market conditions, particularly the context of high prices for cereal grains at the end of the 2000s. Over the six years from 2008 to 2013, this index is roughly constant, indicating that the 17% increase in French pesticide use in 2013 compared to 2008 (as assessed from annual pesticide sales) cannot be even partially attributed to agricultural land use changes. Since 2000, land use changes mainly corresponded to substitutions between crops with similar per-hectare pesticide use intensities, and/or to substitutions with counterbalancing impacts on these intensities. A prospective approach shows that other types of land use changes (e.g. a massive conversion of grassland to arable land or, conversely, a strong diversification of arable crop rotations), could have much higher impacts on pesticide use, with the effect of either offsetting or reinforcing efforts to reduce pesticide use intensity in arable crops. Thus, better coordination is needed between public policies aimed at regulating pesticide use and public policies influencing land use.
      Graphical abstract image

      PubDate: 2016-08-09T13:30:50Z
       
  • Field evaluation of mixed-seedlings with rice to alleviate flood stress
           for semi-arid cereals
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Simon K. Awala, Koji Yamane, Yasuhiro Izumi, Yuichiro Fujioka, Yoshinori Watanabe, Kaede C. Wada, Yoshimasa Kawato, Osmund D. Mwandemele, Morio Iijima
      Flash floods, erratically striking semi-arid regions, often cause field flooding and soil anoxia, resulting in crop losses on food staples, typically pearl millet (Pennisetum glaucum L.) and sorghum (Sorghum bicolor (L.) Moench). Recent glasshouse studies have indicated that rice (Oryza spp.) can enhance flood stress tolerance of co-growing dryland cereals by modifying their rhizosphere microenvironments via the oxygen released from its roots into the aqueous rhizosphere. We tested whether this phenomenon would be expressed under field flood conditions. The effects of mix-planting of pearl millet and sorghum with rice on their survival, growth and grain yields were evaluated under controlled field flooding in semi-arid Namibia during 2014/2015–2015/2016. Single-stand and mixed plant treatments were subjected to 11–22day flood stress at the vegetative growth stage. Mixed planting increased plant survival rates in both pearl millet and sorghum. Grain yields of pearl millet and sorghum were reduced by flooding, in both the single-stand and mixed plant treatments, relative to the non-flooded upland yields, but the reduction was lower in the mixed plant treatments. In contrast, flooding increased rice yields. Both pearl millet–rice and sorghum–rice mixtures demonstrated higher land equivalent ratios, indicating a mixed planting advantage under flood conditions. These results indicate that mix-planting pearl millet and sorghum with rice could alleviate flood stress on dryland cereals. The results also suggest that with this cropping technique, rice could compensate for the dryland cereal yield losses due to field flooding.


      PubDate: 2016-08-04T13:12:24Z
       
  • Explaining rice yields and yield gaps in Central Luzon, Philippines: An
           application of stochastic frontier analysis and crop modelling
    • Abstract: Publication date: Available online 20 July 2016
      Source:European Journal of Agronomy
      Author(s): João Vasco Silva, Pytrik Reidsma, Alice G. Laborte, Martin K. van Ittersum
      Explaining yield gaps is crucial to understand the main technical constraints faced by farmers to increase land productivity. The objective of this study is to decompose the yield gap into efficiency, resource and technology yield gaps for irrigated lowland rice-based farming systems in Central Luzon, Philippines, and to explain those yield gaps using data related to crop management, biophysical constraints and available technologies. Stochastic frontier analysis was used to quantify and explain the efficiency and resource yield gaps and a crop growth model (ORYZA v3) was used to compute the technology yield gap. We combined these two methodologies into a theoretical framework to explain rice yield gaps in farmers’ fields included in the Central Luzon Loop Survey, an unbalanced panel dataset of about 100 households, collected every four to five years during the period 1966–2012. The mean yield gap estimated for the period 1979–2012 was 3.2tonha−1 in the wet season (WS) and 4.8tonha−1 in the dry season (DS). An average efficiency yield gap of 1.3tonha−1 was estimated and partly explained by untimely application of mineral fertilizers and biotic control factors. The mean resource yield gap was small in both seasons but somewhat larger in the DS (1.3tonha−1) than in the WS (1.0tonha−1). This can be partly explained by the greater N, P and K use in the highest yielding fields than in lowest yielding fields which was observed in the DS but not in the WS. The technology yield gap was on average less than 1.0tonha−1 during the WS prior to 2003 and ca. 1.6tonha−1 from 2003 to 2012 while in the DS it has been consistently large with a mean of 2.2tonha−1. Varietal shift and sub-optimal application of inputs (e.g. quantity of irrigation water and N) are the most plausible explanations for this yield gap during the WS and DS, respectively. We conclude that the technology yield gap explains nearly half of the difference between potential and actual yields while the efficiency and resource yield gaps explain each a quarter of that difference in the DS. As for the WS, particular attention should be given to the efficiency yield gap which, although decreasing with time, still accounted for nearly 40% of the overall yield gap.


      PubDate: 2016-07-24T12:55:44Z
       
  • Annual crop rotation of tropical pastures with no-till soil as affected by
           lime surface application
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Carlos A.C. Crusciol, Rubia R. Marques, Antonio C.A. Carmeis Filho, Rogério P. Soratto, Claudio H.M. Costa, Jayme Ferrari Neto, Gustavo S.A. Castro, Cristiano M. Pariz, André M. de Castilhos
      Soil acidity and low natural fertility are the main limiting factors for grain production in tropical regions such as the Brazilian Cerrado. The application of lime to the surface of no-till soil can improve plant nutrition, dry matter production, crop yields and revenue. The present study, conducted at the Lageado Experimental Farm in Botucatu, State of São Paulo, Brazil, is part of an ongoing research project initiated in 2002 to evaluate the long-term effects of the surface application of lime on the soil’s chemical attributes, nutrition and kernel/grain yield of peanut (Arachis hypogaea), white oat (Avena sativa L.) and maize (Zea mays L.) intercropped with palisade grass (Urochloa brizantha cv. Marandu), as well as the forage dry matter yield of palisade grass in winter/spring, its crude protein concentration, estimated meat production, and revenue in a tropical region with a dry winter during four growing seasons. The experiment was designed in randomized blocks with four replications. The treatments consisted of four rates of lime application (0, 1000, 2000 and 4000kgha−1), performed in November 2004. The surface application of limestone to the studied tropical no-till soil was efficient in reducing soil acidity from the surface down to a depth of 0.60m and resulted in greater availability of P and K at the soil surface. Ca and Mg availability in the soil also increased with the lime application rate, up to a depth of 0.60m. Nutrient absorption was enhanced with liming, especially regarding the nutrient uptake of K, Ca and Mg by plants. Significant increases in the yield components and kernel/grain yields of peanut, white oat and maize were obtained through the surface application of limestone. The lime rates estimated to achieve the maximum grain yield, especially in white oat and maize, were very close to the rates necessary to increase the base saturation of a soil sample collected at a depth of 0–0.20m to 70%, indicating that the surface liming of 2000kgha−1 is effective for the studied tropical no-till soil. This lime rate also increases the forage dry matter yield, crude protein concentration and estimated meat production during winter/spring in the maize-palisade grass intercropping, provides the highest total and mean net profit during the four growing seasons, and can improve the long-term sustainability of tropical agriculture in the Brazilian Cerrado.


      PubDate: 2016-07-24T12:55:44Z
       
  • Accounting for both parameter and model structure uncertainty in crop
           model predictions of phenology: A case study on rice
    • Abstract: Publication date: Available online 21 July 2016
      Source:European Journal of Agronomy
      Author(s): Daniel Wallach, Sarath P. Nissanka, Asha S. Karunaratne, W.M.W. Weerakoon, Peter J. Thorburn, Kenneth J. Boote, James W. Jones
      We consider predictions of the impact of climate warming on rice development times in Sri Lanka. The major emphasis is on the uncertainty of the predictions, and in particular on the estimation of mean squared error of prediction. Three contributions to mean squared error are considered. The first is parameter uncertainty that results from model calibration. To take proper account of the complex data structure, generalized least squares is used to estimate the parameters and the variance-covariance matrix of the parameter estimators. The second contribution is model structure uncertainty, which we estimate using two different models. An ANOVA analysis is used to separate the contributions of parameter and model uncertainty to mean squared error. The third contribution is model error, which is estimated using hindcasts. Mean squared error of prediction of time from emergence to maturity, for baseline +2°C, is estimated as 108days2, with model error contributing 86days2, followed by model structure uncertainty which contributes 15days2 and parameter uncertainty which contributes 7days2. We also show how prediction uncertainty is reduced if prediction concerns development time averaged over years, or the difference in development time between baseline and warmer temperatures.


      PubDate: 2016-07-24T12:55:44Z
       
  • Multi-model simulation of soil temperature, soil water content and biomass
           in Euro-Mediterranean grasslands: Uncertainties and ensemble performance
    • Abstract: Publication date: Available online 21 July 2016
      Source:European Journal of Agronomy
      Author(s): R. Sándor, Z. Barcza, M. Acutis, L. Doro, D. Hidy, M. Köchy, J. Minet, E. Lellei-Kovács, S. Ma, A. Perego, S. Rolinski, F. Ruget, M. Sanna, G. Seddaiu, L. Wu, G. Bellocchi
      This study presents results from a major grassland model intercomparison exercise, and highlights the main challenges faced in the implementation of a multi-model ensemble prediction system in grasslands. Nine, independently developed simulation models linking climate, soil, vegetation and management to grassland biogeochemical cycles and production were compared in a simulation of soil water content (SWC) and soil temperature (ST) in the topsoil, and of biomass production. The results were assessed against SWC and ST data from five observational grassland sites representing a range of conditions – Grillenburg in Germany, Laqueuille in France with both extensive and intensive management, Monte Bondone in Italy and Oensingen in Switzerland – and against yield measurements from the same sites and other experimental grassland sites in Europe and Israel. We present a comparison of model estimates from individual models to the multi-model ensemble (represented by multi-model median: MMM). With calibration (seven out of nine models), the performances were acceptable for weekly-aggregated ST (R2 >0.7 with individual models and >0.8–0.9 with MMM), but less satisfactory with SWC (R2 <0.6 with individual models and <∼0.5 with MMM) and biomass (R2 <∼0.3 with both individual models and MMM). With individual models, maximum biases of about −5°C for ST, −0.3m3 m−3 for SWC and 360gDMm−2 for yield, as well as negative modelling efficiencies and some high relative root mean square errors indicate low model performance, especially for biomass. We also found substantial discrepancies across different models, indicating considerable uncertainties regarding the simulation of grassland processes. The multi-model approach allowed for improved performance, but further progress is strongly needed in the way models represent processes in managed grassland systems.


      PubDate: 2016-07-24T12:55:44Z
       
  • The new nitrification inhibitor 3,4-dimethylpyrazole succinic (DMPSA) as
           an alternative to DMPP for reducing N2O emissions from wheat crops under
           humid Mediterranean conditions
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Ximena Huérfano, Teresa Fuertes-Mendizábal, Kevin Fernández-Diez, José María Estavillo, Carmen González-Murua, Sergio Menéndez
      Nowadays agricultural practices are based in the use of N fertilizers which can lead to environmental N losses. These losses can occur as nitrous oxide (N2O) emissions as result of the microbial processes of nitrification and denitrification. N2O together with carbon dioxide (CO2) and methane (CH4) are the strongest greenhouse gases (GHG) associated with agricultural soils. Nitrification inhibitors (NI) have been developed with the aim of decreasing fertilizer-induced N losses and increasing N efficiency. One of the most popular NI is the 3,4-dimethylpyrazol phosphate (DMPP) which have proven to be an advisable strategy to mitigate GHG emissions while maintaining crops yield. A new NI, 3,4-dimethylpyrazole succinic (DMPSA), has been developed. The objective of this study was to compare the impact of the new nitrification inhibitor DMPSA on greenhouse gases emissions, wheat yield and grain protein with respect to DMPP. For this purpose a field-experiment was carried out for two years. Fertilizer dose, with and without NIs, was 180kgNha−1 applied as ammonium sulphate (AS) split in two applications of 60kgNha−1 and 120kgNha−1, respectively. A single application of 180kgNha−1 of AS with NIs was also made. An unfertilized treatment was also included. The new nitrification inhibitor DMPSA reduces N2O emissions up to levels of the unfertilized control treatment maintaining the yield and its components. The DMPSA shows the same behavior as DMPP in relation to N2O fluxes, as well as wheat yield and quality. In spite of applying a double dose of N at stem elongation than at tillering, N2O losses from that period are lower than at tillering as a consequence of the influence of soil water content and temperature reducing the N2O/N2 ratio by denitrification. NI efficiency in reducing N2O losses is determined by the magnitude of the losses from the AS treatment.


      PubDate: 2016-07-24T12:55:44Z
       
  • Seasonal pattern of biomass and rubber and inulin of wild Russian
           dandelion (Taraxacum koksaghyz L. Rodin) under experimental field
           conditions
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Marie Kreuzberger, Thomas Hahn, Susanne Zibek, Joachim Schiemann, Katja Thiele
      The roots of Taraxacum koksaghyz (Tks) are a promising alternative source for local rubber and inulin production in the temperate zone. Recent data on the agronomic performance of Tks are rare, older data partly not reliable. Thus, this study aimed at filling this gap by providing a comprehensive data set on Tks yield performance (root and leaf biomass, rubber, and inulin) and by highlighting the challenges being associated with its cultivation. The yield performance of wild Tks was investigated over a period of 17 months in two studies conducted at one site in Germany. The biennial life cycle of Tks was documented and the seasonal pattern of biomass, expected rubber and inulin yield were investigated over two successive seasons after harvesting Tks at six different dates and growth stages. Due to varying planting densities in the two trials (60,000plantsha−1 (trial 1), 500,000plantsha−1 (trial 2)), all yield parameters differed significantly between the trials at seasonal level e.g. fresh root yield ranged from 1.3 to 1.9tha−1 in trial 1 to 2.2–3.7tha−1 in trial 2. All measured parameters, i.e. biomass yield, rubber/inulin concentration and content, expected rubber/inulin yield, and inulin quality showed a significant seasonal dependency. At maximum, 32 (trial 1) and 62kg of dry rubber could be expected from dry Tks roots harvested from one hectare at the end of flowering during the second season, 14 months post field emergence. At the same time the maximum of expected inulin yield (128kgha−1 (trial 1), 209kgha−1 (trial 2)) was observed. These findings support the thesis of a synchronal harvest of Tks roots for rubber and inulin production with high yield. In addition, the degree of polymerization (DP) of inulin from Tks with >15 indicated it was comparable to chicory inulin. In contrast, low yields of biomass, rubber and inulin of wild Tks make breeding and optimization of agronomic measures in Tks a necessity to turn it into a profitable crop.
      Graphical abstract image

      PubDate: 2016-07-17T01:02:26Z
       
  • Estimating the environmental footprint of barley with improved nitrogen
           uptake efficiency—a Swedish scenario study
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Pernilla Tidåker, Göran Bergkvist, Martin Bolinder, Henrik Eckersten, Holger Johnsson, Thomas Kätterer, Martin Weih
      Plant breeding is a powerful tool for improving nitrogen (N) uptake efficiency and thus reducing the environmental impact relating to crop production. This study evaluated the environmental impact of current barley production systems in two Swedish agricultural areas (South and East) compared with scenarios with improved N uptake efficiency at two levels, in which the fraction of mineral N available for daily crop uptake was increased by 50 and 100%. Life cycle assessment (LCA) methodology was used to quantify energy use, global warming potential (GWP) and acidification and eutrophication potentials along the production chain for spring barley with differing N uptake efficiency, but similar N application rate. The functional unit, to which all energy use and emissions were related, was 1 Mg barley grain. Energy use, GWP and acidification proved to be higher for the East production system, mainly due to lower yield, while eutrophication was higher for South. The two impacts most affected by improved N uptake efficiency were eutrophication and GWP, with GWP decreasing due to a combination of higher yield, soil carbon sequestration and lower indirect emissions of N2O due to lower N leaching. Accounting for land savings due to increased yield, reducing the pressure to transform land elsewhere, would further lower the carbon footprint. Potential eutrophication per Mg grain was reduced by 15% in the production system with the highest N uptake efficiency in southern Sweden. Crops with improved N uptake efficiency can thus be an important complementary measure for reducing N losses to water, provided that the N application rate does not increase. However, incentives for farmers to maintain or even lower the N application rate might be required. Using simulation modelling is a promising approach for assessment of expected effects of improved crop varieties when no long-term experimental data are available. However, advanced crop models are required to better reflect the effect of plant breeding on e.g. expected yield. Future model development should involve expertise in plant breeding, plant physiology and dynamic crop and soil modelling.


      PubDate: 2016-07-17T01:02:26Z
       
  • Short time effects of biological and inter-row subsoiling on yield of
           potatoes grown on a loamy sand, and on soil penetration resistance, root
           growth and nitrogen uptake
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Victor Guaman, Birgitta Båth, Jannie Hagman, Anita Gunnarsson, Paula Persson
      Soil compaction, especially subsoil compaction, in agricultural fields has increased due to widespread use of heavy machines and intensification of vehicular traffic. Subsoil compaction changes the relative distribution of roots between soil layers and may restrict root development to the upper part of the soil profile, limiting water and mineral availability. This study investigated the direct effects of inter-row subsoiling, biological subsoiling and a combination of these two methods on soil penetration resistance, root length density, nitrogen uptake and yield. In field experiments with potatoes in 2013 and 2014, inter-row subsoiling (subsoiler) and biological subsoiling (preceding crops) were studied as two potential methods to reduce soil penetration resistance. Inter-row subsoiling was carried out post planting and the preceding crops were established one year, or in one case two years, prior to planting. Soil resistance was determined with a penetrometer three weeks after the potatoes were planted and root length density was measured after soil core sampling 2 months after emergence. Nitrogen uptake was determined in haulm (at haulm killing) and tubers (at harvest). Inter-row subsoiling had the greatest effect on soil penetration resistance, whereas biological subsoiling showed no effects. Root length density (RDL) in the combined treatment was higher than in the separate inter-row and biological subsoiling treatments and the control, whereas for the separate inter-row and biological subsoiling treatments, RLD was higher than in the control. Nitrogen uptake increased with inter-row subsoiling and was significantly higher than in the biological subsoiling and control treatments. However, in these experiments with a good supply of nutrients and water, no yield differences between any treatments were observed.


      PubDate: 2016-07-17T01:02:26Z
       
  • Agronomic and quality characteristics of old, modern and mixture wheat
           varieties and landraces for organic bread chain in diverse environments of
           northern Italy
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Paola Migliorini, Sandra Spagnolo, Luisa Torri, Marco Arnoulet, Giulio Lazzerini, Salvatore Ceccarelli
      Wheat landraces and old varieties could have an important role for food security not only as source of gene readily available for breeders, but also because they perform well in marginal environments and are more resilient as compared to the modern cultivars. The Italian cereal sector suffers from lack of seed companies that breed specifically adapted varieties for organic and biodynamic farms. Participatory and evolutionary plant breeding (PPB and EPB) have been used in this research to (i) evaluate the agronomic characteristics of old, modern and mixture of varieties and landrace of bread wheat (Triticum aestivum spp.) and their adaptability to organic farming in hilly and mountainous areas; (ii) assess the technological, nutritional and functional properties of grains (rheological characteristic, macro and micro elements contents and antioxidants); (iii) explore the consumers’ preferences for breads obtained by old and modern varieties. Between five and seven old (Sieve, Verna, Gentil Rosso, Andriolo, Gambo di ferro, Frassineto and Abbondanza), two mixtures and four modern (Bolero, Blasco, Arabia and Bologna) varieties were tested for two years in between two and three organic farms (FARM1, FARM2 and FARM3) in hilly areas of Piedmont. Agronomic characteristic were strongly affected by locations and years. On average, Bologna, Abbondanza and Arabia, and the two mixtures were the highest yielding varieties. Flour strength (W) varied greatly ranging from 230 in 2011 for Andriolo to 38 in 2012 for Gambo di ferro. Gluten quality, expressed by GI, was found to be almost within the optimal range but was affected by the year. All six bread samples were acceptable to the 233 consumers who scored them, but the bread produced with old wheat varieties, particularly with Andriolo and Gambo di Ferro, was the preferred one. The old varieties and their mixtures yielded less than the modern varieties but with higher stability as shown by the inability of the modern varieties in FARM1 to survive the winter (they were not harvested) while the old varieties reached maturity showing higher robustness, Therefore, the use of old bread wheat varieties and their mixture, assessed with participatory and evolutionary plant breeding, could represent a strategy for local communities to cope with climate change while improving food security and food quality.


      PubDate: 2016-07-17T01:02:26Z
       
  • Optimising crop production and nitrate leaching in China: Measured and
           simulated effects of straw incorporation and nitrogen fertilisation
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Kiril Manevski, Christen D. Børgesen, Xiaoxin Li, Mathias N. Andersen, Xiying Zhang, Per Abrahamsen, Chunsheng Hu, Søren Hansen
      The sustainability of growing a maize—winter wheat double crop rotation in the North China Plain (NCP) has been questioned due to its high nitrogen (N) fertiliser use and low N use efficiency. This paper presents field data and evaluation and application of the soil–vegetation–atmosphere transfer model Daisy for estimating crop production and nitrate leaching from silty loam fields in the NCP. The main objectives were to: i) calibrate and validate Daisy for the NCP pedo-climate and field management conditions, and ii) use the calibrated model and the field data in a multi-response analyses to optimise the N fertiliser rate for maize and winter wheat under different field managements including straw incorporation. The model sensitivity analysis indicated that a few measurable crop parameters impact the simulated yield, while most of the studied topsoil parameters affect the simulated nitrate leaching. The model evaluation was overall satisfactory, with root mean squared residuals (RMSR) for simulated aboveground biomass and nitrogen content at harvest, monthly evapotranspiration, annual drainage and nitrate leaching out of the root zone of, respectively, 0.9Mgha−1, 20kgNha−1, 30mm, 10mm and 10kgNha−1 for the calibration, and 1.2Mgha−1, 26kgNha−1, 38mm, 14mm and 17kgNha−1 for the validation. The values of mean absolute deviation, model efficiency and determination coefficient were also overall satisfactory, except for soil water dynamics, where the model was often found erratic. Re-validation run showed that the calibrated Daisy model was able to simulate long-term dynamics of crop grain yield and topsoil carbon content in a silty loam field in the NCP well, with respective RMSR of 1.7 and 1.6Mgha−1. The analyses of the model and the field results showed that quadratic, Mitscherlich and linear-plateau statistical models may estimate different economic optimal N rates, underlining the importance of model choice for response analyses to avoid excess use of N fertiliser. The analyses further showed that an annual fertiliser rate of about 300kgNha−1 (100 for maize and 200 for wheat) for the double crop rotation with straw incorporation is the most optimal in balancing crop production and nitrate leaching under the studied conditions, given the soil replenishment with N from straw mineralisation, atmospheric deposition and residual fertiliser. This work provides a sound reference for determining N fertiliser rates that are agro-environmentally optimal for similar and other cropping systems and regions in China and extends the application of the Daisy model to the analyses of complex agro-ecosystems and management practices under semi-arid climate.
      Graphical abstract image

      PubDate: 2016-07-17T01:02:26Z
       
  • An empirical analysis of risk in conventional and organic arable farming
           in The Netherlands
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): P.B.M. Berentsen, M.A.P.M. van Asseldonk
      This paper assesses and compares risk in conventional and organic arable farming in The Netherlands with respect to family farm income and underlying price and production variables. To investigate the risk factors the farm accountancy data network was used containing unbalanced panel data from 196 conventional and 29 organic representative Dutch arable farms (for the period 2002 up to and including 2011). Variables with regard to price and production risk were identified using a family farm income analysis scheme. Price risk variables are input and output prices, while yield volatility of different crops is the main production risk variable. To assess risk, an error components implicit detrending method was applied and the resulting detrended standard deviations were compared between conventional and organic farms. Results indicate that the risk at the level of family farm income is higher in organic farming. The underlying variables show higher risk for organic farms in crop yields, crop prices and variable input costs per crop.


      PubDate: 2016-07-11T03:44:32Z
       
  • Mitigating N2O emissions from cropping systems after conversion from
           pasture − a modelling approach
    • Abstract: Publication date: Available online 6 July 2016
      Source:European Journal of Agronomy
      Author(s): Henrike Mielenz, Peter J. Thorburn, Robert H. Harris, Peter R. Grace, Sally J. Officer
      Converting pasture to cropping is common in many of the world’s agricultural systems. This conversion results in substantial net mineralisation of soil organic matter that builds up during a phase of pasture. A few studies have shown that this mineralisation leads to increased nitrous oxide (N2O) emissions compared to long-term pasture or long-term cropping. Understanding of interactions leading to these significant emissions is still scarce but is needed to identify mitigation options for this situation. In this study, the Agricultural Production Systems sIMulator (APSIM) was used to investigate the optimal timing of pasture termination (relative to crop planting) and management of nitrogen (N) in crops after pasture termination to maximise crop yield and limit N2O emissions. Beforehand, APSIM’s performance in simulating yields and N2O emissions was tested against data from field experiments conducted in the temperate high-rainfall zone of southern Australia where N2O emissions were monitored with automatic gas collection chambers during the first year of cropping wheat after terminating long-term pasture on two adjacent sites in two consecutive years. Field experiments and simulation scenarios showed very high N2O emissions (up to 48kgN2O-Nha−1 yr−1) in the first year of wheat after pasture termination, even without N fertiliser application. Measured cumulative N2O emissions, crop yields and soil mineral N and water content dynamics were simulated well with APSIM. Including a routine into APSIM to account for N2O transport through the soil profile improved the simulation of daily N2O emissions considerably, leading to up to 67% of the measured variability in daily N2O emissions being explained by the model. We predicted that a short fallow between termination of pasture and sowing wheat, instead of a long fallow which is the common practice, reduces N2O emissions by more than half in the first year of cropping without a noteworthy impact on crop yield. Reducing N fertiliser applications in the first few years after pasture termination by taking available soil mineral N into account, and applying the fertiliser six to twelve weeks after sowing instead of at sowing was predicted to further reduce N2O emissions. Since the model was calibrated against experimental data during the first year after pasture termination only, experiments determining N2O emissions in the first two or three years after terminating pasture are needed to confirm our predictions.


      PubDate: 2016-07-11T03:44:32Z
       
  • Mechanisation of organic fertiliser spreading, choice of fertiliser and
           crop residue management as solutions for maize environmental impact
           mitigation
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Jacopo Bacenetti, Daniela Lovarelli, Marco Fiala
      The environmental impact of crop production is mainly related to fossil fuels consumption and to fertilisers application. Emissions arising from the spreading of organic and mineral fertilisers are important contributors for impact categories such as eutrophication and acidification. The choice of the fertilisers and of the spreading techniques as well as the crop residues management can deeply affect the environmental impact related to crop cultivation. In this study, seven scenarios describing fertilising schemes characterised by different organic and mineral fertilisers and by different mechanisation were compared. The aim is to evaluate, using the Life Cycle Assessment (LCA) method, how the environmental performances of grain maize production were affected by these different fertilisers schemes. The study was carried out considering a cradle to farm gate perspective and 1t grain maize was selected as functional unit. Inventory data were collected on a farm located in Po Valley (Northern Italy) during year 2013 and were processed using the composite method recommended by the International Reference Life Cycle Data System (ILCD). The compared scenarios involved organic and mineral fertiliser distribution and were: pig slurry incorporation after >3days after spreading (BS), fast pig slurry incorporation within 2h from spreading (AS1), direct soil injection of pig slurry (AS2), pig slurry incorporation (after >3days) with straw collection (AS3), digestate spreading instead of pig slurry (after >3days) (AS4), only mineral fertilisers (i.e. urea and superphosphate) distribution (AS5) and only mineral fertilisers (i.e. calcium ammonium nitrate and superphosphate) distribution (AS6). The results were not univocal, since climate and soil conditions as well as physical and chemical fertiliser characteristics differently affected the environmental load, especially for particulate matter formation, terrestrial acidification and terrestrial eutrophication impact categories. AS1 and AS2 showed the most beneficial results for these impact categories (between −67% and −73% respect to worst scenario). AS6, on the opposite, showed the highest environmental impact for those impact categories mainly affected by energy and fossil fuel consumption (climate change, ozone depletion, human toxicity with carcinogenic effect, particulate matter, freshwater eutrophication, freshwater ecotoxicity and mineral, fossil and renewable resources depletion), categories on which AS3 and AS4 were the best solutions. AS3 was the most impacting for terrestrial acidification and eutrophication A sensitivity analysis was carried out varying grain maize yield (mostly affected: marine eutrophication) and ammonia volatilisation losses due to organic fertilisers (mainly affected: terrestrial acidification and eutrophication). The achieved results can be useful for the development of “spreading rules” that drive the application of organic fertilisers in agricultural areas where there is an intense livestock activity.


      PubDate: 2016-07-11T03:44:32Z
       
  • Best management practices of tillage and nitrogen fertilization in
           Mediterranean rainfed conditions: Combining field and modelling approaches
           
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Carlos Cantero-Martínez, Daniel Plaza-Bonilla, Pedro Angás, Jorge Álvaro-Fuentes
      In this work, appropriate management practices for crop production under the variable climate conditions of the Mediterranean region, in particular rainfall, were tested with the use of a modelling system applied to long-term (i.e. 18 years) field data. The calibration of the CropSyst model was performed using data collected from 1996 to 1999 at three different Mediterranean locations (i.e., HYP-Guissona, MYP-Agramunt and LYP-Candasnos, i.e. high, medium and low yield potential, respectively) within a degree of yield potential. The model simulated reasonably well barley growth and yield to different tillage and N fertilization strategies. Simulations of barley performance over 50 years with generated weather data showed that yields were often greater and never smaller under no-tillage compared to conventional tillage with a mean increase of 36%, 63% and 18% for HYP-Guissona, MYP-Agramunt and LYP-Candasnos. In MYP-Agramunt, the long-term data showed a 40% increase in grain yields when using no-tillage compared to conventional tillage, as an average of 18 years. The model also predicted that greater N applications in no-tillage were appropriate to take advantage of additional water supply. Taking into account the limited amount of soil water available, overall N fertilizer applications could be reduced to about half of the traditional rate applied by the farmers without yield loss. The 50-yr simulation, confirmed by the long-term experimental data, identified no-tillage as the most appropriate tillage practice for the rainfed Mediterranean areas. Also, N fertilization must be reduced significantly when tillage is used or when increasing aridity. Our work demonstrates the usefulness of the combination of long-term field experimentation and modelling as a tool to identify the best agricultural management practices. It also highlights the importance of posterior analysis with long-term observed field data to determine the performance of simulation results.


      PubDate: 2016-07-11T03:44:32Z
       
  • Girdling and gibberellic acid effects on yield and quality of a seedless
           red table grape for saving irrigation water supply
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Pasquale Crupi, Donato Antonacci, Michele Savino, Rosalinda Genghi, Rocco Perniola, Antonio Coletta
      Table grapes need of substantial water supply for achieving commercial requirements. Viticulture practices such as girdling (G) and gibberellic acid (GA) application, as well as water supply, can improve table grape quality. The study, which was conducted in two consecutive seasons (2010–2011), aimed to assess the counterbalance effect of these viticulture practices on yield and quality parameters and flavonoids composition in case of a significant and unusual irrigation water reduction (40%) applied to a table grape variety. The data from the two-way ANOVA and PCA analyses indicated that viticulture practices were clearly related to anthocyanins and flavonols variations whereas water management appeared mainly involved in the yield parameters variability. Specifically, the reduced water supply (RWS) decreased the grape yield (−20%) with respect to full water supply (FWS); by contrast GA, G, and G×GA treatments determined an increment of grape production ranging from 10 to 23%, independently from irrigation strategy. Moreover, G, in particular applied to RWS grapes, was able to improve the total soluble solids over titrable acidity (TSS/TA), a ratio strictly related to the quality perception by the consumer. Total anthocyanins were found positively linked to FWS whereas flavanols content was indifferent to water management. Instead viticulture practices seemed to have a greater impact on anthocyanin composition, considering that in RWS grapes under GA condition, higher contents of malvidin and peonidin (mainly responsible for the color stability of the skins) were revealed. Furtheremore, catechins and rutin appeared significantly enhanced by G and G×GA, and GA, respectively. From gathered findings, it can be concluded that suitable viticulture practices can allow a sensible reduction of water supply during table grape growth cycle without detrimental effects on yield and quality.
      Graphical abstract image

      PubDate: 2016-07-11T03:44:32Z
       
  • Crop-livestock integration, from single practice to global functioning in
           the tropics: Case studies in Guadeloupe
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): Fabien Stark, Audrey Fanchone, Ivan Semjen, Charles-Henri Moulin, Harry Archimède
      Agricultural systems will have to produce more and better in a changing world. Mixed crop livestock systems (MCLS) are sound alternative ways to progressively achieve these goals through crop-livestock integration (CLI). CLI exploits the synergies between cropping and livestock systems, for example, through organic fertilization and the use of crop residues to feed livestock, and offers many opportunities to improve productivity, as well as to increase resource use efficiency and improve the resilience of the whole farming system. In the scientific literature, authors advocate the interest of MLCS and CLI, based on theoretical considerations, modelling and empirical evidence from local case studies. But these studies do not clearly identify the respective roles of the diversity of activities and CLI management practices in improving performances at the level of the whole farming system. The aim of this study was thus to assess CLI at farm scale in a range of MCLS and to explain farm performances by analyzing the combination of activities and the level of integration. This study was conducted in Guadeloupe, (French West Indies), where MCLS and CLI are complex but important challenges for local agricultural. Ecological network analysis was used to study the structure, functioning and performance of agrosystems. To this end, a range of eight farms was selected to characterize CLI as practices, and as a network of nitrogen flows at farm level. The land and labor productivity were then assessed along with the resilience, efficiency, productivity and self-sufficiency of the network of flows. Results show that CLI only applies to certain types of production, including feeding pigs with a wide range of crop residues (crop residues provide from 16 to 45% of the N supply to pigs) or organic fertilization of small market gardens and plots used to grow tubers (manure provides 24–100% of the N supply to plots). But at whole system level, CLI remains low: in seven cases, the N circulating within the system – ICR- represent only between 0.7 to 3.5% of the total N circulating through the system; only one farm presents a higher intensity of CLI, with an ICR of 18.9%. Consequently, performances and especially efficiency and productivity, depend more on the nature of the activity than on CLI management practices.


      PubDate: 2016-07-11T03:44:32Z
       
  • Nitrogen use efficiency and residual effect of fertilizers with
           nitrification inhibitors
    • Abstract: Publication date: October 2016
      Source:European Journal of Agronomy, Volume 80
      Author(s): M. Alonso-Ayuso, J.L. Gabriel, M. Quemada
      Blending fertilizers with nitrification inhibitors (NI) is a technology to reduce nitrogen (N) losses. The application of NI could increase the soil N supply capacity over time and contribute to an enhancement of N use efficiency (NUE) in some cropping systems. The objectives were to determine in a field experiment located in Central Spain (i) the effect of NI-fertilizers applied to maize (Zea mays L.) during two seasons on yield, N content and NUE compared to conventional fertilizers, (ii) the soil residual effect of NI-fertilizers in a non-fertilized sunflower (Helianthus annuus L.) planted during a third season, and (iii) the possible sources of residual N via laboratory determinations. The maize was fertilized with ammonium sulfate nitrate (ASN) and DMPP (3,4-dimethylpyrazole phosphate) blended ASN (ENTEC®) at two levels (130 and 170kgNha−1). A control treatment with no added N fertilizer was included to calculate NUE. The second year, DMPP application allowed a 23% reduction of the fertilizer rate without decreasing crop yield or grain quality. In addition, the sunflower planted after the maize scavenged more N in treatments previously treated with ENTEC® than with traditional fertilizers, increasing NUE in the cropping systems. After DMPP application, N was conserved in non-ready soil available forms during at least one year and subsequently released to meet the sunflower crop demand. The potential N mineralization obtained from aerobic incubation under controlled conditions of soil samples collected before sunflower sowing was higher for ENTEC® than ASN or control treatments. A higher δ15N in the soil indicated larger non-exchangeable NH4 + fixation in soils from the plots treated with ENTEC® or ASN-170 than from the ASN-130 or the control. These results open the opportunity to increase NUE by designing crop rotations able to profit from the effect of NI on the soil residual N.


      PubDate: 2016-07-11T03:44:32Z
       
  • Soil carbon and nitrogen changes after 28 years of no-tillage management
           under Mediterranean conditions
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Marco Mazzoncini, Daniele Antichi, Claudia Di Bene, Rosalba Risaliti, Monica Petri, Enrico Bonari
      Mouldboard ploughing is known to accelerate soil organic matter (SOM) mineralization rate in Mediterranean regions. Long-term reduced tillage intensity potentially diminishes soil organic carbon (SOC) and total nitrogen (STN) depletions. Here, we compared long-term no-tillage (NT) and conventional tillage (CT) impact on SOC and STN sequestration rates at different depths ranging from 0 to 30cm. The long-term experiment started in 1986 on a Typic Xerofluvent soil in Central Italy using a randomized complete block design with four replications. Ten years after the experiment began, SOC and STN concentrations in the 0–30cm soil layer were already higher under NT compared to CT. The shallow layer (0–10cm) showed the highest SOC and STN concentration increments. However, no differences between tillage systems were observed in the deeper layers. After 28 years, continuous NT increased SOC and STN content in the 30cm soil depth by 22% compared to initial values. In the same period, continuous CT decreased SOC and STN content by 3% and 5%, respectively. On average, the total SOC and STN gains under NT may be attributed to the shallow layer increments. In the 10–20 and 20–30cm soil layers, SOC accumulation over time was negligible also under NT. In the whole profile (0–30cm), the mean annual SOC variation was +0.40 Mg ha−1 yr−1 and −0.06 Mg ha−1 yr−1 under NT and CT, respectively. Under NT, SOC content increased rapidly in the first ten years (+0.75 Mg ha−1yr−1); later on, SOC increments were slower indicating the reaching of a new equilibrium. Data show that NT is a useful alternative management practice increasing carbon sequestration and soil health in Mediterranean conditions.


      PubDate: 2016-06-16T17:59:35Z
       
  • Long-term evaluation of productivity, stability and sustainability for
           cropping systems in Mediterranean rainfed conditions
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Umberto Bonciarelli, Andrea Onofri, Paolo Benincasa, Michela Farneselli, Marcello Guiducci, Euro Pannacci, Giacomo Tosti, Francesco Tei
      Mediterranean cropping systems in rainfed conditions are generally based on rotations with a very high frequency of winter wheat and, therefore, they are at risk of declining trends for yield and soil health in the long-term. In order to quantify this risk, a long-term experiment was set-up in 1971 in central Italy, which is still running at present (2016). This experiment is based on 13 rotations, i.e. three continuous winter wheat systems with different N fertilization rates (W150, W200 and W250), five maize/winter wheat rotations with increasing wheat frequency (maize preceded by 1–5 years of wheat: i.e., WM, 2WM, 3WM, 4WM and 5WM) and five two-year rotations of winter wheat with either pea (WP), faba bean (WFB), grain sorghum (WGS), sugar beet (WSB) or sunflower (WSU). All these rotations are managed either with the removal of crop residues after harvest (REM), or with their burial into the soil at ploughing (BUR). For each rotation, all phases are simultaneously grown in each year, according to a split-plot design (with REM and BUR randomised to main plots), with three replicates in complete blocks and plots of 24.5m2 each. The following data are considered: (1) total and marketable biomass yields from 1983 to 2012; (2) content of Organic carbon (OC) and total nitrogen (N) in soil, as determined in 2014. Considering the 30-year period, BUR resulted in an average positive effect on yield (+3.7%), increased OC (+13.8%) and total N content (+9.4%) in soil, while the C/N ratio was not significantly affected. Wheat in two-year rotations showed a significantly higher (+19.4%) average yield level than in continuous cropping or in 2WM, 3WM, 4WM and 5WM, mainly due to a drop in yield occurring in the first (−13%) and second (−19%) year of recropping. Increasing N fertilisation level from 150 to 250kgNha−1 with continuous cropping resulted in an increase (+3.7%) in long-term average yield and in a decrease in yield stability. All rotations heavily based on wheat (continuous cropping and 5WM) produced the highest amount of buried biomass (>175tha−1 in 30 years), with the highest increase in soil OC content (>16tha−1). All the other rotations produced a lower amount of residues and were less efficient in terms of carbon sequestration in soil, apart from WFB, which gave a high increase in soil organic carbon content (+18.9tha−1 in 30 years), in spite of a low amount of buried residues (158tha−1).


      PubDate: 2016-06-16T17:59:35Z
       
  • IC-FAR - Linking long term observatories with crop system modelling for a
           better understanding of climate change impact and adaptation strategies
           for Italian cropping systems
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Pier Paolo Roggero



      PubDate: 2016-06-16T17:59:35Z
       
  • Effects of species diversity on seasonal variation in herbage yield and
           nutritive value of seven binary grass-legume mixtures and pure grass under
           cutting
    • Abstract: Publication date: August 2016
      Source:European Journal of Agronomy, Volume 78
      Author(s): Anjo Elgersma, Karen Søegaard
      Intensively managed sown temperate grasslands are generally of low species diversity, although swards based on grass-legume mixtures may have superior productivity and herbage quality than grass-only swards. We conducted a cutting experiment over two years to test the effect of species composition and diversity on herbage yield, contents of N, neutral detergent fibre (NDF) and in vitro organic matter digestibility (IVOMD). Perennial ryegrass (PR, Lolium perenne) was sown alone and with each of four forage legumes: red clover (RC, Trifolium pratense), lucerne (LU, Medicago sativa), birdsfoot trefoil (BT, Lotus corniculatus) and white clover (WC, Trifolium repens); WC was also sown with hybrid ryegrass (HR, Lolium × boucheanum), meadow fescue (MF, Festuca pratensis) and timothy (TI, Phleum pratense). Herbage productivity was lowest in pure PR followed by PR/BT, and highest in PR/RC; this mixture had the highest legume proportion, N content and N yield. There was less WC in swards with HR and MF than with PR and TI. These differences were reflected in N contents of herbage of the mixtures. Legumes had higher N and lignin and lower NDF contents and IVOMD than grasses. Among legumes, NDF content was highest and IVOMD lowest in LU, followed by BT and the clovers. The highest N content was in WC. Among grasses, PR and HR had lower NDF contents and a higher IVOMD than MF; the highest N content was in PR. The grass component of mixtures had less effect than the legume component on herbage yield and quality. Results are discussed in terms of their potential to contribute to forage resources in farming practice and enhance resource use efficiency and ecosystem services.
      Graphical abstract image

      PubDate: 2016-06-16T17:59:35Z
       
  • Virtual modeling based on deep phenotyping provides complementary data to
           field experiments to predict plant emergence in oilseed rape genotypes
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): C. Durr, J. Constantin, M.-H. Wagner, H. Navier, D. Demilly, S. Goertz, N. Nesi
      Breeding oilseed rape for oil and protein contents may have led to differences in seedling emergence in genotypes. New opportunities for deep automated phenotyping of germination and seedling growth are being developed on phenotyping platforms. Our aim was to demonstrate that using these data to parameterize a crop emergence model complements field experiments for the evaluation of differences among genotypes. Five genotypes, chosen in a diverse set of winter oilseed rape for their different germination speeds, were phenotyped for germination at different temperatures and water potentials as well as for radicle and hypocotyl growth. These data were used as parameters to run the SIMPLE crop emergence model over a period of 27 years (1985–2012), at two locations, one in France and one in Germany, and at four sowing dates. Field experiments were performed in 2012, 2013 and 2014, and the emergence of the five genotypes was measured at early and late sowing dates. First, model predictions were compared with observed field emergence in the French sowing trials in 2014. The model proved to be rather good at predicting the emergence of the genotypes. Then, for the simulation study, the model extended the observed differences between locations and sowing dates over a greater number of years. The model also identified the main reasons for non-emerging seedlings and their frequencies in the simulated sowings. Differences between the five genotypes were on average very small, but complex interactions appeared that led to bigger differences under certain sowing conditions. This study demonstrates that combining deep phenotyping with crop models in simulation studies paves the way for more precise and detailed evaluation of genotypes.


      PubDate: 2016-06-16T17:59:35Z
       
  • Perennial wild plant mixtures for biomass production: Impact of species
           composition dynamics on yield performance over a five-year cultivation
           period in southwest Germany
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Moritz von Cossel, Iris Lewandowski
      Wild plant mixtures (WPMs) are a promising perennial cultivation system for biogas production with numerous ecological benefits. However, to date, there is little information on their long-term development. To investigate this, two different WPMs (S1, Rieger-Hofmann GmbH, 2016; S2, Saaten-Zeller GmbH, 2016) of up to 27 native, mainly wild species with a combination of annual, biennial and perennial life cycles were established at three sites in southwest Germany in 2011. At Hohenheim (HOH), fertilization was varied (0, 50, 100kgha−1 nitrogen) and a split plot design with three replications was used. At Renningen (REN) and Sankt Johann (SJO) single plots were used and fertilized with 50kgha−1. Harvest and sample analysis were conducted each year over a five-year cultivation period. The development of dry matter yield (DMY), dry matter content (DMC) and species composition dynamics of the WPMs were investigated. The DMYs varied strongly between the mixtures, sites and years, ranging from 2.9–22.5Mg ha−1 yr−1. Significant effects of mixture (P<0.001) and site x age interactions (P<0.05) were found. On average, S2 had about 55% higher yield than S1 over the five years (S2 accumulated DMY: 50.2–74.2Mgha−1 s). For both mixtures, a high number (up to 19) of WPM species were recorded, but this declined over the cultivation period at all sites. The DMYs at REN and SJO increased with time, whereas at HOH the high weed pressure from the grassland pre-crop resulted in decreasing yields. Here, the nitrogen mineralization of the grassland residues was high enough to mask fertilization effects. A good substrate quality for ensilaging (DMC >28%) was achieved at all sites every year except 2011. From these findings, we can recommend the WPM concept based on the S2 mixture as a feasible cultivation system with potentially high ecological benefits, in particular for marginal sites.


      PubDate: 2016-06-16T17:59:35Z
       
  • Estimation of phenotypic variability in symbiotic nitrogen fixation
           ability of common bean under drought stress using 15N natural abundance in
           grain
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Jose Polania, Charlotte Poschenrieder, Idupulapati Rao, Stephen Beebe
      Common bean (Phaseolus vulgaris L.) is the most important food legume, cultivated by small farmers and is usually exposed to unfavorable conditions with minimum use of inputs. Drought and low soil fertility, especially phosphorus and nitrogen (N) deficiencies, are major limitations to bean yield in smallholder systems. Beans can derive part of their required N from the atmosphere through symbiotic nitrogen fixation (SNF). Drought stress severely limits SNF ability of plants. The main objectives of this study were to: (i) test and validate the use of 15N natural abundance in grain to quantify phenotypic differences in SNF ability for its implementation in breeding programs of common bean with bush growth habit aiming to improve SNF, and (ii) quantify phenotypic differences in SNF under drought to identify superior genotypes that could serve as parents. Field studies were conducted at CIAT-Palmira, Colombia using a set of 36 bean genotypes belonging to the Middle American gene pool for evaluation in two seasons with two levels of water supply (irrigated and drought stress). We used 15N natural abundance method to compare SNF ability estimated from shoot tissue sampled at mid-pod filling growth stage vs. grain tissue sampled at harvest. Our results showed positive and significant correlation between nitrogen derived from the atmosphere (%Ndfa) estimated using shoot tissue at mid-pod filling and %Ndfa estimated using grain tissue at harvest. Both methods showed phenotypic variability in SNF ability under both drought and irrigated conditions and a significant reduction in SNF ability was observed under drought stress. We suggest that the method of estimating Ndfa using grain tissue (Ndfa-G) could be applied in bean breeding programs to improve SNF ability. Using this method of Ndfa-G, we identified four bean lines (RCB 593, SEA 15, NCB 226 and BFS 29) that combine greater SNF ability with greater grain yield under drought stress and these could serve as potential parents to further improve SNF ability of common bean.


      PubDate: 2016-06-16T17:59:35Z
       
  • Density responses and spatial distribution of cotton yield and yield
           components in jujube (Zizyphus jujube)/cotton (Gossypium hirsutum)
           agroforestry
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Qi Wang, Shuo Han, Lizhen Zhang, Dongsheng Zhang, Wopke van der Werf, Jochem B. Evers, Hongquan Sun, Zhicheng Su, Siping Zhang
      Trees are the dominant species in agroforestry systems, profoundly affecting the performance of understory crops. Proximity to trees is a key factor in crop performance, but rather little information is available on the spatial distribution of yield and yield components of crop species under the influence of trees in agroforestry systems. Also, little information is available on how crop density may be exploited to optimize the yield in such systems. Here we studied the performance of cotton in jujube/cotton agroforestry. Field experiments were conducted in 2012 and 2013 in Hetian, Xinjiang, China. Cotton was grown at a row distance of 60cm in three densities, 13.5, 18.0 and 22.5plantsm−2 in six m wide paths between tree lines in a jujube plantation. Plant density affected both cotton aboveground dry matter and yield significantly. The highest yield was attained at the intermediate density of 18.0plantsm−2 (20.0plantsm−2 corresponding in sole cotton), lower than the optimal density in sole cotton (25.0plantsm−2). Yield at the lower density was constrained by the low number of bolls per m2 as a direct consequence of the low density, whereas at the high plant density yield was constrained by a lower allocation of assimilates to cotton seed and lint, as a consequence of intraspecific and interspecific competitions. There were strong gradients in yield and yield components in relation to the distance from the tree rows. Leaf area and total dry matter of cotton in rows close to the tree lines were reduced, especially in the rows next to the trees. Moreover, biomass allocation to cotton fruits was reduced in these rows. Competitive influences from the trees on cotton performance extended two rows deep in a six-year old jujube stand, and even three rows deep in a seven-year old stand. Shading effects on cotton yield were compensated by increasing plant density as a result of greater boll numbers per unit ground area. Data from this study help guide the design of optimal plant density of cotton in jujube plantations and give insight in the spatial distribution and dynamics of competitive effects in agroforestry systems in general.


      PubDate: 2016-06-16T17:59:35Z
       
  • Achieving legislation requirements with different nitrogen fertilization
           strategies: Results from a long term experiment
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Laura Zavattaro, Davide Assandri, Carlo Grignani
      The Nitrates Directive (91/676/EEC, Anonymous, 1991) was developed in Europe to limit environmental threats from intensive livestock farming and N fertilizer applications to crops. It imposed several rules on farmers and public bodies, one of which was nutrient fertilization plan adoption. Here we use results from the Tetto Frati (Northern Italy) Long-Term Experiment to verify the terms and coefficients in the official Italian guidelines and evaluate the limitations imposed to organic fertilization amounts. For this purpose, we mined long-term experimental data of crop yield, N uptake, N use efficiency, and soil organic matter content from miscellanea cropping systems fertilized with farmyard manure (FYM) and bovine slurry (SLU), typical of a dairy farm in Northern Italy. N fertilization efficiency indicators (Removal to Fertilizer ratio, Apparent Recovery and Nitrogen Fertilizer Replacement Value) indicated that in the long run, FYM behaved similarly to urea, and better than SLU. Even N supply rates as high as 250kgNha−1 were justified by high rates of crop removal. In fact, among the terms of the mass-balance equation, SOM mineralization was found to be most relevant, followed by meadow rotation residual effects. We conclude that a revised Nitrates Directives application scheme could be more relaxed in its application limit of manure-N, but should be more ambitious in setting efficiency coefficients for manure fertilization.


      PubDate: 2016-06-16T17:59:35Z
       
  • Effects of crop residue management on winter durum wheat productivity in a
           long term experiment in Southern Italy
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Domenico Ventrella, Anna Maria Stellacci, Annamaria Castrignanò, Monia Charfeddine, Mirko Castellini
      A long-term experiment comparing different crop residue (CR) managements was established in 1977 in Foggia (Apulia region, southern Italy). The objective of this study was to investigate the long-term effects of different types of crop residue management on main yield response parameters in a continuous cropping system of winter durum wheat. In order to correctly interpret the results, models accounting for spatial error autocorrelation were used and compared with ordinary least square models. Eight crop residue management treatments, based on burning of wheat straw and stubble or their incorporation with or without N fertilization and irrigation, were compared. The experimental design was a complete randomized block with five replicates. Results indicated that the dynamics of yield, grain protein content and hectolitric weight of winter durum wheat did not show any decline as usually expected when a monoculture is carried out for a long time. In addition, the temporal variability of productivity was more affected by meteorological factors, such as air temperature and rainfall, than CR management treatments. Higher wheat grain yields and hectolitric weights quite frequently occurred after burning of wheat straw compared with straw incorporation without nitrogen fertilization and autumn irrigation and this was attributed to temporary mineral N immobilization in the soil. The rate of 50kgha−1 of N seemed to counterbalance this negative effect when good condition of soil moisture occurred in the autumn period, so yielding the same productive level of straw burning treatment.


      PubDate: 2016-06-16T17:59:35Z
       
  • Functional mechanisms of drought tolerance in maize through phenotyping
           and genotyping under well watered and water stressed conditions
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Mandapaka Maheswari, Vijaya Lakshmi Tekula, Varalaxmi Yellisetty, Basudeb Sarkar, Sushil Kumar Yadav, Jainender Singh, Seshu Babu G., Ashish Kumar, Sushma Amirineni, Jyothilakshmi Narayana, Vanaja Maddi
      Developing tolerant genotypes is crucial for stabilizing maize productivity under drought stress conditions as it is one of the most important abiotic stresses affecting crop yields. Twenty seven genotypes of maize (Zea mays L.) were evaluated for drought tolerance for three seasons under well watered and water stressed conditions to identify interactions amongst various tolerance traits and grain yield as well as their association with SSR markers. The study revealed considerable genetic diversity and significant variations for genotypes, environment and genotype×environment interactions for all the traits. The ranking of genotypes based on drought susceptibility index for morpho-physiological traits was similar to that based on grain yield and principal component analysis. Analysis of trait – trait and trait – yield associations indicated significant positive correlations amongst the water relations traits of relative water content (RWC), leaf water potential and osmotic potential as well as of RWC with grain yield under water stressed condition. Molecular analysis using 40 SSRs revealed 32 as polymorphic and 62 unique alleles were detected across 27 genotypes. Cluster analysis resulted in categorization of the genotypes into five distinct groups which was similar to that using principal component analysis. Based on overall performance across seasons tolerant and susceptible genotypes were identified for eventual utilization in breeding programs as well as for QTL identification. The marker-trait association analysis revealed significant associations between few SSR markers with water relations as well as yield contributing traits under water stressed conditions. These associations highlight the importance of functional mechanisms of intrinsic tolerance and cumulative traits for drought tolerance in maize.


      PubDate: 2016-06-16T17:59:35Z
       
  • Above- and belowground nitrogen uptake of winter catch crops sown after
           silage maize as affected by sowing date
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Martin Komainda, Friedhelm Taube, Christof Kluß, Antje Herrmann
      Regions in north-western Europe characterized by high density of livestock/biogas plants and extensive silage maize production are facing major environmental challenges due to excessive residual soil mineral nitrogen (N) in autumn and hence nitrate leaching. Winter catch crops (CC) have potential to accumulate residual N; however, the N uptake potential after maize harvest in autumn and spring remains unclear. Therefore, a two-year field trial (April 2012–April 2014) was conducted at three sites, to quantify the combined effects of four consecutive CC sowing dates (10 Sep; 20 Sep; 30 Sep and 15 Oct) and two CC species (rye, Secale cereale. L. and Italian ryegrass, Lolium multiflorum Lam.) on DM accumulation and N uptake of CC above- and belowground in autumn and spring, and to derive functional relationships. The results clearly showed that rye was more effective in accumulating biomass and nitrogen than Italian ryegrass. The better performance of rye was related to increased growth intensity of roots and shoot, a different allocation pattern and higher N uptake efficiency. An exponential function of temperature sum (Tsum) produced a reliable prediction of above- and belowground biomass and N. To achieve an agronomically relevant N uptake of 20kgNha−1, rye required 278°Cd Tsum, which corresponds to a sowing date latest in the second decade of September. Under favourable growing conditions, a biomass accumulation of up to 5MgDMha−1, corresponding to 83kgNha−1 above- and belowground, seems achievable under the given environmental conditions. In continuous maize grown under the environmental conditions of Northern Germany, however, catch crops will not reach a relevant N uptake on the long-term average.


      PubDate: 2016-06-16T17:59:35Z
       
  • Evolutionary changes of weed competitive traits in winter wheat composite
           cross populations in organic and conventional farming systems
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): N.O. Bertholdsson, O. Weedon, S. Brumlop, M.R. Finckh
      Seedling root and shoot growth in hydroponics and allelopathic activity using a bioassay have been studied in very diverse populations of winter wheat grown under either organic or conventional conditions for a number of generations and subjected only to natural selection. The study was conducted on seeds from generation 6 (F6) and 11 (F11) from three composite cross populations (CCPs) produced by the Organic Research Centre in the UK. Since the F5 the populations were maintained under organic and conventional conditions in Germany. Two parallel populations were created from each CC, resulting in a total of six organic and six conventional CCPs. The sets of parallel populations showed similar evolutionary trends indicating that the observed changes are related to differences in management rather than chance. Seedling root length and seedling root and shoot weight in the F11 of the organically-managed CCPs were significantly greater than in the organic F6 CCPs. In the conventionally-managed CCPs no such differences were observed. Both organic and conventional CCPs produced for quality showed higher early root and shoot growth than those produced for yield pointing to genetic differences among population types and highlighting the importance of early vigour for NUE. There were no significant differences in the allelopathic activity of the populations and between generations. The Shannon-Weaver diversity indices were similar for the studied traits in organic and conventional CCPs and hence no major changes in diversity had occurred between F6 to F11. As changes in plant height were small and weed pressure in the fields low it is concluded that the observed differences are more related to NUE, rather than intra-specific competition for light or the direct effect of increased weed pressure in the organic system.


      PubDate: 2016-06-16T17:59:35Z
       
  • Outcomes from a long-term study on crop residue effects on plant yield and
           nitrogen use efficiency in contrasting soils
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Chiara Pituello, Riccardo Polese, Francesco Morari, Antonio Berti
      The use of crop residues to increase crop yield and NUE is still a matter of debate since studies in different climates and soil types have led to inconclusive results and this could be partly explained by the numerous and complex factors that affect the residue-derived N cycle in field conditions. Given this complexity, long-term field experiments appear to be the more suitable tools to investigate these dynamics and develop effective management practices. In this paper, we hypothesized that residue incorporation affects crop yield and NUE, both through a direct nutritional effect given by residue decomposition and an indirect influence on soil physical and biological properties related to the input of organic carbon. We used data from a long-term field experiment started in 1970 in North-eastern Italy to evaluate the effects of crop residue incorporation on the productivity and nitrogen use efficiency of different crops (i.e., maize, winter wheat, sugarbeet, tomato and potato) in three contrasting soil types: a Fluvi–Calcaric Cambisol, a Gleyi–Vertic Chernozem and a Calcaric Arenosol. The results showed that incorporation of residues seems to have different effects depending on crop and soil type. For potato and tomato and, to a lesser extent, for sugarbeet, residues can improve crop productivity, while the effects on cereals seem to be lower. Regarding soil type, residues are proportionally more effective in sandy and sandy-loam soils, both through a direct nutritional effect and, possibly, an improvement of soil characteristics. Anyway the residue effect is relatively low, with modest increments of biomass in the most fertile soils and their effect can be compensated by N fertilization. The use of residues as organic amendment or their re-use in other processes (e.g., as a source of bioenergy) therefore has to be carefully analysed considering both the energy and C balances and the positive effects on soil productivity.


      PubDate: 2016-06-16T17:59:35Z
       
  • Long term effects of tillage practices and N fertilization in rainfed
           Mediterranean cropping systems: durum wheat, sunflower and maize grain
           yield
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Giovanna Seddaiu, Ileana Iocola, Roberta Farina, Roberto Orsini, Giuseppe Iezzi, Pier Paolo Roggero
      Long term investigations on the combined effects of tillage systems and other agronomic practices such as mineral N fertilization under Mediterranean conditions on durum wheat are very scanty and findings are often contradictory. Moreover, no studies are available on the long term effect of the adoption of conservation tillage on grain yield of maize and sunflower grown in rotation with durum wheat under rainfed Mediterranean conditions. This paper reports the results of a 20-years experiment on a durum wheat-sunflower (7 years) and durum wheat–maize (13 years) two-year rotation, whose main objective was to quantify the long term effects of different tillage practices (CT=conventional tillage; MT=minimum tillage; NT=no tillage) combined with different nitrogen fertilizer rates (N0, N1, N2 corresponding to 0, 45 and 90kgNha−1 for sunflower, and 0, 90 and 180kgNha−1 for wheat and maize) on grain yield, yield components and yield stability for the three crops. In addition, the influence of meteorological factors on the interannual variability of studied variables was also assessed. For durum wheat, NT did not allow substantial yield benefits leading to comparable yields with respect to CT in ten out of twenty years. For both sunflower and maize, NT under rainfed conditions was not a viable options, because of the unsuitable (i.e., too wet) soil conditions of the clayish soil at sowing. Both spring crops performed well with MT. No significant N×tillage interaction was found for the three crops. As expected, the response of durum wheat and maize grain yield to N was remarkable, while sunflower grain yield was not significantly influenced by N rate. Wheat yield was constrained by high temperatures in January during tillering and drought in April during heading. The interannual yield variability of sunflower was mainly associated to soil water deficit at flowering and air temperature during seed filling. Heavy rains during this latter phase strongly constrained sunflower grain yield. Maize grain yield was negatively affected by high temperatures in June and drought in July, this latter factor was particularly important in the fertilized maize. Considering both yield and yield stability, durum wheat and sunflower performed better under MT and N1 while maize performed better under both CT and MT and with N2 rates. The results of this long term study are suitable for supporting policies on sustainable Mediterranean rainfed cropping systems and also for cropping system modelling.


      PubDate: 2016-06-16T17:59:35Z
       
  • Nitrogen use efficiency and fertiliser fate in a long-term experiment with
           winter cover crops
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): J.L. Gabriel, M. Alonso-Ayuso, I. García-González, C. Hontoria, M. Quemada
      The use of winter cover crops enhances environmental benefits and, if properly managed, may supply economic and agronomic advantages. Nitrogen retained in the cover crop biomass left over the soil reduces soil N availability, which might enhance the N fertiliser use efficiency of the subsequent cash crop and the risk of depressive yield and pre-emptive competition. The main goal of this study was to determine the cover crop effect on crop yield, N use efficiency and fertiliser recovery in a 2-year study included in a long-term (10 years) maize/cover crop production system. Barley (Hordeum vulgare L.) and vetch (Vicia sativa L.), as cover crops, were compared with a fallow treatment during the maize intercropping period. All treatments were cropped following the same procedure, including 130kgNha−1 with 15N fertiliser. The N rate was reduced from the recommended N rate based on previous results, to enhance the cover crop effect. Crop yield and N uptake, soil N mineral and 15N fertiliser recovered in plants and the soil were determined at different times. The cover crops behaved differently: the barley covered the ground faster, while the vetch attained a larger coverage and N content before being killed. Maize yield and biomass were not affected by the treatments. Maize N uptake was larger after vetch than after barley, while fallow treatment provided intermediate results. This result can be ascribed to N mineralization of vetch residues, which results in an increased N use efficiency of maize. All treatments showed low soil N availability after the maize harvest; however, barley also reduced the N in the upper layers before maize planting, increasing the risk of pre-emptive competition. In addition to the year-long effect of residue decomposition, there was a cumulative effect on the soil’s capacity to supply N after 7 years of cover cropping, larger for the vetch than for the barley.


      PubDate: 2016-06-16T17:59:35Z
       
  • Comprehensive assessment of nutrient management technologies for
           cauliflower production under subtropical conditions
    • Abstract: Publication date: September 2016
      Source:European Journal of Agronomy, Volume 79
      Author(s): Kaushik Batabyal, Biswapati Mandal, Dibyendu Sarkar, Sidhu Murmu, Amrit Tamang, Ipsita Das, Gora Chand Hazra, Partha Sarathi Chattopadhyay
      We developed a methodological protocol for comprehensive evaluation of nutrient management (NM) technologies for production of cauliflower taking its yield, quality, profitability, energy balance and environmental sustainability in terms of soil quality as the goal variables. Fifteen NM technologies comprising three sources of nutrients viz., organics [farmyard manure (FYM), vermicompost (VC) and green manure], inorganic fertilizations (recommended NPK at the rate of 200-44-82kgha−1and 125% of recommended NPK) and their selected combinations were tested for producing cauliflower for six consecutive growing seasons during 2006–2011. Integrated NM technology proved to be economically sound and environment-friendly practice. It helped to produce better quality cauliflower with higher value added products such as crude protein, dietary fibre, and vitamin C. Further, it concomitantly maintained better soil quality by improving soil organic carbon stock, microbial biomass carbon, bulk density and extractable plant available nutrients. Combining all the parameters together by employing non-parametric evaluation of regression factor scores through principal component analysis, the NM technology of FYM 5Mgha−1 +125% of recommended NPK and VC 3Mgha−1 +125% of recommended NPK were found to be the best among the NM technologies compared. The superiority of the technologies were attributed to higher curd biomass yield (8.36 and 9.70Mgha−1, respectively), higher economic return (benefit-cost ratio 2.7 and 2.5; marginal rate of return 8.0 and 5.1, respectively), more energy conserving efficiency (net energy 22.4 and 25.7GJha−1; output-input energy ratio 1.86 and 2.00, respectively) and greater improvement in the indices of soil quality (6.219 and 5.709, respectively) and crop quality for human (6.7 and 7.4, respectively) and animal (7.4 and 6.4, respectively) nutrition. Organics were less productive, less profitable, and energetically less efficientas compared to integrated and inorganic systems for cauliflower production in subtropics.


      PubDate: 2016-06-16T17:59:35Z
       
  • Impacts and adaptation of the cropping systems to climate change in the
           Northeast Farming Region of China
    • Abstract: Publication date: August 2016
      Source:European Journal of Agronomy, Volume 78
      Author(s): Xiaogang Yin, Jørgen E. Olesen, Meng Wang, Isik Öztürk, Hailin Zhang, Fu Chen
      The Northeast Farming Region of China (NFR) is a very important crop growing area, comprising seven sub-regions: Xing’anling (XA), Sanjiang (SJ), Northwest Songliao (NSL), Central Songliao (CSL), Southwest Songliao (SSL), Changbaishan (CB) and Liaodong (LD), which has been severely affected by extreme climate events and climatic change. Therefore, a set of expert survey has been done to identify current and project future climate limitations to crop production and explore appropriate adaptation measures in NFR. Droughts have been the largest limitation for maize (Zea mays L.) in NSL and SSL, and for soybean (Glycine max L. Merr.) in SSL. Chilling damage has been the largest limitation for rice (Oryza sativa L.) production in XA, SJ and CB. Projected climate change is expected to be beneficial for expanding the crop growing season, and to provide more suitable conditions for sowing and harvest. Autumn frost will occur later in most parts of NFR, and chilling damage will also decrease, particularly for rice production in XA and SJ. Drought and heat stress are expected to become more severe for maize and soybean production in most parts of NFR. Also, plant diseases, pests and weeds are considered to become more severe for crop production under climate change. Adaptation measures that have already been implemented in recent decades to cope with current climatic limitations include changes in timing of cultivation, variety choice, soil tillage practices, crop protection, irrigation and use of plastic film for soil cover. With the projected climate change and increasing risk of climatic extremes, additional adaptation measures will become relevant for sustaining and improving productivity of crops in NFR to ensure food security in China.


      PubDate: 2016-05-19T16:38:20Z
       
  • Data fusion of spectral, thermal and canopy height parameters for improved
           yield prediction of drought stressed spring barley
    • Abstract: Publication date: August 2016
      Source:European Journal of Agronomy, Volume 78
      Author(s): Pablo Rischbeck, Salah Elsayed, Bodo Mistele, Gero Barmeier, Kurt Heil, Urs Schmidhalter
      Yield modelling based on visible and near infrared spectral information is extensively used in proximal and remote sensing for yield prediction of crops. Distance and thermal information contain independent information on canopy growth, plant structure and the physiological status. In a four-years′ study hyperspectral, distance and thermal high-throughput measurements were obtained from different sets of drought stressed spring barley cultivars. All possible binary, normalized spectral indices as well as thirteen spectral indices found by others to be related to biomass, tissue chlorophyll content, water status or chlorophyll fluorescence were calculated from hyperspectral data and tested for their correlation with grain yield. Data were analysed by multiple linear regression and partial least square regression models, that were calibrated and cross-validated for yield prediction. Overall partial least square models improved yield prediction (R2 =0.57; RMSEC=0.63) compared to multiple linear regression models (R2 =0.46; RMSEC=0.74) in the model calibration. In cross-validation, both methods yielded similar results (PLSR: R2 =0.41, RMSEV=0.74; MLR: R2 =0.40, RMSEV=0.78). The spectral indices R780/R550, R760/R730, R780/R700, the spectral water index R900/R970 and laser and ultrasonic distance parameters contributed favourably to grain yield prediction, whereas the thermal based crop water stress index and the red edge inflection point contributed little to the improvement of yield models. Using only more uniform modern cultivars decreased the model performance compared to calibrations done with a set of more diverse cultivars. The partial least square models based on data fusion improved yield prediction (R2 =0.62; RMSEC=0.59) compared to the partial least square models based only on hyperspectral data (R2 =0.48; RMSEC=0.69) in the model calibration. This improvement was confirmed by cross-validation (data fusion: R2 =0.39, RMSEV=0.76; hyperspectral data only: R2 =0.32, RMSEV=0.79). Thus, a combination of spectral multiband and distance sensing improved the performance in yield prediction compared to using only hyperspectral sensing.


      PubDate: 2016-05-14T13:26:39Z
       
  • Responses of soil properties, root growth and crop yield to tillage and
           crop residue management in a wheat–maize cropping system on the
           North China Plain
    • Abstract: Publication date: August 2016
      Source:European Journal of Agronomy, Volume 78
      Author(s): Xinyuan Mu, Yali Zhao, Kui Liu, Baoyi Ji, Haibin Guo, Zhiwei Xue, Chaohai Li
      Crop residue removal and subsoil compaction are limiting to yield improvement in the North China Plain (NCP). We conducted a field study composed of six consecutive crop growing seasons from 2010 to 2013 in Henan province, China, to determine responses of soil properties, crop root distribution and crop yield to tillage and residue management in a wheat–maize cropping system under irrigated conditions. Tillage practices comprised mouldboard ploughing (MP) to a depth of 15-cm, deep mouldboard ploughing (DMP) to a depth of 30-cm, and chisel ploughing (CP) to a depth of 30-cm. Crop residue management included crop residue retained (CRRet) and crop residue removed (CRRem). The results indicated that yields in DMP and CP increased by 6.0% and 7.3% for wheat and by 8.7% and 9.0% for maize, respectively, relative to MP. The CRRet treatment also increased wheat yield by 6.7% and maize yield by 5.0%. The yield increases under DMP and CP were related to reduced bulk density and soil penetration resistance, increased soil water content, improved total N distribution and improved root density (0–60-cm). Compared with MP, the root mass density under DMP and CP were increased by 43.4% and 42.0% for wheat and by 40.6% and 39.4% for maize, respectively. The yield increases under CRRet were also related to increased soil water content, reduced penetration resistance and increased N status (0–40-cm). Overall, for DMP+CRRet and CP+CRRet, a more favorable soil environment alongside greater root mass density and suitable spatial distribution resulted in higher grain yields of wheat and maize. Thus, compared with conventional shallow tillage practice, DMP or CP with residue application could improve soil quality and agricultural productivity under irrigated areas with loam soil in the NCP.


      PubDate: 2016-05-14T13:26:39Z
       
  • Improvement of spatially and temporally continuous crop leaf area index by
           integration of CERES-Maize model and MODIS data
    • Abstract: Publication date: August 2016
      Source:European Journal of Agronomy, Volume 78
      Author(s): Huaan Jin, Ainong Li, Jindi Wang, Yanchen Bo
      The spatially and temporally continuous leaf area index (LAI) mapping is very crucial for many agricultural applications, such as crop yield estimation and growth status monitoring. Data assimilation technology provides an innovational way to improve spatio-temporally continuous crop LAI estimation through integration of remotely sensed observations and crop growth models. In this study, a very fast simulated annealing (VFSA)-based variational assimilation scheme was proposed to integrate the crop growth model (CERES-Maize), MODIS reflectance product (MOD09A1) and a two-layer canopy reflectance model (ACRM) to estimate time-series crop LAI at regional scale. Simultaneously, a new sensitivity analysis method (called “histogram comparison”) was developed to identify sensitive parameters of CERES-Maize and ACRM models. The proposed scheme was applied for continuous crop LAI estimation during the maize growing season in the dominating spring maize planting area of Jilin province, China. Results showed that R2 values between LAI estimations from the proposed assimilation scheme (referred to as assimilated LAI) and fine resolution LAI reference maps were 0.24 and 0.63, with RMSE values of 0.21 and 0.54 for Julian day 176, 2010, and Julian day 196, 2010, respectively. The assimilated results were closer to LAI reference maps than the MODIS LAI product and ACRM-based inversion results (referred to as ACRM LAI). Moreover, by introducing the prior information of LAI dynamics depicted by a crop growth model, the assimilated LAI showed better temporal consistency than the MODIS LAI product, LAI profiles simulated by CERES-Maize model (referred to as CERES-Maize LAI), and ACRM LAI. It was found that the accuracies of LAI estimations could be enhanced by assimilating satellite observations into a crop simulation model in the VFSA framework at a regional scale.


      PubDate: 2016-05-07T00:34:08Z
       
  • Environmental performances of giant reed (Arundo donax L.) cultivated in
           fertile and marginal lands: A case study in the Mediterranean
    • Abstract: Publication date: August 2016
      Source:European Journal of Agronomy, Volume 78
      Author(s): Simona Bosco, Nicoletta Nassi o Di Nasso, Neri Roncucci, Marco Mazzoncini, Enrico Bonari
      Perennial rhizomatous grasses (PRGs) tend to have a high yield combined with a low environmental impact. Cultivation in marginal or poorly cultivated land is recommended in order not to compromise food security and to overcome land use controversies. However, the environmental impacts of using different types of soil are still unclear. We thus assessed the environmental impact of two giant reed (GR) systems cultivated in a fertile soil (FS) and in a marginal soil (MS) through a cradle-to-plant gate LCA. We analyzed energy balance, GHG emissions (including LUC, not including iLUC), and the main impacts on air, water and soil quality. In both systems the annualized soil carbon sequestration was more than twofold the total GHG emitted, equal to −6464kg CO2eq ha−1 in FS and −5757kg CO2eq ha−1 in MS. Overall, soil characteristics affected not only GR yield level, but also its environmental impact, which seems to be higher in the MS system both on a hectare and tonne basis. The production of GR biomass in marginal soil could thus lead to higher environmental impacts and a more extensive land requirement.


      PubDate: 2016-05-07T00:34:08Z
       
  • Use of biofertilizers obtained from sewage sludges on maize yield
    • Abstract: Publication date: August 2016
      Source:European Journal of Agronomy, Volume 78
      Author(s): Manuel Tejada, Bruno Rodríguez-Morgado, Isidoro Gómez, Luis Franco-Andreu, Concepción Benítez, Juan Parrado
      Maize production plays an essential role in global food security. In order to maintain both high quality and maize production, there is a great demand for fertilizers. The main objective of this work was to study, over two experimental seasons, the effect of a biofertilizer obtained from sewage sludge (SS) on the yield and on the quality of maize crops (Zea mays L.). The biofertilizer was applied in two ways: (i) to soil, at rates of 0, 10 and 20Mgha−1 before sowing, and (ii) via foliar fertilization, applying 0, 3.6 and 7.2lha−1 three times during each growing season accounting for a total rate of 0, 10.8lha−1 and 21.6lha−1. This study is novel because there are no previous studies of the effect of this biofertilizer on any agricultural crops. The results obtained show that, when the SS was applied directly to the soil, the macro- and micronutrients analyzed in both soil and leaves showed no significant differences between either of the fertilizer treatments. Foliar application of SS, however, increased the leaf concentrations of macro- and micronutrients. When the SS rate was 7.2lha−1, grain protein concentration increased significantly by about 30% and the yield increased significantly by about 17% compared with the control treatment (SS not applied). These results suggested that, in order to improve agricultural maize yields, quality and nutritional, this SS should be applied as a foliar fertilizer instead of applying it to soil.


      PubDate: 2016-05-07T00:34:08Z
       
  • Organic input quality is more important than its quantity: C turnover
           coefficients in different cropping systems
    • Abstract: Publication date: Available online 22 March 2016
      Source:European Journal of Agronomy
      Author(s): Antonio Berti, Francesco Morari, Nicola Dal Ferro, Gianluca Simonetti, Riccardo Polese
      Annual C input to soil is a major factor affecting soil organic carbon (SOC) dynamics. However different types of C-sources can have different behaviour, in relation to their chemical characteristics and how they interact with soil. Root-derived C, in particular, should be more efficient than other organic materials as a result of the physicochemical and biological characteristics of the surrounding environment, leading to a reduction in the C decomposition rate. To test this hypothesis, we considered a long-term experiment underway in Northern Italy since 1962, comparing permanent meadow and 6 different crop rotations over a wide range of nutrient inputs, in both organic and inorganic forms. C inputs from amendments were measured and those from crops were calculated using allometric functions and crop and residues yields. The time evolution of SOC was studied through a single-pool, first-order kinetic model, allowing the estimation of humification coefficients for residues, roots, farmyard manure and cattle slurries. The highest value of the humification coefficient was estimated for farmyard manure, which confirmed its high efficiency in stabilising SOC content. Root C presented a humification coefficient 1.9 times higher than above-ground plant materials while slurries were intermediate, with a humification coefficient roughly half that of farmyard manure and even lower that of roots. The quality of C input thus seems of fundamental importance for evaluating the sustainability of different cropping systems in terms of SOC dynamics.


      PubDate: 2016-03-23T21:17:42Z
       
 
 
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