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  Subjects -> AGRICULTURE (Total: 782 journals)
    - AGRICULTURAL ECONOMICS (77 journals)
    - AGRICULTURE (532 journals)
    - CROP PRODUCTION AND SOIL (91 journals)
    - DAIRYING AND DAIRY PRODUCTS (31 journals)
    - POULTRY AND LIVESTOCK (51 journals)

AGRICULTURE (532 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  [2817 journals]
  • Variations in soil-water use by grapevine according to plant water status
           and soil physical-chemical characteristics—A 3D spatio-temporal
           analysis
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Luca Brillante, Benjamin Bois, Jean Lévêque, Olivier Mathieu
      Understanding plant and soil-water relationships is crucial to optimise agricultural management. In this multidisciplinary work, soil geophysics and plant physiological measurements are coupled and a statistical method is proposed to visualising plant soil-water uptake in space and time. The method is applied in a vineyard context and shows differences in the use of tranpirable soil water by grapevine according to the type of soil and the time of the day (day/night). During two years the water stress experienced by a single Chardonnay/SO4 grapevine clone was monitored both at pre-dawn and midday by leaf water potentials in two field plots exclusively differenced by soil properties. At the same time, variations of electrical resistivity were monitored through electrical resistivity tomography, and then transformed in fraction of tranpirable soil water by the use of pedotransfer functions appositely developed in these soils. Spatio-temporal variations of transpirable soil water was used to predict plant leaf water potentials and the contribution of each soil region to grapevine water status was evaluated by statistical-learning methods. Strong spatio-temporal variability was observed both vertically and laterally between the two plots and within each plot at a fine scale. Principal causes of such differences were the level of plant water stress, along the season and during the day, and differences in soil physical-chemical properties. Soil contribution to plant water status varies in space and time at a fine scale. This paper introduces a novel methodological approach, transposable in any field survey, and brings further insight in the description of plant and soil relationships.
      Graphical abstract image

      PubDate: 2016-05-03T00:27:06Z
       
  • Geostatistical interpolation and aggregation of crop growth model outputs
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Luc Steinbuch, Dick J. Brus, Lenny G.J. van Bussel, Gerard B.M. Heuvelink
      Many crop growth models require daily meteorological data. Consequently, model simulations can be obtained only at a limited number of locations, i.e. at weather stations with long-term records of daily data. To estimate the potential crop production at country level, we present in this study a geostatistical approach for spatial interpolation and aggregation of crop growth model outputs. As case study, we interpolated, simulated and aggregated crop growth model outputs of sorghum and millet in West-Africa. We used crop growth model outputs to calibrate a linear regression model using environmental covariates as predictors. The spatial regression residuals were investigated for spatial correlation. The linear regression model and the spatial correlation of residuals together were used to predict theoretical crop yield at all locations using kriging with external drift. A spatial standard deviation comes along with this prediction, indicating the uncertainty of the prediction. In combination with land use data and country borders, we summed the crop yield predictions to determine an area total. With spatial stochastic simulation, we estimated the uncertainty of that total production potential as well as the spatial cumulative distribution function. We compared our results with the prevailing agro-ecological Climate Zones approach used for spatial aggregation. Linear regression could explain up to 70% of the spatial variation of the yield. In three out of four cases the regression residuals showed spatial correlation. The potential crop production per country according to the Climate Zones approach was in all countries and cases except one within the 95% prediction interval as obtained after yield aggregation. We concluded that the geostatistical approach can estimate a country’s crop production, including a quantification of uncertainty. In addition, we stress the importance of the use of geostatistics to create tools for crop modelling scientists to explore relationships between yields and spatial environmental variables and to assist policy makers with tangible results on yield gaps at multiple levels of spatial aggregation.
      Graphical abstract image

      PubDate: 2016-05-03T00:27:06Z
       
  • Short and long-term effects of different irrigation and tillage systems on
           soil properties and rice productivity under Mediterranean conditions
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Javier Sánchez-Llerena, Antonio López-Piñeiro, Ángel Albarrán, David Peña, Daniel Becerra, José Manuel Rato-Nunes
      In Mediterranean environments, flood irrigation of rice (Oryza sativa L.) crops is in danger of disappearance due to its unsustainable nature. The aim of the present study was to determine the short- and long-term effects of aerobic rice production, combined with conventional and no-tillage practices, on soils' physical, physicochemical, and biological properties, as well as on the rice yield components and productivity in the semi-arid Mediterranean conditions of SW Spain. A field experiment was conducted for three consecutive years (2011, 2012, and 2013), with four treatments: anaerobic with conventional tillage and flooding (CTF), aerobic with conventional tillage and sprinkler irrigation (CTS), aerobic with no-tillage and sprinkler irrigation (NTS), and long-term aerobic with no-tillage and sprinkler irrigation (NTS7). Significant soil properties improvements were achieved after the long-term implementation of no-tillage and sprinkler irrigation (NTS7). The short-term no-tillage and sprinkler irrigated treatment (NTS) gave lower yields than CTF in 2011 and 2012, but reached similar yields in the third year (NTS 8229kgha−1; CTF 8926kgha−1), with average savings of 75% of the total amount of water applied in CTF. The NTS7 data showed that high yields (reaching 9805kgha−1 in 2012) and water savings are sustainable in the long term. The highest water productivity was with NTS7 in 2011 (0.66gL−1) and 2012 (1.46gL−1), and with NTS in 2013 (1.05gL−1). Thus, mid- and long-term implementation of sprinkler irrigation combined with no-tillage may be considered as a potentially productive and sustainable rice cropping system under Mediterranean conditions.


      PubDate: 2016-04-27T00:12:32Z
       
  • Improving the management of coexistence between GM and non-GM maize with a
           spatially explicit model of cross-pollination
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Benoît Ricci, Antoine Messéan, Agnès Lelièvre, François-Christophe Coléno, Frédérique Angevin
      The European Commission have established the concept of coexistence, according to which, farmers should be able to grow whatever type of agricultural crops they wish (genetically modified (GM), conventional or organic), provided that they comply with the legal obligations for labeling and/or purity standards. In the case of maize, the main factor conditioning the feasibility of coexistence is gene flow from GM fields to other types of production. The distance between fields has been identified as a key factor governing this gene flow. As a consequence, the existing regulations mostly concern the maintenance of a fixed isolation distance between GM fields and the closest non-GM field. However, other factors, such as temporal dynamics of pollen shedding, wind, relative field sizes and shapes and the spatial distribution of the different types of fields, may greatly modulate the effect of distance. Moreover, uniform distance-based rules create a “domino effect”, in which it is difficult for GM crops and non-GM crops to co-exist at the landscape scale. In this study, we hypothesized that the use of a spatially explicit gene-flow model, MAPOD®, would result in a significant gain in proportionality and freedom of choice for the farmer over uniform distance-based rules. To test this hypothesis, we performed a global sensitivity analysis on this process-based model but, instead of exploring a random set of situations, the sensitivity analysis was carried out on a subset of realistic scenarios based on farmers’ strategies. To select those scenarios, we constructed a multicriteria decision-making model describing the decision process used by farmers when deciding whether or not to grow GM maize, and used this model to generate realistic allocation scenarios for GM, non-GM conventional and organic maize cultivation. We showed that the coexistence method based on the MAPOD® model allowed the presence of a higher percentage of GM maize in the landscape than the distance-based method. This made it possible to follow the farmer’s field intended allocations more closely, whilst complying with the legal threshold requirements. This gain in proportionality was greater at high maize densities, for which the distance-based method allowed almost no cultivation of GM crops. However, in case of high proportions of organic fields, our study indicated that coexistence between GM maize and organic maize at the landscape level is difficult, if not impossible in case of farm-saved seeds, without a spatial aggregation of fields, leading de facto to separate non-GM and GM zones. Finally, the use of MAPOD® resulted in better discrimination between acceptable and risky situations, and greater flexibility, which is crucial for the implementation of an efficient coexistence strategy.


      PubDate: 2016-04-27T00:12:32Z
       
  • The influence of crop sequence on fungicide and herbicide use intensities
           in North German arable farming
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Sabine Andert, Jana Bürger, Susanne Stein, Bärbel Gerowitt
      The reduction of pesticide use intensity is a societal and political ambition. Crop rotation is one important method to control pests and diseases in arable farming. We investigated the contribution of crop rotation to the variability of herbicide and fungicide use of 60 farms in four regions of Northern Germany. Our study aimed at answering the question: do diverse crop sequences lead to reduced herbicide and fungicide use in arable farming? Ten-year data on chemical plant protection measures and field management were examined for six field crops. We classified crop sequences (triplets of three succeeding crops) according to their susceptibility for weeds and diseases (= ’riskiness’). The Treatment Frequency Index (TFI) of the last crop in the triplet was set in relation to the crop triplet riskiness, additionally also in combination with tillage. In general, herbicide and fungicide use intensities were smaller in more diverse crop sequences. Diversified cereal sequences, involving roots and tubers, maize or spring cereals were less dependent on herbicides. Cultivation of maize in three subsequent years increased herbicide use. Crop sequences including high proportion of winter cereals increased fungicide use in cereals, while roots and tubers, winter oilseed rape and set-aside in the crop sequence decreased it. In winter oilseed rape, sequences with roots and tubers also increased fungicide use. In sugar beets, sequences with maize or a high concentration of sugar beets led to increasing fungicide use. If farmers chose riskier crop sequences tillage by plough decreased the need for herbicide and fungicide use. To reduce herbicide and fungicide use intensities we recommend increasing the diversity of crop rotations, including a higher number of crops per rotation together with ploughing. Simplifying both crop sequence diversity and tillage intensity implies higher use of herbicides and fungicides. Results will be useful for convincing farmers to diversify crop sequences.


      PubDate: 2016-04-17T14:33:24Z
       
  • Light grazing of crop residues by sheep in a Mediterranean-type
           environment has little impact on following no-tillage crops
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Cara J. Allan, Ben Jones, Simon Falkiner, Cameron Nicholson, Sarah Hyde, Suzan Mauchline, De-Anne Ferrier, Phil Ward, Kadambot H.M. Siddique, Ken C. Flower
      Crop residue is often grazed by sheep after harvest, over the dry summer period from December to March in Mediterranean environments. However, soil cover provided by crop residues is a key component of conservation agriculture for maintaining favourable soil structure and high yields. A series of 31 site×year experiments was conducted to assess the effect of summer stubble grazing on residue levels and following crop yields. Relatively light grazing, with stocking rates below 10 dry sheep equivalent (DSE) and between 90 and 471 DSE days ha−1, had no significant effect on the amount of residue, soil properties, soil water, weeds or yield in the following crop. The main effect of grazing was to knock down and scatter the standing crop residues. However, longer term grazing at relatively high intensity (956 DSE days ha−1) on heavy soil, over both summer and winter, as in a pasture phase, did significantly reduce residue levels, infiltration and yield (by 59%). The effect of summer grazing on soil mineral N was small and inconsistent, with increased mineral N, by about 3–7kgNha−1, following grazing at two of the 13 sites. By contrast, higher mineral N, by 2–15kgNha−1, was measured in the un-grazed plots at three of the 13 sites. This was due to increased growth of legume pastures in the absence of grazing. More research is needed to confirm the yield effects when cropping after an annual pasture/fallow that is grazed over summer and winter, particularly on different soil types.


      PubDate: 2016-04-17T14:33:24Z
       
  • Do floral resources influence pollination rates and subsequent fruit set
           in pear (Pyrus communis L.) and apple (Malus x domestica Borkh)
           cultivars?
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Muriel Quinet, Martin Warzée, Maryse Vanderplanck, Denis Michez, Georges Lognay, Anne-Laure Jacquemart
      Pear and apple are among the main fruit crops worldwide. These species can be planted in mixed orchards, and they both depend on insect pollination for fruit set. As pollinating insects are attracted by the floral resources, we investigated nectar and pollen production and chemical composition in four pear (‘Concorde’, ‘Conférence’, ‘Doyenné du Comice’, ‘Triomphe de Vienne’) and five apple (‘Braeburn’, ‘Golden Reinders’, ‘Jonagored’, ‘Pinova’, ‘Wellant’) cultivars commonly grown in Belgium. We also investigated whether insect flower visitation rate and pollination efficiency are linked to floral resource quantity and quality. The pear cultivars flowered one week before the apple cultivars in early spring, and their flowers were about six times less visited by insects. The visitors foraged more on the pollen of the pear trees and the nectar of the apple trees. Pear flowers produced higher volumes of nectar than apple flowers (1.3–3.2μl vs. 0.4-0.6μl), but with lower sugar concentration (9.6%-10.8% vs. 28.3%-36.4%). Pear flowers also produced fewer pollen grains per anther than apple flowers (2425–4937 vs. 3284–7919), but these had higher polypeptide (346–362μg/mg vs. 216–303μg/mg), amino-acid (40–77μg/mg vs. 12–18μg/mg) and phytosterol (21–47μg/mg vs. 15–43μg/mg) concentrations. The foraging behavior of the insects is thus better explained by nectar and pollen quality rather than quantity. Despite the differences in flower visitation rates, pollination of both species resulted in valuable fruit production.


      PubDate: 2016-04-17T14:33:24Z
       
  • Commercially available wheat cultivars are broadly adapted to location and
           time of sowing in Australia’s grain zone
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): R.A. Lawes, N.D. Huth, Z. Hochman
      Farmers must choose which cultivar to grow based on the phenology of the cultivar and anticipated season length. The current study investigated the established doctrine of sowing fast maturing cultivars late, and slow maturing cultivars early. This was explored by quantifying the genotype (G)×environment (E)×management (M) available to farmers using commercially released cultivars, where management relates to the time of sowing. Nineteen cultivars of spring wheat (Triticum aestivum) were sown at 3 times of sowing (early, conventional and late) at 13 sites in 2011 and 2012. Sites were located throughout the Australian grain growing region in Queensland, New South Wales, Victoria, South Australia and Western Australia from latitudes 27°34′S to 35°09′S where annual rainfall ranged from 237mm to 747mm. In general, the three way interaction between G, E and M for yield was small and cultivar could not overcome the yield penalty associated with a late time of sowing. At 11 of the 13 sites, fast to moderately fast maturing cultivars sown early generated the highest yields. Fast maturing cultivars sown late could not compensate for a late time of sowing. Commercial cultivars were broadly adapted to environment and management, and with these cultivars, the Australian grain growing region could be split into just two environments, south and north. Even then, season appears to be the main arbiter of environment, rather than location per se as individual sites moved from one group to the other, depending on season. There was no evidence to suggest farmers could exploit a cultivar by management interaction for time of sowing with commercial cultivars, as the outcome of the season is unpredictable, and with current technology farmers should simply choose the best performing cultivar for their region and sow it as early as possible.


      PubDate: 2016-04-12T23:40:18Z
       
  • Adapting maize production to drought in the Northeast Farming Region of
           China
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Xiaogang Yin, Jørgen E. Olesen, Meng Wang, Kurt-Christian Kersebaum, Huang Chen, Sanmohan Baby, Isik Öztürk, Fu Chen
      Maize (Zea mays L.) is the most prominent crop in the Northeast Farming Region of China (NFR), and drought has been the largest limitation for maize production in this area during recent decades. The question of how to adapt maize production to drought has received great attention from policy makers, researchers and farmers. In order to evaluate the effects of adaptation strategies against drought and examine the influences of policy supports and farmer households’ characteristics on adopting decisions, a large scale household survey was conducted in five representative maize production counties across NFR. Our survey results indicated that using variety diversification, drought resistant varieties and dibbling irrigation are the three major adaptation strategies against drought in spring, and farmers also adopted changes in sowing time, conservation tillage and mulching to cope with drought in spring. About 20% and 18% of households enhanced irrigation against drought in summer and autumn, respectively. Deep loosening tillage and organic fertilizer are also options for farmers to resist drought in summer. Maize yield was highly dependent on soil qualities, with yields on land of high soil quality approximately 1050kg/ha and 2400kg/ha higher than for normal and poor soil conditions, respectively. Using variety diversification and drought resistant varieties can respectively increase maize yield by approximately 150 and 220kg/ha under drought. Conservation tillage increased maize yield by 438–459kg/ha in drought years. Irrigation improved maize yield by 419–435kg/ha and 444–463kg/ha against drought in summer and autumn, respectively. Offering information service, financial and technical support can greatly increase the use of adaptation strategies for farmers to cope with drought. However, only 46% of households received information service, 43% of households received financial support, and 26% of households received technical support against drought from the local government. The maize acreage and the irrigation access are the major factors that influenced farmers’ decisions to apply adaptation strategies to cope with drought in each season, but only 25% of households have access to irrigation. This indicates the need for enhanced public support for farmers to better cope with drought in maize production, particularly through improving access to irrigation.


      PubDate: 2016-04-12T23:40:18Z
       
  • Impact on soil physical properties of using large-grain legumes for catch
           crop cultivation under different tillage conditions
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Jan Rücknagel, Philipp Götze, Barbara Koblenz, Nora Bachmann, Stefanie Löbner, Sarah Lindner, Joachim Bischoff, Olaf Christen
      In Central Europe, various plant species including large-grain legumes and their mixtures are grown as catch crops, particularly between grains harvested early and subsequent summer crops. This article investigates the question of how soil structure in the topsoil is influenced when catch cropping with large-grain legumes (experimental factor A: without catch crop, with catch crop) under different ploughless tillage conditions during catch crop seeding (experimental factor B: deep tillage/25–30cm, shallow tillage/8–10cm). Five one-year trials were performed using standard machinery at various sites in Germany. Soil core samples extracted from the topsoil in the spring after catch crop cultivation served to identify air capacity, saturated hydraulic conductivity and precompression stress. The above-ground and below-ground biomass yields of the catch crops were also determined at most of the sites. In addition, the soil compaction risk for the working steps in the experiments was calculated using the REPRO model. The dry matter yield of the catch crops varied considerably between the individual trial sites and years. In particular, high levels of dry matter were able to form in the case of early seeding and a sufficient supply of precipitation. The soil structure was only rarely affected positively by catch crop cultivation, and catch crops did not contribute in the short term to loosening already compacted topsoils. In contrast, mechanical soil stresses caused by driving over the ground and additional working steps used in cultivating catch crops often led to lower air capacity in these treatments. This is consistent with the soil compaction risks calculated using the REPRO model, which were higher in the treatments with catch cropping. Catch crop cultivation also only resulted in improved mechanical stability at one location. The positive effect of deep ploughless tillage on air capacity and saturated hydraulic conductivity, however, became more clearly evident regardless of catch crop cultivation. In order for catch crop cultivation with large-grain legumes to be able to have a favourable impact on soil structure, it is therefore important that cultivating them does not result in any new soil compaction. In the conditions evaluated, deep tillage was more effective at loosening compacted topsoil than growing catch crops.


      PubDate: 2016-04-07T22:44:05Z
       
  • An approach to understanding persistent yield variation—A case study
           in North China Plain
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Yi Zhao, XinPing Chen, David B. Lobell
      Large gaps between maize yields on average farmers’ fields and the highest yields achieved by either experiment or farmers are typical throughout the developing world, including in the North China Plain (NCP). Understanding the underlying causes to this yield gap is important for prioritizing strategies for shrinking this gap and improving food security. Quzhou county in Hebei province is typical of the winter-wheat summer-maize system in NCP where the average plot size is only 0.25ha. To analyze this cropping system amidst the challenge of substantial heterogeneity, we identified fields that were either persistently higher or lower yielding according to remote sensing yield estimates, and then conducted detailed field surveys. We found irrigation facility to be a major constraint to yield both in terms of irrigation water quality and farmers’ access to wells. In total, improving the access to unsalty water would be associated with a 0.32t/ha (4.2%) increase in multi-year average yield. In addition, farmers’ method of choosing cultivar, which likely relates to their overall knowledge level, significantly explained yield variation. In particular, those choosing cultivars according to technician advice, personal experiences and high yielding neighbors’ advice had on average higher yield than farmers that either followed seed sellers’ advice or collectively purchased seeds.


      PubDate: 2016-04-02T22:01:33Z
       
  • Effect of rainfall concentration with different ridge widths on winter
           wheat production under semiarid climate
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Xiaolong Ren, Tie Cai, Xiaoli Chen, Peng Zhang, Zhikuan Jia
      Ridge and furrow rainfall concentration (RC) system has gradually been popularized to increase water availability to crops for improving and stabilizing agricultural production in the semiarid area of northwest China. The system is comprised of two elements: the plastic-covered ridge serves as rainfall harvesting zones and the furrow serves as planting zones. To make this system more perfect for alleviating drought stress in semiarid region, it is necessary to test optimum planting systems. A field experiment was conducted from 2007 to 2010 to evaluate the effects of RC planting on soil moisture, wheat yield and water use efficiency (WUE) under different ridge widths. Four planting systems were designed (RC40: 40cm ridge with 60cm furrow width, RC60: 60cm ridge with 60cm furrow width, RC80: 80cm ridge with 60cm furrow width, and CF: conventional flat without ridging). The results showed that RC planting can significantly increase soil moisture in 0–200cm during the growing seasons of winter wheat. The rainfall-harvesting effect increased with ridge width increasing. Winter wheat yield and WUE was significantly higher under RC60 than under CF by 405.1kgha − 1 and 2.39kgmm − 1 ha − 1, respectively, on average across the three experimental years (P <0.05). The above findings indicate that RC60 can benefit winter wheat cropping for higher yield through improving soil moisture. It could be concluded that the RC planting system with 60cm ridge and furrow width will offer a sound opportunity for sustainable farming in semiarid dryland agricultural area.


      PubDate: 2016-04-02T22:01:33Z
       
  • Contribution of incident solar radiation on leaves and pods to soybean
           seed weight and composition
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Mariana L. Bianculli, Luis A.N. Aguirrezábal, Gustavo A. Pereyra Irujo, María M. Echarte
      The weight and composition of soybean seeds (Glycine Max L. Merrill) depend on changes in carbon and nitrogen assimilate supply during grain filling. Soybean pods and seeds are green, evidencing their capacity to capture light. However, the current physiological knowledge does not consider any effect of incident solar radiation reaching the pods on seed weight and composition. The objective of this work was to investigate the response of seed weight and composition to changes in assimilate supply from leaves, to the incident solar radiation reaching the pods and to the combination of both, changes in assimilate supply from the leaves and incident solar radiation on pods of soybean plants. Field experiments were performed during two growing seasons at Balcarce, Argentina. Treatments modified the amount of assimilates supplied by the leaves (plant shading, defoliation), the solar radiation reaching the pods (pod shading) or both (defoliation and pod shading) during seed filling. Plant shading and defoliation reduced seed weight, oil concentration and oil and protein content and increased the concentration of saturated and poli-unsaturated fatty acids while reduced oleic acid percentage. Pod shading increased the concentration of stearic acid and reduced the concentration of linolenic acid. When pods were shaded on defoliated plants, seed weight and oil and protein content decreased while fatty acid composition was similar to values obtained under defoliation treatment. Based on these results, a conceptual model that considers photoheterotrophic nature of reproductive structures of soybean is proposed. Seed weight, oil and protein content and oil fatty acid composition depended on assimilate availability for the seeds. The response of oil and protein content to assimilate supply depended on whether leaves were present or not. The effect of solar radiation incident on pods depended on the amount of assimilates available for the seeds: (i) when carbon allocated was low (defoliation treatments), pods contributed to seed carbon economy but solar radiation incident on them did not affect fatty acid composition; (ii) when carbon allocated to the seeds was high (intact plants), contribution of pods to seed carbon economy was not significant, but the amount of solar radiation incident on pods produced significant changes in fatty acid composition.


      PubDate: 2016-03-23T21:17:42Z
       
  • 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
       
  • Opposite oleic acid responses to temperature in oils from the seed and
           mesocarp of the olive fruit
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Georgina Paula García-Inza, Diego Nicolás Castro, Antonio Juan Hall, María Cecilia Rousseaux
      Olive oil is mostly extracted from the mesocarp (∼95%) of the fruit with the seed (endosperm and embryo, ∼5%) containing little oil. There are correlative and manipulative evidence that temperature modulates fruit oil content and fatty acid composition of the oil from the whole fruit (i.e., with no distinction being made between oils derived from each oil-bearing structure) of olive. Notably, oleic acid concentration of olive oil decreases as fruit mean growth temperature increases. This response in the olive fruit is opposite to that documented in annual oil-seed crops such as sunflower and soybean. The objectives of the present study were: i) to compare temperature effects on fatty acid composition of oil derived from seed and from mesocarp; ii) to compare temperature effects on seed and mesocarp dry weights and oil concentrations. To do this, fruiting branches were enclosed in transparent plastic chambers with individualized temperature control. Temperature was manipulated during the seed growth (Period A) and during the second half of mesocarp growth (Period B) subphases. In both periods, the oleic acid proportion in mesocarp oil decreased as temperature increased, and was accompanied by increases of palmitic acid, linoleic and linolenic acids. Mesocarp dry weight did not respond significantly to temperature, but mesocarp oil concentration fell significantly as temperature increased. Seed dry weight, oil concentration and fatty acid composition exhibited responses to temperature during Period A only, with seed dry weight increasing between 20 and 25°C with a sharp decrease at higher temperature, and oil concentration linearly falling 1.2% per°C. In contrast, seed oil oleic acid percentage increased between 20 and 28°C, and fell slightly with higher temperature. Palmitic and stearic acids in seed oil increased sigmoidally with temperature, while linoleic acid decreased sigmoidally. Oleic acid percentage showed opposite responses in oil from the seed and the mesocarp. The response of the seed to temperature was similar to those observed in oil from embryos of annual oil-seed crops, although the abrupt fall in palmitic and stearic acid with temperature>25°C seems to be distinctive for olive seed oil.
      Graphical abstract image

      PubDate: 2016-03-19T06:48:57Z
       
  • Interoperability of agronomic long term experiment databases and crop
           model intercomparison: the Italian experience
    • Abstract: Publication date: Available online 10 March 2016
      Source:European Journal of Agronomy
      Author(s): Fabrizio Ginaldi, Marco Bindi, Anna Dalla Marta, Roberto Ferrise, Simone Orlandini, Francesco Danuso
      The IC-FAR national project (Linking long term observatories with crop system modelling for better understanding of climate change impact, and adaptation strategies for Italian cropping systems) initiated in 2013 with the primary aim of implementing data from 16 long term Italian agronomic experiments in a common, interoperable structure. The building of a common database (DB) structure demands a harmonization process aimed at standardising concepts, language and data in order to make them clear, and has to produce a well-documented and easily available tool for the whole scientific community. The Agricultural Model Intercomparison and Improvement Project (AgMIP) has made a great effort in this sense, improving the vocabulary developed by the International Consortium for Agricultural Systems Applications (ICASA) and defining harmonization procedures. Nowadays, these ones have also to be addressed to facilitate the extraction of input files for crop model simulations. Substantially, two alternative directions can be pursued: adapting data to models, building a standard storage structure and using translators that convert DB information to model input files; or adapting models to data, using the same storage structure for feeding modelling solutions constituted by combining model components, re-implemented in the same model platform. The ICFAR information management system simplifies data entry, improves model input extraction (implementing System Dynamics ontology), and satisfies both the paradigms. This has required the development of different software tools: ICFAR-DB for data entry and storage; a model input extractor for feeding the crop models (MoLInEx); SEMoLa platform for building modelling solutions and performing via scripts the model intercomparison. The use of the standard AgMIP/ICASA nomenclature in the ICFAR-DB and the opportunity to create files with MoLInex for feeding AgMIP model translators allow full system interoperability.


      PubDate: 2016-03-13T06:24:05Z
       
  • Long-Term Experiments with cropping systems: Case studies on data analysis
    • Abstract: Publication date: Available online 10 March 2016
      Source:European Journal of Agronomy
      Author(s): Andrea Onofri, Giovanna Seddaiu, Hans-Peter Piepho
      Data analysis for Long-Term Experiments (LTEs) with cropping systems requires some careful thinking, especially for the most complex designs, characterised by rotations with different durations and/or a different number of test-crops per rotation cycle. This paper takes an example-based approach, built upon a number of datasets, covering the main types of LTEs, with increasing levels of complexity. A procedure is outlined to build statistical models for data analysis that is useful for all LTEs characterised by the simultaneous presence of all rotation phases in all years, together with within-year replication. This procedure is based on the assumption that correct analyses can be performed separately for each year. The use of mixed models and REML estimation is advocated for model fitting with all LTEs, due to the fact that most designs are non-orthogonal, as plots may not produce data for the test-crop under study in all years. Mixed models are also useful to account for the autocorrelation of residuals over time and hints are given for the selection of an appropriate variance-covariance structure. For all our examples, variances were not constant across years and compound symmetry correlation structures with variance heterogeneity of years proved to be the best compromise between parsimony and statistical accuracy. Methods are outlined to test for the need of other more complex correlation structures and examples are also given on how to test for fixed effects, model fertility trends and assess the long-term stability of cropping systems.


      PubDate: 2016-03-13T06:24:05Z
       
  • Long-term evaluation of productivity, stability and sustainability for
           cropping systems in Mediterranean rainfed conditions
    • Abstract: Publication date: Available online 10 March 2016
      Source:European Journal of Agronomy
      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: 2016-03-13T06:24:05Z
       
  • Germination ecology of nutraceutical herbs for agronomic perspectives
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Stefano Benvenuti, Alberto Pardossi
      The growing need for nutraceutical foods has elicited increasing interest in the herbs traditionally used for ethnobotanical purposes. Their richness in antioxidants inspired this research, which is aimed at cultivating them as crops. Sixteen wild species of crucial interest as food were studied in term of seed propagation. The frequent dormancy was reduced or removed by physical, or physiological seed treatments in laboratory experiments in Petri dishes. However, their direct field sowing, in spring and autumn, did not show the same performance in spite of the efficacy of the treatments. This specially occurs in the case of species with very small seeds suggesting a burial involvement of this soil-mediated inhibition. This inhibition was markedly lower after greenhouse sowing in a soft substrate (peat–pearlite) confirming the hypothesis that the soil acts (via hypoxia) as a crucial obstacle to germination. The study of the emergence reduction by a slight burial (1cm), compared to unburied germination, allowed to evaluate, for each species, the burial-mediated inhibition. After the 1000 seed weight measurement a relation between these two parameters (burial inhibition and seed weight) was fitted. A polynomial regression confirmed the inverse relationship between seed weight and burial-mediated inhibition showing the remarkable burial-intolerance of very small seeds. Consequently the greenhouse sowing in substrate appears the most suitable agronomic strategy overall for food herbs characterized by little seeds. Critical issues are discussed regarding these weeds becoming real nutraceutical crops.


      PubDate: 2016-03-13T06:24:05Z
       
  • Seed priming improves stand establishment and productivity of no till
           wheat grown after direct seeded aerobic and transplanted flooded rice
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Ahmad Nawaz, Muhammad Farooq, Riaz Ahmad, Shahzad Maqsood Ahmad Basra, Rattan Lal
      No tillage (NT) in wheat (Triticum aestivum L.) offers a pragmatic option for resolving the time and edaphic conflicts in rice (Oryza sativa L.)–wheat cropping system (RWS). However, poor stand establishment is an issue in NT wheat, which adversely affects crop growth, grain yield, and profitability. Therefore, a 2-year field study was conducted to assess the potential role of seed priming in improving the stand establishment, grain yield, water productivity and profitability of NT and plough till (PT) wheat grown after direct seeded aerobic (conservation) and puddled transplanted flooded (conventional) rice-based systems. For seed priming, wheat seeds were soaked in aerated water (hydropriming) or solution of CaCl2 (ψs −1.25MPa; osmopriming) for 12h, and non-primed seeds were used as control. After harvest of rice, grown as direct seeded aerobic and puddled transplanted flooded crop, primed and non-primed wheat seeds were sown following NT and PT. In both years, stand establishment of NT wheat after direct seeded aerobic and puddled transplanted flooded rice was impeded. Nonetheless, seed priming improved the stand establishment which was visible through earliness and better uniformity of seedling emergence. Overall, primed seeds completed 50% emergence in 6.4 days, against 7.8 days taken by non-primed seeds in NT wheat. The highest emergence index (41.7) was recorded in primed seeds versus 32.0 for non-primed seeds. Improved stand establishment enhanced growth, grain yield, water productivity and profitability in NT wheat. In this regard, osmopriming was the most effective, and produced grain yield of 4.5Mgha−1 against 3.8Mgha−1 for non-primed seeds in NT wheat. Water productivity of the NT wheat grown from osmoprimed seeds was 8.72kgha−1 mm−1 while that from non-primed seeds was 7.21kgha−1 mm−1. Among the RWSs, the maximum wheat biomass was produced with PT after direct seeded aerobic rice. However, grain yield, water productivity, and profitability were the highest in NT wheat following direct seeded aerobic rice. Wheat yields grown after direct seeded aerobic rice and transplanted flooded rice were 4.4 and 4.2Mgha−1 respectively. Planting NT wheat after direct seeded aerobic rice provided the highest system productivity (1.80) than other RWSs. Thus, seed priming is a viable option to improve the stand establishment, grain yield, water productivity and profitability of NT wheat in the RWS. Nonetheless, osmopriming was a better option than hydropriming in this regard.


      PubDate: 2016-03-13T06:24:05Z
       
  • Phosphorus uptake and utilization efficiency in response to potato
           genotype and phosphorus availability
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Patricio Sandaña
      Increased phosphorus (P) use efficiency (PUE) of potato production systems through P uptake and P utilization efficiency (PUPE and PUTE, respectively) is one of the main challenges for potato breeding and crop management programs. The aim of this study was to assess PUE, PUPE, PUTE and related traits in different potato genotypes (Solanum tuberosum L.) in response to P availability. Three field experiments were carried out in southern Chile in Andisol soils. In each experiment treatments were the factorial combination of (i) 22 genotypes of potatoes and (ii) two P fertilization rates (0 and 130kgPha−1, −P and +P, respectively). On average, biomass, P concentrations and P uptakes were reduced (P< 0.05) 32, 13 and 41% by −P, respectively. Conversely, −P increased PUTE (1.2-fold), PUPE (7-fold) and consequently PUE (8.3-fold). All traits were consistently affected (P < 0.01) by genotype (G), and the coefficient of variation (up to 47%) for each trait reflects the genotypic variability under both +P and −P. In all experiments, PUE and its main components were affected (P< 0.01) by P×G interaction. PUE was highly correlated with tuber yield, total biomass, P uptake and PUPE (P < 0.01; r = 0.74 − 0.99) but not to PUTE. In addition, PUPE was well correlated to yield and highly correlated with total P uptake (P < 0.01; r = 0.94–0.99). By contrast, PUTE was strongly negatively correlated (P < 0.01; r = −0.85−0.89) with P concentration in tubers. Genotypes from native (1 and 4), national cultivar (Puren-INIA, Yagana-INIA and Patagonia-INIA) and advanced line (R 89063 and RD 36–35) groups were among the best regarding PUE under −P. The PUPE was found to be more important than PUTE in determining PUE across a broad range of genotypes. Moreover, there is important genotypic variability in these traits with the potential to be used to improve PUE in potato crops through breeding and crop management programs.


      PubDate: 2016-03-09T06:14:30Z
       
  • Long term effects of tillage practices and N fertilization in rainfed
           Mediterranean cropping systems: durum wheat, sunflower and maize grain
           yield
    • Abstract: Publication date: Available online 7 March 2016
      Source:European Journal of Agronomy
      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: 2016-03-09T06:14:30Z
       
  • Effects of crop residue management on winter durum wheat productivity in a
           long term experiment in Southern Italy
    • Abstract: Publication date: Available online 7 March 2016
      Source:European Journal of Agronomy
      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: 2016-03-09T06:14:30Z
       
  • Soil carbon and nitrogen changes after 28 years of no-tillage management
           under Mediterranean conditions
    • Abstract: Publication date: Available online 7 March 2016
      Source:European Journal of Agronomy
      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: 2016-03-09T06:14:30Z
       
  • Coupling a generic disease model to the WARM rice simulator to assess leaf
           and panicle blast impacts in a temperate climate
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): S. Bregaglio, P. Titone, G. Cappelli, L. Tamborini, G. Mongiano, R. Confalonieri
      Blast disease (Magnaporthe oryzae B. Couch) is one of the most important causes of rice yield losses worldwide. Although farmers implement countermeasures to limit its impacts, blast disease is still an important constraint to rice production in both tropical and temperate environments. This study presents the coupling of a generic disease model to the WARM rice simulator to quantify the pathogen impact on key physiological processes and thus on final yield. The impact of leaf blast was simulated by reducing the photosynthetic leaf area index and in turn radiation interception, as a function of disease progress rate. Panicle blast damage was reproduced by decreasing the percentage of photosynthates translocated to kernels. The modelling solution was calibrated and evaluated using field observations of blast impact at harvest, collected on 20 rice cultivars with different blast resistance and grown in five sites in Northern Italy in the period 1996–2012 (total 272 observations). Results showed a good correlation between simulated impacts (fraction of potential yield) and observations (0–5 scale used for the visual assessment, with 0=no impact and 5=complete crop failure), for both calibration (R 2 =0.57) and evaluation (R 2 =0.51) datasets. Model outputs were converted to the same scale used for the visual assessments to perform an in-depth evaluation of the modelling solution, which exactly matched the 46% of observed impact values, and presented an error of 1 class in 48.2% of the cases. This study demonstrated the soundness of the approach developed for crop-pathogen interactions and its suitability for the application in research—e.g., to explore the impacts of climate change on blast-related yield losses —and operational contexts—e.g., to test alternate fungicide strategies to optimize agricultural chemical applications.


      PubDate: 2016-03-09T06:14:30Z
       
  • Using a multicriteria assessment model to evaluate the sustainability of
           conservation agriculture at the cropping system level in France
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): D. Craheix, F. Angevin, T. Doré, S. de Tourdonnet
      Several international research and development organizations are promoting conservation agriculture in a wide range of contexts. Conservation agriculture is based on a combination of three main principles: (i) minimal or no mechanical soil disturbance; (ii) diversified crop rotations and (iii) permanent soil cover (consisting of a growing crop or a dead mulch of crop residues). However, in the face of the diversity of practices that can be associated with conservation agriculture, of goals assigned to agricultural systems, and pedoclimatic contexts, there is still no empirical evidence about the overall performance of conservation agriculture in France. Global assessments of conservation agriculture, with the full or partial application of its principles and in different contexts, are required to provide a more comprehensive picture of the performance of such systems. We tackled these objectives simultaneously, by evaluating 31 cropping systems with the MASC® model (for Multicriteria Assessment of the Sustainability of Cropping Systems). These systems were selected to represent a wide diversity of practices, from ploughed conventional systems to crop sequences based on the full application of conservation agriculture principles. Positive interactions were observed between the key elements of conservation agriculture, resulting in better sustainability performances (particularly in terms of environmental criteria). Nevertheless, the systems most closely respecting the principles of conservation agriculture displayed several weaknesses, principally of a social or technical nature, in this study. Careful attention should be paid to attenuating these weaknesses. A more detailed analysis of the results also suggested that decreasing soil tillage tends to decrease the overall performance of the system unless associated with a diversification of the crop rotation.


      PubDate: 2016-02-26T11:16:53Z
       
  • Trade-offs between water-use related traits, yield components and mineral
           nutrition of wheat under Free-Air CO2 Enrichment (FACE)
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Alireza Houshmandfar, Glenn J. Fitzgerald, Allene A. Macabuhay, Roger Armstrong, Sabine Tausz-Posch, Markus Löw, Michael Tausz
      This study investigated trade-offs between parameters determining water use efficiency of wheat under elevated CO2 in contrasting growing seasons and a semi-arid environment. We also evaluated whether previously reported negative relationships between nutrient content and transpiration efficiency among wheat genotypes will be maintained under elevated CO2 conditions. Two cultivars of wheat (Triticum aestivum L.), Scout and Yitpi, purportedly differing in water use efficiency related traits (e.g. transpiration efficiency) but with common genetic backgrounds were studied in a high yielding, high rainfall (2013), and in a low yielding, very dry growing season (2014) under Free-Air CO2 Enrichment (FACE, CO2 concentration of approximately 550μmolmol−1) and ambient (approximately 390μmolmol−1) CO2. Gas exchange measurements were collected diurnally between stem elongation and anthesis. Aboveground biomass and nutrient content (sum of Ca, K, S, P, Cu, Fe, Zn, Mn and Mg) were determined at anthesis. Yield, yield components and harvest index were measured at physiological maturity. Cultivar Scout showed transiently greater transpiration efficiency (measured by gas exchange) over cultivar Yitpi under both ambient and elevated CO2 conditions, mainly expressed in the high yielding but not in the low yielding season. Nutrient content was on average 13% greater for the lower transpiration efficiency cultivar Yitpi than the cultivar with higher transpiration efficiency (Scout) in the high yielding season across both CO2 concentrations. Elevated CO2 stimulated grain yield to a greater extent in the high yielding season than in the low yielding season where increased aboveground biomass earlier in the season did not translate into fertile tillers in cultivar Yitpi. Yield increased 27 and 33% in the high yielding and 0 and 19% in the low yielding season for cultivars Yitpi and Scout, respectively. Intraspecific variation in CO2 responsiveness related mechanisms of grain yield were observed. These results suggest CO2-driven trade-offs between traits governing water use efficiency are related to both growing season and intraspecific variations, and under very dry finishes, the trade-offs may even reverse. The negative relationship between nutrient content and transpiration efficiency among wheat genotypes will be maintained under elevated CO2 conditions.


      PubDate: 2016-02-26T11:16:53Z
       
  • Evaluation of small site-specific N fertilization trials using uniformly
           shaped response curves
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Ingo Pahlmann, Ulf Böttcher, Henning Kage
      The spatial variability of yields and optimal N rates is well documented for several crops and the benefit of studying site-specific N response seems self-evident. Unfortunately, trials established to examine site-specific N response are mostly quite large and expensive, since those trials usually cover nearly the whole field. Selecting only small subareas of a field to host an N fertilization trial will reduce costs and therefore possibly allow more trials on different locations. On the other hand, the evaluation of small trials can become difficult, resulting from a low number of observations compared to the number of parameters that need to be estimated. Aim of this study was to develop a framework that allows evaluating yield response from small site-specific trials by reducing the number of parameters of the response curves. The framework was tested on a data-base of a two-year site-specific N fertilization trial in northern Germany. Three different types of N response curves were evaluated individually for each subarea: Linear plus plateau (LP), quadratic (Q) and quadratic plus plateau (QP). In a second step an alternative parameterization that includes a shape parameter was introduced. For each type of response curve, this shape parameter was set to a common value for all subareas within a field and year, thus reducing the number of parameters that need to be estimated. Results show that the reduction of parameters did not reduce the goodness of fit when describing yield response, since the yield response of each subarea still depends on different maximum yields and different N amounts to attain their maximum yield. It turned out that the models using a common shape parameter allowed to evaluate even subareas with separately indetermined parameter values. Furthermore, agronomically meaningful correlations of the estimated response curves to the empirically observed characteristics of their respective subareas were improved.


      PubDate: 2016-02-26T11:16:53Z
       
  • Effect of irrigation and nitrogen fertilization on the production of
           biogas from maize and sorghum in a water limited environment
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Stefano Amaducci, Michele Colauzzi, Ferdinando Battini, Alessandra Fracasso, Alessia Perego
      The expansion of biogas production from anaerobic digestion in the Po Valley (Northern Italy) has stimulated the cultivation of dedicated biomass crops, and maize in particular. A mid-term experiment was carried out from 2006 to 2010 on a silt loamy soil in Northern Italy to compare water use and energy efficiency of maize and sorghum cultivation under rain fed and well-watered treatments and at two rates of nitrogen fertilization. The present work hypothesis were: (i) biomass sorghum, for its efficient use of water and nitrogen, could be a valuable alternative to maize for biogas production; (ii) reduction of irrigation level and (iii) application of low nitrogen fertilizer rate increase the efficiency of bioenergy production. Water treatments, a rain fed control (I0) and two irrigation levels (I1 and I2; only one in 2006 and 2009), were compared in a split–split plot design with four replicates. Two fertilizer rates were also tested: low (N1, 60kgha−1 of nitrogen; 0kgha−1 of nitrogen in 2010) and high (N2, 120kgha−1 of nitrogen; 100kgha−1 of nitrogen in 2010). Across treatments, sorghum produced more aboveground biomass than maize, respectively 21.6 Mgha−1 and 16.8 Mgha−1 (p <0.01). In both species, biomass yield was lower in I0 than in I1 and I2 (p <0.01), while I1 and I2 did differ significantly. Nitrogen level never affected biomass yield. Water use efficiency was generally higher in sorghum (52kgha−1 mm−1) than in maize (38kgha−1 mm−1); the significant interaction between crop and irrigation revealed that water use efficiency did not differ across water levels in sorghum, whereas it significantly increased from I0 and I1 to I2 in maize (p <0.01). The potential methane production was similar in maize and sorghum, while it was significantly lower in I0 (16505MJha−1) than in I1 and I2 (21700MJha−1). The only significant effect of nitrogen fertilization was found in the calculation of energy efficiency (ratio of energy output and input) that was higher in N1 than in N2 (p <0.01). These results support the hypothesis that (i) sorghum should be cultivated rather than maize to increase energy efficiency, (ii) irrigation level should replace up to 36% of ETr and (iii) nitrogen fertilizer rate should be minimized to maximize the efficiency in biomass production for anaerobic digestion in the Po Valley.


      PubDate: 2016-02-26T11:16:53Z
       
  • Performance and sensitivity of the DSSAT crop growth model in simulating
           maize yield under conservation agriculture
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Marc Corbeels, Guillaume Chirat, Samir Messad, Christian Thierfelder
      With the practice of conservation agriculture (CA) soil water and nutrient dynamics are modified by the presence of a mulch of crop residues and by reduced or no-tillage. These alterations may have impacts on crop yields. The crop growth model DSSAT (Decision Support Systems for Agrotechnology Transfer) has recently been modified and used to simulate these impacts on crop growth and yield. In this study, we applied DSSAT to a long-term experiment with maize (Zea mays L.) grown under contrasting tillage and residue management practices in Monze, Southern Province of Zambia. The aim was (1) to assess the capability of DSSAT in simulating crop responses to mulching and no-tillage, and (2) to understand the sensitivity of DSSAT model output to input parameters, with special attention to the determinants of the model response to the practice of CA. The model was first parameterized and calibrated for the tillage treatment (CP) of the experiment, and then run for the CA treatment by removing tillage and applying a mulch of crop residues in the model. In order to reproduce observed maize yields under the CP versus CA treatment, optimal root development in the model was restricted to the upper 22cm soil layer in the CP treatment, while roots could optimally develop to 100 cm depth under CA. The normalized RMSE values between observed and simulated maize phenology and total above ground biomass and grain yield indicated that the CA treatment was equally well simulated as the CP treatment, for which the model was calibrated. A global sensitivity analysis using co-inertia analysis was performed to describe the DSSAT model response to 32 model input parameters and crop management factors. Phenological cultivar parameters were the most influential model parameters. This analysis also demonstrated that in DSSAT mulching primarily affects the surface soil organic carbon content and secondly the total soil moisture content, since it is negatively correlated with simulated soil water evaporation and run-off. The correlations between the input parameters or crop management factors and the output variables were stable over a wide range of seasonal rainfall conditions. A local sensitivity analysis of simulated maize yield to three key parameters for the simulation of the CA practice revealed that DSSAT responds to mulching particularly when rooting depth is restricted, i.e., when water is a critical limiting crop growth factor. The results of this study demonstrate that DSSAT can be used to simulate crop responses to CA, in particular through simulated mulching effects on the soil water balance, but other, often site-specific, factors that are not modeled by DSSAT, such as plough pan formation under CP or improved soil structure under CA, may need to be considered in the model parameterization to reproduce the observed crop yield effects of CA versus CP.


      PubDate: 2016-02-20T11:02:26Z
       
  • Organic and mineral fertilization management improvements to a
           double-annual cropping system under humid Mediterranean conditions
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): B. Perramon, A.D. Bosch-Serra, F. Domingo, J. Boixadera
      The efficient use by crops of nitrogen from manures is an agronomic and environmental issue, mainly in double-annual forage cropping systems linked to livestock production. A six-year trial was conducted for a biennial rotation of four forage crops: oat-sorghum (first year) and ryegrass-maize (second year) in a humid Mediterranean area. Ten fertilization treatments were introduced: a control (without N); two minerals equivalent to 250kgNha−1 year−1 applied at sowing or as sidedressing; dairy cattle manure at a rate of 170, 250 and 500kgNha−1 year−1 and four treatments where the two lowest manure rates were supplemented with 80 or 160kg mineral Nha−1 year−1. They were distributed according to a randomized block design with three blocks. The highest N mineral soil content was found in the summer of the third rotation, in plots where no manure was applied. The yearly incorporation of manure reduced, in successive cropping seasons, the amount of additional mineral N needed as sidedressing to achieve the highest yields. Besides, in the last two years, there was no need for mineral N application for the manure rate of 250kgNha−1 year−1. This amount always covered the oat-sorghum N uptake. In the ryegrass-maize sequence uptakes were as high as 336kgNha−1 year−1. In the medium term, the intermediate manure rate (250kgNha−1 year−1) optimizes nutrient recycling within the farming system, and it should be considered in the analysis of thresholds for N of organic origin to be applied to systems with high N demand.


      PubDate: 2016-02-15T12:33:38Z
       
  • Yield and yield components of wheat and maize in wheat–maize
           intercropping in the Netherlands
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Fang Gou, Martin K. van Ittersum, Guoyu Wang, Peter E.L. van der Putten, Wopke van der Werf
      Intercropping is widely used by smallholder farmers in developing countries, and attracting attention in the context of ecological intensification of agriculture in developed countries. There is little experience with intercropping of food crops in Western Europe. Yields in intercrops depend on planting patterns of the mixed species in interaction with local growing conditions. Here we present data of two years field experimentation on yield and yield components of a wheat–maize intercrop system in different planting configurations in the Netherlands. Treatments included sole crops of wheat (SW) and maize (SM), a replacement intercrop consisting of strips of six wheat rows alternating with two maize rows (6:2WM), as well as subtractive or additive designs, based on skip-row (6:0WM, 0:2WM) and add-row (8:2WM, 6:3WM) configurations. The land equivalent ratio (LER) of intercrops varied from 1.18 to 1.30 in 2013 and from 0.97 to 1.08 in 2014. Wheat grown in the border rows of wheat strips had higher ear number per meter row, greater kernel number per ear, and greater yield per meter row than wheat in inner rows and sole wheat, indicating reduced competition. Wheat in the border rows in the intercrops had, however, reduced thousand kernel weight and harvest index, indicating that competition in border rows intensified over time. Intercropping negatively affected maize biomass and thousand kernel weight, especially in add-row treatments. This study indicates that there is a potential yield benefit for the wheat–maize intercropping system under Western European growing conditions. However, the LER was affected by yearly variation in weather conditions and significantly greater than one in only one of the two years of the study.


      PubDate: 2016-02-15T12:33:38Z
       
  • Field scale functional agrobiodiversity in organic wheat: Effects on weed
           reduction, disease susceptibility and yield
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Ambrogio Costanzo, Paolo Bàrberi
      Deployment of diversity at the species and at the genetic levels can improve the ability of crops to withstand a wide range of biotic and abiotic stressors in organic and low-input cropping systems, where the response to stresses through external input is limited or restricted in comparison with conventional systems. Although there are several strategies to use agrobiodiversity in wheat-based systems, their implementation is limited by the lack of a clear relationship between agrobiodiversity and provision of key agroecosystem services. In a three-year field trial in Central Italy we compared common wheat Italian and Hungarian pure lines, Italian old cultivars and Hungarian and British Composite Cross Populations (CCPs), grown with or without a contemporarily sown Subterranean clover living mulch. We aimed at linking crop performance, in terms of yield, weed reduction and disease susceptibility, to three categories of functional diversity: (1) functional identity, represented by the identifying traits of cultivars, (2) functional diversity, represented by the genetic heterogeneity of wheat crop population, and (3) functional composition, represented by the co-presence of wheat and the living mulch. Concerning cultivars, effects of functional identity were predominant for weed reduction and grain yield. Old cultivars tended to better suppress weeds but to be less yielding. Italian cultivars were more advantaged than cultivars of foreign origin, thanks to a better matching of their growth cycle into local climate. Functional diversity effects on yield and weed reduction were confounded with identity effects, given that all the CCPs were of foreign origin. In fact, the performance of CCPs was generally aligned with a central-European pure line. However, differences in yield components suggest that CCPs can evolve peculiar yield formation strategies. Moreover, CCPs were less susceptible than pure lines to foliar diseases. For functional composition, the living mulch was able to reduce dicotyledonous weed abundance and weed biomass without reducing wheat yield unless wheat was poorly established. Despite the strong morphological and phenological differences among the tested cultivars, no interactions were found between cultivar and living mulch presence, suggesting that, in conditions similar to our experiments, there is room to freely combine elements of crop diversity. Crop diversification strategies in wheat should be further explored and optimized, especially by constituting CCPs from locally adapted germplasms and by improving the feasibility and efficacy of legume living mulches.


      PubDate: 2016-02-15T12:33:38Z
       
  • Impacts of long-term jujube tree/winter wheat–summer maize
           intercropping on soil fertility and economic efficiency—A case study
           in the lower North China Plain
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Lilin Yang, Xinquan Ding, Xiaojing Liu, Pingman Li, A. Egrinya Eneji
      Agroforesry is a common traditional practice in China, especially in the saline-alkaline regions, like the lower North China Plain (LNCP) characterized by lower yields of food crops. Adding trees to the agricultural land creates additional fruitsets or woody biomass besides food crops, enabling farmers to diversify the provision of farm commodities. However, the productivity of many agroforestry systems has been lower than expected in recent years, highlighting the need for a mechanistic understanding of below- or above-ground interactions. The study combined investigation and experimental data together to evaluate the effects of long-term intercropping agroforestry system [jujube tree (Zizyphus jujuba Mill. var. inermis (Bunge) Rehd.)/winter wheat–summer maize] on soil fertility balance, crop production and system economic efficiency over the past 22 years in LNCP, with a view to developing an effective fertilization management for the moderately alkaline soils. Except remain higher pH, the soils are basically free of sodic and soil salinity is not the major restriction factor for intercrops, even through there are some fluctuation with season and distance from jujube tree. The intercropping system significantly reduced soil nutrient contents, like soil organic C (SOC), total N (TN), available P (avail. P) and K (avail. K) in most parts of the ecotone of the system, but increased those nutrients in the belt of underneath the edge of tree canopy, The growth of intercrops at the belt of 3.5m from tree was severely negative stressed by jujube tree in term of lower soil moisture, nitrate, avail. P and K although receiving more photosynthetically active radiation (PAR), whereas the winter wheat growing at the 2.5m row had more water and nutrients supplied and thus produced more grain yield. Uneven fertilization to the ecotone (about 1–2.5m of the intercrop field boundary) could partly offset the consumption and competition for nutrients between the tree and the intercrops, and improved the grain yields by 12.1% and 14.5% in the ecotone regions (distance from jujube trees) of 1.5m for winter wheat and 2.5m for summer maize by increasing respective yield components. Although the mean grain yield of intercropped winter wheat and summer maize was reduced by 35.6 and 35.2%, respectively, compared to sole cropping system, the intercropping system proved to be a profitable land use type based on net income and economic returns, in addition to the wood and ecological benefits of the jujube tree in the moderate desalinate- alkaline regions.


      PubDate: 2016-02-10T21:41:33Z
       
  • Organic amendment and minimum tillage in winter wheat grown in
           Mediterranean conditions: Effects on yield performance, soil fertility and
           environmental impact
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): G. Debiase, F. Montemurro, A. Fiore, C. Rotolo, K. Farrag, A. Miccolis, G. Brunetti
      The experiment was conducted to evaluate the agronomic benefit of the application of organic fertilizers combined with different soil tillage on quantitative and qualitative components of winter wheat (Triticum durum Desf., cv. ‘Simeto’) and on chemical soil fertility parameters. The environmental impact, due to heavy metals introduced in soil-plant system, was further investigated. Soil tillage treatments consisted of conventional (CT) and minimum tillage (MT). Fertilization treatments were: mineral at 100kgNha−1 (Nmin); municipal solid waste compost at 100kgNha−1 (Ncomp); 50kgNha−1 of both compost and mineral fertilizers (Nmix); sewage sludge at 100kgNha−1 (Nss). These treatments were compared with an unfertilized control (N0). No significant difference was observed between the two soil tillage treatments for quantitative yield production, while among the fertilization treatments Nss did not show any significant difference compared to Nmin. At the end of the research, the fertility of the soil (oxidable carbon, total nitrogen, available phosphorus) was on average higher in Ncomp and Nss treatments compared to the N0 and Nmin ones. The overall distribution of heavy metals in soil-plant system respect to the different fertilizer treatments has not allowed to grouped their effects with Principal Components Analysis. This result showed that the amount of potential pollutants applied by organic amendments did not modified the dynamic equilibrium of the soil–plant system. The MT, as well as the fertilization with the application of sewage sludge (Nss), allowed to reach productive performance similar to conventional management (CT with Nmin). Here we demonstrate that, in the short term period, sustainable agronomical techniques can replace the conventional one with environmental benefit.


      PubDate: 2016-02-10T21:41:33Z
       
  • Yield losses on wheat crops associated to the previous winter crop: Impact
           of agronomic practices based on on-farm analysis
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Sebastián R. Mazzilli, Oswaldo R. Ernst, Vanesa Pereira de Mello, Carlos A. Pérez
      Wheat is one of the most important cultivated cereals worldwide. In Uruguay, the area increased from 153.000ha to 453.000ha between 2004 and 2012, nowadays representing 80% of the total winter crops area. As the high area of the crop, is common planting wheat in a field with wheat as previous winter crop (“wheat after wheat”). This practice leads to a high inoculum pressure of necrotrophic pathogens which guarantees disease inoculation mainly of Pyrenophora tritici-repentis (tan spot—TS) and Zymoseptoria tritici (septoria leaf blotch—SLB). There is strong evidence that integrated crop management practices such as nitrogen (N) fertilization, genetic resistance to leaf diseases and fungicides could mitigate yield losses associated with monoculture. However, the impacts of integrated technologies based on actual field data have not been reported before. We based our study in an on-farm wheat yield and management database to assess the previous winter crop effect on wheat yield under no-till systems. This database corresponds to a set of farmers grouped in CREA (Consorcio Regional de Experimentación Agrícola). A complete database of 1292 no-till wheat fields was analyzed. The effect of previous winter crop on yield and the impact of different technologies were estimated based on two approaches: (i) yield quartile analysis and (ii) yield frontier analysis. The crop rotation had a significant impact on yield. The practice of growing “wheat after wheat” was associated with a yield loss of ca 500kgha−1. The selection of a diseases resistant cultivar under “wheat after wheat” fields increases yields in ≈700kgha−1. The percentage of fields with an efficiency higher than 80% improved from 49 to 77% when a resistant cultivar to TS and SLB was selected, and when N fertilizer was applied earlier and in higher rates. Unexpectedly, only 18% of the “wheat after wheat” fields are applying these two technologies in scenarios under high inoculum pressure. This study, based in on-farm data, highlights the relevance of integrated disease management, and remarks the potential of this approach to minimize the interference of foliar diseases in fields with high inoculum pressure of stubble-borne pathogens.


      PubDate: 2016-02-10T21:41:33Z
       
  • Simulating farming practices within a region using a stochastic
           bio-decisional model: Application to irrigated maize in south-western
           France
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): D. Leenhardt, L. Maton, J.-E. Bergez
      Agricultural is a major contributor to environmental resource management problems. Modelling the distribution of agricultural land use to evaluate current situations or scenarios is an important issue for policy-makers and natural resource managers. A promising approach is the use of bio-decisional models based on decision rules. However, at the regional scale, the large number of farmers makes it difficult to identify decision rules, and the diversity of farmers' decisions is rarely considered. To this end, we developed SIMITKO, a spatialised and stochastic bio-decisional model, able to simulate the spatial and temporal variability in farming practices. We focused on the choice of varietal earliness and sowing practices of maize (Zea mays L.) in the Baïse sector (south-western France). Model development was based on statistical analyses of surveys of farmers’ practices to identify their current strategies, the best variables to describe the practices and the probabilities associated with the values of the variables for each strategy. We tested SIMITKO by simulating the dynamics of areas sown with maize. Comparing model predictions of practices to observed data showed generally good predictions of sowing dynamics but less satisfactory predictions of varietal earliness choices. Possible improvements are suggested.


      PubDate: 2016-02-10T21:41:33Z
       
  • Early assessment of ecological services provided by forage legumes in
           relay intercropping
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Sylvain Vrignon-Brenas, Florian Celette, Agnès Piquet-Pissaloux, Marie-Hélène Jeuffroy, Christophe David
      In organic agriculture, weeds and nitrogen deficiency are the main factors that limit crop production. The use of relay-intercropped forage legumes may be a way of providing ecological services such as weed control, increasing N availability in the cropping system thanks to N fixation, reducing N leaching and supplying nitrogen to the following crop. However, these ecological services can vary considerably depending on the growing conditions. The aim of this study was to identify early indicators to assess these two ecological services, thereby giving farmers time to adjust the management of both the cover crop and of the following crop. Nine field experiments were conducted over a period of three years. In each experiment, winter wheat was grown as sole crop or intercropped with one of two species of forage legumes; Trifolium repens L. or Trifolium pratense L. Two levels of fertilization were also tested (0 and 100kgNha−1). After the intercropping stage, the cover crop was maintained until the end of winter and then destroyed by plowing before maize was sown. Legume and weed biomass, nitrogen content and accumulation were monitored from legume sowing to cover destruction. Our results showed that a minimum threshold of about 2tha−1 biomass in the aboveground parts of the cover crop was needed to decrease weed infestation by 90% in early September and to ensure weed control up to December. The increase in nitrogen in the following maize crop was also correlated with the legume biomass in early September. The gain in nitrogen in maize (the following crop) was correlated with legume biomass in early September, with a minimum gain of 60kgNha−1 as soon as legume biomass reached more than 2tha−1. Legume biomass in early September thus appears to be a good indicator to predict weed control in December as well as the nitrogen released to the following crop. The indicator can be used by farmers as a management tool for both the cover crop and following cash crop. Early estimation of available nitrogen after the destruction of the forage legume can be used to adjust the supply of nitrogen fertilizer to the following crop.


      PubDate: 2016-02-10T21:41:33Z
       
  • Enhanced nutrient use efficiencies from liquid manure by positioned
           injection in maize cropping in northwest Germany
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Carl-Philipp Federolf, Matthias Westerschulte, Hans-Werner Olfs, Gabriele Broll, Dieter Trautz
      Maize (Zea mays L.), the dominating crop in northwestern Germany usually receives mineral nitrogen (N) and phosphorous (P) fertilizer side dressed (MSD) at planting as a starter to ensure proper early-growth development, on top on a usually nutrient demand covering manure application. Recently developed injection techniques, along with auto-guidance systems allow liquid manure injection below the maize seeds in a separate operation. Thus, the need for starter fertilizer might be obviated. Field trials were conducted on seven sites in northwestern Germany to compare liquid manure broadcast application versus injection at recommended rate with and without addition of a nitrification inhibitor in 2013. Several treatments were tested with and without MSD (23–10kg N–P ha−1). In 2014, the trials were adapted to a proper two-factorial setup with additional reduced manure application rate treatments. Biomass accumulation and nitrogen uptake were assessed at V8 growing stage and at harvest. Compared to broadcast application with MSD, liquid manure injection without MSD showed retarded early-growth, but equal yield and N uptake at harvest in both years. Adding a nitrification inhibitor to injected liquid manure led to equal early-growth and yield, but significantly increased N uptake by 7% in 2013 and 6% in 2014, respectively. Regarding the proper performance of reduced rate injection treatments, the increase in N use efficiency is even more noticeable. The reduction of P input did not influence early growth and yield. P use efficiency from manure is higher when manure is injected prior to planting. These results indicate that liquid manure injection might reduce N and P surpluses in maize growing and therefore benefit farmers and environment.


      PubDate: 2016-02-10T21:41:33Z
       
  • Interaction of deep placed controlled-release urea and water retention
           agent on nitrogen and water use and maize yield
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Liwei Guo, Tangyuan Ning, Liangpeng Nie, Zengjia Li, Rattan Lal
      Controlled-release urea has been widely adopted to increase nitrogen (N) use efficiency and crop production, and these effects can range widely depending on water availability in soil. However, limited information is available on the interaction of controlled-release urea placement depth with water retention agent (WRA) on N and water use and the yield of crops. The objectives of this study were to assess the consequences of this interaction on N and water use and the maize (Zea mays L.) yield by a split-plot design with WRA as the main plots and five application methods of urea as sub-plots. The five application methods consisted of inter-row side dressing of conventional urea at 5cm and 10cm depths, inter-row side dressing of controlled-release urea at 5cm and 10cm depths, and deep placement of the controlled-release urea at a 15cm depth. Soil water stocks, dry matter accumulation, 1000-grain weight, grain-filling rate, N and water use efficiencies, and economic benefits were evaluated. The results revealed that the year, WRA, urea, and their interactions had significant effects on N and water use efficiencies, yield and benefits. When controlled-release urea was placed deep, soil water stocks were higher from the male tetrad stage to maturity and evapotranspiration (ETα) increased. Deep placement of controlled-release urea at a 15cm depth without WRA enhanced the agronomic efficiency of N and water. The yield and net income were increased compared with controlled-release urea at a 5cm depth. The combination of WRA and deep placement of controlled-release urea at a 15cm depth had a significant effect on water use efficiency. However, this combination had no significant effects on N use efficiency, yield and benefits. WRA used with conventional urea can maintain higher soil water stocks, and increase the dry matter production, grain-filling rate, N and water use efficiencies. The differences were more significant during the dry season. Conventional urea at a 10cm depth with WRA enhanced N and water use efficiencies, yield and net income by 6.5, 3.2, 6.5 and 4.2% respectively when compared with conventional urea without WRA. Thus, the best solution to obtain higher yield, water and N use efficiencies, and net income is placing controlled-release urea at 15-cm depth without WRA. When controlled-release urea is not available, placing conventional urea at a 10-cm depth combined with WRA is an interesting alternative for farmers.


      PubDate: 2016-02-10T21:41:33Z
       
  • Bayesian network modeling of early growth stages explains yam interplant
           yield variability and allows for agronomic improvements in West Africa
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Denis Cornet, Jorge Sierra, Régis Tournebize, Benoît Gabrielle, Fraser I. Lewis
      Yams (Dioscorea spp.) are important species, especially for resource-poor farmers of West Africa, where crop yields are affected by early plant size hierarchy linked with uneven emergence. Although the causes of this phenomenon are not fully known, yams, like other vegetatively propagated crops, have heavy planting material that is liable to induce such interplant variability. In addition, planting practices may mitigate this phenomenon via the selection of the seed-tuber size or state. To gain further insight into yam interplant variability, this study identified and quantified, for the first time, the direct and indirect dependency between planting practices, early growth variables and yield components of Dioscorea rotundata and Dioscorea alata, the two main food yam species. The experimental dataset came from six field trials carried out in Benin at two locations between 2007 and 2009. Additive Bayesian network modeling was used for structure discovery—its directed acyclic graph offers an ideal background for discussing complex systems when theoretical knowledge is lacking, e.g., for yams. Here we found that the emergence date was the only direct cause of plant yield variability common to both species. For D. rotundata, we observed a direct contribution of the cataphyll number to the plant tuber weight. These combined results suggest the existence of some uncontrolled latent variables (i.e., seed-tuber physiological age and reserves). For D. alata, the model did not reveal any effect of seed-tuber size, despite a strong effect noted for D. rotundata. We suggest that the transposition of traditional native D. rotundata planting practices may have led to oversized D. alata seed-tubers, resulting in wastage of planting material. This study demonstrated that traditional West African cropping systems have a serious drawback concerning the uncontrolled wide range of physiological ages and reserves in seed-tuber lots, which affect the plant size hierarchy and ultimately the marketable yield.


      PubDate: 2016-02-10T21:41:33Z
       
  • Nitrogen use efficiency of cotton (Gossypium hirsutum L.) as influenced by
           wheat–cotton cropping systems
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Xiangbei Du, Binglin Chen, Yuxiao Zhang, Wenqing Zhao, Tianyao Shen, Zhiguo Zhou, Yali Meng
      Wheat–cotton rotations largely increase crop yield and improve resources use efficiency, such as the radiation use efficiency. However, little information is available on the nitrogen (N) utilization and requirement of cotton under wheat–cotton rotations. This study was to determine the N uptake and use efficiency by evaluating the cotton (Gossypium hirsutum L.) N use and the soil N balances, which will help to improve N resource management in wheat–cotton rotations. Field experiments were conducted during 2011/2012 and 2012/2013 growing seasons in the Yangtze River region in China. Two cotton cultivars (Siza 3, mid-late maturity with 130 days growth duration; CCRI 50, early maturity with 110 days growth duration) were planted under four cropping systems including monoculture cotton (MC), wheat/intercropped cotton (W/IC), wheat/transplanted cotton (W/TC) and wheat/direct-seeded cotton (W/DC). The N uptake and use efficiency of cotton were quantified under different cropping systems. The results showed that wheat–cotton rotations decreased the cotton N uptake through reducing the N accumulation rate and shortening the duration of fast N accumulation phase as compared to the monoculture cotton. Compared with MC, the N uptake of IC, TC and DC were decreased by 12.0%, 20.5% and 23.4% for Siza 3, respectively, and 7.3%, 10.7% and 17.6% for CCRI 50, respectively. Wheat–cotton rotations had a lower N harvest index as a consequence of the weaker sink capacity in the cotton plant caused by the delayed fruiting and boll formation. Wheat–cotton rotations used N inefficiently relative to the monoculture cotton, showing consistently lower level of the N agronomic use efficiency (NAE), N apparent recovery efficiency (NRE), N physiological efficiency (NPE) and N partial factor productivity (NPFP), particularly for DC. Relative to the mid–late maturity cultivar of Siza 3, the early maturity cultivar of CCRI 50 had higher N use efficiency in wheat–cotton rotations. An analysis of the crop N balance suggested that the high N excess in preceding wheat (Triticum aestivum L.) in wheat–cotton rotations led to significantly higher N surpluses than the monoculture cotton. The N management for the cotton in wheat–cotton rotations should be improved by means of reducing the base fertilizer input and increasing the bloom application.


      PubDate: 2016-01-30T21:10:23Z
       
  • Can arbuscular mycorrhizal fungi improve competitive ability of
           dill+common bean intercrops against weeds?
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Weria Weisany, Saeid Zehtab-Salmasi, Yaghoub Raei, Yousef Sohrabi, Kazem Ghassemi-Golezani
      Competition for soil resources plays a key role in the crop yield of intercropping systems. There is a lack of knowledge on the main factors involved in competitive interactions between crops and weeds for nutrients uptake. Hence, the purpose of this work was to compare the effects of arbuscular mycorrhial fungi (Funneliformis mosseae) colonization in interspecific competitive relations and its effect on nutrients uptake and weed control in dill and common bean intercropping. Two field experiments were carried out with factorial arrangements based on randomized complete block design with three replications during 2013–2014. The factors were cropping systems including a) common bean (Phaseolus vulgaris L.) sole cropping (40 plantsm−2), b) dill (Anethum graveolens L.) sole cropping at different densities (25, 50 and 75 plantsm−2) and c) the additive intercropping of dill+common bean (25+40, 50+40 and 75+40 plantsm−2). All these treatments were applied with (+AM) or without (-AM) arbuscular mycorrhiza colonization. In both cropping systems, inoculation with F. mosseae increased the P, K, Fe and Zn concentrations of dill plants by 40, 524, 57 and 1.0μgkg−1 DW, respectively. Intercropping increased Mn concentration in common bean (4.0μgkg−1 DW) and dill (3.0μgkg−1 DW), and also seed yields of both crops (198gm−2 and161gm−2, respectively). AM colonization improved seed yields of dill and common bean by 169 and 177gm−2 in 2013 and 2014, respectively. Moreover, AM application enhanced competitive ability of dill+common bean intercrops against weeds at different intercropping systems. Intercropping significantly changed weed density compared to sole cropping, as weed density was decreased in the dill+common bean intercropping. Diversity (H), Evenness (E) and richness of weed species of weeds for intercrops were higher than those for sole crops.


      PubDate: 2016-01-30T21:10:23Z
       
  • Dense planting with less basal nitrogen fertilization might benefit rice
           cropping for high yield with less environmental impacts
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Xiangcheng Zhu, Jun Zhang, Zhenping Zhang, Aixing Deng, Weijian Zhang
      Dense planting and less basal nitrogen (N) fertilization have been recommended to further increase rice (Oryza sativa L.) grain yield and N use efficiency (NUE), respectively. The objective of this study was to evaluate the integrative impacts of dense planting with reduced basal N application (DR) on rice yield, NUE and greenhouse gas (GHG) emissions. Field experiments with one conventional sparse planting (CK) and four treatments of dense planting (increased seedlings per hill) with less basal N application were conducted in northeast China from 2012 to 2013. In addition, a two-factor experiment was conducted to isolate the effect of planting density and basal N rate on CH4 emission in 2013. Our results show that an increase in planting density by about 50% with a correspondingly reduction in basal N rate by about 30% (DR1 and DR2) enhanced NUE by 14.3–50.6% and rice grain yield by 0.5–7.4% over CK. Meanwhile, DR1 and DR2 reduced GWP by 6.4–12.6% and yield-scaled GWP by 7.0–17.0% over CK. According to the two-factor experiment, soil CH4 production and oxidation and CH4 emission were not affected by planting density. However, reduced basal N rate decreased CH4 emission due to it significantly reduced soil CH4 production with a smaller reduction in soil CH4 oxidation. The above results indicate that moderate dense planting with less basal N application might be an environment friendly mode for rice cropping for high yield and NUE with less GHG emissions.


      PubDate: 2016-01-30T21:10:23Z
       
  • Attributes of wheat cultivars for late autumn sowing in genes expression
           and field estimates
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Anna Wenda-Piesik, Ludmila Holková, Eva Solařová, Radovan Pokorný
      Due to the growing interest in Central and Eastern Europe on cropping of wheat in optional late autumn terms, called facultative, genetic research and field evaluation were taken on four spring cultivars: Tybalt (NL), Monsun (DE), Ostka Smolicka (PL) and Bombona (PL), currently being recommended by breeders. The PPD gene analyze, expression level of dehydrine genes (WCS120 and WDHN13) in cooling test, and qPCR for RNA isolation and analyses of WCS120 and WDHN13 gene expression at the BBCH12 stage of wheat were estimated. Molecular analysis of PPD-D1 gene confirmed the presence of photoperiod sensitive allele ppd-D1b in all tested genotypes. The highest level of NRE WCS120 gene was detected in cultivars Tybalt and Bombona. Two-year field experimental study assessed the growth, development and productivity of facultative and spring crops of studied cultivars. Based on our results from field experiments and result of molecular analysis of alleles of PPD-D1 gene, the tested genotypes can be considered as potentially facultative genotypes.


      PubDate: 2016-01-24T20:53:39Z
       
  • Productivity and profitability of cotton–wheat system as influenced
           by relay intercropping of insect resistant transgenic cotton in bed
           planted wheat
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Muhammad Asghar Shah, Muhammad Farooq, Mubshar Hussain
      Cotton (Gossypium hirsutum L.) is the leading cash crop being grown across the globe including Pakistan. By the inclusion of insect resistant transgenic cotton (BT cotton), the cotton production has mounted many folds in Pakistan. BT cotton is mostly grown in Southern Punjab in cotton–wheat cropping system of Pakistan; however there exists a time conflict among wheat harvest and BT cotton sowing in this system. Wheat is harvested during late April but the ideal sowing time of BT cotton is early-mid March indicating a time conflict of 4–6 weeks which is becoming the main concern leading to wheat exclusion from this system. Intercropping of BT cotton in standing wheat is one of the possible options to manage this overlapping period. This two year field study was, therefore, conducted at two locations (Multan, Vehari) to evaluate the economic feasibility of relay intercropping of BT cotton through different sowing methods in BT cotton–wheat cropping system. BT cotton–wheat cropping systems included in the study were: conventionally tilled cotton (CTC) on fallow land during early and late March, CTC during late April after harvest of flat sown wheat (FSW), bed sown wheat (BSW)+intercropped cotton during early and late March, and ridge sown wheat (RSW)+intercropped cotton during early and late March. Planting cotton in fallow land with conventional tillage during early March had more seed cotton yield; whereas planting in the same way during April after wheat harvest had minimum seed cotton yield. Likewise, FSW had more yield than ridge and bed sown wheat with intercropped BT cotton during early or late March. However, the system productivity in terms of net income, benefit: cost ratio and marginal rate of return of BSW+intercropped BT cotton during early March was the highest during both years at both locations. However, the system with sole crop of BT cotton sown on fallow land during late or early March was the least economical even than the system with CTC during late April after harvest of FSW. In conclusion, BSW+intercropped cotton during early March may be opted to manage the time conflict and improve the economic productivity of BT cotton–wheat cropping system without wheat exclusion from the system.


      PubDate: 2016-01-19T20:30:27Z
       
  • How do timing, duration, and intensity of drought stress affect the
           agronomic performance of winter rye?
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Lorenz Kottmann, Peer Wilde, Siegfried Schittenhelm
      Winter rye (Secale cereale L.) will be especially affected by drought induced yield losses in Central and Eastern Europe in the future because it is predominantly cultivated on low-fertile soils with a poor water-holding capacity. In order to examine the performance of winter rye under different drought conditions, field experiments were carried out during the years 2011, 2012, and 2013 near Braunschweig, Germany. Two sets of genotypes were tested under severe, mild, pre-anthesis, and post-anthesis drought stress in rain-out shelters as well as under rainfed and well-watered conditions. The grain, straw, and total above ground biomass yields, harvest index, grain yield components, leaf area index (LAI), and phenological characteristics were examined, as well as phenotypic correlations between grain yield and further characteristics. Drought induced grain yield reduction ranged from 14 to 57%, while straw yield and harvest index were lesser affected by drought than the grain yield. Under drought conditions, fully ripe was reached up to twelve days earlier than under non water-limited conditions. Pre-anthesis drought mainly reduced spikes m−2 and kernels spike−1 while drought during grain filling reduced the 1000-kernel weight (TKW) only. The grain yield was positively associated with straw yield, spikes m−2, and kernels spike−1 under water limited conditions while the TWK was only positively associated with grain yield under drought during grain filling. Consequently, high pre-anthesis biomass as well as high numbers of spikes m−2 and kernels spike−1 are especially important for obtaining high grain yields under water-limited conditions. Focusing on these traits is, therefore, recommendable for developing drought tolerant rye genotypes.


      PubDate: 2016-01-15T20:06:28Z
       
  • Optimized single irrigation can achieve high corn yield and water use
           efficiency in the Corn Belt of Northeast China
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Zizhong Li, Zenghui Sun
      Decreasing the corn (Zea mays L.) gap between the potential yield and farm yield and reducing the risk of grain yield of drought are very important for corn production in the Corn Belt of Northeast China (CBNC). To achieve a high and stable corn yield, the effects of supplementary irrigation on yield, water use efficiency (WUE) and irrigation water use efficiency (IWUE) were studied using a modelling approach. The Root Zone Water Quality Model 2 was parameterized and evaluated using two years of experimental data in aeolian sandy soil and black soil. The evaluated model was then used to investigate responses to various irrigation strategies (rainfed, full irrigation and 12 single irrigation scenarios) using long-term weather data from 1980 to 2012. Full irrigation guarantees a high and stable corn grain yield (12.92Mgha−1 and has a coefficient of variation (CV) of 14.8% in aeolian sandy soil; 12.30kgMa−1 and CV of 11.1% in black soil), but has a low water use efficiency (19.92 and 21.81kgha−1 mm−1) and a low irrigation water use efficiency (10.01 and 11.03kgha−1 mm−1). A single irrigation can increase corn yields by 3–35% for aeolian sandy soil and 5–35% for black soil over different irrigation dates compared with no irrigation. The most suitable single irrigation date was during late June to early July for aeolian sandy soil (yield=10.73Mgha−1 and WUE=27.94kgha−1 mm−1) and early to mid-July for black soil (yield=11.20Mgha−1 and WUE=27.70kgha−1 mm−1). The lowest yield risk of falling short of the yield goal of 8, 9, and 10Mgha−1 were 9.1%, 18.2%, and 33.33% in aeolian sandy soil and 3.0%, 15.25, and 21.2% in black soil when an optimized single irrigation was applied in late June or early July, respectively. Therefore, an optimized single irrigation should be applied in late June to early July with the irrigation amount to refill soil water storage of root zone to field capacity in CBNC.


      PubDate: 2016-01-15T20:06:28Z
       
  • Long-term atmospheric CO2 enrichment impact on soil biophysical properties
           and root nodule biophysics in chickpea (Cicer arietinum L.)
    • Abstract: Publication date: April 2016
      Source:European Journal of Agronomy, Volume 75
      Author(s): Saurav Saha, D. Chakraborty, Vinay K. Sehgal, Lata Nain, Madan Pal
      Impact of atmospheric CO2 enrichment on soil aggregation, carbon and other nutrient availability and soil enzyme activities in relation to root and nodule biophysics in chickpea (Cicer arietinum L.; Pusa-1105 genotype) was studied in an open top chamber experiment at IARI, New Delhi, India, continuing since 2003. Soil samples were collected at the end of the crop growing seasons of 2010–11 and 2011–12, and analyzed. Root growth and nodulation were also studied in these seasons. Soil C and P pools, and associated enzyme activities responded differently to CO2 enrichment, while total soil N did not change. Soil labile C fractions viz., water soluble carbohydrate (WSC) and microbial biomass C (MBC) significantly increased, although recalcitrant C fraction declined marginally. The soil-CO2 flux increased by 28%. Dehydrogenase and fluorescein diacetate hydrolysis activity in soil increased by 44% and 67% respectively; and the β-glucosidase activity enhanced by 20% under enriched CO2 condition. The CO2 enrichment induced root growth and N2-fixation by root nodules, which were evidenced by increase in legheamoglobin content and nitrogenase activity. Nodules were bulky and had higher starch and soluble sugar contents under enriched atmospheric CO2 condition, allowing for greater N2-fixation. The rhizosphere C:N ratio, however, remained unaffected. It could be possible that larger partitioning of C to roots along with greater N2-fixation by nodules in chickpea might stabilize the net C:N ratio in the soil. Moreover, the increased soil biological activity under CO2 enrichment resulted in marginal depletion of soil recalcitrant C with increase in labile C pools. These are likely to offset the stability of soil C pools in a legume-based agroecosystems under the enriched CO2 condition in the semi-arid climate.


      PubDate: 2016-01-10T19:47:12Z
       
  • Dry matter partitioning and canopy traits in wheat and barley under
           varying N supply
    • Abstract: Publication date: March 2016
      Source:European Journal of Agronomy, Volume 74
      Author(s): Klaus Sieling, Ulf Böttcher, Henning Kage
      The prediction of the allocation of carbon and nitrogen into the different organs, e.g., leaves, stems, roots of a growing plant is a pivotal part of mechanistic growth models. Based on 2 year (winter wheat) and 3 year (winter barley) field trials with different N treatments (0–240kgNha−1), the objectives of this study were to verify currently used parameters for (i) specific leaf area, and (ii) allometric relationships between leaf and stem dry matter (DM). Green area index (GAI) differed between years and increased with N supply rate. The course of the specific leaf area (SLA) within the growth period after winter showed a large variation between the years as well as between the N treatments. During stem elongation, SLA positively correlated with GAI in both crops, indicating that leaves became thinner when the canopy was denser. The allometric relationships between stem and leaf dry DM clearly varied with the growth stages. Stem DM of wheat showed a higher proportion of the total above-ground biomass compared to barley. The effect of N fertilization on allometry remained small during early growth stages in barley, whereas in wheat, an increased N supply significantly decreased the proportion of stem DM. Our results suggest similar GAI and SLA patterns for wheat and barley, albeit depending on the N supply. Especially, using a constant SLA in plant growth models seems to be not suitable.


      PubDate: 2015-12-12T20:31:19Z
       
 
 
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