for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> AGRICULTURE (Total: 703 journals)
    - AGRICULTURAL ECONOMICS (73 journals)
    - AGRICULTURE (474 journals)
    - CROP PRODUCTION AND SOIL (92 journals)
    - DAIRYING AND DAIRY PRODUCTS (25 journals)
    - POULTRY AND LIVESTOCK (39 journals)

AGRICULTURE (474 journals)            First | 1 2 3 4 5     

The end of the list has been reached. Please navigate to previous pages.

  First | 1 2 3 4 5     

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  [2588 journals]
  • Relating soil microbial properties to yields of no-till canola on the
           Canadian prairies
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): Newton Z. Lupwayi , K. Neil Harker , John T. O’Donovan , T. Kelly Turkington , Robert E. Blackshaw , Linda M. Hall , Christian J. Willenborg , Yantai Gan , Guy P. Lafond , William E. May , Cynthia A. Grant
      Soil microorganisms mediate many important biological processes for sustainable agriculture. However, correlations between soil microbial properties and crop productivity cannot always be demonstrated. We collected soil microbial data from a canola (Brassica napus L.) study that was conducted at seven sites on the Canadian prairies about agricultural practices focused on increasing canola yields. The treatments consisted of two canola seeding rates (75 or 150seedsm−2), two nitrogen rates (1× and 1.5× soil test recommendation) and three nitrogen form–fungicide (prothioconazole) combinations (uncoated urea, no fungicide; uncoated urea+fungicide; and 50% polymer-coated urea+fungicide) in a 2×2×3 factorial arrangement. Microbial biomass C (MBC), β-glucosidase enzyme activity and functional bacterial diversity (based on C substrate utilization patterns) were determined in canola rhizosphere and in bulk soil and related to canola yields. The effects of seeding rate, nitrogen (N) rate and N form on soil microbial biomass, enzyme activity or bacterial functional diversity were usually not statistically significant. In the few cases where significance occurred, doubling the seeding rate from 75 to 150seedsm−2 usually increased these microbial properties in canola rhizosphere or bulk soil. Increasing N rate to 1.5× the recommended rate had mostly positive effects in canola rhizosphere and negative effects in bulk soil. The effects of N form (including addition of fungicide) were inconsistent. Soil MBC and β-glucosidase enzyme activity correlated positively with canola grain yield at the five sites where yields were <4000kgha−1 (r =0.51** to 0.76**), but no or weak negative correlations were observed at the two sites with yields >4000kgha−1. The functional diversity of soil bacteria was not or was weakly negatively correlated with grain yields. Some of these relationships appeared to be influenced by canola root maggot damage because root damage was usually negatively correlated with the soil microbial characteristics, but the correlations were too weak to be relevant. These results suggest underground feedback interactions between crops and soil microbes, i.e., crop/soil management practices that enhance crop growth also enhance soil microbial communities and their activities, and vice versa.


      PubDate: 2015-03-20T07:18:55Z
       
  • Comparative advantages of conservation agriculture based rice–wheat
           rotation systems under water and salt dynamics typical for the irrigated
           arid drylands in Central Asia
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): K.P. Devkota , J.P.A. Lamers , A.M. Manschadi , M. Devkota , A.J. McDonald , P.L.G. Vlek
      In Central Asia, the increasing water shortage and labor scarcity, high cost of production, increasing secondary soil salinization, and land abandonment are compelling farmers to change to water saving irrigation and conservation agriculture (CA) technologies. Such CA practices aim at maximizing profits while making a better use of soil and water resources lowering labor demands, farm power and production costs. The CA experiments with rice–wheat systems combined two establishment methods (beds and flats) with three residue levels (all zero tillage) and with alternate wet and dry (AWD) irrigation followed by surface seeded wheat (SSW); and conventional tillage (dry tillage) and continuously flooded rice (water seeded rice, WSR) followed by SSW. These were evaluated for 2 years (2008–2010) by using several financial indicators such as gross margins (GMs) estimates and benefit/cost ratio (BCR) while accounting for the soil water balance and soil salinity dynamics. The GM and BCR were higher under WSR–SSW than under treatments of dry seeded rice (DSR)–SSW. Both were higher under residue removal compared to residue retainments in DSR-SSW. Surface seeded wheat, which involved minor production costs, yielded >6tha−1 in both years in all treatments. Furthermore, >80% of the total irrigation water was applied to rice. Yet, >90% from WSR–SSW and ∼67% from DSR–SSW were lost through seepage and percolation. Dry seeded rice in bed (DSRB)–SSW saved 15% more irrigation water compared to dry seeded rice in flat (DSRF)–SSW and 67% compared to WSR–SSW. Soil salinity decreased with rice cultivation. After 2 years, WSR–SSW had the lowest while residue-removed DSRB–SSW had the highest salinity level at all soil depths. Groundwater salinity under deep groundwater tables was higher under treatments of DSR–SSW than under WSR–SSW. However, under shallow groundwater tables, groundwater salinity was higher under WSR–SSW than under DSR–SSW. Under the conditions that irrigation water is subsidized or even free of charge, conventional WSR–SSW into the standing rice field (20 days before rice harvest) is the most profitable option. However, under water scarce conditions, the CA based rice–wheat system could be a suitable alternative to cope with water scarcity and secondary soil salinization. Before this crop production system can be advocated and promoted, it needs to be flanked by adequate water pricing policies.


      PubDate: 2015-03-20T07:18:55Z
       
  • Differential physiological and biochemical responses to drought in
           grapevines subjected to partial root drying and deficit irrigation
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): Alexandros Beis , Angelos Patakas
      The effects of two different irrigation methodologies, partial root drying (PRD) and deficit irrigation (DI), on grapevines (Vitis vinifera L., cv. Mavrodafni) physiological and biochemical parameters were studied using split-rooted potted plants. Five irrigation treatments were applied: fully irrigated (FI) at both parts of the rootzone to soil capacity; deficit irrigated (DI50 and DI25) receiving 50% and 25% irrigation water of FI plants, respectively, to the entire rootzone and partial root drying (PRD50 and PRD25) receiving 50% and 25% irrigation water of FI plants, respectively, which was successively applied to one and the other part of the rootzone. Compared with DI50, PRD50 plants exhibited higher stomatal conductance and photosynthetic rate maintaining more favorable plant water status throughout the experimental period. On the contrary, no significant differences in physiological parameters between PRD25 and DI25 plants were observed, suggesting that irrigation amount could influence different irrigation methodologies effects on plant's performance. Leaf abscisic acid (ABA) concentration at the end of the drought period was significantly higher in DI compared to PRD plants while the opposite trend was evident concerning cytokinins (Cks) concentration. Irrespective the irrigation amount applied, stomatal conductance (g s ) in DI plants exhibited the strongest correlation with leaf abscisic acid (ABA) concentration among the treatments but this relationship was significantly weakened when g s was regressed against ABA/CKs ratio. PRD plant's stomatal conductance was also strongly correlated with leaf abscisic acid (ABA) concentration but this relationship was markedly improved when ABA/CKs ratio was used. These results imply a more pronounced role of CKs in mediating stomatal responses in PRD plants. In contrast in DI grapevines ABA concentration seemed to dominate stomatal responses to drought.


      PubDate: 2015-03-20T07:18:55Z
       
  • Effects of nitrogen application rate on grain yield and grain nitrogen
           concentration in two maize hybrids with contrasting nitrogen
           remobilization efficiency
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): Yanling Chen , Changxin Xiao , Dali Wu , Tingting Xia , Qinwu Chen , Fanjun Chen , Lixing Yuan , Guohua Mi
      A target in crop production is to simultaneously increase grain yield (GY) and grain nitrogen concentration (GNC). In maize, nitrogen (N) and genotype are two major factors affecting GY and GNC. Both N remobilization from vegetative tissues and post-silking N uptake contribute to grain N, but their relative contributions are genotype specific, and are affected by the N application rate. It is unclear whether the responses of GY and GNC to N application differ between genotypes with different post-silking N uptake and vegetative N remobilization characteristics. We investigated the effect of N application rate on post-silking N uptake, vegetative N remobilization, GY, and GNC of two high-yielding maize hybrids, ZD958 and XY335, which have contrasting N remobilization characteristics. We tested five N application rates (0, 60, 120, 180, 240kgNha−1) in a 4-year field study (from 2010 to 2013). There was a significant year×N×genotype interaction in the amount of vegetative N remobilization and N remobilization efficiency (NRE), and residual stalk N concentration at maturity. Compared with the low-NRE cultivar ZD958, XY335 showed the same GY but higher GNC because it had higher vegetative N remobilization, NRE but lower residual stalk N concentration under the favorable weather condition in 2010. The response of GNC to increasing N levels was the same between XY335 and ZD958 and was not affected by year conditions. The N level required to obtain the highest GY was the same in the two hybrids (156±13kgha−1and 159±19kgha−1), but that required to obtain the highest GNC was greater in XY335 (216±30kgha−1) than in ZD958 (195±23kgha−1). From these results, we conclude that precise N fertilizer management as well as the selection of high-yielding hybrids with high NRE can increase GNC without negatively affecting GY or leading to surplus N storage in vegetative organs.


      PubDate: 2015-03-20T07:18:55Z
       
  • Impact of a woody biochar on properties of a sandy loam soil and spring
           barley during a two-year field experiment
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): Victoria Nelissen , Greet Ruysschaert , Delphine Manka’Abusi , Tommy D’Hose , Kristof De Beuf , Bashar Al-Barri , Wim Cornelis , Pascal Boeckx
      Biochar is often proposed to increase soil quality and crop yield, while sequestering carbon. Despite the growing number of studies in temperate regions, the claimed positive effects are still unsure for northwestern European soils. Moreover, there is a need to upscale results from lab and pot studies in these soil types to field experiments. The objectives of this study were therefore to investigate the effect of biochar application to a temperate agricultural soil on soil chemical, physical and biological properties, and on crop growth and nutrient uptake under field circumstances. A field trial, located in Merelbeke (Belgium), was established in October 2011 and monitored until August 2013. The biochar applied was produced from a mixture of hard- and softwood at 480°C. The biochar dose was 0 (control) or 20tha−1 (on dry weight basis). Over two years, biochar addition to soil did not affect soil chemical properties, except for organic carbon content and C:N ratios. Effects on bulk density, porosity and soil water retention curves were non-consistent over time, possibly due to interaction with tillage operations. Biochar increased soil water content in 2012, although mostly not significantly. However, in 2013, when soil water content was overall lower compared to 2012, it was not affected by biochar addition. Soil temperature, as measured at a soil depth interval of 8–20cm, was not changed by biochar addition. Furthermore, biochar addition to soil did only slightly influence soil microbiological community structure during the first year after biochar application, as only certain bacterial biomarker PLFAs were significantly affected by biochar addition, but no fungal biomarker PLFAs. Hence, it was not surprising that biochar addition did not affect crop yield, N or P uptake during the first two years after biochar application.


      PubDate: 2015-03-20T07:18:55Z
       
  • Effect of temperature and precipitation on nitrate leaching from organic
           cereal cropping systems in Denmark
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): Mohamed Jabloun , Kirsten Schelde , Fulu Tao , Jørgen E. Olesen
      The effect of variation in seasonal temperature and precipitation on soil water nitrate (NO3 N) concentration and leaching from winter and spring cereals cropping systems was investigated over three consecutive four-year crop rotation cycles from 1997 to 2008 in an organic farming crop rotation experiment in Denmark. Three experimental sites, varying in climate and soil type from coarse sand to sandy loam, were investigated. The experiment included experimental treatments with different rotations, manure rate and cover crop, and soil nitrate concentrations was monitored using suction cups. The effects of climate, soil and management were examined in a linear mixed model, and only parameters with significant effect (P <0.05) were included in the final model. The model explained 61% and 47% of the variation in the square root transform of flow-weighted annual NO3 N concentration for winter and spring cereals, respectively, and 68% and 77% of the variation in the square root transform of annual NO3 N leaching for winter and spring cereals, respectively. Nitrate concentration and leaching were shown to be site specific and driven by climatic factors and crop management. There were significant effects on annual N concentration and NO3 N leaching of location, rotation, previous crop and crop cover during autumn and winter. The relative effects of temperature and precipitation differed between seasons and cropping systems. A sensitivity analysis revealed that the predicted N concentration and leaching increased with increases in temperature and precipitation.


      PubDate: 2015-03-20T07:18:55Z
       
  • Assessing nitrate leaching in cropping systems based on integrated weed
           management using the STICS soil–crop model
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): C. Bécel , N.M. Munier-Jolain , B. Nicolardot
      Agriculture in Europe and other parts of the world is currently under strong pressure to reduce its reliance on pesticides. Regarding arable crops, strategies based on integrated weed management (IWM) combine several agronomic practices aimed at reducing herbicide use, but these strategies can generate negative collateral effects, such as increased nitrate leaching. An evaluation of nitrate leaching in a long-term experiment set up in 2000 was performed for five tested cropping systems: four IWM-based systems and one reference system. After the validation of the predictive performance of the STICS soil–crop model, nitrate leaching was simulated for the five cropping systems tested over the 12 years of the experiment and over 12 years of implementing alternative scenarios (i.e. the introduction of early sowing for winter cereals, ceasing deep tillage and the introduction of a mustard catch crop). The results showed that the total amount of nitrate leaching varied between cropping systems and was lowest in the cropping system using no herbicide and that with no tillage, two systems combining several agronomic practices. Alternative scenarios based on both early sowing of winter crops and the introduction of catch crops can reduce the total amount of nitrate leached by 25 to 43% over the 12 years of simulations, although early sowing can, in some cases, increase nitrate leaching. This study contributes to the multi-criteria evaluation of innovative cropping systems.


      PubDate: 2015-03-20T07:18:55Z
       
  • Effect of depth of fertilizer banded-placement on growth, nutrient uptake
           and yield of oilseed rape (Brassica napus L.)
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): Wei Su , Bo Liu , Xiaowei Liu , Xiaokun Li , Tao Ren , Rihuan Cong , Jianwei Lu
      A better understanding of crop growth and nutrient uptake responses to the depth of fertilizer banded-placement in the soil is needed if growth and nutrient uptake responses are to be maximized. A two-year field study covering two rape seasons (2010–2011 and 2011–2012) was conducted to examine the effect of banded-placement of N–P–K fertilizer at various depths on growth, nutrient uptake and yield of oilseed rape (Brassica napus L.). The results showed that fertilization at 10cm and 15cm soil depth produced greater taproot length and dry weight than fertilization at 0cm and 5cm. 0 cm and 5cm deep fertilization significantly increased the lateral root distribution at 0–5cm soil depth, while 10cm and 15cm deep fertilization induced more lateral root proliferation at 5–15cm soil depth. At 36 days after sowing (DAS), 5cm deep fertilization produced better aboveground growth and nutrient uptake than 10cm and 15cm deep fertilization. However, reversed results were observed after 36 DAS. 10 cm and 15cm deep fertilization produced more rapeseed than 0cm and 5cm deep fertilization, moreover, the yield difference was more significant in drought season (2010–2011) than in relatively normal season (2011–2012). In summary, these results preliminarily suggest that both 10cm and 15cm are relatively proper fertilizer placement depth when the practice of banding fertilizer is used in oilseed rape production. But from the viewpoint of diminishing the production cost, 10cm deep fertilization should be recommended in actual farming. Because 15cm deep fertilization may require higher mechanical power input, and thus resulting in higher cost of production.


      PubDate: 2015-03-20T07:18:55Z
       
  • Analyzing the impact of the farming context and environmental factors on
           cropping systems: A regional case study in Burgundy
    • Abstract: Publication date: May 2015
      Source:European Journal of Agronomy, Volume 66
      Author(s): N. Aouadi , J.N. Aubertot , J. Caneill , N. Munier-Jolain
      Developing cropping systems able to improve overall sustainability requires socio-economic drivers, farm features, environmental conditions and local constraints to be taken into account. The aim of this study was to analyze the relationship between the farming context and the cropping system (CS) and to identify the components of a production situation (PS) that drive the CS characteristics. Surveys on cropping practices in 2006 in the Burgundy region were analyzed using multivariate analysis including hierarchical clustering. Thirteen groups of CS were identified and their crop sequence and level of pesticide and fertilizer use were described. A multivariate analysis was used to study the diversity in PS according to their climate, soil, and farm features. Classification and the regression tree method (CART) identified the PS variables which were most influential on CS, and defined six groups of PS that minimized intra-group CS variability. However, this variability remained high, suggesting that differences in farmer’s objectives and knowledge also contributed to differentiate cropping systems in the region studied.


      PubDate: 2015-03-20T07:18:55Z
       
  • Impact of conservation agriculture practices on energy use efficiency and
           global warming potential in rainfed pigeonpea–castor systems
    • Abstract: Publication date: May 2015
      Source:European Journal of Agronomy, Volume 66
      Author(s): G. Pratibha , I. Srinivas , K.V. Rao , B.M.K. Raju , C.R. Thyagaraj , G.R. Korwar , B. Venkateswarlu , Arun K. Shanker , Deepak K. Choudhary , K.Srinivas Rao , Ch. Srinivasarao
      Identification of agricultural practices which maximize crop productivity, energy use efficiency (EUE) and minimize greenhouse gas (GHG) emissions is essential. There is dearth of information in rainfed agriculture in general and conservation agriculture in particular, hence a study was conducted to assess the EUE and GHG emissions of different tillage practices like conventional tillage (CT), reduced tillage (RT) and zero tillage (ZT) and residue levels (harvesting heights resulting in 0, 10 and 30cm anchored residue) in pigeonpea–castor systems under semi-arid rainfed regions of India. CT recorded 30 and 31% higher energy inputs than ZT in pigeonpea and castor, respectively. The fuel consumption in ZT was 58 and 81% lower than CT in pigeonpea and castor, respectively. This lower fuel consumption in ZT reduced the GHG emissions by 21 and 23% in pigeonpea and castor, respectively, in comparison with CT. EUE and energy productivity were maximum in ZT with 10cm anchored residue. Further, castor grown on pigeonpea residue recorded 10 and 20% higher energy inputs and GHG emissions over pigeonpea grown on castor residues. Our results indicate that, reduction in one tillage operation with residue have a minimal impact on the crop yields but have a substantial environmental benefits.


      PubDate: 2015-03-20T07:18:55Z
       
  • Using indicators to assess the environmental impacts of wine growing
           activity: The INDIGO® method
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): Marie Thiollet-Scholtus , Christian Bockstaller
      Environmental assessment methods are needed by agronomists working on the enhancement of cropping systems to meet the demand for more sustainable farming practices. A growing number of operational methods based on a set of indicators have been designed, more for arable crops and livestock than for perennial crops like viticulture. Among them, the INDIGO® method, originally developed for arable crops, offers a compromise between feasibility and predictive quality. Here we present a modified and expanded version of INDIGO® for viticulture. The development of new indicators specific to viticulture and the adaptation of existing ones followed a five step approach: (i) preliminary definition of the objectives and identification of the end-users, (ii) construction of the indicator, (iii) selection of a reference value, (iv) sensitivity analysis and (v) validation. Stakeholders from professional institutions and winegrower organizations were closely associated with step (i) to define the framework and step (ii) to supply technical databases. We designed INDIGO® indicators with all available scientific and expert knowledge which was aggregated into expert systems associating fuzzy subsets or, when possible, quantitative equations. Four indicators; pesticides, nitrogen, energy and soil organic matter, were directly adapted from the initial INDIGO® method, whereas soil cover and frost protection management were new indicators. Potentialities of their use are highlighted by examples of implementation on different scales and for various purposes.
      Graphical abstract image

      PubDate: 2015-03-20T07:18:55Z
       
  • Strategic double cropping on Vertisols: A viable rainfed cropping option
           in the Indian SAT to increase productivity and reduce risk
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): V. Nageswara Rao , H. Meinke , P.Q. Craufurd , D. Parsons , M.J. Kropff , Niels P.R. Anten , S.P. Wani , T.J. Rego
      Our study suggests the possibility for transformational change in the productivity and risk profile of some of India's rainfed cropping systems. In the semi-arid regions of Southern India, farmers traditionally crop sorghum or chickpea on Vertisols during the post-rainy season, keeping the fields fallow during the rainy season. This practice avoids land management problems, but limits the potential for crop intensification to increase systems productivity. A long-term (15 year) experiment at ICRISAT demonstrated that cropping during the rainy season is technically feasible, and that grain productivity of double cropped sorghum+chickpea (SCP–SCP) and mung bean+sorghum (MS–MS) sequential systems were higher than their conventional counterparts with rainy season fallow, i.e. fallow+post-rainy sorghum (FS–FS) and fallow+post-rainy chickpea (FS–FCP). Without N application, mean grain yield of post-rainy sorghum in the MS–MS system was significantly greater (2520kgha−1 per two-year rotation) than in the FS–FS system (1940kgha−1 per two-year rotation), with the added benefit of the mung bean grain yield (1000kgha−1 per two-year rotation) from the MS–MS system. In the SCP–SCP system the additional grain yield of rainy sorghum (3400kgha−1 per two-year rotation) ensured that the total productivity of this system was greater than all other systems. Double cropping MS–MS and SCP–SCP sequential systems had significantly higher crop N uptake compared to traditional fallow systems at all rates of applied nitrogen (N). The intensified MS–MS and SCP–SCP sequential systems without any N fertilizer applied recorded a much higher median gross profit of Rs. 20,600 (US $ 375) and Rs. 15,930 (US $ 290) ha−1 yr−1, respectively, compared to Rs. 1560 (US $ 28) ha−1 yr−1) with the FS–FS system. Applying 120kg of Nha−1 considerably increased the profitability of all systems, lifting median gross profits of the sorghum+chickpea system over Rs. 60,000 (US $ 1091) ha−1 yr−1 and the conventional system to Rs. 20,570 (US $ 374) ha−1 yr−1. The gross profit margin analysis showed that nitrogen is a key input for improving productivity, particularly for the double cropping systems. However, traditional systems are unviable and risky without N application in the variable climates of the semi-arid tropics. Together, our results show that on Vertisols in semi-arid India, double cropping systems increase systems’ productivity, and are financially more profitability and less risky than traditional fallow post-rainy systems while further benefits can be achieved through fertilizer application.


      PubDate: 2015-03-20T07:18:55Z
       
  • Validity of the pineapple crop model SIMPIÑA across the climatic
           gradient in Réunion Island
    • Abstract: Publication date: January 2015
      Source:European Journal of Agronomy, Volume 62
      Author(s): Elodie Dorey , Patrick Fournier , Mathieu Lechaudel , Philippe Tixier
      Models used for designing cropping systems and for responding to cropping problems caused by climate variations must generate accurate predictions. Here, we describe the SIMPIÑA model, which simulates the development and growth of the ‘Queen Victoria’ pineapple cultivar and which accounts for stress resulting from nitrogen and water deficiencies. We present the calibration and the validation of SIMPIÑA with 15 independent data sets derived from experiments carried out on Réunion Island and covering wide ranges of climatic conditions and management practices. Comparison of simulations with data sets shows that the predictive accuracy of SIMPIÑA is very good, with relative RMSE values ranging from 0.06 to 0.19 for plant fresh biomass; such precision is sufficient for informing management decisions. Interestingly, there was no bias between observed and simulated values. A process-removal approach allowed us to determine how stress processes resulting from water or nitrogen deficiency influence the predictive capacity of the model across a broad range of climatic conditions. There was no clear trend for the effect of climate on model error in comparisons of the model with stress processes removed. When stress processes were partially removed from the model, fruit biomass error was particularly high when the effect of stress was removed from the radiation conversion efficiency and from biomass remobilization. Given its ability to correctly predict crop dynamics under contrasting conditions, SIMPIÑA appears to include the essential processes at the correct level of complexity.


      PubDate: 2015-03-20T07:18:55Z
       
  • Net ecosystem carbon balance of an apple orchard
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Damiano Zanotelli , Leonardo Montagnani , Giovanni Manca , Francesca Scandellari , Massimo Tagliavini
      Fruit tree ecosystems represent an important land use type in Southern Europe. Nevertheless, limited information and large uncertainty currently exist about their potential role as a sink of atmospheric CO2, which is measured through an index that accounts for all inputs and outputs of C, namely the net ecosystem carbon balance (NECB). In this paper, we studied the fluxes of C assimilation, the C release and the lateral C and their contribution to the NECB in an apple orchard at different time scales. Data of net ecosystem productivity (NEP) were recorded by eddy covariance and converted into ecosystem respiration and gross primary productivity (GPP). The net primary productivity (NPP) and the C partitioning among tree organs were also biometrically assessed. The study was carried out in the period 2009–2012 in a commercial apple orchard located in an intensive fruit production district of South Tyrol, Italy. We found a positive NEP from March to October and yearly NEP values of 403gCm−2. GPP (1346gCm−2 year−1 on average) was highest between May and September, when leaves intercepted the highest amount of PPFD. Tree growth accounted for more than 90% of the total new biomass produced in the orchard, the remaining part being represented by the herbaceous vegetation covering the orchard floor. Trees allocated to fruits approximately half of the yearly NPP, while they increased only to a limited extent their standing biomass. A significant fraction of NPP was also allocated to organs (leaves, pruned woody organs, etc.,) that feed the detritus cycle. The NECB was on average positive (69gCm−2) but showed high variation among years, and in the year when fruit yields was very high (74t fruits/ha), the NECB was even negative. NECB was accounted to a greater extent by the yearly increase of tree woody organs and to a minor extent by the C transfer to the soil from the decomposing litter. The most relevant agronomical suggestion of this study is that tree vegetative growth resulting into either increasing standing biomass and/or increasing tree litter should not be reduced if we aim at maintaining the CO2 sink capacity of the apple orchard.


      PubDate: 2015-03-20T07:18:55Z
       
  • Significant decrease in yield under future climate conditions: Stability
           and production of 138 spring barley accessions
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Cathrine Heinz Ingvordsen , Gunter Backes , Michael Foged Lyngkjær , Pirjo Peltonen-Sainio , Jens Due Jensen , Marja Jalli , Ahmed Jahoor , Morten Rasmussen , Teis Nørgaard Mikkelsen , Anders Stockmarr , Rikke Bagger Jørgensen
      The response in production parameters to projected future levels of temperature, atmospheric carbon dioxide ([CO2]), and ozone ([O3]) was investigated in 138 spring barley accessions. The comprehensive set of landraces, cultivars, and breeder-lines, were during their entire life cycle exposed to a two-factor treatment of combined elevated temperature (+5°C day/night) and [CO2] (700ppm), as well as single-factor treatments of elevated temperature (+5°C day/night), [CO2] (700ppm), and [O3] (100–150ppb). The control treatment was equivalent to present average South Scandinavian climate (temperature: 19/12°C (day/night), [CO2]: 385ppm). Overall grain yield was found to decrease 29% in the two-factor treatment with concurrent elevation of [CO2] and temperature, and this response could not be predicted from the results of treatments with elevated [CO2] and temperature as single factors, where grain yield increased 16% and decreased 56%, respectively. Elevated [O3] was found to decrease grain yield by 15%. Substantial variation in response to the applied climate treatments was found between the accessions. The results revealed landraces, cultivars, and breeder-lines with phenotypes applicable for breeding towards stable and high yield under future climate conditions. Further, we suggest identifying resources for breeding under multifactor climate conditions, as single-factor treatments did not accurately forecast the response, when factors were combined.


      PubDate: 2015-03-20T07:18:55Z
       
  • In field non-invasive sensing of the nitrogen status in hybrid
           bermudagrass (Cynodon dactylon × C. transvaalensis Burtt Davy) by a
           fluorescence-based method
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Giovanni Agati , Lara Foschi , Nicola Grossi , Marco Volterrani
      The level of N fertilization and the content of leaf N in Cynodon dactylon × C. transvaalensis Burtt Davy cv. ‘Tifway 419’ bermudagrass were evaluated non-destructively with a fluorescence-based method. It was applied directly into the field by using the Multiplex portable fluorimeter during two consecutive seasons (2010 and 2011). In the 2010 experiment, the nitrogen balance index (NBI1) provided by the sensor was able to discriminate (at P <0.05) six different N levels applied, up to 250kgha−1, with a precision (root mean square error, RMSE) in the rate estimate of 3.29kgha−1. In 2011, the index was insensitive to the N treatment between 150kgha−1 and 250kgha−1 N rates, and its precision was 39.98kgha−1. Calibration of the sensor by using the destructive analysis of turf samplings showed a good linear regression between NBI1 and the leaf N content for both 2010 (R 2 =0.81) and 2011 (R 2 =0.93) experiments. This allowed mapping of the leaf N spatial distribution acquired by the sensor in the field with a prediction error of 0.21%. Averaging the overall estimates of leaf N content per N treatment provided an upper limit of 200kgha−1 for the required fertilization, corresponding to a critical level of leaf N of about 2.3%. Our results confirm the usefulness of the new fluorescence-based method and sensor for a precise management of fertilization in turfgrass.


      PubDate: 2015-03-20T07:18:55Z
       
  • On-farm evaluation of integrated weed management tools for maize
           production in three different agro-environments in Europe: Agronomic
           efficacy, herbicide use reduction, and economic sustainability
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): V.P. Vasileiadis , S. Otto , W. van Dijk , G. Urek , R. Leskovšek , A. Verschwele , L. Furlan , M. Sattin
      The development and implementation of integrated weed management (IWM) strategies that provide good weed control while reducing dependence on herbicides, and preferably without having side effects on the overall system economic performance, is still a challenge that has to be met. In 2011 and 2012, nine on-farm experiments (i.e., real field conditions on commercial farms, with natural weed flora) were conducted in three important European maize producing regions-countries, which represent the range of climatic and edaphic conditions in Europe, to evaluate the efficacy of different locally selected IWM tools for direct weed control in maize vs. the conventional approach (CON) followed by the farms. The IWM tools tested were: (1) early post-emergence herbicide band application combined with hoeing followed by a second hoeing in Southern Germany, (2) early post-emergence herbicide broadcast application when indicated by a predictive model of weed emergence after performing one scouting in the field to supply data for the model, followed by hoeing in Northern Italy, and (3) tine harrowing at 2–3rd leaf stage of maize and low dose of post-emergence herbicide in Slovenia. Results showed that the IWM tools tested in the different countries: (1) provided sufficient weed control without any significant differences in yields, (2) greatly reduced maize reliance on herbicides, and (3) IWM implementation was economically sustainable as no significant differences in gross margin were observed in any country compared to CON.


      PubDate: 2015-03-20T07:18:55Z
       
  • Yield and energy balance of annual and perennial lignocellulosic crops for
           bio-refinery use: A 4-year field experiment in Belgium
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Hilde Muylle , Steven Van Hulle , Alex De Vliegher , Joost Baert , Erik Van Bockstaele , Isabel Roldán-Ruiz
      In densely populated regions, such as, Belgium, value chains in the bio-economy can be organized on locally produced primary feedstock, allowing cutting down transport costs and reducing greenhouse gas emissions. The energy use efficiency of three major cropping systems under two fertilizer regimes was compared side by side in a 4-year field trial, with the farm-gate as system border. The annual crops maize, sorghum, and Italian ryegrass were compared with the grassland species perennial ryegrass, cocksfoot, timothy and tall fescue, and the lignocellulosic crops miscanthus, switchgrass, common reed, reed canary grass, and willow. Maize yielded as average a dry matter of 19.6tha−1 y−1 at medium fertilization level. The average dry matter yield of the other crops varied between 3tha−1 y−1 for common reed and 21.1tha−1 y−1 for Miscanthus × giganteus. However, the highest energy use efficiency was obtained for switchgrass and willow. The factors with the most important impact on the total energy input (EI) were fertilizer application, up to 79% for perennial ryegrass, and the preparation of starting material (e.g., up to 81% of the total EI is attributed to the production of miscanthus rhizomes). Targets for further improvement of the sustainability of the primary feedstock production are the development of resource efficient varieties, e.g., fertilizer use efficient maize varieties or seed-based miscanthus varieties, or the inclusion of energy efficient crops into the rotation system, such as energy beet instead of Italian ryegrass. This study provides interesting insight in the energy balances at the farm level for both the farmer and the industrial actors in the locally organized bio-refinery chains.


      PubDate: 2015-03-20T07:18:55Z
       
  • Integrative effects of soil tillage and straw management on crop yields
           and greenhouse gas emissions in a rice–wheat cropping system
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Li Zhang , Jianchu Zheng , Liugen Chen , Mingxing Shen , Xin Zhang , Mingqian Zhang , Xinmin Bian , Jun Zhang , Weijian Zhang
      Significant efforts have been made to assess the impact of tillage regimes on crop yields and/or greenhouse gas (GHG) emissions across single crop growing season. However, few studies have quantified the impact across a whole rotation cycle in multiple cropping systems. Utilizing on a long-term tillage experiment with the rice–wheat rotation system in East China, we examined the GHG emissions under different tillage practices with or without crop straw incorporation. Results showed that compared to the no-straw control, straw incorporation increased wheat yield by 28.3% (P <0.05), irrespective of tillage practices, but had no significant effect on rice yield. Although straw incorporation did not significantly affect CH4 emissions during the wheat season and N2O emissions during the whole rice–wheat cycle, it significantly stimulated CH4 emissions by 98.8% (P <0.01) during the rice season. Also, there were no significant differences in CH4 and N2O emissions between tillage practices during the wheat season. Compared to plowing, rotary tillage increased CH4 emissions significantly by an average of 38.8% (P <0.01) but had no significant impacts on N2O emissions during the rice season. Across the rotation cycle, annual yield-scaled global warming potential of CH4 and N2O emissions under no-tillage plus rotary tillage was 26.8% (P <0.01) greater than that of rotary tillage plus plowing with or without straw incorporation. Significant interactions between soil tillage and straw management practices were found on annual GHG emissions, but not on crop yields. Together, these results indicate that plowing in the rice season plus rotary tillage in the wheat season may reduce GHG emissions while increasing crop yield in rice–wheat cropping areas.


      PubDate: 2015-03-20T07:18:55Z
       
  • Genetic improvement of root growth increases maize yield via enhanced
           post-silking nitrogen uptake
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Xiaohuan Mu , Fanjun Chen , Qiuping Wu , Qinwu Chen , Jingfeng Wang , Lixing Yuan , Guohua Mi
      Root breeding has been proposed as a key factor in the “second green revolution” for increasing crop yield and the efficient use of nutrient and water resources. However, few studies have demonstrated that the genetic improvement of root characteristics directly contributes to enhancing nutrient-use-efficiency in crops. In this study, we evaluated the contribution of root growth improvement to efficient nitrogen (N) acquisition and grain yield under two different N-levels in a 3-year field experiment. We used two near-isogenic maize testcrosses, T-213 (large-root) and T-Wu312 (small-root), derived from a backcross of a BC4F3 population from two parents (Ye478 and Wu312) with contrasting root size. We found that the root length density, root surface area, and dry weight at the silking stage were 9.6–19.5% higher in T-213 compared with the control T-Wu312. The root distribution pattern in the soil profile showed no significant differences between the two genotypes. The overall increase in root growth in T-213 enhanced post-silking N uptake, which increased grain yield by 17.3%. Correspondingly, soil nitrate concentrations in the >30cm soil layer were reduced in T-213 under the high N treatment. These positive effects occurred under both adequate and inadequate N-supply and different weather conditions. Our study provides a successful case that increasing root size via genetic manipulation contributes directly to efficient N-uptake and higher yield.


      PubDate: 2015-03-20T07:18:55Z
       
  • Effects of free air CO2 enrichment on root growth of barley, sugar beet
           and wheat grown in a rotation under different nitrogen supply
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Andreas Pacholski , Remigius Manderscheid , Hans-Joachim Weigel
      Elevated atmospheric CO2 concentrations [CO2] are known to change plant growth by stimulation of C3 photosynthesis and by reduction of transpiration of both C3 and C4 crops. In comparison to the information on above ground plant responses only limited knowledge exists on the response of root growth of arable crops to elevated [CO2] which is particularly true for temperate crop species under real field conditions. A free air CO2 enrichment (FACE) study (550ppm at daylight hours) was carried out in a crop rotation of winter barley, sugar beet and winter wheat repeated twice in the course of six years on a sandy loam soil at Braunschweig, Northern Germany. Winter barley and sugar beet were included for the first time in a FACE study. A possible interaction with restricted nitrogen (N) supply was studied by fertilizing the CO2 treatment plots with adequate and 50% of adequate N supply. Fine root samples were taken in the plough layer and below at 3–4 sampling dates during the vegetation period and root dry matter (excluding sugar beet storage root), shoot root ratio, root length density, specific root length and root tissue composition (CN ratio) were determined. Main effects of elevated [CO2] on the investigated variables were slightly significant. Significant CO2 effects were observed in interaction with the sampling date. In most cases elevated [CO2] increased root dry matter early in the vegetation period with a maximum growth stimulation of up to 54% as compared to ambient [CO2]. Concomitantly, root length densities were increased in both winter wheat and sugar beet. For winter barley also a significant decrease in root dry weight and significant increase of shoot root ratio was detected at final harvest while such an effect was not significant for sugar beet. Specific root length as an indicator of root morphology was mainly influenced by crop species. As a result, there was no consistent overall effect of elevated [CO2] on biomass partitioning in this study as changes in shoot root ratio only occurred at specific sampling dates indicating a similar stimulation of roots and above-ground biomass due to elevated [CO2]. Nitrogen supply did not alter the effect of elevated [CO2] on any of the root variables apart from CN ratios. A significant increase of root CN ratios in wheat and sugar beet was observed under elevated [CO2], but this effect was much smaller than the effect of N supply.


      PubDate: 2015-03-20T07:18:55Z
       
  • Response of primary production and biomass allocation to nitrogen and
           water supplementation along a grazing intensity gradient in semiarid
           grassland
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Xiao Ying Gong , Nicole Fanselow , Klaus Dittert , Friedhelm Taube , Shan Lin
      Herbivory and resource availability interactively regulate plant growth, biomass allocation, and production. However, the compensatory growth of plants under grazing intensities and manipulated environmental conditions is not well understood. A 2-year experiment with water (unirrigated and irrigated) and nitrogen fertilizer (0 and 75kgNha−1 year−1) addition was conducted at sites with 4 grazing intensities (0–7 sheepha−1) in an annually rotational grazing system in Inner Mongolia. In this study, grazing had no significant effect on aboveground net primary production (ANPP) and net primary production (NPP). However, high grazing intensity strongly reduced the fraction of belowground net primary production to NPP. Water and nitrogen additions significantly increased ANPP by 39% and by 23%, respectively, but had no effect on belowground net primary production. ANPP showed lower response to nitrogen addition at high grazing intensity sites than at low grazing intensity sites. We found no evidence for grazing optimization on primary production of semiarid steppe, regardless of resource supplementations. Grazed plants minimized the reduction of ANPP by altering allocation priority and morphological traits. Our study highlights the “whole-plant” perspective when studying plant–herbivore interactions.


      PubDate: 2015-03-20T07:18:55Z
       
  • Determining the effects of land consolidation on the multifunctionlity of
           the cropland production system in China using a SPA-fuzzy assessment model
           
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Beibei Guo , Xiaobin Jin , Xuhong Yang , Xu Guan , Yinan Lin , Yinkang Zhou
      The purpose of this study was to identify and measure the effect of land consolidation (LC) on the multifunctionality of cropland ecosystems. LC can serve agriculture multifunctionality, but it can also have a huge impact on the individual functions within the sector. We took 2006–2012 as study period, based on an analysis of county scale land consolidation projects (LCP) in the 31 provinces of China, this study found that the wide range of LC implementation has comprehensively influenced the multifunctionality of agriculture. LCP have significantly improved the production function of cropland, driven investment in agriculture, promoted development of the rural agricultural economy, maintained food security and stability in the rural area, and increased crop supply in most provinces. However, it also slightly impaired rural ecological benefits in some provinces. During the study period, land consolidation influenced the agricultural supply function in 14 provinces, covering 43.97% of the LC affected area and producing an increase of 1.25 million ha in cropland; In five provinces it influenced the production function over 31.18% of the LC area, changing the supply function outcome most and the ecological function least. Thus, the widespread implementation of LCP can result in significant impacts on the crop production system.


      PubDate: 2015-03-20T07:18:55Z
       
  • Evaluating coffee yield gaps and important biotic, abiotic, and management
           factors limiting coffee production in Uganda
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): N. Wang , L. Jassogne , P.J.A. van Asten , D. Mukasa , I. Wanyama , G. Kagezi , K.E. Giller
      Coffee is Uganda’s biggest export commodity, produced mainly by an estimated one million smallholder farmers (<2.5ha). Arabica (Coffea arabica L.) and Robusta (Coffea canephora Pierre ex Froehn.) are the two coffee species grown. Robusta is dominantly cultivated at lower elevations (<1400m) such as in Central and Northern Uganda and Arabica is dominant at higher elevations (>1400m) such as Eastern, Southwest, and Northwest Uganda. Actual yields are far below (<30%) potential due to various biotic, abiotic, and management constraints, yet there is no quantitative information on site-specific production constraints and the yield gaps attributed to those constraints. In this study, yields and diverse production factors were monitored in 254 plots of five major coffee growing regions (i.e., Central, North, East, Southwest, and Northwest). Boundary line analysis was applied to evaluate the relative importance of the individual production factors in limiting coffee production and to quantify the associated yield gaps at regional level. The impacts of rainfall variation on coffee yield were evaluated separately by regression analysis. The results of boundary line analysis indicated that biotic constraints (coffee twig borer) and poor management practices (unproductive coffee trees and low coffee plant density) restricted Robusta production in the Central region; poor soil nutrient status (especially potassium) and lack of mulching were the causes of yield loss of Robusta grown in the Northern region. For Arabica, unfavorable soil properties (high soil pH and phosphorus concentration) and excessive number of shade trees were the most important constraints in the East; high soil magnesium concentration and poor mulching limited coffee yield in the Southwest; poor soil nutrient status (especially phosphorus and potassium) and low coffee plant density were the important yield limitations in the Northwest. Average explained yield gaps of individual coffee plot due to the most important production constraints were 45%, 52%, 57%, 49%, and 50% of attainable yield, respectively, in the Central, Northern, Eastern, Southwest, and Northwest regions. Considerably less annual precipitation was received in 2009/2010 coffee growing season compared with that in the previous three years (2006–2008). Seasonal rainfall shortage occurred in the Southwest was a significant limitation to Arabica production, while excessive rainfall across the whole growing season was associated with yield reduction in the Eastern and Northwest regions. We conclude that there was a large yield gap for both Robusta and Arabica coffee grown in Uganda. Boundary line analysis allows the evaluation of relative importance of individual production constraint directly in the plot. The important production constraints varied strongly depending on the regions, which calls for site-specific management implementations. Soil fertility can be improved by implementing integrated soil fertility management (ISFM) that makes use of nutrients from the soil, recycled crop residues, mulch and chemical fertilizers. Attentions should also be given to other management practices such as coffee plant density, unproductive coffee trees and shade trees etc.


      PubDate: 2015-03-20T07:18:55Z
       
  • Leaf gas exchange and radiation use efficiency of sunflower (Helianthus
           annuus L.) in response to different deficit irrigation strategies: From
           solar radiation to plant growth analysis
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Pasquale Garofalo , Michele Rinaldi
      Most studies on radiation use efficiency (RUE) have focussed only on the relationship between intercepted solar radiation and biomass accumulation, without considering the intermediate steps that underlie the development of the crop. The present study aims to estimate the RUE of sunflower (Helianthus annuus L.) under different deficit irrigation schemes, with the introduction of an intermediate step at the leaf scale, the net photosynthesis rate (PN), and the exploration of the relationship between RUE and PN. The linear relationship between intercepted photosynthetically active radiation (iPAR) and total plant dry matter was defined during the vegetative phase, and a single value of RUE (2.08gMJ−1) was predictive of biomass accumulation; the curvilinear response of RUE with respect to PN explained one of the hierarchical processes that governs the smooth and stable conversion efficiency of iPAR to biomass. However, different RUE values should be used to estimate seed yield when irrigation is suspended at the heading (RUE, 0.29gMJ−1), flowering (RUE, 0.35gMJ−1) or milking (RUE, 0.44gMJ−1) stages, because after the vegetative stage, synchronization of the processes underlying the late growth – grain filling phases was lost. Despite this, even if the yield performance followed the water treatment (2.69, 3.61 and 4.36tha−1 for increasing water supply), the productivity of sunflower with small (150mm) or moderate (270mm) amounts of water ensured satisfactory seed production and water saving (74% and 53% reduction, compared to well-watered treatment) in water-limited environments.


      PubDate: 2015-03-20T07:18:55Z
       
  • Effects of increased day and night temperature with supplemental infrared
           heating on winter wheat growth in North China
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Shibo Fang , Davide Cammarano , Guangsheng Zhou , Kaiyan Tan , Sanxue Ren
      The main future challenge is to feed 9 billion people under a changed climate, and the projected increase in global temperature will affect, negatively or positively, future wheat production depending on the geographical location. Temperature is a key factor in crop growth, development and yield. Global temperatures are rising asymmetrically with the daily minimum temperature rising faster than the daily maximum temperature. The objectives of this study are to evaluate wheat biomass growth, development, yield and harvest index under whole day and night time temperatures increased by 2.5°C in field conditions. The field experiment was carried out during three growing seasons (2008/09, 2009/10, and 2010/11) in Hebei Province, which is the main wheat region of the North China Plain. The experiment was carried out using a warming system with infrared radiation lamps suspended 2.3m above the ground which increased the mean air temperature by 2.0–2.5°C . The treatments were: (1) ambient control (CK: not warmed), (2) higher night temperature (HNT: warmed from 19:00 to 7:00), and (3) higher day–night temperature (HDNT: warmed from 9:00 to 17:00 and 19:00 to 7:00). Each treatment was replicated four times for a total of 12 plots (2×4m2 each) in a randomized complete block design for the growing season 2009/10 and 2010/11 and 5 times in 2008/09. Results of this study, showed that overall wheat biomass increased by 30% and yield by 20% under heating conditions with the highest relative increase for the cold year (2009/10). Grain yield under control treatments, for the cold year, decreased by 37% because the number of days of minimum temperature below 0°C increased by 14 days. Overall, the different warming timing (night-time only versus day–night) did not cause any significant difference in yield and biomass increase. However, as an overall pattern, warming increased aboveground biomass, grain yield, plant height and panicle numbers, but decreased harvest index. In conclusion, wheat growth and yield were significantly increased by artificial warming indicating that a warming in such area of China has potential benefits to current wheat cultivars. Higher temperatures changed the ratio of beginning/length of overwintering causing a significant change in stem numbers.


      PubDate: 2015-03-20T07:18:55Z
       
  • Assessment of plant nitrogen status using chlorophyll fluorescence
           parameters of the upper leaves in winter wheat
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Wei Feng , Li He , Hai-Yan Zhang , Bin-Bin Guo , Yun-Ji Zhu , Chen-Yang Wang , Tian-Cai Guo
      Non-destructive, rapid diagnosis of plant nitrogen status is important for the evaluation of wheat growth and the dynamic management of nitrogen nutrition. Two wheat cultivars, Zhengmai 366 (high protein content) and Aikang 58 (medium protein content) were grown in field trials at five different nitrogen levels (0, 90, 180, 270 and 360kgha−1) in two consecutive growing seasons at Zhengzhou, China. Leaf chlorophyll fluorescence (ChlF) parameters, leaf and stem biomass, and nitrogen content were measured simultaneously at different growth stages, establishing an evaluation model of plant nitrogen nutrition in wheat using ChlF parameters. The results showed that the differences in ChlF parameters between the three top leaves (1–3LFT) was small from the reviving to the flowering stages. With increasing nitrogen levels, the difference in ChlF parameters between the fourth leaf (4LFT) and the first three leaves (1–3LFT) decreased gradually, indicating that 4LFT is sensitive to N fertilizer application and has a disadvantage in competition for redistributed N. The correlation coefficients between ChlF parameters for the upper, fully expanded leaves and N concentration of the corresponding leaves were 0.628 for F v, 0.607 for F m, 0.579 for F v/F o, and 0.600 for F v/F m at P <0.01, but only 0.248 for F o at P <0.05. At the reviving and jointing stages, the relationships between the normalized differences between 1–2LFT and 4LFT (NDF12/4) for F v/F o and F v/F m to plant nitrogen concentration (PNC) were the most significant (r <−0.79, P <0.001), the determination coefficient (R 2) for F v/F m was much higher than for F v/F o, and the two regression equations were grouped at reviving and jointing with similar R 2 values between the stages. At booting and flowering, the normalized differences between 1–2LFT and 4LFT for F o, F m, and F v better reflected the changes in PNC; the R 2 values were 0.654–0.797 (P <0.001) at booting and 0.515–0.584 (P <0.001) at anthesis, and the two regression equations were grouped at booting and anthesis with greater differences in R 2 between the stages. The unified regression equation could be used to express the relationship between plant nitrogen sufficiency index (NSI) and ChlF parameters with R 2 values of 0.623 (P <0.001) for NDF12/4 for F v/F m, and 0.567 (P <0.001) for NDF12/4 for F v/F o during the reviving and jointing stages, while R 2 =0.666 (P <0.001) for NDF12/4 for F m and 0.615 (P <0.001) for NDF12/4 for F v during booting and anthesis. These results show that the relationship between NDF and NSI was stable and reliable over the different years, varieties, and N supply levels. We conclude that the spatial differences in ChlF parameters between 1–2LFT and 4LFT should be ideal indicators of plant nitrogen status in wheat, and will provide a decision-making method for N diagnosis and regulation in field production.


      PubDate: 2015-03-20T07:18:55Z
       
  • Splitting the application of 3,4-dimethylpyrazole phosphate (DMPP):
           Influence on greenhouse gases emissions and wheat yield and quality under
           humid Mediterranean conditions
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Ximena Huérfano , Teresa Fuertes-Mendizábal , Miren K. Duñabeitia , Carmen González-Murua , José María Estavillo , Sergio Menéndez
      Wheat is among the most widely grown cereals in the world. In order to enhance its production, its management is based on the addition of nitrogen (N) fertilizers. Nevertheless, its application could increase nitrous oxide (N2O) emissions, which effects are very pernicious to the environment, being a strong greenhouse gas (GHG). Regarding GHG, soil processes can also produce or consume carbon dioxide (CO2) and methane (CH4). Nitrification inhibitors (NI) have been developed with the aim of decreasing fertilizer-induced N losses and increase N efficiency. The fact that the application of a NI enhances N use efficiency is a good reason to think that more N should be also available for increasing the grain N concentration of wheat plants. If the application of NI means an increase in N use efficiency, it is plausible to consider that more N would be available, hence, increasing the grain N concentration of wheat. We present a two-year field-experiment to evaluate the influence of the NI 3,4-dimethylpyrazol phosphate (DMPP) on grain yield, grain quality and GHG emissions. Fertilizer dose, with and without DMPP, was 180kgNha−1 applied as ammonium sulfate nitrate (ASN) splitted in two applications of 60kgNha−1 and 120kgNha−1, respectively. A treatment with a non-splitted application of ASN with DMPP and an unfertilized treatment were also included. The splitted application of ASN with DMPP was able to reduce N2O emissions, without affecting yield and its components. The alternative management of a non-splitted application of DMPP was more efficient mitigating N2O emissions, whilst keeping yield and slightly reducing grain protein content. In consequence of the low N2O fluxes from our soils, the EF applied in our region should be lower than the default value of 1% proposed by IPCC.


      PubDate: 2015-03-20T07:18:55Z
       
  • Morphological traits associated with vegetative growth of rice (Oryza
           sativa L.) during the recovery phase after early-season drought
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Midori Okami , Yoichiro Kato , Nobuya Kobayashi , Junko Yamagishi
      Rapid leaf growth during the recovery period after a dry spell is essential for the adaptation of rice (Oryza sativa L.) to drought–prone environments. However, how rice plants resume growth when the drought stress ends is not well understood. The objective of this study was to determine the traits and mechanisms associated with the above-ground morphological response to rewatering after early-season drought, by comparing three rice lines with contrastive plant architectures. In the field, we measured the above-ground architecture, carbohydrate partitioning, and consumption of non-structural carbohydrates by IR64 (indica rice), a New Plant Type line (tropical japonica rice) and an IR64 introgression line (IL) with large leaves and reduced tillering under fully irrigated and drought+rewatered conditions. In an ancillary pot experiment, we monitored changes in tiller number and leaf growth under fully irrigated, droughted and drought+rewatered conditions. There were genotypic differences in recovery growth patterns upon rewatering after drought: the New Plant Type lines prioritized individual tiller growth, while IR64 and the IR64 IL prioritized the production of new tillers and concomitantly consumed much carbohydrate. The increase in tiller number during the recovery period was lower in the IR64 IL than in IR64 owing to the longer phyllochron and larger amount of assimilate required to produce new tillers in the IL. Rice development during the recovery period depends on the plant type (constitutive tiller number to size ratio) and tillering response to soil moisture regime, which would be mediated mainly by phyllochron and tiller production per assimilate. Rapid increase in tiller number upon rewatering in IR64 was associated with the low amount of assimilate required to produce new tillers rather than with the short phyllochron.


      PubDate: 2015-03-20T07:18:55Z
       
  • Influence of temperature and solar radiation on grain yield and quality in
           irrigated rice system
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Nanyan Deng , Xiaoxia Ling , Yang Sun , Congde Zhang , Shah Fahad , Shaobing Peng , Kehui Cui , Lixiao Nie , Jianliang Huang
      An insight into optimal temperature and radiation (T&R) in different rice phenological stages will contribute to rice cultivation management and crop modeling. This study was aimed to unravel the responses of various rice cultivars to different T&R conditions and to identify the optimal T&R for both yield and quality in the Yangtze River Valley in China. For this purpose, two Indica and three Japonica cultivars were grown under irrigation conditions, respectively, on three sowing dates (April 30, May 10 and May 30) in 2012 and 2013 to acquire different combinations of T&R conditions. Various morphological, yield- and quality-related traits were investigated. This study demonstrated that temperature in this region is a limiting factor compared with radiation. Besides, there was a smaller variation of the average T&R in reproductive stage than in vegetative and grain filling stages. Therefore, T&R in various phenological stages were classified into three major combinations, namely, HL, LH, MM mainly based on temperature in vegetative and grain filling stages. MM combination had similar average daily temperature in both vegetative and grain filling stages compared with the average temperature of rice growth season. HL combination was of higher (at least 1°C) average daily temperature in vegetative stage and lower (at least 1°C) in grain filling stage compared with MM. Opposite to HL, LH combination was of lower average daily temperature in vegetative stage and higher in grain filling stage compared with MM. Most of the cultivars harvested the highest grain yield with highest T&R use efficiency in HL combination compared to the other two combinations. When the average temperature in vegetative stage was estimated to be 26–28°C and 22–27°C in grain filling stage, higher grain yield can be gained. Moreover, highly significant correlation was found between temperature and LAI (leaf area index), CGR (crop growth rate), and TDW (total above ground biomass) in vegetative stage. HI (harvest index) and all grain-processing and appearance-quality-related traits was highly significantly correlated with temperature in grain filling stage. In conclusion, HL combination with average daily temperature ranges of 26–28°C in vegetative stage, and 22–27°C in grain filling stage are recommended to achieve high grain yield and quality for irrigated rice in the Yangtze River Valley in China by adjusting sowing date and crop establishment.


      PubDate: 2015-03-20T07:18:55Z
       
  • Maize yields benefit from injected manure positioned in bands
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): J.J. Schröder , G.D. Vermeulen , J.R. van der Schoot , W. van Dijk , J.F.M. Huijsmans , G.J.H.M. Meuffels , D.A. van der Schans
      The use of positioned mineral fertilizer phosphorus (P) starters reduces the risk of yield penalties in maize production. However, it also increases the soil P surplus and attendant risk of P losses to the environment, in particular on farms with ample supplies of livestock manures. We examined whether routine applications of starter P can be refrained from if manure is injected in subsurface bands close to the anticipated position of the maize rows as an alternative to the conventional even injection at random lateral positions relative to the rows. Fourteen field experiments were executed on sandy soils in The Netherlands. In these experiments comparisons were made of the nitrogen (N) and P-concentrations in shoots and of dry matter (DM), N and P-yields over time, between evenly injected liquid manure (with and without starter P) and band-injected liquid manure. Silage yields of DM, N and P generally responded positively (P <0.05) to starter P applied at a rate of 9–31kg per hectare where manure had been applied at rates of circa 120kg N and circa 20kg P per hectare, but less so when the manure was band-injected. This positive response to P was not reflected in the concentration of P in shoots. Positioning of manure via band-injection without extra starter P resulted in silage maize dry matter yields that were similar to yields after even injection combined with a P-starter. Band-injection improved the recovery of the N and P (P <0.05) supplied by the manure and reduced the soil surpluses of N and P. Planting maize close to bands where liquid manure had been injected, thus increased silage yields and contributed to a better balance between the inputs and outputs of plant nutrients.
      Graphical abstract image

      PubDate: 2015-03-20T07:18:55Z
       
  • Does a freely tillering wheat cultivar benefit more from elevated CO2 than
           a restricted tillering cultivar in a water-limited environment?
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Sabine Tausz-Posch , Raymond W. Dempsey , Saman Seneweera , Robert M. Norton , Glenn Fitzgerald , Michael Tausz
      This study addresses whether a freely tillering wheat cultivar with greater vegetative sink strength (cv. “Silverstar”) can benefit more from increasing atmospheric CO2 concentration [CO2] than a restricted tillering cultivar with greater reproductive sink strength (cv. H45) in a water-limited cropping system. Growth, yield, yield components and nitrogen at three developmental stages (stem elongation, anthesis, maturity) and water soluble carbohydrates (WSC, anthesis) were evaluated at two CO2 concentrations (ambient [CO2], ∼395ppm, elevated e[CO2], ∼550ppm) across six environments using the Australian Grains Free Air CO2 Enrichment (AGFACE) facility. Cv. “Silverstar” had more tillers than cv. “H45” throughout development; whereas, cv. “H45” had greater WSC storage and more and heavier kernels per spike. CO2 enrichment stimulated grain yield in both cultivars similarly, but this stimulation was caused differently: For cv. “Silverstar”, grain yield increase was exclusively linked to an increased number of fertile tillers; whereas, in cv. “H45”, yield stimulation was additionally associated with increased kernel weight and kernel numbers per spike. We conclude that in a Mediterranean-type, water-limited environment high tillering capacity alone does not ensure greater benefits from CO2 fertilization but that both pre and post-anthesis source-sink relationships play a significant role in this environment as well.


      PubDate: 2015-03-20T07:18:55Z
       
  • Quantifying the effects of soil variability on crop growth using apparent
           soil electrical conductivity measurements
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Anja Stadler , Sebastian Rudolph , Moritz Kupisch , Matthias Langensiepen , Jan van der Kruk , Frank Ewert
      Spatial heterogeneity of crop growth within fields is rarely quantified but essential for estimating yield and optimizing crop management. Relationships in fields between crop growth and soil physical characteristics have been described before but an unrealistically high number of invasive measurements have to be made to obtain spatially continuous soil information. Alternatively, non-invasive methods are available for characterizing soil heterogeneity but relationships to growth characteristics have rarely been investigated. Here, we use an electromagnetic induction (EMI) sensor to measure the apparent electromagnetic conductivity of the soil (ECa), which can be used as a proxy for the relative spatial variability of the prevailing soil properties. We evaluate relationships between ECa and soil and crop characteristics assuming that measured ECa patterns relate to observed growth patterns in the field. The test fields were located in Western Germany where different crops (winter wheat, winter barley, and sugar beet) were grown between 2011 and 2013. Measurements include soil texture, soil moisture and crop growth characteristics taken frequently throughout the vegetation periods for plant height, leaf area index (LAI), dry matter of plants and selected organs (green leaves and storage organs). Spatial variability was observed for soil and crop characteristics that differed among fields, crops and years. Good correlations between ECa and soil texture and soil moisture confirmed that ECa measurements are suitable for characterizing spatial differences in soil properties for our test sites. Averaged over all sampling dates of a vegetation period the differences in the spatial variability of crop characteristics were small between the years and crops considered. However, the within-field crop growth heterogeneity changed throughout the growing period depending on the crop development stage. Correlations were found between ECa and the crop characteristics that varied with time and were most pronounced in the main growth phase when LAI approached its maximum. Crop height correlated better with ECa than yield, LAI, and dry matter but differences were observed between fields, years and crops. Our results suggest that in dry years soil patterns have a stronger influence on the crop growth patterns than in wetter years when water limitation is less severe. We conclude that ECa measurements are suitable for detecting spatial patterns in soil characteristics that influence the spatial crop growth patterns for the region, years and crops considered. However, relationships between patterns in crop growth and soil characteristics within fields are more complex and require further investigation.


      PubDate: 2015-03-20T07:18:55Z
       
  • The use of 13C and 15N based isotopic techniques for assessing soil C and
           N changes under conservation agriculture
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Kenza Ismaili , Mohammed Ismaili , Jamal Ibijbijen
      A four years experiment was conducted to investigate the effect of tillage and addition of crop residues in wheat–faba bean rotation. The soil was fertilized with a total of 150kgnitrogen (N)ha−1 enriched with 9.96 percent nitrogen-15 (15N) atom excess, in four applications. The first crop was corn, a C4 plant cropped under till (T) and no-till (NT) conditions. Percent N derived from fertilizer (Ndff) by corn was 37.12–48.62. The leaves had the lowest delta carbon-13 (δ 13C) values of −12.7 and the seeds the highest (−11.8). Soil δ 13C was affected by addition of C4 plant residues. Soil under residue and till treatment (RT) had the highest percent 15N values. Residues and no-till (RNT) had the lower percent 15N values. At the end of the corn crop soil percent 15N was 0.211, 0.26, and 0.253 in the three soil depths. Residues and tillage increased significantly the Ndff of wheat: from 6.43 to 6.46kgNha−1 for no residues no-till (NRNT) and no-residues and till (NRT) and from 11.1 to 13kgNha−1 in RNT and RT treatments. In wheat nitrogen derived from residues (Ndfr) was 4.68 and 1.53kgNha−1 in grain and residues, respectively. Residues and tillage affected significantly soil C, N, 15N, and δ 13C from seeding to two months after and have no effect at harvest. The interaction was always significant. After four years the 15N fertilizer contributed only with 1.5–2.85kgNha−1 in NRNT and NRT, respectively, and 3.3–5.63kgNha−1 in RNT and RT, respectively. Cumulated N recovered during the three growing seasons following corn was 8.59–11.07kgNha−1 for NRNT and NRT; 20.24–15.6kgNha−1 for RT and RNT, respectively. Residues increased N mineralization by 50 percent and the quantity of 15N available to plants increased with tillage.


      PubDate: 2015-03-20T07:18:55Z
       
  • Evaluation of monocropped and intercropped grain legumes for cover
           cropping in no-tillage and reduced tillage organic agriculture
    • Abstract: Publication date: April 2015
      Source:European Journal of Agronomy, Volume 65
      Author(s): Lars Rühlemann , Knut Schmidtke
      Intensive tillage by means of mouldboard ploughing can be highly effective for weed control in organic farming, but it also carries an elevated risk for rapid humus decomposition and soil erosion. To develop organic systems that are less dependent on tillage, a two-year study at Reinhardtsgrimma and Köllitsch, Germany was conducted to determine whether certain legume cover crops could be equally successfully grown in a no-till compared with a reduced tillage system. The summer annual legumes faba bean (Vicia faba L.), normal leafed field pea (Pisum sativum L.), narrow-leafed lupin (Lupinus angustifolius L.), grass pea (Lathyrus sativus L.), and common vetch (Vicia sativa L.) were examined with and without sunflower (Helianthus annuus L.) as a companion crop for biomass and nitrogen accumulation, symbiotic nitrogen fixation (N2 fixation) and weed suppression. Total cover crop biomass, shoot N accumulation and N2 fixation differed with year, location, tillage system and species due to variations in weather, inorganic soil N resources and weed competition. Biomass production reached up to 1.65 and 2.19Mgha−1 (both intercropped field peas), and N2 fixation up to 53.7 and 60.5kgha−1 (both common vetches) in the no-till and reduced tillage system, respectively. In the no-till system consistently low sunflower performance compared with the legumes prevented significant intercropping effects. Under central European conditions no-till cover cropping appears to be practicable if weed density is low at seeding. The interactions between year, location, tillage system and species demonstrate the difficulties in cover crop species selection for organic conservation tillage systems.


      PubDate: 2015-03-20T07:18:55Z
       
  • Heat stress in cereals: Mechanisms and modelling
    • Abstract: Publication date: March 2015
      Source:European Journal of Agronomy, Volume 64
      Author(s): Ehsan Eyshi Rezaei , Heidi Webber , Thomas Gaiser , Jesse Naab , Frank Ewert
      Increased climate variability and higher mean temperatures are expected across many world regions, both of which will contribute to more frequent extreme high temperatures events. Empirical evidence increasingly shows that short episodes of high temperature experienced around flowering can have large negative impacts on cereal grain yields, a phenomenon increasingly referred to as heat stress. Crop models are currently the best tools available to investigate how crops will grow under future climatic conditions, though the need to include heat stress effects has been recognized only relatively recently. We reviewed literature on both how key crop physiological processes and the observed yields under production conditions are impacted by high temperatures occurring particularly in the flowering and grain filling phases for wheat, maize and rice. This state of the art in crop response to heat stress was then contrasted with generic approaches to simulate the impacts of high temperatures in crop growth models. We found that the observed impacts of heat stress on crop yield are the end result of the integration of many processes, not all of which will be affected by a “high temperature” regime. This complexity confirms an important role for crop models in systematizing the effects of high temperatures on many processes under a range of environments and realizations of crop phenology. Four generic approaches to simulate high temperature impacts on yield were identified: (1) empirical reduction of final yield, (2) empirical reduction in daily increment in harvest index, (3) empirical reduction in grain number, and (4) semi-deterministic models of sink and source limitation. Consideration of canopy temperature is suggested as a promising approach to concurrently account for heat and drought stress, which are likely to occur simultaneously. Improving crop models’ response to high temperature impacts on cereal yields will require experimental data representative of field production and should be designed to connect what is already known about physiological responses and observed yield impacts.


      PubDate: 2015-03-20T07:18:55Z
       
  • Impact of data resolution on heat and drought stress simulated for winter
           wheat in Germany
    • Abstract: Publication date: April 2015
      Source:European Journal of Agronomy, Volume 65
      Author(s): E. Eyshi Rezaei , S. Siebert , F. Ewert
      Heat and drought stress can reduce crop yields considerably which is increasingly assessed with crop models for larger areas. Applying these models originally developed for the field scale at large spatial extent typically implies the use of input data with coarse resolution. Little is known about the effect of data resolution on the simulated impact of extreme events like heat and drought on crops. Hence, in this study the effect of input and output data aggregation on simulated heat and drought stress and their impact on yield of winter wheat is systematically analyzed. The crop model SIMPLACE was applied for the period 1980–2011 across Germany at a resolution of 1km×1km. Weather and soil input data and model output data were then aggregated to 10km×10km, 25km×25km, 50km×50km and 100km×100km resolution to analyze the aggregation effect on heat and drought stress and crop yield. We found that aggregation of model input and output data barely influenced the mean and median of heat and drought stress reduction factors and crop yields simulated across Germany. However, data aggregation resulted in less spatial variability of model results and a reduced severity of simulated stress events, particularly for regions with high heterogeneity in weather and soil conditions. Comparisons of simulations at coarse resolution with those at high resolution showed distinct patterns of positive and negative deviations which compensated each other so that aggregation effects for large regions were small for mean or median yields. Therefore, modelling at a resolution of 100km×100km was sufficient to determine mean wheat yield as affected by heat and drought stress for Germany. Further research is required to clarify whether the results can be generalized across crop models differing in structure and detail. Attention should also be given to better understand the effect of data resolution on interactions between heat and drought impacts.


      PubDate: 2015-03-20T07:18:55Z
       
  • Seasonal changes in nutrient content and concentrations in a mature
           deciduous tree species: Studies in almond (Prunus dulcis (Mill.) D. A.
           Webb)
    • Abstract: Publication date: April 2015
      Source:European Journal of Agronomy, Volume 65
      Author(s): Saiful Muhammad , Blake L. Sanden , Bruce D. Lampinen , Sebastian Saa , Muhammad I. Siddiqui , David R. Smart , Andres Olivos , Kenneth A. Shackel , Theodore DeJong , Patrick H. Brown
      Knowledge of the pattern of nutrient uptake and loss and the within-tree allocation of nutrients in trees is critical to the understanding of ecosystem nutrient fluxes and to the management of applied nutrients in agricultural ecosystems. Fluxes of nutrients in whole trees and determination of total annual uptake, nutrient allocation within organs and loss in annual organs were obtained in a mature commercial almond (Prunus dulcis) orchard managed with non-limiting irrigation under varied nitrogen (N) and potassium (K) fertilization regimes from 2008 through 2012. Whole tree nutrient dynamics were derived from multiple in-season measurements of nutrients in leaves and fruits and biomass in all years. Whole tree nutrient budgets in perennial tree parts were derived from whole tree excavations and tree coring in 2011 and 2012 when the orchard had reached >85% full canopy closure. The annual N increment in perennial tree organs was 21kg, 41kg, 44kg and 45kgha−1 for the four N application rates of 140kg, 224kg, 309kg and 392kgha−1 N, respectively. In this orchard maximum agronomic productivity (yield plus increment in tree size) was recorded with an N application rate of 309kgha−1. Under optimal N application the annual increment in P, K, Ca and Mg was 8kg, 38kg, 3.5kg and 2.8kgha−1. Total N in leaves in midsummer in 2012 (a low yield year) was 37kg, 43kg, 54kg and 58kgha−1 for the four N application rates. In contrast, total N in leaves at mid-summer in 2011 (high yield year) was 21kg, 28kg, 35kg and 39kgha−1 for the four N application rates. In years 2009 through 2011 nitrogen in fruit at harvest represented 90% of whole tree N fluxes. In trees provided just adequate N to achieve maximal yield (309kgha−1 in this experiment in years 2009–11), N, P, K, S, Ca and Mg export in fruit was 212kg–366kgha−1, 26kg–45kgha−1, 265kg–389kgha−1, 7.9kg–14.4kgha−1, 24.7kg–29.6kgha−1 and 15.9kg–22.6kgha−1, respectively. The majority of whole tree macro and micronutrient uptake occurred between anthesis and kernel fill with 35–50% of total N uptake occurring before 40 days after full bloom (DAFB) and 80–90% of the total N being accumulated by 112 DAFB coinciding with kernel filling. Over 70% of the total P and 65–80% of the total K was accumulated in fruits by mid-season. Ninety percent of total S, 80–90% of total Ca and 70–85% of total Mg accumulated in fruit by 112 DAFB. The findings from the study can be used for in-season fertilizer management according to plant demand based on expected yield.


      PubDate: 2015-03-20T07:18:55Z
       
  • Designing eco-efficient crop rotations using life cycle assessment of crop
           combinations
    • Abstract: Publication date: April 2015
      Source:European Journal of Agronomy, Volume 65
      Author(s): Thomas Nemecek , Frank Hayer , Emmanuel Bonnin , Benoît Carrouée , Anne Schneider , Christophe Vivier
      Intensive arable crop production has major impacts on the environment and solutions for their reduction are needed. Diversification of crop rotations together with improved nitrogen management is an option for more eco-efficient cropping systems. The potentials for reducing the environmental impacts cropping systems were investigated by means of life cycle assessment (LCA) in three regions in France (Beauce, Burgundy and Moselle). The crop management data were compiled by the Chambers of Agriculture in the three regions based on field survey data (2002–2009 in Burgundy and Moselle and 2004–2008 in Beauce) and completed by experts. The LCA calculations were carried out by the SALCA-crop tool, using the ecoinvent and SALCA inventory databases and SALCA emission models. The LCAs were calculated for crop combinations, which were an efficient way to analyse a large number of crop rotations. A crop combination is defined as the inventory of a given crop, with a defined preceding crop and eventually including a catch crop. Nitrogen management revealed to be a key driver for the environmental impacts. It dominated the non-renewable energy demand, the global warming potential, the ozone formation potential, the acidification potential, and the eutrophication potential. Strong correlations between N fertilisation and these environmental impacts were found. The introduction of pea allowed to reduce the total eutrophication over the whole crop rotation. The mitigation of environmental impacts was not only possible per hectare, but also per € gross margin II. The eco-efficiency can thus be improved by reducing the level of N fertilisation. A reduction of N fertilisation could be achieved also by a reduction of the fertiliser doses to the non-legume crops, in addition to the introduction of legumes. Both ways proved to be effective and the combination of both was the most promising. However, trade-off between environmental and economic goals was identified. Diversification of cereal intensive crop rotations proved to be generally favourable from an environmental point of view. Catch crops had favourable effects on nutrient leaching a slightly favourable effects on biodiversity and soil quality. The ecotoxicity potentials were dominated by a few active ingredients only; the diversification did not lead to generally reduced ecotoxicity potentials. Diverse crop rotations with reduced N input are a promising way to reduce the environmental impacts of intensive arable crop rotations.


      PubDate: 2015-03-20T07:18:55Z
       
  • “Productivity, quality and sustainability of winter wheat under
           long-term conventional and organic management in Switzerland”
    • Abstract: Publication date: April 2015
      Source:European Journal of Agronomy, Volume 65
      Author(s): Jochen Mayer , Lucie Gunst , Paul Mäder , Marie-Françoise Samson , Marina Carcea , Valentina Narducci , Ingrid K. Thomsen , David Dubois
      Long-term sustainability and high resource use efficiency are major goals for high quality baking wheat production throughout the world. Present strategies are low input systems such as organic agriculture or improved conventional systems (integrated). The fertilisation level and strategy, crop protection as well as preceding crop effects may modulate system performance with respect to wheat grain yield, quality and environmental performance of the systems. Our aim was to evaluate data of winter wheat (Triticum aestivum L.) performance from the DOK long-term systems experiment in Switzerland comparing two mixed organic (biodynamic and bioorganic: BIODYN and BIOORG) and a mixed conventional cropping system (CONFYM) using mineral fertilisers and farmyard manure at two fertilisation intensities (level 1: 50% of standard fertilisation, level 2: standard fertilisation) since 1978. A conventional system was fertilised exclusively minerally at level 2 (CONMIN) and a control remained unfertilised (NOFERT). We compared crop yields, baking quality parameters, the nitrogen use efficiency and the effect of maize and potatoes as preceding crops obtained between 2003 and 2010 along with long-term soil sustainability parameters. The mean grain yields across both fertiliser levels of the organic cropping systems (BIODYN and BIOORG) were 64% of CONFYM, whereas crude protein contents were 79% of CONFYM at fertilisation level 2 and achieved 90% at level 1. The main driving factor of lower yields was a reduction of the numbers of ears per m2 and the thousand kernel weight. The apparent nitrogen use efficiency decreased with increasing N fertilisation. Doubling the organic fertilisation in the organic systems only slightly improved wheat grain yields but was not able to improve grain baking quality, due to low mineral N additions via slurry and farmyard manure. In contrast the effects of the preceding crop potatoes in comparison with preceding silage maize outperformed the organic fertilisation effects, resulting in 33% higher yields and 11% higher crude protein contents. The yield components recorded in the case of preceding potatoes demonstrated a more synchronised nutrient supply throughout the wheat development. Over all low input systems and both fertilisation levels in the conventional mixed farm system at half standard fertilisation (level 1) performed best with distinctly higher grain yields and crude protein contents than in the organic systems with standard fertilisation. However, all systems, organic and conventional, with the low or zero organic fertiliser inputs performed poorly considering the long-term soil quality parameters, indicating a degradation of soil quality. The DOK long-term experiment allows an integrated view on the performance of baking wheat production and long-term sustainability. The results emphasise the importance of a sufficient supply of soils with organic fertilisers as well as the need to improve the availability of organic nitrogen and synchrony between nutrient supply and demand in organic baking wheat production, beside the selection of a suitable preceding crop.


      PubDate: 2015-03-20T07:18:55Z
       
  • Cotton yield and fiber quality affected by row spacing and shading at
           different growth stages
    • Abstract: Publication date: April 2015
      Source:European Journal of Agronomy, Volume 65
      Author(s): Fábio R. Echer , Ciro A. Rosolem
      Carbohydrate production and reproductive structure development in cotton (Gossypium hirsutum) depends on light availability, a determinant of cotton yield. Light availability is decreased by cloud cover or self-shading when cotton plants are grown in dense populations. The objective of this study was to evaluate the effects of shading during cotton growth and its interactions with plant row spacings on yield and fiber quality. Three independent experiments were conducted as follows: in Paranapanema (23°39′S; 48°58′W), cotton was planted in November in row spacings of 0.45, 0.75 and 0.96m; in Primavera do Leste (15°33′S; 54°11′W), planting was in January with at row spacings of 0.45 and 0.76m; and in Chapadão do Céu (18°38′S; 52°40′W), cotton was planted in February in rows spaced at 0.45 and 0.90 m. Plants were exposed to shading during the phenological stages B1 (floral bud), F1 (early flowering), PF (peak flowering) and 3OB (fruit maturity). In addition, there was one treatment without shade. There were no interactions of crop spacing with shading. Increasing plant population and shading both decreased net photosynthetic rate. The number of bolls m−2 increased with higher plant populations only when planting was delayed, and were not affected by shading. When cotton was planted in November and January, higher yields were obtained at 0.75/0.76m, but when planting was delayed to February, 0.45m resulted in higher yields with no effect on fiber quality. Shading for eight or ten days decreases boll weight and yields, but do not affect fiber quality. Cotton yield is the most decreased when shading occurs during flowering. These results may be used to build management strategies to minimize shading effects by adjusting cotton sowing time and plant density, by selecting cultivars with increased shade tolerance and by choosing an adequate irrigation period to improve yield.


      PubDate: 2015-03-20T07:18:55Z
       
  • Climatic risk assessment to improve nitrogen fertilisation
           recommendations: A strategic crop model-based approach
    • Abstract: Publication date: April 2015
      Source:European Journal of Agronomy, Volume 65
      Author(s): B. Dumont , B. Basso , B. Bodson , J.-P. Destain , M.-F. Destain
      Within the context of nitrogen (N) management, since 1950, with the rapid intensification of agriculture, farmers have often applied much larger fertiliser quantities than what was required to reach the yield potential. However, to prevent pollution of surface and groundwater induced by nitrates, The European Community launched The European Nitrates Directive 91/6/76/EEC. In 2002, in Wallonia (Belgium), the Nitrates Directive has been transposed under the Sustainable Nitrogen Management in Agriculture Program (PGDA), with the aim of maintaining productivity and revenue for the country’s farmers, while reducing the environmental impact of excessive N application. A feasible approach for addressing climatic uncertainty lies in the use of crop models such as the one commonly known as STICS (simulateur multidisciplinaire pour les cultures standard). These models allow the impact on crops of the interaction between cropping systems and climatic records to be assessed. Comprehensive historical climatic records are rare, however, and therefore the yield distribution values obtained using such an approach can be discontinuous. In order to obtain better and more detailed yield distribution information, the use of a high number of stochastically generated climate time series was proposed, relying on the LARS-Weather Generator. The study focused on the interactions between varying N practices and climatic conditions. Historically and currently, Belgian farmers apply 180kgNha−1, split into three equal fractions applied at the tillering, stem elongation and flag-leaf stages. This study analysed the effectiveness of this treatment in detail, comparing it to similar practices where only the N rates applied at the flag-leaf stage were modified. Three types of farmer decision-making were analysed. The first related to the choice of N strategy for maximising yield, the second to obtaining the highest net revenue, and the third to reduce the environmental impact of potential N leaching, which carries the likelihood of taxation if inappropriate N rates are applied. The results showed reduced discontinuity in the yield distribution values thus obtained. In general, the modulation of N levels to accord with current farmer practices showed considerable asymmetry. In other words, these practices maximised the probability of achieving yields that were at least superior to the mean of the distribution values, thus reducing risk for the farmers. The practice based on applying the highest amounts (60–60–100kgNha−1) produced the best yield distribution results. When simple economical criteria were computed, the 60–60–80kgNha−1 protocol was found to be optimal for 80–90% of the time. There were no statistical differences, however, between this practice and Belgian farmers’ current practice. When the taxation linked to a high level of potentially leachable N remaining in the soil after harvest was considered, this methodology clearly showed that, in 3 years out of 4, 30kgNha−1 could systematically be saved in comparison with the usual practice.


      PubDate: 2015-03-20T07:18:55Z
       
  • Associations between drought resistance, regrowth and quality in a
           perennial C4 grass
    • Abstract: Publication date: April 2015
      Source:European Journal of Agronomy, Volume 65
      Author(s): Yi Zhou , Christopher J Lambrides , Shu Fukai
      Climate change has brought a sharp and renewed focus on plant breeding programs to develop cultivars with improved performance in dry environments. The pleiotropic effects of selection for drought resistance are not well understood in perennial C4 grasses. The objective of this study was to determine the commercial production characteristics including sod strength and post-harvest regrowth of bermudagrass ecotypes selected for drought resistance. These attributes were studied in a set of bermudagrasses (Cynodon dactylon), a species used extensively around the world for forage and turfgrass. Three field experiments using 12 genotypes contrasting for drought resistance were evaluated, on bermudagrass turf production facilities, for quality and regrowth after the canopy (sod) was mechanically removed. Among the genotypes tested, there was large genotypic variation for rhizome dry matter (RhDM) (0.01–0.81kgm−2), aboveground dry matter (ADM) (0.59–0.17kgm−2) and root dry matter (RDM) (0.04–0.12kgm−2). Regrowth of the canopy was positively correlated to RhDM (r=0.79∼0.80) and negatively correlated to ADM (r=−0.69∼−0.74) but there was no association with RDM. Biomass partitioning determined at the time of the second harvest revealed that genotypes with more rapid regrowth had larger proportional DM distributed to rhizome (63.5% vs 7.1%) than to aboveground (27.2% vs 86.5%) and root (8.5% vs 8.1%). Our previous research with these genotypes showed a strong correlation between drought resistance and RhDM prior to the drought period. Consequently, an analysis of the relationship between drought resistance measured previously and post-harvest regrowth in the experiments described here revealed a strong positive correlation (r>0.64). Genotypic variation for sod strength, an important turf quality attribute, was large ranging from 1281kgm−2 to 5671kgm−2. However, sod strength was neither correlated to drought resistance, nor the traits measured from harvested sod such as stolon diameter, internode length, number of branches and single stolon strength, nor to dry matter distribution. These results may reflect the existence of a range of different mechanisms for sod strength present in the material tested. Nevertheless, there were genotypes e.g., MED1 that combined the favorable traits of drought resistance, faster regrowth rate and higher sod strength and could be used as an important genetic resource for future breeding. MED1 was one of several highly rhizomatous genotypes in the study that originated from the Mediterranean climatic zone of Australia.


      PubDate: 2015-03-20T07:18:55Z
       
  • Nitrogen management is the key for low-emission wheat production in
           Australia: A life cycle perspective
    • Abstract: Publication date: May 2015
      Source:European Journal of Agronomy, Volume 66
      Author(s): Weijin Wang , Ram C. Dalal
      Farm management affects the global greenhouse gas (GHG) budget by changing not only soil organic carbon (SOC) stocks and nitrous oxide (N2O) emissions but also other pre-farm, on-farm and off-site emissions. The life cycle assessment (LCA) approach has been widely adopted to assess the “carbon footprint” of agricultural products, but rarely used as a tool to identify effective mitigation strategies. In this study, the global warming impacts of no-till (NT) vs. conventional till (CT), stubble retention (SR) vs. stubble burning (SB), and N fertilization (NF) vs. no N fertilization (N0) in an Australian wheat cropping system were assessed using in situ measurements of N2O fluxes over three years, SOC changes over forty years and including other supply chain GHG sources and sinks. The results demonstrated the importance of full GHG accounting compared to considering SOC changes or N2O emissions alone for assessing the global warming impacts of different management practices, and highlighted the significance of accurately accounting for SOC changes and N2O emissions in LCAs. The GHG footprints of wheat production were on averaged 475kg carbon dioxide equivalent (CO2-e) ha−1 (or 186kg CO2-e t−1 grain) higher under NF than N0. Where fertilizer N was applied (70kgNha−1), the life cycle emissions were 200kg CO2-e ha−1 (or 87t−1 grain) lower under NT than CT and 364kg CO2-e ha−1 (or 155t−1 grain) lower under SR than SB. Classification of the emission sources/sinks and re-calculation of published data indicated that under the common practices of SR combined with NT, N-related GHG emissions contributed 60–95% of the life cycle emissions in the predominantly rain-fed wheat production systems in Australia. Therefore, future mitigation efforts should aim to improve N use efficiency, explore non-synthetic N sources, and most importantly avoid excessive N fertilizer use whilst practising NT and SR.


      PubDate: 2015-03-20T07:18:55Z
       
  • Do soil organic carbon levels affect potential yields and nitrogen use
           efficiency? An analysis of winter wheat and spring barley field trials
           
    • Abstract: Publication date: May 2015
      Source:European Journal of Agronomy, Volume 66
      Author(s): Myles Oelofse , Bo Markussen , Leif Knudsen , Kirsten Schelde , Jørgen E. Olesen , Lars Stoumann Jensen , Sander Bruun
      Soil organic carbon (SOC) is broadly recognised as an important parameter affecting soil quality, and can therefore contribute to improving a number of soil properties that influence crop yield. Previous research generally indicates that soil organic carbon has positive effects on crop yields, but in many studies it is difficult to separate the effect of nutrients from the effect of SOC in itself. The aim of this study was to analyze whether the SOC content, in itself, has a significant effect on potential yields of commonly grown cereals across a wider range of soil types in Denmark. The study draws on historical data sets from the Danish national field trials consisting of 560 winter wheat (Triticum aestivum L.) trials and 309 spring barley (Hordeum vulgare L.) trials conducted over the past 20 and 17 years, respectively. We hypothesised that for these two crops, the potential grain yield, the yield with no fertiliser N application and the N use efficiency would be positively affected by SOC level. A statistical model was developed to explore relationships between SOC and potential yield, yields at zero N application and N use efficiency (NUE). The model included a variety of variables and aimed to elucidate the sole effect of SOC by controlling for potential confounding variables. No significant effect of SOC on potential winter wheat was found, whilst for spring barley, only for the course sandy loam soil type was a borderline significantly positive effect of SOC on potential yields found. The relationship between unfertilized plot yields and SOC was positive for winter wheat, although not significant, whilst for spring barley a significant positive effect of SOC was found only for the coarse sandy soil type, and a borderline significant positive effect of SOC was found for the coarse sandy loam soil type. A significant negative relationship was found between SOC and NUE for both winter wheat and spring barley. Based on the large dataset analyzed, we cautiously challenge the importance of SOC in contributing to crop productivity in contexts with similar soils and climate, and we speculate that in situations where nutrient limitation does not occur, SOC levels above 1% may be sufficient to sustain yields. In light of the findings presented in this study, further work should be conducted which can further elucidate the effect of SOC on yields.


      PubDate: 2015-03-20T07:18:55Z
       
  • Analyzing inter-factor substitution and technical progress in the Chinese
           agricultural sector
    • Abstract: Publication date: May 2015
      Source:European Journal of Agronomy, Volume 66
      Author(s): Boqiang Lin , Rilong Fei
      In this paper, we employ a trans-log production function model for China’s agricultural sector, with capital, labor and energy as input factors. The output elasticity, substitution elasticity and relative difference in technical progress among the factors are analyzed. The results show that during the period 1980–2012 the growth of the agricultural economy in China benefited from the combined effects of factors accumulation and technical progress. Among the factors, the output elasticity of labor is the largest, followed by capital and energy. Capital, labor and energy are substitutes for one another, but the elasticity of substitution between capital and energy is the highest, with a value of 1.1. In the meantime, the relative difference in technical progress among these factors is insignificant and there is a convergence trend over time. We suggest increasing technological innovation in order to improve the contribution of technology progress as well as allocating more capital into the agricultural sector in order to alleviate the shortage of energy supply and the current problem of “hollow” in the rural labor force. This is of great significance to reducing energy consumption and improving the total factor productivity in the China’s agricultural sector.


      PubDate: 2015-03-20T07:18:55Z
       
  • Surface liming and nitrogen fertilization for crop grain production under
           no-till management in Brazil
    • Abstract: Publication date: May 2015
      Source:European Journal of Agronomy, Volume 66
      Author(s): E.F. Caires , A. Haliski , A.R. Bini , D.A. Scharr
      Supplying a large amount of NO3 − in the subsurface can be a strategy to combat subsoil acidity under no-till systems. However, soil acidification caused by ammoniacal fertilizers can increase both aluminum toxicity and lime requirement. A field experiment was performed in the period from 2004 to 2012 in Parana State, Brazil, on a loamy, kaolinitic, thermic Typic Hapludox to evaluate the effects of surface liming and ammoniacal fertilization on soil chemical attributes and yields of crops in rotation under continuous no-till. The region has a mesothermal, humid subtropical climate, with mild summer, frequent frosts during the winter, and no defined dry season. The average altitude is 970m and the annual precipitation is about 1550mm. The treatments consisted of annual applications of NH4NO3 at 0, 60, 120, and 180kgNha−1 to subplots within plots with surface-applied lime previously at 0, 4, 8, and 12Mgha−1, calculated to raise the base saturation in the topsoil (0–20cm) to 40, 65, and 90%. Lime was broadcast on the soil surface in May 2004. The nitrogen rates were applied during the period from 2004 to 2011 in top dressing at tillering of winter crops [black oat (Avena strigosa Schreb.) or wheat (Triticum aestivum L.)], before growing corn (Zea mays L.), soybean (Glycine max L. Merr.) or bean (Phaseolus vulgaris L.) during the summer (2004–2012). Surface-applied lime under no-till was effective in alleviating soil acidity from the soil surface to a 20cm depth. The soil pH increased in the layers below the soil surface to 20cm depth during a 6 years period following surface lime application. Ammoniacal fertilization had an acidifying effect and did not change the effectiveness of surface applied lime to alleviate subsoil acidity. Soil organic matter content was higher in the upper few centimeters under no-till and remained unchanged over time after surface liming and ammoniacal fertilization. Increasing the rate and frequency of ammoniacal fertilizer application increased crop response to surface liming, but did not change the lime requirement to achieve higher crop grain yields. The lime rate estimated by the soil base saturation method at 70% in the 0–20cm depth was appropriate for surface liming recommendation, even when substantial amounts of ammoniacal fertilizer were applied in a no-till system. The results suggest that nitrogen fertilizer use for winter crops could be dramatically reduced in areas under a continuous no-till system, particularly where lime has been applied.


      PubDate: 2015-03-20T07:18:55Z
       
  • Modeling nitrous oxide emissions from organic and conventional
           cereal-based cropping systems under different management, soil and climate
           factors
    • Abstract: Publication date: May 2015
      Source:European Journal of Agronomy, Volume 66
      Author(s): Jordi Doltra , Jørgen E. Olesen , Dolores Báez , Aránzazu Louro , Ngonidzashe Chirinda
      Mitigation of greenhouse gas emissions from agriculture should be assessed across cropping systems and agroclimatic regions. In this study, we investigate the ability of the FASSET model to analyze differences in the magnitude of N2O emissions due to soil, climate and management factors in cereal-based cropping systems. Forage maize was grown in a conventional dairy system at Mabegondo (NW Spain) and wheat and barley in organic and conventional crop rotations at Foulum (NW Denmark). These two European sites represent agricultural areas with high and low to moderate emission levels, respectively. Field trials included plots with and without catch crops that were fertilized with either mineral N fertilizer, cattle slurry, pig slurry or digested manure. Non-fertilized treatments were also included. Measurements of N2O fluxes during the growing cycle of all the crops at both sites were performed with the static chamber method with more frequent measurements post-fertilization and biweekly measurements when high fluxes were not expected. All cropping systems were simulated with the FASSET version 2.5 simulation model. Cumulative soil seasonal N2O emissions were about ten-fold higher at Mabegondo than at Foulum when averaged across systems and treatments (8.99 and 0.71kgN2O-Nha−1, respectively). The average simulated cumulative soil N2O emissions were 9.03 and 1.71kgN2O-Nha−1 at Mabegondo and at Foulum, respectively. Fertilization, catch crops and cropping systems had lower influence on the seasonal soil N2O fluxes than the environmental factors. Overall, in its current version FASSET reproduced the effects of the different factors investigated on the cumulative seasonal soil N2O emissions but temporally it overestimated emissions from nitrification and denitrification on particular days when soil operations, ploughing or fertilization, took place. The errors associated with simulated daily soil N2O fluxes increased with the magnitude of the emissions. For resolving causes of differences in simulated and measured fluxes more intensive and temporally detailed measurements of N2O fluxes and soil C and N dynamics would be needed.


      PubDate: 2015-03-20T07:18:55Z
       
  • Light interception, leaf nitrogen and yield prediction in almonds: A case
           study
    • Abstract: Publication date: May 2015
      Source:European Journal of Agronomy, Volume 66
      Author(s): Jose L. Zarate-Valdez , Saiful Muhammad , Sebastian Saa , Bruce D. Lampinen , Patrick H. Brown
      Crop yield prediction is important for the optimization of irrigation water, fertilizers, and other inputs and resources on the farm. In perennial crops, yield prediction is influenced by multiple factors regulated within the tree such as carry over effects from previous years, source-sink interactions and resource allocation and remobilization, but the bases for those regulation mechanisms are not well understood. This study reports the analysis of intensive sampling of light interception, leaf and nut nutrient concentration and yield of 768 almond trees subjected to fertilization and irrigation treatments within a mid-age commercial orchard. Nitrogen fertilization had a significant effect on individual tree fPAR, LAI, leaf nitrogen content and nut yield. While light interception and leaf area index (LAI) were poor predictors of kernel yield (R 2 =0.16–0.36 for light interception and 0.21–0.40 for LAI), leaf nitrogen pool (LNP) was able to predict 71–76% of the tree yield variability observed in two and three years. Near harvest, the LNP was highly correlated with fruit nitrogen pool (FNP) (R 2 =0.87). The results indicate that tree yield and nitrogen demand can be predicted based on leaf nitrogen content.


      PubDate: 2015-03-20T07:18:55Z
       
  • Changes in bread-making quality attributes of bread wheat varieties
           cultivated in Spain during the 20th century
    • Abstract: Publication date: February 2015
      Source:European Journal of Agronomy, Volume 63
      Author(s): Miguel Sanchez-Garcia , Fanny Álvaro , Ariadna Peremarti , Juan A. Martín-Sánchez , Conxita Royo
      Genetic gains in quality traits were assessed in grain samples from 4 field experiments involving 16 bread wheat varieties representative of those most widely cultivated in Spain during the 20th century. The allelic composition at three glutenin loci (Glu-A1, Glu-B1, and Glu-D1) was obtained by PCR-based DNA markers and published references. From 1930 to 2000 grain protein content decreased by −0.030%y−1, or in relative terms by −0.21%y−1, but the protein produced per hectare increased by 0.39%y−1. Alveographic tests revealed significant changes in dough rheological properties. Dough strength (W) and tenacity (P) increased at relative rates of 1.38%y−1 and 0.99%y−1, respectively, while dough extensibility (L) decreased by −0.46%y−1, resulting in an increase of 1.45%y−1in dough equilibrium (P/L). The rise in protein quality could be related to the replacement of the null allele by subunits 1 or 2* at Glu-A1 and the prevalence of subunits 7+8 and 5+10 at Glu-B1 and Glu-D1 loci, respectively, in the most recent varieties. Dough extensibility was affected by water input during the crop cycle, this relationship being partially explained by the presence of the 5+10 HMW glutenin subunit. Fermentation tolerance was improved in the most modern varieties. Collapse during fermentation was avoided only in doughs with a W ≥159 J ×10−4 and a P/L ≥0.56mm H2O mm−1, levels achieved by most of the modern varieties. The over-strong and unbalanced rheological properties of some modern varieties resulted in highly porous doughs, and no clear advances in dough maximum height during fermentation were attained.


      PubDate: 2014-12-09T14:56:09Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2015