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  Subjects -> AGRICULTURE (Total: 779 journals)
    - AGRICULTURAL ECONOMICS (77 journals)
    - AGRICULTURE (527 journals)
    - CROP PRODUCTION AND SOIL (92 journals)
    - DAIRYING AND DAIRY PRODUCTS (31 journals)
    - POULTRY AND LIVESTOCK (52 journals)

AGRICULTURE (527 journals)

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Journal Cover European Journal of Agronomy
  [SJR: 1.381]   [H-I: 60]   [9 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1161-0301
   Published by Elsevier Homepage  [2970 journals]
  • Soil carbon and nitrogen changes after 28 years of no-tillage management
           under Mediterranean conditions
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Marco Mazzoncini, Daniele Antichi, Claudia Di Bene, Rosalba Risaliti, Monica Petri, Enrico Bonari
      Mouldboard ploughing is known to accelerate soil organic matter (SOM) mineralization rate in Mediterranean regions. Long-term reduced tillage intensity potentially diminishes soil organic carbon (SOC) and total nitrogen (STN) depletions. Here, we compared long-term no-tillage (NT) and conventional tillage (CT) impact on SOC and STN sequestration rates at different depths ranging from 0 to 30cm. The long-term experiment started in 1986 on a Typic Xerofluvent soil in Central Italy using a randomized complete block design with four replications. Ten years after the experiment began, SOC and STN concentrations in the 0–30cm soil layer were already higher under NT compared to CT. The shallow layer (0–10cm) showed the highest SOC and STN concentration increments. However, no differences between tillage systems were observed in the deeper layers. After 28 years, continuous NT increased SOC and STN content in the 30cm soil depth by 22% compared to initial values. In the same period, continuous CT decreased SOC and STN content by 3% and 5%, respectively. On average, the total SOC and STN gains under NT may be attributed to the shallow layer increments. In the 10–20 and 20–30cm soil layers, SOC accumulation over time was negligible also under NT. In the whole profile (0–30cm), the mean annual SOC variation was +0.40 Mg ha−1 yr−1 and −0.06 Mg ha−1 yr−1 under NT and CT, respectively. Under NT, SOC content increased rapidly in the first ten years (+0.75 Mg ha−1yr−1); later on, SOC increments were slower indicating the reaching of a new equilibrium. Data show that NT is a useful alternative management practice increasing carbon sequestration and soil health in Mediterranean conditions.


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


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



      PubDate: 2016-06-16T17:59:35Z
       
  • Sugar beet rotation effects on soil organic matter and calculated humus
           balance in Central Germany
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Philipp Götze, Jan Rücknagel, Anna Jacobs, Bernward Märländer, Heinz-Josef Koch, Bettina Holzweißig, Michael Steinz, Olaf Christen
      In order to quantify the influence of land use systems on the level of soil organic matter (SOM) to develop recommendations, long-term field studies are essential. Based on a crop rotation experiment which commenced in 1970, this paper investigated the impact of crop rotations involving increased proportions of sugar beet on SOM content. To this end, soil samples were taken in 2010 and 2012 from the following crop rotation sequences: sugar beet–sugar beet–winter wheat–winter wheat (SB–SB–WW–WW=50%), sugar beet–sugar beet–sugar beet–winter wheat (SB–SB–SB–WW=75%), sugar beet–grain maize (SB–GM=50%) and sugar beet-monoculture (SB=100%); these were analysed in terms of total organic carbon (TOC) and microbial biomass carbon (MBC) content, MBC/TOC ratio and the TOC stocks per hectare. In addition, humus balances were created (using the software REPRO, reference period 12 years) in order to calculate how well the soil was supplied with organic matter. In the field experiment, harvest by-products (WW and GM straw as well as SB leaves) were removed. After 41 years, no statistically significant differences were measured between the crop rotations for the parameters TOC, MBC, MBC/TOC ratio and the TOC stock per hectare. However, the calculated humus balance was significantly affected by the crop rotation. The calculated humus balance became increasingly negative in the order SB–SB–WW–WW, SB–SB–SB–WW, SB monoculture and SB–GM, and correlated with the soil parameters. The calculated humus balances for the reference period did not reflect the actual demand for organic matter by the crop rotations, but instead overestimated it.


      PubDate: 2016-06-16T17:59:35Z
       
  • A cropping system assessment framework—Evaluating effects of
           introducing legumes into crop rotations
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Moritz Reckling, Jens-Martin Hecker, Göran Bergkvist, Christine A. Watson, Peter Zander, Nicole Schläfke, Frederick L. Stoddard, Vera Eory, Cairistiona F.E. Topp, Juliette Maire, Johann Bachinger
      Methods are needed for the design and evaluation of cropping systems, in order to test the effects of introducing or reintroducing crops into rotations. The interaction of legumes with other crops (rotational effects) requires an assessment at the cropping system scale. The objective of this work is to introduce a cropping system framework to assess the impacts of changes in cropping systems in a participatory approach with experts, i.e., the integration of legumes into crop rotations and to demonstrate its application in two case studies. The framework consists of a rule-based rotation generator and a set of algorithms to calculate impact indicators. It follows a three-step approach: (i) generate rotations, (ii) evaluate crop production activities using environmental, economic and phytosanitary indicators, and (iii) design cropping systems and assess their impacts. Experienced agronomists and environmental scientists were involved at several stages of the framework development and testing in order to ensure the practicability of designed cropping systems. The framework was tested in Västra Götaland (Sweden) and Brandenburg (Germany) by comparing cropping systems with and without legumes. In both case studies, cropping systems with legumes reduced nitrous oxide emissions with comparable or slightly lower nitrate-N leaching, and had positive phytosanitary effects. In arable systems with grain legumes, gross margins were lower than in cropping systems without legumes despite taking pre-crop effects into account. Forage cropping systems with legumes had higher or equivalent gross margins and at the same time higher environmental benefits than cropping systems without legumes. The framework supports agronomists to design sustainable legume-supported cropping systems and to assess their impacts.


      PubDate: 2016-06-16T17:59:35Z
       
  • Energy of biomass sorghum irrigated with reclaimed wastewaters
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Pasquale Campi, Alejandra Navarro, A. Domenico Palumbo, Francesca Modugno, Carolina Vitti, Marcello Mastrorilli
      The sustainability of biomass sorghum (Sorghum bicolor L. Moench) in the Mediterranean environments is linked to the potential to increasing the crop productivity using irrigation water of different qualities: fresh and wastewater. An experiment was conducted in Southern Italy during 2012 and 2013 growing seasons to determine the biomass production and to estimate the yielded energy from sorghum irrigated with fresh water and municipal wastewaters. Two stages of wastewater reclamation process were compared: tertiary and secondary treatments. During the growing seasons, the crop growth (biomass and LAI) was surveyed on sorghum crops irrigated with three water qualities. In order to determine the effects of the irrigation water qualities on the final energy yielded, on the harvested biomass, structural components (cellulose, hemicellulose and lignin contents for deriving the ethanol production) and high heating value were analyzed. The data obtained during two crop seasons showed that, sorghum irrigated with municipal wastewater plant produced more dry biomass (23.3 vs 20.3tha−1), energy yield (383 vs 335GJha−1), and ethanol (6824 vs 6092Lha−1) than sorghum biomass with fresh water. As a consequence, the water efficiency for producing bioenergy increased when the waste waters were supplied in substitution of fresh waters. Different indices were calculated for comparing the effect of the water quality on the water use efficiency (WUE) of biomass sorghum crops.


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

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


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


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


      PubDate: 2016-06-16T17:59:35Z
       
  • Low-input cropping systems to reduce input dependency and environmental
           impacts in maize production: A multi-criteria assessment
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Simon Giuliano, Matthew R. Ryan, Grégory Véricel, Gaël Rametti, François Perdrieux, Eric Justes, Lionel Alletto
      Intensification of cropping systems in recent decades has increased their productivity but affected air, soil and water quality. These harmful environmental impacts are exacerbated in Maize Monoculture (MM) and hasten the need for solutions to overcome the trade off between crop yield and environmental impacts. In a three-year cropping systems experiment, a conventional intensive maize monoculture (MMConv), with a winter bare fallow, deep soil tillage, non-limiting irrigation was compared to three Low Input Cropping Systems (LI-CS) designed as alternatives to the conventional system. They were managed with decision-rules implemented to reach specific objectives of input reduction. The LI-CS designed with Integrated Weed Management (IWM) techniques and other sustainable cropping practices, were:(i) MMLI—an IWM Low Input MM; (ii) MMCT—a Conservation Tillage combined with cover crop MM; and (iii) Maize-MSW—an IWM maize grown in rotation with soybean and wheat. A comprehensive multi-criteria assessment was carried out to quantify the agronomic, economic, social, and environmental performances of each system. A canonical discriminant analysis of performance metrics revealed large differences between the four systems. Yields were significantly higher in MMConv (11.0Mgha−1) and MMLI (10.3Mgha−1) than in Maize-MSW (8.6Mgha−1) and MMCT (7.8Mgha−1). MMCT had the largest weed infestation (density and biomass) despite the greatest use of herbicides. The Herbicide Treatment Frequency Index (HTFI), used to indicate differences in herbicide use, revealed that the MMLI (HTFI=1.0) and Maize-MSW (1.1) halved the herbicide use as compared to the MMConv (2.1), despite having similar weed abundance levels. The LI-CS, especially MMCT, produced high biomass winter cover crops and then less nitrogen fertilization was required as compared to MMConv. Gross margins in the MMLI (1254 €ha−1) and MMConv (1252 €ha−1) were higher than the MMCT (637 €ha−1) and Maize-MSW (928 €ha−1). MMLI and MMConv had similar labour requirements. Water drainage, pesticide leaching, energy use, and estimated greenhouse gas emissions were higher in MMConv than in the LI-CS in most years. Results from this research show good potential for the MMLI to reduce the environmental impacts of MMConv while maintaining its economic and social performance.
      Graphical abstract image

      PubDate: 2016-06-16T17:59:35Z
       
  • Editorial for Innovation in crop sciences
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76




      PubDate: 2016-06-16T17:59:35Z
       
  • Integrating simulation data from a crop model in the development of an
           agri-environmental indicator for soil cover in Switzerland
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Lucie Büchi, Alain Valsangiacomo, Enguerrand Burel, Raphaël Charles
      Agriculture generates important impacts on the environment, which can be evaluated with agri-environmental indicators. A key element of environment protection in agriculture is the maintenance of a dense soil cover for the longest possible period. Notably, soil cover is known to diminish erosion risks and nitrate leaching. In this study, an agri-environmental indicator for soil cover is presented, which integrates data from the crop model STICS to quantify vegetation growth dynamics. Simulations were conducted with STICS for the major crops cultivated in Switzerland across several contrasting pedoclimatic situations. They were then integrated with data for crop residue cover to evaluate soil cover at the field and farm levels in the framework of a farm network survey. At the field level, for the period from the harvest of the previous crop through the harvest of the main crop, the highest soil cover was achieved by silage maize and winter barley. A high variability between fields was observed, due to the diversity of cultural practices during the period preceding the seeding of the main crops. Some crops, winter wheat in particular, showed a high number of days with insufficient soil cover (under 30%), leading to potential environmental risks. This shows the crucial need of promoting conservation agriculture principles (permanent soil cover, minimum soil disturbance, diversification of crop rotation) in arable systems to better protect the soils and the environment. The soil cover indicator presented here provided a continuous quantification of soil cover, whereas most of the currently used indicators provide qualitative or roughly quantitative results.


      PubDate: 2016-06-16T17:59:35Z
       
  • The interactions between genotype, management and environment in regional
           crop modelling
    • Abstract: Publication date: Available online 3 June 2016
      Source:European Journal of Agronomy
      Author(s): Edmar I. Teixeira, Gang Zhao, John de Ruiter, Hamish Brown, Anne-Gaelle Ausseil, Esther Meenken, Frank Ewert
      Biophysical models to simulate crop yield are increasingly applied in regional climate impact assessments. When performing large-area simulations, there is often a paucity of data to spatially represent changes in genotype (G) and management (M) across different environments (E). The importance of this uncertainty source in simulation results is currently unclear. In this study, we used a variance-based sensitivity analysis to quantify the relative contribution of maize hybrid (i.e. G) and sowing date (i.e.M) to the variability in biomass yield (YT, total above-ground biomass) and harvest index (HI, fraction of grain in total yield) of irrigated silage maize, across the extent of arable lands in New Zealand (i.e. E). Using a locally calibrated crop model (APSIM-maize), 25G x M scenarios were simulated at a 5 arc minute resolution (∼5km grid cell) using 30 years of historical weather data. Our results indicate that the impact of limited knowledge on G and M parameters depends on E and differs between model outputs. Specifically, the sensitivity of YT and HI to genotype and sowing date combinations showed different patterns across locations. The absolute impact of G and M factors was consistently greater in the colder southern regions of New Zealand. However, the relative share of total variability explained by each factor, the sensitivity index (Si), showed distinct spatial patterns for the two output variables. The YT was more sensitive than HI in the warmer northern regions where absolute variability was the smallest. These patterns were characterised by a systematic response of Si to environmental drivers. For example, the sensitivity of YT and HI to hybrid maturity consistently increased with temperature. For the irrigated conditions assumed in our study, inter-annual weather conditions explained a higher share of total variability in the southern colder regions. Our results suggest that the development of methods and datasets to more accurately represent spatio-temporal G and M variability can reduce uncertainty in regional modelling assessments at different degrees, depending on prevailing environmental conditions and the output variable of interest.


      PubDate: 2016-06-16T17:59:35Z
       
  • An overview on long-term agro-ecosystem experiments: Present situation and
           future potential
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Antonio Berti, Anna Dalla Marta, Marco Mazzoncini, Francesco Tei
      Modern Long Term Agricultural experiments (LTAE) have a long history initiated when modern agricultural science was just at its beginning. After about 180 years from the start of the first of the classical Rothamsted experiments in 1843, these experiments still maintains a consistent appeal for researchers and the interest on LTAEs is growing, as shown by the increasing number of papers dealing with long-term effect of agricultural practices, frequently considering topics, such as sustainability, environmental quality, species-adaptation impacts, that were never envisioned by the founders of classical LTAEs. However, these experiments have numerous constraints and weakness that have to be clearly understood and evaluated when using the data, especially for up-scaling or modelling purposes. Nevertheless, in our vision, the strengths and the opportunities of LTAEs are still overwhelming, particularly if connected in networks allowing a standardisation of procedures and facilitating the access to data and to the experiments of researchers external to the institution hosting the LTAE.


      PubDate: 2016-06-16T17:59:35Z
       
  • Implications of climate model biases and downscaling on crop model
           simulated climate change impacts
    • Abstract: Publication date: Available online 7 June 2016
      Source:European Journal of Agronomy
      Author(s): D. Cammarano, M. Rivington, K.B. Matthews, D.G. Miller, G. Bellocchi
      In estimating responses of crops to future climate realisations, it is necessary to understand and differentiate sources of uncertainty. This paper considers the specific aspect of input weather data quality from a Regional Climate Model (RCM) leading to differences in estimates made by three crop models. The availability of hindcast RCM estimates enables comparison of crop model outputs derived from observed and modelled weather data. Errors in estimating the past climate implies biases in future projections, and thus affect modelled crop responses. We investigate the complexities in using climate model projections representing different spatial scales within climate change impacts and adaptation studies. This is illustrated by simulating spring barley with three crop models run using site-specific observed (12 UK sites), original (50×50km) and bias corrected downscaled (site-specific) hindcast (1960–1990) weather data from the HadRM3 RCM. Though the bias correction downscaling method improved the match between observed and hindcast data, this did not always translate into better matching of crop model estimates. At four sites the original HadRM3 data produced near identical mean simulated yield values as from the observed weather data, despite evaluated (observed-hindcast) differences. This is likely due to compensating errors in the input weather data and non-linearity in the crop models processes, making interpretation of results problematic. Understanding how biases in climate data manifest themselves in individual crop models gives greater confidence in the utility of the estimates produced using downscaled future climate projections and crop model ensembles. The results have implications on how future projections of climate change impacts are interpreted. Fundamentally, considerable care is required in determining the impact weather data sources have in climate change impact and adaptation studies, whether from individual models or ensembles.


      PubDate: 2016-06-16T17:59:35Z
       
  • Interoperability of agronomic long term experiment databases and crop
           model intercomparison: the Italian experience
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Fabrizio Ginaldi, Marco Bindi, Anna Dalla Marta, Roberto Ferrise, Simone Orlandini, Francesco Danuso
      The IC-FAR national project (Linking long term observatories with crop system modelling for better understanding of climate change impact, and adaptation strategies for Italian cropping systems) initiated in 2013 with the primary aim of implementing data from 16 long term Italian agronomic experiments in a common, interoperable structure. The building of a common database (DB) structure demands a harmonization process aimed at standardising concepts, language and data in order to make them clear, and has to produce a well-documented and easily available tool for the whole scientific community. The Agricultural Model Intercomparison and Improvement Project (AgMIP) has made a great effort in this sense, improving the vocabulary developed by the International Consortium for Agricultural Systems Applications (ICASA) and defining harmonization procedures. Nowadays, these ones have also to be addressed to facilitate the extraction of input files for crop model simulations. Substantially, two alternative directions can be pursued: adapting data to models, building a standard storage structure and using translators that convert DB information to model input files; or adapting models to data, using the same storage structure for feeding modelling solutions constituted by combining model components, re-implemented in the same model platform. The ICFAR information management system simplifies data entry, improves model input extraction (implementing System Dynamics ontology), and satisfies both the paradigms. This has required the development of different software tools: ICFAR-DB for data entry and storage; a model input extractor for feeding the crop models (MoLInEx); SEMoLa platform for building modelling solutions and performing via scripts the model intercomparison. The use of the standard AgMIP/ICASA nomenclature in the ICFAR-DB and the opportunity to create files with MoLInex for feeding AgMIP model translators allow full system interoperability.


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


      PubDate: 2016-05-07T00:34:08Z
       
  • Variations in soil-water use by grapevine according to plant water status
           and soil physical-chemical characteristics—A 3D spatio-temporal
           analysis
    • Abstract: Publication date: July 2016
      Source:European Journal of Agronomy, Volume 77
      Author(s): Luca Brillante, Benjamin Bois, Jean Lévêque, Olivier Mathieu
      Understanding plant and soil-water relationships is crucial to optimise agricultural management. In this multidisciplinary work, soil geophysics and plant physiological measurements are coupled and a statistical method is proposed to visualising plant soil-water uptake in space and time. The method is applied in a vineyard context and shows differences in the use of tranpirable soil water by grapevine according to the type of soil and the time of the day (day/night). During two years the water stress experienced by a single Chardonnay/SO4 grapevine clone was monitored both at pre-dawn and midday by leaf water potentials in two field plots exclusively differenced by soil properties. At the same time, variations of electrical resistivity were monitored through electrical resistivity tomography, and then transformed in fraction of tranpirable soil water by the use of pedotransfer functions appositely developed in these soils. Spatio-temporal variations of transpirable soil water was used to predict plant leaf water potentials and the contribution of each soil region to grapevine water status was evaluated by statistical-learning methods. Strong spatio-temporal variability was observed both vertically and laterally between the two plots and within each plot at a fine scale. Principal causes of such differences were the level of plant water stress, along the season and during the day, and differences in soil physical-chemical properties. Soil contribution to plant water status varies in space and time at a fine scale. This paper introduces a novel methodological approach, transposable in any field survey, and brings further insight in the description of plant and soil relationships.
      Graphical abstract image

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

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


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


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


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


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


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


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


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


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


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


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


      PubDate: 2016-03-23T21:17:42Z
       
  • Organic input quality is more important than its quantity: C turnover
           coefficients in different cropping systems
    • Abstract: Publication date: Available online 22 March 2016
      Source:European Journal of Agronomy
      Author(s): Antonio Berti, Francesco Morari, Nicola Dal Ferro, Gianluca Simonetti, Riccardo Polese
      Annual C input to soil is a major factor affecting soil organic carbon (SOC) dynamics. However different types of C-sources can have different behaviour, in relation to their chemical characteristics and how they interact with soil. Root-derived C, in particular, should be more efficient than other organic materials as a result of the physicochemical and biological characteristics of the surrounding environment, leading to a reduction in the C decomposition rate. To test this hypothesis, we considered a long-term experiment underway in Northern Italy since 1962, comparing permanent meadow and 6 different crop rotations over a wide range of nutrient inputs, in both organic and inorganic forms. C inputs from amendments were measured and those from crops were calculated using allometric functions and crop and residues yields. The time evolution of SOC was studied through a single-pool, first-order kinetic model, allowing the estimation of humification coefficients for residues, roots, farmyard manure and cattle slurries. The highest value of the humification coefficient was estimated for farmyard manure, which confirmed its high efficiency in stabilising SOC content. Root C presented a humification coefficient 1.9 times higher than above-ground plant materials while slurries were intermediate, with a humification coefficient roughly half that of farmyard manure and even lower that of roots. The quality of C input thus seems of fundamental importance for evaluating the sustainability of different cropping systems in terms of SOC dynamics.


      PubDate: 2016-03-23T21:17:42Z
       
  • Long-Term Experiments with cropping systems: Case studies on data analysis
    • Abstract: Publication date: Available online 10 March 2016
      Source:European Journal of Agronomy
      Author(s): Andrea Onofri, Giovanna Seddaiu, Hans-Peter Piepho
      Data analysis for Long-Term Experiments (LTEs) with cropping systems requires some careful thinking, especially for the most complex designs, characterised by rotations with different durations and/or a different number of test-crops per rotation cycle. This paper takes an example-based approach, built upon a number of datasets, covering the main types of LTEs, with increasing levels of complexity. A procedure is outlined to build statistical models for data analysis that is useful for all LTEs characterised by the simultaneous presence of all rotation phases in all years, together with within-year replication. This procedure is based on the assumption that correct analyses can be performed separately for each year. The use of mixed models and REML estimation is advocated for model fitting with all LTEs, due to the fact that most designs are non-orthogonal, as plots may not produce data for the test-crop under study in all years. Mixed models are also useful to account for the autocorrelation of residuals over time and hints are given for the selection of an appropriate variance-covariance structure. For all our examples, variances were not constant across years and compound symmetry correlation structures with variance heterogeneity of years proved to be the best compromise between parsimony and statistical accuracy. Methods are outlined to test for the need of other more complex correlation structures and examples are also given on how to test for fixed effects, model fertility trends and assess the long-term stability of cropping systems.


      PubDate: 2016-03-13T06:24:05Z
       
  • Yield and yield components of wheat and maize in wheat–maize
           intercropping in the Netherlands
    • Abstract: Publication date: May 2016
      Source:European Journal of Agronomy, Volume 76
      Author(s): Fang Gou, Martin K. van Ittersum, Guoyu Wang, Peter E.L. van der Putten, Wopke van der Werf
      Intercropping is widely used by smallholder farmers in developing countries, and attracting attention in the context of ecological intensification of agriculture in developed countries. There is little experience with intercropping of food crops in Western Europe. Yields in intercrops depend on planting patterns of the mixed species in interaction with local growing conditions. Here we present data of two years field experimentation on yield and yield components of a wheat–maize intercrop system in different planting configurations in the Netherlands. Treatments included sole crops of wheat (SW) and maize (SM), a replacement intercrop consisting of strips of six wheat rows alternating with two maize rows (6:2WM), as well as subtractive or additive designs, based on skip-row (6:0WM, 0:2WM) and add-row (8:2WM, 6:3WM) configurations. The land equivalent ratio (LER) of intercrops varied from 1.18 to 1.30 in 2013 and from 0.97 to 1.08 in 2014. Wheat grown in the border rows of wheat strips had higher ear number per meter row, greater kernel number per ear, and greater yield per meter row than wheat in inner rows and sole wheat, indicating reduced competition. Wheat in the border rows in the intercrops had, however, reduced thousand kernel weight and harvest index, indicating that competition in border rows intensified over time. Intercropping negatively affected maize biomass and thousand kernel weight, especially in add-row treatments. This study indicates that there is a potential yield benefit for the wheat–maize intercropping system under Western European growing conditions. However, the LER was affected by yearly variation in weather conditions and significantly greater than one in only one of the two years of the study.


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


      PubDate: 2016-02-15T12:33:38Z
       
 
 
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