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  Subjects -> AGRICULTURE (Total: 662 journals)
    - AGRICULTURAL ECONOMICS (72 journals)
    - AGRICULTURE (444 journals)
    - CROP PRODUCTION AND SOIL (84 journals)
    - DAIRYING AND DAIRY PRODUCTS (25 journals)
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Journal Cover European Journal of Agronomy
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   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1161-0301
     Published by Elsevier Homepage  [2563 journals]   [SJR: 1.191]   [H-I: 53]
  • Contrasting the spatial management of nitrogen and phosphorus for improved
           water quality: Modelling studies in New Zealand and France
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): R.W. McDowell , P. Moreau , J. Salmon-Monviola , P. Durand , P. Leterme , P. Merot
      Critical source areas (CSAs) define areas of a farm or catchment that emit the majority of water quality contaminants but account for a minority of the area at a field, farm or catchment scale. Using process based modelling we tested the hypothesis that the definition and management of CSAs would decrease losses of phosphorus (P) in two New Zealand catchments and nitrogen (N) in a French catchment. In the New Zealand catchment, CSAs of P loss were isolated to small areas within fields commensurate with surface flow pathways, while in the French catchment, CSAs for N loss were influenced by factors (inputs and land use) relevant at a field (or multiple field) scale. Scenarios were tested that examined the management of CSAs versus whole field management for P, and decreasing N loss within CSAs by increasing the proportion of grassland fields and changing their location relative to cropland. The results showed that N losses decreased by up to 25% as more grassland was incorporated into the catchment, especially in wet areas near valley bottoms due to a longer growth period and better utilisation/storage of N than cropland. For P, focusing mitigation on CSAs decreased catchment losses to a similar degree as mitigations applied across the whole catchment, but was on average 6–7 times more cost-effective. Therefore, the definition and management of CSAs at an appropriate scale is recommended to improve water quality and minimise the impact on farm profitability.


      PubDate: 2014-07-25T01:01:29Z
       
  • Agroecological principles for the redesign of integrated
           crop–livestock systems
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): Thierry Bonaudo , Amaury Burlamaqui Bendahan , Rodolphe Sabatier , Julie Ryschawy , Stéphane Bellon , François Leger , Danièle Magda , Muriel Tichit
      Combining crops and livestock within integrated crop–livestock systems (ICLS) represents an opportunity to improve the sustainability of farming systems. The objective of this paper is to analyse how agroecological principles can help farmers to redesign and improve the resilience, self-sufficiency, productivity, and efficiency of ICLS. Relying on case studies from Brazil and France, we examine how the transformation of two conventional, specialised systems into more integrated-production systems illustrates the different dynamics towards agroecological ICLS. The French case study, based on self-sufficient farming systems belonging to a sustainable agriculture network, highlights that cost-cutting management led to a win–win strategy comprising good economic and environmental performances. The farms decreased their dependence on external inputs and had only a limited loss of production. The past trajectories of the farms illustrate how increasing the interactions between subsystems improved the self-sufficiency and efficiency of the farms. The Brazilian case study compares slash-and-burn agriculture in the Amazonian region with the recovery of degraded grazing area by ICLS. A small increase in chemical inputs linked to a diversification of productions led to a large increase in production and a large decrease in environmental impacts (deforestation). The Brazilian case study also illustrates how the diversification of production increased the resilience of the system to market shocks. Reconstructing the links among soil, crops, and animals following agroecological principles could improve the different performances of ICLS. New agroecological ICLS, benefiting from diversified productions and increased interactions between subsystems, are likely to offset the trade-off between agricultural production and environmental impacts observed in current ICLS.


      PubDate: 2014-07-25T01:01:29Z
       
  • Exploring integrated crop–livestock systems in different ecoregions
           of the United States
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): R. Mark Sulc , Alan J. Franzluebbers
      Large-scale, energy-intensive, specialized production systems have dominated agricultural production in the United States for the past half-century. Although highly productive and economically successful, there is increasing concern with unintended negative environmental impacts of current agricultural systems. Production systems integrating crops and livestock have potential for providing additional ecosystem services from agriculture by capturing positive ecological interactions and avoiding negative environmental outcomes, while sustaining profitability. A diversity of ecologically sound integrated crop-livestock systems have been and can be employed in different ecoregions: sod-based crop rotations, grazing cover crops in cash-crop rotations, crop residue grazing, sod intercropping, dual-purpose cereal crops, and agroforestry/silvopasture. Improved technologies in conservation tillage, weed control, fertilization, fencing, and planting, as well as improved plant genetics offer opportunities to facilitate successful adoption of integrated systems. This paper explores the use and potential of integrated crop-livestock systems in achieving environmental stewardship and maintaining profitability under a diversity of ecological conditions in the United States.


      PubDate: 2014-07-25T01:01:29Z
       
  • Evolution in crop–livestock integration systems that improve farm
           productivity and environmental performance in Australia
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): Lindsay W. Bell , Andrew D. Moore , John A. Kirkegaard
      Australian farming systems have an enduring history of crop–livestock integration which emerged in the face of high climate variability, infertile soils and variable landscapes. Ley farming systems with phases of shorter annual legume pasture phases with cereal crops predominate but, emerging sustainability issues and the need to manage risk is driving ongoing innovation in crop–livestock integration. We discuss the recent evolution of selected innovations that integrate crop and livestock production and their impacts on farm productivity, sustainability and business risk. Dual-purpose use of cereals and canola (Brassica napus) for forage during the vegetative stage while still harvesting for grain is now practiced throughout southern Australia's cropping zone. This practice provides risk management benefits, diversifies crop rotations, reduces pressure on other feed resources and can significantly increase both livestock and crop productivity from farms by 25–75% with little increase in inputs. Sacrificially grazing crops when expected grain yield is low and/or livestock prices are attractive relative to grain provides further flexibility in crop–livestock management systems vital for business risk management in a variable climate. Replacing annual pastures with perennial pasture phases in rotation with crops can provide a range of benefits including improved hydrological balance to reduce dryland salinity, subsoil acidification and water-logging, provide a management tool for herbicide-resistant or problem weeds, improved soil nutrient and carbon stocks as well as increased livestock productivity by filling feed gaps. In some environments, integration of perennial forages in mixtures with cropping, such as alley cropping and inter-cropping, also provide options for improving environmental outcomes. These practices are all innovations that provide flexibility and enable tactical decisions about the mix of enterprises and allocation of land and forage resources to be adjusted in response to climate and price. We discuss these innovations in the context of the emerging constraints to crop–livestock integration in Australia including the continuing decline in labour availability on farms and increasing management skill required to optimise enterprise profitability.


      PubDate: 2014-07-25T01:01:29Z
       
  • Integrated crop–livestock systems in the Brazilian subtropics
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): Anibal de Moraes , Paulo César de Faccio Carvalho , Ibanor Anghinoni , Sebastião Brasil Campos Lustosa , Sérgio Ely Valadão Gigante de Andrade Costa , Taise Robinson Kunrath
      In the subtropical region of Brazil, integrated crop–livestock systems (ICLSs) are characterized by the annual rotation of pastures and crops in a no-till system where the pasture component is used to produce either meat or milk. These systems focus on integration within the farm rather than between farms, being characterized by alternating cropping and pasturing in the same area. Independent of the crop rotations possible in a subtropical environment, the main integrated farming system found was rotation or succession of summer crops (Glycine max, Zea mays, Phaseolus vulgaris or Oryza sativa) with winter annual grazing grasses (mixed or solely Avena strigosa and Lolium multiflorum) or successive natural pastures. The high variability of crop yield in the Brazilian subtropics (due to climate extremes) as well as associated high costs and low prices has encouraged farmers to integrate livestock into their enterprises as a low-risk diversification option. Long-term experiments have demonstrated the benefits of crop–livestock integration with respect to many aspects of the soil–plant–animal system. There is evidence that such a system is not only a livestock–agriculture combination but also a unique system reaching a new complexity threshold, resulting in emergent properties with novel functionalities, some of which have yet to be investigated. In addition to greater environmental gains with less vulnerability, there are higher yields and more financial gain by the farmer, compared to that in the use of monocultures or non-integrated livestock farming. We conclude that ICLSs in Subtropical Brazil provide the opportunity for intensification with sustainability.


      PubDate: 2014-07-25T01:01:29Z
       
  • Toward agricultural sustainability through integrated crop–livestock
           systems. II. Production responses
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): Alan J. Franzluebbers , Gilles Lemaire , Paulo César de Faccio Carvalho , R. Mark Sulc , Benoît Dedieu



      PubDate: 2014-07-25T01:01:29Z
       
  • Effects of planting soybean in summer fallow on wheat grain yield, total N
           and Zn in grain and available N and Zn in soil on the Loess Plateau of
           China
    • Abstract: Publication date: August 2014
      Source:European Journal of Agronomy, Volume 58
      Author(s): Ning Yang , Zhaohui Wang , Yajun Gao , Hubing Zhao , Keyi Li , Fucui Li , Sukhdev S. Malhi
      Dryland wheat is the major contributor to wheat production in the world, where water deficiency and poor soil fertility are key factors limiting wheat grain yields and nutrient concentrations. A field experiment was carried out from June 2008 to June 2011 at Shilipu (latitude 35.12°N, longitude 107.45°E and altitude 1200m above sea level) on the Loess Plateau (a typical dryland) in China, to investigate the effects of rotation with soybean (Glycine max) green manure (GM) on grain yield, total N and total Zn concentrations in subsequent wheat (Triticum aestivum L.), and on nitrate-N and available Zn in the soil. The benefits of crop rotation with soybean GM on wheat grain yields became more evident with time. In the second and third years, the grain yields of wheat rotated with soybean GM reached 4871 and 5089kgha−1 at the 108kgNha−1 rate. These yields were 21% and 12% higher than the highest yields of wheat under a fallow-winter wheat (FW) rotation. Rotation with soybean GM reduced the amount of N fertilizer required to obtain wheat grain yields and biomass levels similar to wheat grown in the FW rotation by 20–33%. In the first 2 years, average grain N concentrations over all N rates increased by 6% and 12%, and those of Zn increased by 26% and 14% under the soybean GM-winter wheat (SW) rotation, compared with the FW rotation. The increased grain N and Zn concentrations were found to be related to the increased concentrations of nitrate-N and available Zn in the soil, particularly at the sowing of winter wheat. However, grain N and Zn concentrations were not improved by rotation with soybean GM in the third year. This was attributed to the dilution effect caused by the more grain yield increase than its nutrient export. In conclusion, planting soybean for GM in fallow fields reduced the need for N fertilizer to enhance wheat yields in this dryland region. Change in wheat grain N and Zn concentrations was related to soil nutrient concentrations, and to the balance between increased grain yield and its nutrient export.


      PubDate: 2014-07-25T01:01:29Z
       
  • Intercropping soybean and palisade grass for enhanced land use efficiency
           and revenue in a no till system
    • Abstract: Publication date: August 2014
      Source:European Journal of Agronomy, Volume 58
      Author(s): C.A.C. Crusciol , A.S. Nascente , G.P. Mateus , C.M. Pariz , P.O. Martins , E. Borghi
      Integrated no-till crop and livestock production systems may help rejuvenate degraded pastures, increase land use efficiency (LUE), and increase enterprise revenue. Our objectives were to evaluate: (1) planting date effects on seed yield and nutrient concentration of an early-maturing, no-till system (NTS) soybean (Glycine max) when intercropped with palisade grass (Brachiaria brizantha); (2) dry matter production and protein concentration of the grass pasture after soybean harvest; and (3) overall revenue and LUE for the intercrop system. Experiments were performed during two growing seasons in Botucatu, Brazil using a randomized complete block experimental design. When palisade grass and soybean were sown simultaneously, soybean yield averaged 3.28Mgha−1. Similar seed yields were observed when palisade grass was planted either 30d after soybean emergence (DAE) (3.29Mgha−1) or at the soybean reproductive stage R6 (full seed) (3.50Mgha−1). Monocrop soybean yield averaged 3.50Mgha−1. First cut dry matter forage production was greater when palisade grass was sown at the same time as soybean or 30 DAE of soybean. This indicates that interseeding palisade grass with soybean does not significantly affect soybean nutrition or yield. Intercropping did increase LUE and resulted in 1.6 times more revenue than soybean alone. However, sowing palisade grass at the soybean reproductive stage R6 (full seed) significantly reduced the forage yield compared to early planting.


      PubDate: 2014-07-25T01:01:29Z
       
  • Pasture grazing intensity and presence or absence of cattle dung input and
           its relationships to soybean nutrition and yield in integrated
           crop–livestock systems under no-till
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): Francine Damian da Silva , Telmo Jorge Carneiro Amado , Christian Bredemeier , Carolina Bremm , Ibanor Anghinoni , Paulo Cesar de Faccio Carvalho
      In integrated soybean–beef cattle systems, the pasture grazing intensity affects the grain crop performance in succession. In addition, the dung cattle input influences the soil nutrients distribution in the field affecting the grain crop yield. This experiment aims to evaluate the effects of winter pasture heights and cattle dung input in soybean crop performance in succession. Main soil macronutrient content, soybean plant population, dry shoot biomass, plant height, plant nutrient content, soybean yield and yield components were assessed in the 10th experimental year. The experiment was conducted in the state of Rio Grande do Sul, Southern Brazil, in a long-term integrated crop–livestock systems implemented in 2001. Treatments were arranged in a split plot design with four pasture heights (0.10, 0.20, 0.30, and 0.40m) and two levels of dung input (with or without). For all the variables analyzed, there was no interaction between pasture heights and cattle dung input (P >0.05). The pasture height management had only effect in soil P content, soybean dry biomass production, plant height and number of grains per pod. The increase in grazing intensity was associated to the rise in soybean plant height and dry mass production but was without effect on grain yield. The presence of grazing animals in the integrated soybean–beef cattle systems, and the resultant augmentation of dung input increased by 122% and 38% the availability of soil K and P, respectively in relation to the absence. Thus, the content of such nutrients in the plant were increased in 41% and 7%, respectively. The improvement in soybean nutrition increases the amount of pods per plant by 20%, and resulting in a 23% increase in soybean yield. These results indicate that cattle dung input resulting from grazing animals in the pasture phase increased soybean grain yield due to better plant nutrition. Although, the occurrence of cattle dung was very concentrated in some spots of the field and thus future studies should address strategies to improve spatial distribution of cattle dung input.


      PubDate: 2014-07-25T01:01:29Z
       
  • Italian ryegrass establishment by self-seeding in integrated
           crop–livestock systems: Effects of grazing management and crop
           rotation strategies
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): Armindo Barth Neto , Jean Victor Savian , Radael Marinho Tres Schons , Olivier Jean François Bonnet , Marcos Weber do Canto , Aníbal de Moraes , Gilles Lemaire , Paulo César de Faccio Carvalho
      We evaluated the re-establishment of an Italian ryegrass pasture by self-seeding on a no-till integrated crop–livestock systems (ICLS) in the southern region of Brazil. This work is part of a long-term experimental protocol initiated in 2003. We tested the effects of various management practices, such as summer crop systems (soybean vs. maize–soybean rotation), stocking methods (continuous vs. rotational) and grazing intensities (low vs. moderate), on Italian ryegrass pasture establishment. In addition, we tested resilience of the system by testing pasture's ability to re-establish following a year without seed head production. The experiment consisted in the rotation, on the same area, of Italian ryegrass pasture grazed by sheep during the winter and up to the end of the grass production cycle, and soybean or soybean–maize grain crops rotation cultivated during the summer. The pasture established itself by self-seeding since 2005. Data were collected in 2011 and 2012 stocking season. The soybean summer crop, continuous stocking and low grazing intensity, all positively affected the production of reproductive tillers in 2011. Grazing intensity in 2011 strongly influenced early vegetative tiller densities (before crop harvest) in 2012. However, none of the grazing intensity or the stocking method treatments affected herbage mass at the end of pasture establishment in 2011 or 2012. On the other hand, the soybean summer crop positively affected pasture establishment, both in term of tiller densities and herbage mass at the end of pasture establishment. The removal of all seed heads in 2011 (preventing seed production) resulted in the total failure of pasture establishment in 2012. Overall, Italian ryegrass establishment by self-seeding relies on the annual replacement of the soil seed bank. This experiment demonstrated that under various stocking methods, moderate grazing intensity and maize or soybean summer crop, Italian ryegrass pasture establishment by self-seeding remains successful even when the stocking periods extended up to the end of the grass production cycle. Self-seeding with moderate grazing intensity ensures successful pasture establishment, reduces labour and costs and allows to increase the stocking period and so animal live weight gain over the grazing season.


      PubDate: 2014-07-25T01:01:29Z
       
  • Management targets for continuously stocked mixed oat×annual ryegrass
           pasture in a no-till integrated crop–livestock system
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): Taise Robinson Kunrath , Mónica Cadenazzi , Daniel Martins Brambilla , Ibanor Anghinoni , Anibal de Moraes , Raquel Santiago Barro , Paulo César de Faccio Carvalho
      Feeding livestock with cover crops can improve the efficiency and sustainability of integrated crop–livestock systems under no-till. However, no-till systems are based on permanent soil cover by organic material, so grazing livestock can compete for soil cover. Hence, managing stocking rates during the grazing period of the cultivated forage species is a key factor to assure enough herbage mass for maintaining long-term sustainable no-till systems. In this context, the objective of this study was to determine sward management targets for a continuously stocked mixed oat (Avena strigosa)×annual ryegrass (Lolium multiflorum) pasture in rotation with soybean in a no-till integrated crop–livestock system to determine the optimum balance between animal production and herbage mass for soil cover. The effects of sward height management on animal performance and herbage mass covers were evaluated. Treatments corresponded to four sward heights: 10, 20, 30 and 40cm, maintained throughout the experimental period through continuous stocking and variable stocking rate, plus a no-grazing control area. Treatments were arranged in a randomized complete block design with three replications. Herbage mass and animal performance increased linearly with sward height, but weight gain per hectare decreased. Grazing efficiency fitted to a quadratic regression and conversion efficiency a logarithmic model. Equilibrium between grazing and conversion efficiencies was reached on swards managed at 20cm, indicating that this sward height provided enough herbage mass to allow both animal performance and no-till crop demand for soil cover.


      PubDate: 2014-07-25T01:01:29Z
       
  • Crop and cattle production responses to tillage and cover crop management
           in an integrated crop–livestock system in the southeastern USA
    • Abstract: Publication date: July 2014
      Source:European Journal of Agronomy, Volume 57
      Author(s): Alan J. Franzluebbers , John A. Stuedemann
      Integrated crop–livestock systems can help achieve greater environmental quality from disparate crop and livestock systems by recycling nutrients and taking advantage of synergies between systems. We investigated crop and animal production responses in integrated crop–livestock systems with two types of winter cover cropping (legume-derived N and inorganic fertilizer N), two types of tillage [conventional disk (CT) and no tillage (NT)], and whether cover crops were grazed by cow/calf pairs or not. The 13-ha field study was a modification of a previous factorial experiment with four replications on Ultisols in Georgia, USA. Recurring summer drought severely limited corn and soybean production during all three years. Type of cover crop had little influence and grazing of cover crops had minor influence on crop production characteristics. Cattle gain from grazing of winter cover crops added a stable component to production. No-tillage management had large positive effects on corn grain (95 vs. 252gm−2 under CT and NT, respectively) and stover (305 vs. 385gm−2) production, as well as on soybean grain (147 vs. 219gm−2) and stover (253 vs. 375gm−2) production, but little overall effect on winter wheat grain (292gm−2) and stover (401gm−2) production. Our results suggest that robust, diversified crop–livestock systems can be developed for impoverished soils of the southeastern USA, especially when managed under no tillage to control environmental quality and improve resistance of crops to drought.


      PubDate: 2014-07-25T01:01:29Z
       
  • Agricultural sciences in transition from 1800 to 2020: Exploring knowledge
           and creating impact
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): Huub Spiertz
      Transitions in agricultural sciences are brought about by incorporating new findings and insights emerging from biological, chemical and biophysical sciences, by more advanced ways of experimentation and last but not least by quantitative methods and models for data analyses and processing. Major breakthroughs occurred from 1800 onwards when new insights on photosynthesis and mineral nutrition were incorporated in the theory on the growth of crops. It took almost half a century before the humus theory was replaced by a more sound theory on mineral nutrition. The publication by Darwin on domestication in 1868 and the rediscovery of Mendel's laws in 1900 gave a boost to genetics underlying classical plant and animal breeding, which was mainly based on crossing and selection. A major accomplishment of the evolutionary synthesis was the compatibility of Mendelian inheritance with Darwinian natural selection. The discovery of the DNA-structure in the mid-fifties of the 20th century on modern plant breeding showed already impact within some decades. To assess the wide diversity of plant traits for the performance of plants in yield and quality of the produce advanced phenotyping method under controlled conditions has become popular. Genome-wide selection for environments with multiple stresses, however, does require phenotyping in situ. Since 1800 the transition from observations on the plant, field and farm towards dedicated experimentation took place. During the 19th and 20th century the methods for experimentation and data analyses were strongly improved. It took until the mid-20th century before the importance of experiments under controlled conditions was recognized. Studies of plant processes under controlled conditions provided the building blocks for mechanistic modelling of crop growth and production. A systems approach combining knowledge at different scales and incorporating cutting-edge findings from the basic sciences into applied sciences will become important for making a great leap forward in developing agricultural science with impact. Transitions in agricultural research will continue to depend on progress made in the related basic sciences and the capacity for agricultural research and innovation. Therefore, an adequate public funding is required to maintain or even accelerate progress in sciences. This requires the support of the public at large. Public–private partnerships will be needed to bridge the gap between science and innovation.


      PubDate: 2014-07-25T01:01:29Z
       
  • Evaluation of optical sensor measurements of canopy reflectance and of
           leaf flavonols and chlorophyll contents to assess crop nitrogen status of
           muskmelon
    • Abstract: Publication date: August 2014
      Source:European Journal of Agronomy, Volume 58
      Author(s): Francisco M. Padilla , M. Teresa Peña-Fleitas , Marisa Gallardo , Rodney B. Thompson
      Nitrogen losses from intensive vegetal production systems are commonly associated with contamination of water bodies. Sustainable and optimal economic N management requires correct and timely on-farm assessment of crop N status to detect N deficiency or excess. Optical sensors are promising tools for the assessment of crop N status throughout a crop or at critical times. We evaluated optical sensor measurement of canopy reflectance and of leaf flavonols and chlorophyll contents to assess crop N status weekly throughout a muskmelon crop. The Crop Circle ACS 470 was used for reflectance measurement, the SPAD 502 for leaf chlorophyll, and the DUALEX 4 Scientific for leaf chlorophyll and flavonols. Four indices of canopy reflectance (NDVI, GNDVI, RVI, GVI), leaf flavonols and chlorophyll contents and the nitrogen balance index (NBI), the ratio of chlorophyll to flavonols contents, were linearly related to crop N content and to crop Nitrogen Nutrition Index (NNI) throughout most of the crop. NBI most accurately predicted crop N status; in five consecutive weekly measurements, R 2 values were 0.80–0.95. For NDVI during the same period, R 2 values were 0.76–0.87 in the first three measurements but R 2 values in the last two measurements were 0.39–0.45. Similar relationships were found with the three other reflectance indices. Generally, the relationships with NNI were equal to or slightly better than those with crop N content. These optical sensor measurements provided (i) estimation of crop N content in the range 1.5–4.5%, and (ii) an assessment of whether crop N content was sufficient or excessive for optimal crop growth for NNI ranges of 0.8–2.0. Composite equations that integrated the relationships between successive measurements with the optical sensors and crop N content or NNI for periods of ≥2 weeks (often 2–3 weeks) were derived for most indices/parameters. Overall, these results demonstrated the potential for the use of these optical sensor measurements for on-farm monitoring of crop N status in muskmelon.


      PubDate: 2014-07-25T01:01:29Z
       
  • Which farmers benefit most from sustainable intensification' An
           ex-ante impact assessment of expanding grain legume production in Malawi
    • Abstract: Publication date: August 2014
      Source:European Journal of Agronomy, Volume 58
      Author(s): A.C. Franke , G.J. van den Brand , K.E. Giller
      Legume technologies are widely promoted among smallholders in southern Africa, providing an opportunity for sustainable intensification. Farms and farming strategies of smallholders differ greatly within any given locality and determine the opportunities for uptake of technologies. We provide an ex-ante assessment of the impact of grain legumes on different types of farms and identify niches for grain legumes in Malawi. After creation of a farm typology, detailed farm characterisations were used to describe the farming system. The characterisations provided the basis for the construction of simplified, virtual farms on which possible scenarios for expanding and intensifying grain legume production were explored using the farm-scale simulation model NUANCES-FARMSIM. Observed yields and labour inputs suggested that maize provides more edible yield per unit area with a higher calorific value and greater labour use efficiency than groundnut and soybean. Crop yields simulated by the model partly confirmed these yield trends, but at farm level maize-dominated systems often produced less food than systems with more grain legumes. Improved management practices such as addition of P-based fertiliser to grain legumes and inoculation of soybean were crucial to increase biological nitrogen fixation and grain yields of legumes and maize, and created systems with increased area of legumes that were more productive than the current farms. Improved legume management was especially a necessity for low resource endowed farmers who, due to little past use of P-based fertiliser and organic inputs, have soils with a poorer P status than wealthier farmers. Economic analyses suggested that legume cultivation was considerably more profitable than continuous maize cropping. Highest potential net benefits were achieved with tobacco, but the required financial investment made tobacco cultivation riskier. Grain legumes have excellent potential as food and cash crops particularly for medium and high resource endowed farmers, a role that could grow in importance as legume markets further develop. For low resource endowed farmers, legumes can improve food self-sufficiency of households, but only if legumes can be managed with P fertiliser and inoculation in the case of soybean. Given that low resource endowed farmers tend to be risk averse and have few resources to invest, the ability of poorer farmers to adopt legume technologies could be limited.


      PubDate: 2014-07-25T01:01:29Z
       
  • Elytrigia repens population dynamics under different management schemes in
           organic cropping systems on coarse sand
    • Abstract: Publication date: August 2014
      Source:European Journal of Agronomy, Volume 58
      Author(s): Ilse A. Rasmussen , Bo Melander , Margrethe Askegaard , Kristian Kristensen , Jørgen E. Olesen
      Elytrigia repens is a rhizomatous perennial weed prevalent in organic cropping systems in Scandinavia. This study analysed the population dynamics of E. repens in a long-term crop rotation experiment on coarse sand in Denmark in order to gain insights into the factors influencing its population changes, especially those important for outbreaks of E. repens infestations. Data were obtained from three cycles of four-year crop rotations with various cash crops and annual grass–clover subjected to four treatment combinations: with and without animal manure and with and without catch crops. E. repens was controlled by different tillage and mowing strategies between and within crops. Pulses and spring cereals caused the highest population increases, especially when preceded by grass–clover. Potatoes grown in ridges and winter rye suppressed the E. repens population, but tillage between crops was necessary to decrease the population. Manuring generally reduced E. repens growth by 28%. Thus there are crops that need particular attention when designing crop sequences, provision of sufficient nutrients is important to strengthen crop suppression of weeds, and mechanical interventions are needed to manage E. repens satisfactorily.


      PubDate: 2014-07-25T01:01:29Z
       
  • MIMYCS.Moisture, a process-based model of moisture content in developing
           maize kernels
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): Andrea Maiorano , Davide Fanchini , Marcello Donatelli
      Moisture content influences harvest timing and the consequent drying process and drying costs, and the development of spoilage fungi during pre- and post-harvest phases. Maize kernel development in the field can be partitioned into three phases: i) lag phase, ii) grain filling and maturation drying, and iii) post-maturity dry-down. A model simulating maize kernel moisture content during maturation can help either monitoring or foreseen maize kernel humidity during the harvest period. Also, it would be useful in simulation studies via crop models to estimate the infield feasibility of harvest but also the interaction with diseases responsible for mycotoxin production, against weather scenarios. A process-based model was developed, called MIMYCS.Moisture. When the hybrids were analyzed all together, MIMYCS.Moisture showed a good general predictive capability with an average error in moisture estimation of ±3.28% moisture (considering the root mean square error – RMSE). The model efficiency (EF) was positive (0.85) and the model was able to explain the 89.7% of variation. When the two sub-models were analyzed separately, the RMSE remained approximately at the same level of the general model, while the other indicators changed revealing the different characteristics of the two models. The developmental moisture sub-model has a slight tendency to overestimate, while the dry-down sub-model tended to underestimate final moisture content. However, when the model was analyzed separately for each hybrid, both calibration and validation results suggested that more data are needed to improve the model likely with respect to kernel characteristics of hybrids. Finally, the equilibrium moisture content equation used, taken from industrial drying models, might not be adequate for simulating the field conditions where temperature is well below the one in dryers and environmental air humidity may vary considerably across sites and harvest periods.


      PubDate: 2014-07-25T01:01:29Z
       
  • Evaluation of WARM for different establishment techniques in Jiangsu
           (China)
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): Valentina Pagani , Caterina Francone , ZhiMing Wang , Lin Qiu , Simone Bregaglio , Marco Acutis , Roberto Confalonieri
      WARM is a model for rice simulation accounting for key biotic and a-biotic factors affecting quantitative and qualitative (e.g., amylose content, chalkiness) aspects of production. Although the model is used in different international contexts for yield forecasts (e.g., the EC monitoring and forecasting system) and climate change studies, it was never explicitly evaluated for transplanting, the most widespread rice establishment method especially in tropical and sub-tropical Asia. In this study, WARM was tested for its ability to reproduce nursery growth and transplanting shock, using data on direct sown and transplanted (both manual and mechanical) rice collected in 24 dedicated field experiments performed at eight sites in Jiangsu in 2011, 2012 and 2013. The agreement between measured and simulated aboveground biomass data was satisfactory for both direct sowing and transplanting: average R 2 of the linear regression between observed and simulated values was 0.97 for mechanical transplanting and direct sowing, and 0.99 for manual transplanting. RRMSE values ranged from 5.26% to 30.89%, with Nash and Sutcliffe modelling efficiency always higher than 0.78; no notable differences in the performance achieved for calibration and validation datasets were observed. The new transplanting algorithm – derived by extending the Oryza2000 one – allowed WARM to reproduce rice growth and development for direct sown and transplanted datasets (i) with comparable accuracy and (ii) using the same values for the parameters describing morphological and physiological plant traits. This demonstrates the reliability of the proposed transplanting simulation approach and the suitability of the WARM model for simulating rice biomass production even for production contexts where rice is mainly transplanted.


      PubDate: 2014-07-25T01:01:29Z
       
  • Use of soil and vegetation spectroradiometry to investigate crop water use
           efficiency of a drip irrigated tomato
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): S. Marino , M. Aria , B. Basso , A.P. Leone , A. Alvino
      An agronomic research was conducted in Tuscany (Central Italy) to evaluate the effects of an advanced irrigation system on the water use efficiency (WUE) of a tomato crop and to investigate the ability of soil and vegetation spectroradiometry to detect and map WUE. Irrigation was applied following an innovative approach based on CropSense system. Soil water content was monitored at four soil depths (10, 20, 30 and 50cm) by a probe. Rainfall during the crop cycle reached 162mm and irrigation water applied with a drip system amounted to 207mm, distributed with 16 irrigation events. Tomato yield varied from 7.10 to 14.4kgm−2, with a WUE ranging from 19.1 to 38.9kgm−3. The irrigation system allowed a high yield levels and a low depth of water applied, as compared to seasonal ET crop estimated with Hargraves’ formula and with the literature data on irrigated tomato. Measurements were carried out on geo-referenced points to gather information on crop (crop yield, eighteen Vegetation indices, leaf area index) and on soil (spectroradiometric and traditional analysis). Eight VIs, out of nineteen ones analyzed, showed a significant relationship with georeferenced yield data; PVI maps seemed able to return the best response, before harvesting, to improve the knowledge of the area of cultivation and irrigation system. CropSense irrigation system reduced seasonal irrigation volumes. Some vegetation indexes were significantly correlated to tomato yield and well identify, a posteriori, crop area with low WUE; spectroradiometry can be a valuable tool to improve irrigated tomato field management.


      PubDate: 2014-07-25T01:01:29Z
       
  • Evaluation of pixel- and object-based approaches for mapping wild oat
           (Avena sterilis) weed patches in wheat fields using QuickBird imagery for
           site-specific management
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): Isabel Luisa Castillejo-González , José Manuel Peña-Barragán , Montserrat Jurado-Expósito , Francisco Javier Mesas-Carrascosa , Francisca López-Granados
      This paper compares of pixel- and object-based techniques for mapping wild oat weed patches in wheat fields using multi-spectral QuickBird satellite imagery for site-specific weed management. The research was conducted at two levels: (1) at the field level, on 11 and 15 individual infested wheat fields in 2006 and 2008, respectively, and (2) on a broader level, by analysing the entire 2006 and 2008 images. To evaluate the wild oat patches mapping at the field level, both pixel- and object-based image analyses were tested with six classification algorithms: Parallelepipeds (P), Mahalanobis Distance (MD), Maximum Likelihood (ML), Spectral Angle Mapper (SAM), Support Vector Machine (SVM) and Decision Tree (DT). The results showed that weed patches could be accurately detected with both analyses obtaining global accuracies between 80% and 99% for most of the fields. The MD and SVM classifiers were the most accurate for both the pixel- and object-based images from 2006 and 2008, respectively. In the broad-scale analysis, all of the wheat fields were identified in the imagery using a multiresolution hierarchical segmentation based on two scales. The first segmentation scale was classified using the MD and ML algorithms to discriminate wheat fields from other land uses. Accuracies greater than 85% were obtained for MD and 88% for ML for both imagery. A hierarchical analysis was then performed with the second segmentation scale, increasing the accuracies to 93% and 91% for 2006 and 2008 imagery, respectively. Finally, based on the most accurate results obtained in the field-level study, pixel-based classifications using the MD, ML and SVM algorithms were applied to the wheat fields identified. The results of these broad-level analyses showed that wild oat patches were accurately discriminated in all the wheat fields present in the entire images with accuracies greater than 91% for all the classifiers tested.


      PubDate: 2014-07-25T01:01:29Z
       
  • Global warming over 1960–2009 did increase heat stress and reduce
           cold stress in the major rice-planting areas across China
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): Zhao Zhang , Pin Wang , Yi Chen , Xiao Song , Xing Wei , Peijun Shi
      Increasing extreme temperature events have raised concerns regarding the risk of rice production to extreme temperature stress (ETS). However, across China what places were exposed to higher ETS during rice-growing period and how ETS has changed over the past five decades, remain unclear. Here, we first compared two indexes for characterizing ETS on rice crop, including Duration-based ETS index (DETS) and Growing Degree Days (GDD). Then, based on the better-performing index and an improved dataset of rice phenological records, we comprehensively assessed the spatio-temporal patterns of ETS at county scale in the major rice-planting areas across China during 1960–2009. The results showed that GDD had an advantage over DETS in characterizing ETS, due to fully consideration of both the specific intensity and duration of extreme temperature events. Based on GDD, we found that ETS on rice crops had significantly changed in both space and time over the last five decades. Spatially, single rice in Northeast China (Region I) and late rice in southern China (Region IV) saw high exposure to cold stress, especially during the heading-flowering stage. The hot spots of heat stress were found for single rice in the Yangtze River basin (Region III) (2.25°C) during the booting stage, and for early rice in Region IV (4.42°C) during the heading-flowering stage. During 1960–2009, global warming did increase heat stress (0.04 and 0.12°Cyear−1 for the stages of booting and heading-flowering, respectively) and reduce cold stress (−0.03 and −0.21°Cyear−1 for the stages of booting and heading-flowering, respectively) in the major rice-planting areas across China. Some particular areas, such as Yunan Province (P4) with increasing cold stress and Zhejiang Province (P13) with increasing heat stress, should be priorities for adaptations to cope with the rising risk of ETS under climate warming.


      PubDate: 2014-07-25T01:01:29Z
       
  • Assessment of insurance coverage and claims in rainfall related risks in
           processing tomato in Western Spain
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): A. Castañeda-Vera , L. Barrios , A. Garrido , I. Mínguez
      An extension of guarantees related to rainfall-related risks in the insurance of processing tomato crops has been accompanied with a large increase in claims in Western Spain, suggesting that damages may have been underestimated in previous years. A database was built by linking agricultural insurance records, meteorological data from local weather stations, and topographic data. The risk of rainfall-related damages in processing tomato in the Extremenian Guadiana river basin (W Spain) was studied using a logistic model. Risks during the growth of the crop and at harvesting were modelled separately. First, the risk related to rainfall was modelled as a function of meteorological, terrain and management variables. The resulting models were used to identify the variables responsible for rainfall-related damages, with a view to assess the potential impact of extending insurance coverage, and to develop an index to express the suitability of the cropping system for insurance. The analyses reveal that damages at different stages of crop development correspond to different hazards. The geographic dependence of the risk influences the scale at which the model might have validity, which together with the year dependency, the possibility of implementing index based insurances is questioned.


      PubDate: 2014-07-25T01:01:29Z
       
  • Carbon assimilation, leaf area dynamics, and grain yield in contemporary
           earlier- and later-senescing maize hybrids
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): Horacio A. Acciaresi , Eduardo A. Tambussi , Mariana Antonietta , María S. Zuluaga , Fernando H. Andrade , Juan J. Guiamét
      Maize breeding during the past 50 years has been associated with a delay of leaf senescence, but it is not clear whether this trait is likewise associated with higher grain yield in modern hybrids. Post-silking growth, leaf area dynamics, photosynthetic parameters and yield were compared in modern maize hybrids differing in canopy senescence rate. In the first two experiments, four hybrids were grown in the field at Balcarce, Argentina (37°45′ S, 58°18 W). In spite of differences in chlorophyll retention and photosynthesis of the ear leaf, post-silking growth and grain yield were very similar in all four hybrids while kernel N concentration was lower in the later-senescing hybrids. In a third experiment, a later-senescing (NK870) and an earlier-senescing (DK682) hybrid were grown to analyze the potential photosynthetic contribution of delayed leaf senescence. Leaf area and chlorophyll content were larger in NK870, especially at the lower canopy level (0.75m above the ground). However, hybrids did not differ for canopy light interception. Because photosynthetic photon flux density below 1m above the ground was less than 10% of incident radiation and photosynthesis quantum yield did not change during senescence, the potential photosynthetic output of lower leaves below 1m was very low. Lower leaves of NK870 had N concentrations higher than those needed to sustain photosynthesis at the light conditions below 1m. Therefore, we show that delayed senescence does not necessarily improve post-silking C accumulation because: (i) canopy light interception is not reduced by senescence except at very late stages of grain filling; (ii) contrasting hybrids show more pronounced senescence differences at canopy levels receiving less than 10% of incident radiation; (iii) delayed senescing hybrids present lower kernel N concentrations while extra N is retained in leaves exposed to a light limiting micro-environment. Delayed senescence at lower canopy levels may be unproductive, at least under non-stressing conditions.


      PubDate: 2014-07-25T01:01:29Z
       
  • Assessment of irrigation scenarios to improve performances of Lingot bean
           (Phaseolus vulgaris) in southwest France
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): H. Marrou , T.R. Sinclair , R. Metral
      In the context of climate change, producing the same amount of food with less water has become a challenge all over the world. This is also true for the Lingot bean production in the area of Castelnaudary of southwest France where market competition with imported bean has made it crucial to achieve high yields to maintain production in the area. The use of an appropriate and robust crop model can help to identify crop management solutions to face such issues. We used SSM-legumes, a crop model generic to legume species, as well as field observations recorded over five years on eight farms of the Castelnaudary area to assess the effect of different irrigation scenarios on bean yield and water consumption. First, it was demonstrated that the SSM-legumes model is robust in simulating the development and growth of Lingot bean in non-stressed or moderately stressed conditions of this region regarding water and nutrient availability. Then, the use of the model to compare irrigation scenarios provided guidance on how to improve irrigation management for Lingot bean production. These results showed that farmers could achieve slightly higher yields with less water by basing irrigation decisions on the water content of the soil.


      PubDate: 2014-07-25T01:01:29Z
       
  • Application of pig slurry—First year and residual effects on yield
           and N balance
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): Klaus Sieling , Kang Ni , Henning Kage
      Crops generally utilize nitrogen (N) from slurries less efficiently than from mineral fertilizers. In order to compare the effects of slurry and mineral N application on yield and residual fertilization effects, a long-term field trial was established in autumn 1994, where pig slurry was applied to oilseed rape (OSR), winter wheat and winter barley at the same application dates as mineral N fertilizer. N amounts ranged from 0 to 240kg total Nha−1. The same treatment regimes were applied to the same plots in each year. Starting in 2010 (2011), wheat (barley) received no N fertilization in order to allow for testing residual fertilizer effects. Every year seed yield and N offtake by the seeds were determined. Accounting only for ammonia N of pig slurry, similar seed yields in OSR and slightly higher grain yields in wheat and barley compared to mineral N fertilizer were achieved. This indicates that mineralization of organically bounded slurry N compensated gaseous ammonia losses. In plots without N fertilization, OSR showed no yield trends during the experimental period, whereas wheat (barley) yield started to decrease after 10 (13) years without N fertilization. In the highly fertilized treatments, no significant trend in seed yield or N amount required for maximum yield could be detected. In the subsequent unfertilized wheat crop, accumulated slurry effects increased grain yield more than those of mineral N fertilizer. Barley grown in the second year without N supply remained unaffected by the previous slurry N application.


      PubDate: 2014-07-25T01:01:29Z
       
  • Low yield gap of winter wheat in the North China Plain
    • Abstract: Publication date: September 2014
      Source:European Journal of Agronomy, Volume 59
      Author(s): Kenan Li , Xiaoguang Yang , Zhijuan Liu , Tianyi Zhang , Shuo Lu , Yuan Liu
      The yield gap (YG) between the potential yields (Yp) and the average on-farm yields (Ya) is an indicator of the potential improvement for crop production. Understanding how large the current gap is and how this gap has changed over the past few decades is essential for increasing wheat production to meet increased food demand in China. This paper describes a study conducted using an APSIM-Wheat model and farm-level crop yield to analyze the spatio-temporal distribution of the yield gap of winter wheat from 1981 to 2010 in the North China Plain. Nine varieties were calibrated and evaluated based on the data from 16 agro-meteorological experimental sites and then potential yields were estimated considering cultivar replacement. In addition, a trend pattern analysis of on-farm yields for the period 1981–2010 was conducted. Results revealed an estimated yield gap across the entire North China Plain region of 1140–6810kgha−1, with a weight average of 3630kgha−1 in 1981–2010. Expressed as a relative yield (yield gap % of potential yields), the range was 15–80%, and the weight average was 45%. Despite the negative effects of increasing temperature and decreasing radiation, the potential yields significantly increased by 45kgha−1 per year due to cultivar improvement. On-farm yields increased even more notably because of new cultivar selection, increased fertilizer application and other management improvements, but were stagnating in 32.3% of wheat areas, located mainly in Hebei province, Shandong province, Beijing and Tianjin. The improvement of on-farm yields have substantially contributed to yield gap spatio-temporal variation. As a result, the yield gap decreased from 4200kgha−1 (56%) in 1981–1990 to 3000kgha−1 (35%) in 2001–2010 at a rate of −69kgha−1 per year. However, yields stagnation will expand to the northern Henan province without cultivar potential productivity improving, where yield gap was close to or less than 20% of the potential yields and proved difficult to reduce. To further improve the total production of winter wheat in the coming decades, efforts should be paid to break the potential ceiling and reduce the yield gap by breeding higher yield variety and introduction of new agricultural technology.


      PubDate: 2014-07-25T01:01:29Z
       
  • Integrated crop and livestock systems in Western Europe and South America:
           A review
    • Abstract: Publication date: Available online 27 March 2014
      Source:European Journal of Agronomy
      Author(s): Jean-Louis Peyraud , Miguel Taboada , Luc Delaby
      For many years, we have seen an increasing specialization of agricultural systems and territories, with a clear separation between territories with very high animal densities and those devoted to the growing of annual crops. This development is explained by market and sector economic logic and has been reinforced by the availability of low-cost inputs and animal housing systems based on direct grazing not requiring straw. It has, however, also involved negative environmental impacts and, in some cases, the impoverishment of soil fertility, a loss of biodiversity, and excesses of N and P, leading to eutrophication and hot spots of ammonia emission in livestock-breeding territories. Having recapped the mechanisms behind the specialization of systems and territories, we examined the extent to which the development of innovative mixed-farming systems that reconnect livestock and crop production on various territorial scales (farm, district, region) can reduce the negative impacts of agriculture on the environment, produce valuable ecosystem services and achieve acceptable economic efficiency for farming enterprises. Examples from temperate regions will be used to show that mixed-farming systems increase the possibilities of better recycling of nutrients within systems, limiting recourse to the purchase of increasingly expensive inputs and safeguarding the biodiversity of agricultural ecosystems.


      PubDate: 2014-04-28T17:21:07Z
       
  • Optimisation of fertiliser rates in crop production against energy use
           indicators
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): Helis Rossner , Christian Ritz , Alar Astover
      Optimising mineral nitrogen (N) use in crop production is inevitable target as mineral fertilisers reflect one of the highest inputs both in terms of economy and energy. The aim of the study was to compare the relationship between the rate of N fertiliser application and different measures of energy parameters exemplary data for spring-wheat in boreal climate condition in Estonia in 2006–2010. The effect of mineral N with rates 0, 40, 80, 120 and 160kgNha−1 was studied on the background of composted cow manure and without organic fertilisers. Univalent parameters, energy gain (EG) (energy output−energy input) and energy ratio (ER) (energy output/energy input) were calculated. To aggregate parameters with different units (ER and EG) we proposed two standardisation approaches for combined indices. ER maximisation gave both organic fertilisation background optimum N norms significantly lower than EG (p <0.05) optimisation. Both the new combined indices gave optimum N norms in between the rate of ER an EG. Composted cow manure background did not affect mineral N optimisation significantly. We suggest optimisation of mineral N according to bi-dimensional parameters as they capture important features of production efficiency and are more objective using as advisory tool for sustainable production systems.
      Graphical abstract image

      PubDate: 2014-04-28T17:21:07Z
       
  • Yams (Dioscorea spp.) plant size hierarchy and yield variability:
           Emergence time is critical
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): D. Cornet , J. Sierra , R. Tournebize , B. Ney
      Yam crops (Dioscorea spp.) present a very high and unexplained interplant variability which hinders attempts at intensification. This paper aims to characterize the plant-to-plant variability in yield and to identify its underlying causes for the two major yam species (Dioscorea alata and Dioscorea rotundata). Four field experiments were carried out between 2006 and 2009 in Benin. Yams were grown using a traditional cropping method (i.e. in mounds at 0.7plantsm−2) without biotic or abiotic stresses. In order to test interplant competition, a low density treatment (0.08plantsm−2) was included for D. alata in the 2006 experiment. Throughout four years of experimentation, yields varied from 12Mgha−1 to 21Mgha−1. Both yam species presented a high interplant coefficient of variation (CV) for tuber yield (42–71%). The unbiased Gini coefficient (G′) was used to measure how steep a hierarchy is in an absolute sense. CV and G′ of individual plant biomass both confirm clear plant size hierarchies from early growth. However, no difference in the CV of plant size and plant tuber yield was observed between high and low plant density. This implies that, despite early interaction between neighbouring plants, competition was not the driving factor controlling plant variability. In fact uneven emergence proved to be the primary cause. Yam emergence takes place over a long period (e.g. it took 51 and 47 days for the 90% central range to emerge for D. alata and D. rotundata, respectively), creating an early inter-plant size hierarchy which later affected tuber production. For both species, plants which emerged early initiated their tuberization earlier in the growing season and reached higher maximum yield regardless of weather conditions (e.g. 1200 and 764g plant−1 for early-emerging D. alata and D. rotundata plants respectively, and 539 and 281g plant−1 for late-emerging plants). Plant size hierarchization together with its observed left-skewed distribution, led to reduce total and marketable yield by increasing the proportion of small tubers. These results highlight the need to better understand the underlying mechanisms controlling the yams’ uneven emergence before attempting to improve traditional cropping systems.


      PubDate: 2014-04-28T17:21:07Z
       
  • Tree height quantification using very high resolution imagery acquired
           from an unmanned aerial vehicle (UAV) and automatic 3D
           photo-reconstruction methods
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): P.J. Zarco-Tejada , R. Diaz-Varela , V. Angileri , P. Loudjani
      This study provides insight into the assessment of canopy biophysical parameter retrieval using passive sensors and specifically into the quantification of tree height in a discontinuous canopy using a low-cost camera on board an unmanned aerial vehicle (UAV). The UAV was a 2-m wingspan fixed-wing platform with 5.8kg take-off weight and 63km/h ground speed. It carried a consumer-grade RGB camera modified for color-infrared detection (CIR) and synchronized with a GPS unit. In this study, the configuration of the electric UAV carrying the camera payload enabled the acquisition of 158ha in one single flight. The camera system made it possible to acquire very high resolution (VHR) imagery (5cmpixel−1) to generate ortho-mosaics and digital surface models (DSMs) through automatic 3D reconstruction methods. The UAV followed pre-designed flight plans over each study site to ensure the acquisition of the imagery with large across- and along-track overlaps (i.e. >80%) using a grid of parallel and perpendicular flight lines. The validation method consisted of taking field measurements of the height of a total of 152 trees in two different study areas using a GPS in real-time kinematic (RTK) mode. The results of the validation assessment conducted to estimate tree height from the VHR DSMs yielded R 2 =0.83, an overall root mean square error (RMSE) of 35cm, and a relative root mean square error (R-RMSE) of 11.5% for trees with heights ranging between 1.16 and 4.38m. An assessment conducted on the effects of the spatial resolution of the input images acquired by the UAV on the photo-reconstruction method and DSM generation demonstrated stable relationships for pixel resolutions between 5 and 30cm that rapidly degraded for input images with pixel resolutions lower than 35cm. RMSE and R-RMSE values obtained as a function of input pixel resolution showed errors in tree quantification below 15% when 30cmpixel−1 resolution imagery was used to generate the DSMs. The study conducted in two orchards with this UAV system and the photo-reconstruction method highlighted that an inexpensive approach based on consumer-grade cameras on board a hand-launched unmanned aerial platform can provide accuracies comparable to those of the expensive and computationally more complex light detection and ranging (LIDAR) systems currently operated for agricultural and environmental applications.


      PubDate: 2014-04-28T17:21:07Z
       
  • Combined impacts of climate and nutrient fertilization on yields of pearl
           millet in Niger
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): E. Eyshi Rezaei , T. Gaiser , S. Siebert , B. Sultan , F. Ewert
      Effects of climate variability and change on yields of pearl millet have frequently been evaluated but yield responses to combined changes in crop management and climate are not well understood. The objectives of this study were to determine the combined effects of nutrient fertilization management and climatic variability on yield of pearl millet in the Republic of Niger. Considered fertilization treatments refer to (i) no fertilization and the use of (ii) crop residues, (iii) mineral fertilizer and (iv) a combination of both. A crop simulation model (DSSAT 4.5) was evaluated by using data from field experiments reported in the literature and applied to estimate pearl millet yields for two historical periods and under projected climate change. Combination of crop residues and mineral fertilizer resulted in higher pearl millet yields compared to sole application of crop residues or fertilizer. Pearl millet yields showed a strong response to mean temperature under all fertilization practices except the combined treatment in which yields showed higher correlation to precipitation. The crop model reproduced reported yields well including the detected sensitivity of crop yields to mean temperature, but underestimated the response of yields to precipitation for the treatments in which crop residues were applied. The crop model simulated yield declines due to projected climate change by −11 to −62% depending on the scenario and time period. Future crop yields in the combined crop residues+fertilizer treatment were still larger than crop yields in the control treatment with baseline climate, underlining the importance of crop management for climate change adaptation. We conclude that nutrient fertilization and other crop yield limiting factors need to be considered when analyzing and assessing the impact of climate variability and change on crop yields.


      PubDate: 2014-04-28T17:21:07Z
       
  • Winter cover crop: the effects of grass–clover mixture proportion
           and biomass management on maize and the apparent residual N in the soil
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): B. Kramberger , A. Gselman , J. Kristl , M. Lešnik , V. Šuštar , M. Muršec , M. Podvršnik
      The advantages and disadvantages of varying mixture proportion of crimson clover (Trifolium incarnatum L.) and Italian ryegrass (Lolium multiflorum Lam.), used as winter cover crops, and cover crop biomass management before maize sowing (Zea mays L.) were studied in a series of field experiments in Eastern Slovenia. Pure stands and mixtures of cover crops on the main plots were split into different cover crop biomass management subplots: whole cover crop biomass ploughed down before maize sowing, aboveground cover crop biomass removed before ploughing and sowing, or aboveground cover crop biomass removed before sowing directly into chemically killed residues. Cover crop and cover crop biomass management affected the N content of the whole aboveground and of grain maize yields, and the differences between actual and critical N concentrations in the whole aboveground maize yield. The whole aboveground and grain maize dry matter yields, and the apparent remaining N in the soil after maize harvesting, showed significant interaction responses to cover crop×management, indicating positive and negative effects. Crimson clover in pure stand provided high, and pure Italian ryegrass provided low maize dry matter yields and N content in the yields in all the observed methods of biomass management. However, within individual management, mixtures containing high proportions of crimson clover sustained maize yields and N contents similar to those produced by pure crimson clover. Considering the expected ecological advantages of the mixtures, the results thereby support their use.


      PubDate: 2014-04-28T17:21:07Z
       
  • Attainable yield achieved for plastic film-mulched maize in response to
           nitrogen deficit
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): Ling-duo Bu , Jian-liang Liu , Lin Zhu , Sha-sha Luo , Xin-ping Chen , Shi-qing Li
      Nitrogen (N) stress limits the yields of maize (Zea mays L.) that have been plastic film-mulched in northwest China. Using the tested Hybrid-Maize simulation model, which was combined with field experiments using four levels of N fertilisers (0, 100, 250 and 400kgNha−1), we aimed to understand the variability of the attainable yield in response to N stress under plastic film mulching. We show that the application of N250 or N400 results in 100% simulated potential LAI, which is, thus, close to 100% of the simulated potential of both biomass and grain yield. However, N stress treatments significantly decreased the biomass and grain yields, achieving only 40–50% of the simulated potential (N0 treatment) and 70–80% of the simulated potential (N100 treatment). Growth dynamic measurements showed that N stress significantly decreased the LAI, delaying the source capacity growth (canopies) around the silking stage and resulting in lower final kernel numbers. The lower LAI resulted in decreased dry matter accumulation and allocation during the reproductive stage; this decrease led to a decrease in the kernel growth rate and in the grain filling duration, which resulted in a significantly lower kernel weight. This knowledge could be helpful for the optimisation of N management to close the yield gaps of dryland maize in semi-arid monsoon climate regions.


      PubDate: 2014-04-28T17:21:07Z
       
  • Comparative assessment of maize, finger millet and sorghum for household
           food security in the face of increasing climatic risk
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): J. Rurinda , P. Mapfumo , M.T. van Wijk , F. Mtambanengwe , M.C. Rufino , R. Chikowo , K.E. Giller
      Questions as to which crop to grow, where, when and with what management, will be increasingly challenging for farmers in the face of a changing climate. The objective of this study was to evaluate emergence, yield and financial benefits of maize, finger millet and sorghum, planted at different dates and managed with variable soil nutrient inputs in order to develop adaptation options for stabilizing food production and income for smallholder households in the face of climate change and variability. Field experiments with maize, finger millet and sorghum were conducted in farmers’ fields in Makoni and Hwedza districts in eastern Zimbabwe for three seasons: 2009/10, 2010/11 and 2011/12. Three fertilization rates: high (90kgNha−1, 26kgPha−1, 7tha−1 manure), low (35kgNha−1, 14kgPha−1, 3tha−1 manure) and a control (zero fertilization); and three planting dates: early, normal and late, were compared. Crop emergence for the unfertilized finger millet and sorghum was <15% compared with >70% for the fertilized treatments. In contrast, the emergence for maize (a medium-maturity hybrid cultivar, SC635), was >80% regardless of the amount of fertilizer applied. Maize yield was greater than that of finger millet and sorghum, also in the season (2010/11) which had poor rainfall distribution. Maize yielded 5.4tha−1 compared with 3.1tha−1 for finger millet and 3.3tha−1 for sorghum for the early plantings in the 2009/10 rainfall season in Makoni, a site with relatively fertile soils. In the poorer 2010/11 season, early planted maize yielded 2.4tha−1, against 1.6tha−1 for finger millet and 0.4tha−1 for sorghum in Makoni. Similar yield trends were observed on the nutrient-depleted soils in Hwedza, although yields were less than those observed in Makoni. All crops yielded significantly more with increasing rates of fertilization when planting was done early or in what farmers considered the ‘normal window’. Crops planted early or during the normal planting window gave comparable yields that were greater than yields of late-planted crops. Water productivity for each crop planted early or during the normal window increased with increase in the amount of fertilizer applied, but differed between crop type. Maize had the highest water productivity (8.0kgdrymattermm−1 ha−1) followed by sorghum (4.9kgmm−1 ha−1) and then finger millet (4.6kgmm−1 ha−1) when a high fertilizer rate was applied to the early-planted crop. Marginal rates of return for maize production were greater for the high fertilization rate (>50%) than for the low rate (<50%). However, the financial returns for finger millet were more attractive for the low fertilization rate (>100%) than for the high rate (<100%). Although maize yield was greater compared with finger millet, the latter had a higher content of calcium and can be stored for up to five years. The superiority of maize, in terms of yields, over finger millet and sorghum, suggests that the recommendation to substitute maize with small grains may not be a robust option for adaptation to increased temperatures and more frequent droughts likely to be experienced in Zimbabwe and other parts of southern Africa.


      PubDate: 2014-04-28T17:21:07Z
       
  • Corrigendum to “Comparing an empirical crop model with a functional
           structural plant model to account for individual variability”
           [Europ. J. Agronomy 53 (2014) 16–27]
    • Abstract: Publication date: Available online 26 April 2014
      Source:European Journal of Agronomy
      Author(s): Lu Feng , Jean-Claude Mailhol , Hervé Rey , Sébastien Griffon , Daniel Auclair , Philippe De Reffye



      PubDate: 2014-04-28T17:21:07Z
       
  • The effect of harvest time and pre harvest treatment on the moisture
           content of Miscanthus×giganteus
    • Abstract: Publication date: May 2014
      Source:European Journal of Agronomy, Volume 56
      Author(s): P. Meehan , K. Mc Donnell , J. Grant , J. Finnan
      This study aims to determine the most appropriate time to harvest Miscanthus × giganteus between January and April, over three possible harvest windows (Jan, Feb and Mar), relative to the harvest method being employed to cut the crop. The moisture content (MC) of biomass cut in January increased compared to the standing crop (control). From an initial MC of 53% in 2009 and 63% in 2010, the control was 12% and 13% lower than Cut Jan after 4 weeks of the treatment in respective years. The MC of Cut Feb was 19% lower than the control after 4 weeks in 2009. Despite Cut Feb being 4% higher than the control after one week in 2010, both treatments reached 34% MC after 3 weeks. A difference of 16% occurred between the Cut Mar and the control after one week in 2009 while in 2010 Cut Mar was 5% higher than the control after one week. Examining the relationship between stem MC, meteorological parameters and evapotranspiration showed that a combination of relative humidity and evaporation rate (Penman equation.) demonstrated the strongest relationship with crop MC. If harvesting early, lower MC can be achieved by cutting and collecting the crop immediately. An increase in the rate of moisture loss can be achieved later in spring by cutting the material and allowing it to dry for a period of time prior to collection if suitable drying conditions occur. An analysis across several sites showed that such conditions are most likely to occur in February.


      PubDate: 2014-04-28T17:21:07Z
       
  • Choosing the most representative technical management routes within
           diverse management practices: Application to vineyards in the Loire Valley
           for environmental and quality assessment
    • Abstract: Publication date: May 2014
      Source:European Journal of Agronomy, Volume 56
      Author(s): Christel Renaud-Gentié , Stéphane Burgos , Marc Benoît
      Diversity of agricultural systems can be described at different scales in terms of three main types of variables: technical management of cropping systems, farming systems and food supply chains. We focus on the diversity of technical management routes (TMRs), defined as logical successions of technical options (TOs) designed by the farmers. The study, comparison and assessment of this great diversity of complex routes are impossible with classical agronomic experiments or exhaustive assessments such as life cycle assessment (LCA). Hence, the selection of representative cases is necessary. Multidimensional data analysis methods permit the characterization of a diversity of TMRs and the construction of typologies but do not allow the consideration of the specific associations of TOs constituting the various TMRs. The aim of this paper is threefold: (i) to propose a new combined method, “Typ-iti”, to classify the field TMRs of farmers, to identify key TO associations and to select the most relevant cases for study; (ii) to test this method on vineyard management diversity using a panel of vineyard fields of Loire Valley producers; and (iii) to discuss the capability of the proposed Typ-iti method for use in the characterization and selection of cases of other agricultural systems at diverse scales. The example developed in this paper is the selection of vineyard management cases for grape LCA combined with grape quality evaluation. The cases were selected to represent the regional diversity of management practices. A detailed on-farm survey of management methods was performed on a diverse range of wine production estates in the Middle Loire Valley. The Typ-iti method was constructed and implemented on the survey database. It combines a multidimensional analysis of qualitative survey data and typology and partitioning (clustering) associated with data mining methods (frequent pattern mining search and association rules). The surveyed sample was partitioned into 5 types of management practices, 2 of which were organic and 3 conventional. The partitioning was driven primarily by choices involving pest management and floor management. Each type was characterized by specific TOs, specific associations of TOs and remarkable TMRs. The cases were chosen on the basis of these 3 parameters. The Typ-iti method can be applied to other crops and at different scales; the only limitation is the availability of precise information on the practices used by farmers in their fields.
      Graphical abstract image

      PubDate: 2014-04-28T17:21:07Z
       
  • Relationships between soil fertility, herbage quality and manure
           composition on grassland-based dairy farms
    • Abstract: Publication date: May 2014
      Source:European Journal of Agronomy, Volume 56
      Author(s): J.A. Reijneveld , G.W. Abbink , A.J. Termorshuizen , O. Oenema
      It is reasonable to expect that compliance with grassland fertilization recommendations in the long run results in optimal soil fertility, and subsequent herbage quality. Here, we evaluate the development of soil, herbage and manure characteristics and their relation over the last decades. We hypothesized that herbage and manure quality are related with soil fertility. We used a large database with results of soil tests, spring forage quality characteristics, and manure analyses, which were made on demand of dairy farmers. We considered the Netherlands as a whole and three selected regions with contrasting soil types (sandy soil, riverine clay, and peaty marine clay). Effects of soil fertility on herbage quality were evident when comparing farms. Farms higher in soil P and K generally have correspondingly higher contents in forage. On average, soil fertility and herbage characteristics were within or just above the agronomical optimal range during the last decades. Herbage crude protein content decreased in all regions during last two decades, which is likely an effect of legislative measures on decreasing the application of N. Selenium (Se) and sulphur (S) contents increased sharply on sandy soils, likely because of increased use of Se and S containing fertilizers. Manure composition did not differ between soil types. In conclusion, at farm level, the element composition of herbage reflected the soil fertility status. The contents of S, P, K, Na, Mg, and Ca in the herbage were all significantly influenced by soil fertility characteristics. Our results emphasize the importance of maintaining soil fertility for high quality roughage production.


      PubDate: 2014-04-28T17:21:07Z
       
  • Influence of subsurface drainage on the productivity of poorly drained
           paddy fields
    • Abstract: Publication date: May 2014
      Source:European Journal of Agronomy, Volume 56
      Author(s): Abdullah Darzi-Naftchali , Ali Shahnazari
      Because of the relatively flat topography of Northern Iran consolidated paddy fields and inadequate natural drainage facilities, these lands are usually confronted with waterlogging due to periodic excess of water from rainfall during the wet months. The productivity of these areas could be greatly increased if their drainage problems were solved by subsurface drainage. Subsurface drainage may also facilitate the mid-season drainage (MSD), one of the water management methods during the rice growing season. A drainage pilot consisting of surface and subsurface drainage with different drain depths and spacings was designed at Sari Agricultural Sciences and Natural Resources University, Iran, to explore the effect of different drainage systems on the productivity of paddy fields. Rice cultivation was carried out during two cropping seasons, 2011 and 2012. In 2011, after rice harvest, canola seed was cultivated in the subsurface drained area. For MSD, the fields were drained 25 days after rice transplanting and remained drained for 7 days. Randomized complete block design was used to find the effect of drainage on crops. The implementation of MSD through subsurface drainage, significantly increased yield, yield components and growth parameters of rice. Rice yield of the subsurface drained area was approximately 1.22–1.66 and 1.32–1.7 times higher than that of the surface drained area in 2011 and 2012, respectively. Subsurface drainage provided better condition for canola cropping while, because of waterlogging, it was not possible under surface drainage. An economic analysis showed that the cost of installing subsurface drainage systems was readily justified by annual increased rice and canola yields. Based on the results, the introduction of the subsurface drainage resulted in an increase in both crop yield and cropping intensity in the study area.


      PubDate: 2014-04-28T17:21:07Z
       
  • Agronomic performance of an IR64 introgression line with large leaves
           derived from New Plant Type rice in aerobic culture
    • Abstract: Publication date: August 2014
      Source:European Journal of Agronomy, Volume 58
      Author(s): Midori Okami , Yoichiro Kato , Nobuya Kobayashi , Junko Yamagishi
      Aerobic culture is a promising water-saving technology in irrigated rice ecosystems, but the vulnerability of plants to fluctuations in soil moisture constrains leaf expansion and yield. The objective of this study was to examine whether an aboveground architecture with large leaves and reduced tillering is associated with vigorous leaf growth in aerobic rice culture. In a series of field experiments, we evaluated the agronomic performance of an IR64 introgression line, YTH323 (IR84640-11-27-1-9-3-2-4-2-2-2-B), with fewer tillers and larger leaves than IR64, derived from New Plant Type rice, under various water and nitrogen conditions. In flooded culture, YTH323 yielded the same as IR64 and 38% more than IR65564-44-51 (a New Plant Type rice) (9.0 vs. 6.6tha−1). In aerobic culture, in contrast, it yielded 81% more than IR64 in slightly dry soils (5.1 vs. 2.8tha−1). YTH323 had a higher leaf area index than IR64 and IR65564-44-51 under slightly dry soil conditions and under a range of nitrogen conditions. The higher and more stable yield of YTH323 in aerobic culture was attributable to greater early vigor, high specific leaf area, a high ratio of leaf weight to total biomass, and larger leaves, along with the characteristics of high-yield cultivars such as high responsiveness to fertilizers and good grain filling. We conclude that genetic modification of the aboveground architecture of IR64, a typical tropical lowland rice cultivar, to reduce tiller and leaf number improves adaptation to aerobic culture.


      PubDate: 2014-04-28T17:21:07Z
       
  • Changes in the morphological traits of maize genotypes in China between
           the 1950s and 2000s
    • Abstract: Publication date: August 2014
      Source:European Journal of Agronomy, Volume 58
      Author(s): D.L. Ma , R.Z. Xie , X.K. Niu , S.K. Li , H.L. Long , Y.E. Liu
      Maize (Zea mays L.) morphological traits influence light attenuation within the canopy, and, ultimately, yield. The objectives of this 3-year field study were to: (i) examine the morphological characteristics of specific genotypes using varieties of maize that were widely used in Chinese agriculture from the 1950s to the 2000s; (ii) assess the canopies and yields of maize populations in relation to changes in their morphological characteristics. There were significant decrease on the ear ratio, center of gravity height and leaf angle with improved genotypes regardless of plant density. However, the ear leaves and adjacent leaves appeared to be longer in improved maize varieties. The mean leaf orientation value (LOV) and individual LOVs increased considerably during the time series of the genotypes, but more obvious changes in LOV occurred in the uppermost leaves. The average leaf area (LA) per plant and LA on the ears increased significantly from the 1950s to the 2000s. At the optimum density, current hybrid's canopy architecture was more compact, having short plant height and more upright leaf. The SDLA above or under ear significantly increased with improving genotypes, mainly due to new hybrids allowing the use of more individuals per area and thus increasing leaf area index (LAI). At the highest plant density, new hybrids had the rates of light transmittance (0.04–0.05), low attenuation coefficient (K =0.47) and gained the highest yield. Leaf angle and LOV were highly correlated with TPAR/IPAR on ear, K, grain yield. Consequently, yield improvement in maize was probably a result of increased plant density tolerance through dependence on changes in leaf orientation characteristics.


      PubDate: 2014-04-28T17:21:07Z
       
  • Development of critical nitrogen dilution curve in rice based on leaf dry
           matter
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): Xia Yao , Syed Tahir Ata-Ul-Karim , Yan Zhu , Yongchao Tian , Xiaojun Liu , Weixing Cao
      The critical nitrogen (N c), defined as the minimum N concentration required for maximum growth, is proposed for diagnosis of the in-season N status in crop plants. It has been established for several crops including rice on whole-plant dry matter (DM) basis but has not been determined for canopy leaf basis. This research was undertaken to develop a new N c dilution curve based on leaf dry matter (L DM) and to assess its applicability to estimate the level of N nutrition for Japonica rice in east China. Three field experiments were conducted with varied N rates (0–360kgNha−1) and three Japonica rice (Oryza sativa L.) hybrids, Lingxiangyou-18 (LXY-18), Wuxiangjing-14 (WXJ-14) and Wuyunjing (WYJ) in Jiangsu province of east China. Five hills from each plot were sampled from active tillering to heading for growth analysis and leaf N determination. The N c dilution curve on leaf N concentration was described by the equation N c =3.76W −0.218, when L DM ranged from 0.67 to 4.25tha−1. However, for L DM <0.67tha−1, the constant critical value N c =4.09%L DM was applied. This N c dilution curve on L DM basis was slightly higher than the curves on plant DM basis in Japonica rice, yet both lower than the reference curve of high yielding Indica rice in tropics. The N nutrition index (NNI) and accumulated N deficit (N and) of leaves ranged from 0.65 to 1.06 and 79.62 to −6.39kgha−1, respectively, during main growth stages under varied N rates in 2010 and 2011. The results indicate that the present N c dilution curve and derived NNI and N and adequately identified the situations of N-limiting and non-N-limiting nutrition in two rice varieties and could be used as reliable indicators of N status during growth of Japonica rice in east China.


      PubDate: 2014-01-24T19:18:02Z
       
  • Phosphorus levels in croplands of the European Union with implications for
           P fertilizer use
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): Gergely Tóth , Rannveig-Anna Guicharnaud , Brigitta Tóth , Tamás Hermann
      In the frame of the Land Use/Land Cover Area Frame Survey sampling of topsoil was carried out on around 22,000 points in 25 EU Member States in 2009 and in additional 2 Member States in 2012. Besides other basic soil properties soil phosphorus (P) content of the samples were also measured in a single laboratory in both years. Based on the results of the LUCAS topsoil survey we performed an assessment of plant available P status of European croplands. Higher P levels can be observed in regions where higher crop yields can be expected and where high fertilizer P inputs are reported. Plant available phosphorus levels were determined using two selected fertilizer recommendation systems: one from Hungary and one from the United Kingdom. The fertilizer recommendation system of the UK does not recommend additional fertilizer use on croplands with highest P supply, which covers regions mostly in Belgium and the Netherlands. According to a Hungarian advisory system there is a need for fertilizer P input in all regions of the EU. We established a P fertilizer need map based on integrating results from the two systems. Based on data from 2009 and 2012, P input demand of croplands in the European Union was estimated to 3,849,873  tons ( P 2 O 5 ) / year . Meanwhile we found disparities of calculated input need and reported fertilizer statistics both on local (country) scale and EU level. The first ever uniform topsoil P survey of the EU highlights the contradictions between soil P management of different countries of the Union and the inconsistencies between reported P fertilizer consumption and advised P doses. Our analysis shows a status of a baseline period of the years 2009 and 2012, while a repeated LUCAS topsoil survey can be a useful tool to monitor future changes of nutrient levels, including P in soils of the EU.


      PubDate: 2014-01-24T19:18:02Z
       
  • Quantifying growth and development of bulb turnips
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): M.P. Andreucci , D.J. Moot , A.D. Black
      Bulb brassicas are used as supplementary feed in intensive pastures systems. However, there is a lack of quantitative data to define their growth and development. This has limited the creation and use of prediction models and decision support systems. Thus a field experiment measured growth and development of ‘Barkant’ and ‘Green Globe’ turnips sown on five dates from November 2008 to March 2009. In a second field experiment ‘Green Globe’ turnips were sown on four dates from December 2009 to March 2010, under two ground cover treatments that changed mean soil temperature by ∼2°C. Bulb initiation was defined botanically as when the hypocotyl was 10mm thick, at 360°Cd (±13.0) for ‘Barkant’ and 420°Cd (±13.7) (T b =3.6°C) for ‘Green Globe’. However, the bulb participation in dry matter production occurs after an 18mm hypocotyl thickness, which occurred at ∼500°Cd for both turnip cultivars. A single base parameter of 0.995 described the exponential decline of the leaf:bulb ratio. Relationships also described how leaf production and total leaf area expansion changed up until bulb initiation. Radiation use efficiency (RUE) ranged from 1.13 to 1.33g DM/MJ total. A constant rate of total leaf area expansion (0.015m2/m2/°Cd) was obtained up to LAIc for ‘Green Globe’ turnips. A third pot experiment confirmed the thermal time requirement to bulb initiation based on direct assessment of the hypocotyl thickening of ‘Barkant’ and ‘Green Globe’ turnips. Temperature was shown as the main driver of bulb development and growth. The relationships provided could be used to improve the performance of prediction models.


      PubDate: 2014-01-16T22:58:01Z
       
  • Maize grain and silage yield and yield stability in a long-term cropping
           system experiment in Northern Italy
    • Abstract: Publication date: April 2014
      Source:European Journal of Agronomy, Volume 55
      Author(s): Lamberto Borrelli , Fabio Castelli , Enrico Ceotto , Giovanni Cabassi , Cesare Tomasoni
      This study assesses maize yield and yield stability over a 26-year period in several cropping systems that are part of a long-term crop rotation and agronomic input experiment established in 1985 in Lodi, Lowland of Lombardy, Po Valley, Northern Italy. This experiment compares five fodder crop rotations, specifically: (i) an annually repeated double crop (R1) of autumn-sown Italian ryegrass+spring-sown maize, both used for silage; (ii) a three-year rotation (R3): grain maize (first year) – autumn-sown barley (Hordeum vulgare L.)+spring-sown maize, both for silage (second year) – Italian ryegrass+maize, both for silage (third year); (iii) a six-year rotation (R6): Italian ryegrass+silage maize, both for silage (years 1, 2 and 3 of rotation) – a mixed meadow of white clover (Trifolium repens L.) and tall fescue (Festuca arundinacea Schreb) for hay making (years 4, 5 and 6 of rotation); (iv) a continuous grain maize (CM); and (v) a permanent meadow, established at the beginning of the experiment. All phases of the rotations were carried out every year. Each crop rotation received two levels of agronomic inputs consisting in synthetic and manure fertilization and herbicide rate, corresponding to high (A) and low (B). Treatment A represented a snapshot of agronomic inputs (synthetic fertilizers N–P–K, manure and herbicide amounts) normally applied by the farmers in the region in 1985, when the experiment was undertaken, while treatment B consisted in a 30% reduction of synthetic and manure fertilizers and a 25% reduction of herbicide rate compared to treatment A. The primary objective of this study was to evaluate the long-term effects of crop rotations and the reduction of inputs on maize yield and yield variability. The following conclusions can be drawn: firstly, over 26 years, the yield of grain maize in rotation increased steadily whilst the yield of continuous maize decreased slightly; secondly, a 30% reduction of agronomic inputs decreased the average yield less than proportionally for both grain and silage maize; thirdly, within a given crop rotation, grain and silage maize yields are more stable with higher inputs; and finally, yield stability of grain and silage maize increases with longer rotations. Therefore, management options oriented at increasing cropping system biodiversity have important implications on reducing the temporal variability on maize yield.


      PubDate: 2014-01-16T22:58:01Z
       
  • Barley–hairy vetch mixture as cover crop for green manuring and the
           mitigation of N leaching risk
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): Giacomo Tosti , Paolo Benincasa , Michela Farneselli , Francesco Tei , Marcello Guiducci
      Adopting mixtures of legumes and non-legumes can be an efficient tool to merge the advantages of the single species in the fall-sown cover crop practice. Cover crop mixtures are supposed to provide an additional benefit in reducing N leaching risks as compared to pure legume thanks to the N trapping skill of the non-legume companion, but to our knowledge no data are available on the effect of mixed cover crops on N leaching. For this reason, in a three-year study we investigated the effect of barley (Hordeum vulgare L.) and hairy vetch (Vicia villosa Roth.) grown in 100% pure stands or in 50:50 mixtures on the N leaching below the rooting zone as compared to the bare soil. The NO3-N concentration in the soil solution was monitored by suction cup lysimeters placed at 0.9m depth during the whole growing cycle and after cover crop incorporation into the soil and the amount of leached N was calculated on the basis of estimated drainage. The mixture showed variable biomass accumulation and proportion in the biomass accumulated by companion species across years, but a rather constant N accumulation, with a biomass C/N ratio intermediate between those of the pure crops. In all years, the N trapping effect of the mixture was clear as it decreased NO3-N leaching at the same level of pure barley, both during its own growing cycle and after cover crop incorporation into the soil. Pure vetch showed the highest N source potential as green manure but no NO3-N leaching mitigation effect as compared to the bare soil. Thus we demonstrate here that a mixture of barley and vetch, which was already known to be a “self-buffered system” able to guarantee a good and rather stable N accumulation, is also a “buffering system” for the agroecosystems in the Mediterranean conditions by acting as a N trapping crop able to reduce N leaching.


      PubDate: 2013-12-23T15:15:12Z
       
  • Alternative strategies for nitrogen fertilization of overwinter processing
           spinach (Spinacia oleracea L.) in Southern Italy
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): S. Canali , M. Diacono , C. Ciaccia , O. Masetti , F. Tittarelli , F. Montemurro
      To identify the best practice for nitrogen (N) fertilization of overwinter processing spinach, two field experiments were carried out in the Foggia plain (Southern Italy), one of the most vocated area for leafy vegetables production. The field trials were aimed to define and suggest the proper fertilizer dose, typology and the right time of application. Experiment 1 evaluated four N fertilizer doses (0, 150, 225, 300kgha−1) in a two-year field trial. Experiment 2 was aimed to assess the effect of the split distribution of prilled urea fertilizer in comparison with the application of nitrification inhibitor (DMPP) containing urea fertilizer, broadcasted at sowing. Spinach yield, yield quality (nitrate – NO3 − – and carotenoids content), N-use efficiency and risk of soil nitrate (NO3 −-N) leaching were evaluated. The processing spinach yielded 37.8 and 3.6tha−1 of fresh and dry yield, respectively (average of the two experiments). Fresh and dry yield among the fertilizing treatments were similar. Also the β-carotene and the lutein content of spinach leaves (19.5 and 38.1mgkg−1, respectively) were not affected by the N fertilizer dose. Conversely, the N dose strongly influenced the NO3 − content of the leafy vegetable tissues (1286mgkg−1 on average, 58% lower than the limits imposed by the EC regulation). As expected, the different rainfall pattern influenced both the leaf NO3 − content and the risk of soil NO3 −-N leaching. The results achieved demonstrated that, in order to get a favorable trade-off, among yield, yield quality, N-use efficiency and environmental impact, the processing spinach growers of the Foggia plain area should be encouraged to apply 225kgNha−1 as maximum fertilization rate. Also, the split urea fertilizer application appeared as the more effective strategy for N fertilization of overwinter spinach in comparison with the use of the nitrification inhibitor containing urea fertilizer, being the last strategy not able to adequately match the N crop demand.


      PubDate: 2013-12-23T15:15:12Z
       
  • Is time to flowering in wheat and barley influenced by nitrogen?: A
           critical appraisal of recent published reports
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): Antonio J. Hall , Roxana Savin , Gustavo A. Slafer
      The literature includes a number of reports, relating to both crop and non-crop species, showing conflicting responses of developmental plasticity to nitrogen availability. We reviewed 1130 papers published from 1990 to 2010 drawn from 14 agriculture-themed journals and conducted a critical appraisal of the effects of fertiliser nitrogen on time to heading or anthesis in barley and wheat, species for which there is a good deal of data. Features of the analysis were the use of relative responses (respect to unfertilised controls) of yield and time to flowering to nitrogen as a proxy for crop nitrogen status and developmental differences, respectively, and the standardisation of the start point for calculating time (in both calendar and thermal units) to flowering in autumn-sown winter cultivars to March 1 (N Hemisphere). The resulting database (180 cases) covered a broad range of unfertilised crop yields (1–8Mgha−1), and times to flowering (47–168 days). In very few cases (19 out of 118), the relative time to flowering in fertilised crops differed by more than 5% from those of unfertilised crops across a range of yield responses to fertiliser nitrogen from negligible to three-fold. Currently available evidence does not provide solid support to a plastic response of time to flowering to nitrogen in these two species.


      PubDate: 2013-12-23T15:15:12Z
       
  • Yield of bolting winter beet (Beta vulgaris L.) as affected by plant
           density, genotype and environment
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): E. Reinsdorf , H.-J. Koch , J. Loel , C.M. Hoffmann
      Winter beet roots and shoots might be a favorable substrate for biogas production in Central Europe. However, detailed information about the attainable yield of this crop is lacking. Thus, the impact of plant density, genotype and environmental conditions on total dry matter yield of winter beet crops that bolt after winter was investigated. A significant increase of the dry matter yield (esp. shoot) was expected by harvesting the 1st shoot after flowering in June followed by a final harvest of the whole plant in July. In 2009/10, 2010/11 and 2011/12, three series of field trials with (i) 3 target plant densities (148, 246, 370 thousand plants ha−1) and (ii) 3 different sugar beet genotypes were conducted at Göttingen (Lower Saxony, GER) and Kiel (Schleswig-Holstein, GER); (iii), additional field trials with 5 different sugar beet genotypes cultivated at 2 target plant densities (148, 246 thousand plants ha−1) were conducted in 2011/12, to investigate the relation between maximum taproot diameter and the shoot and taproot yield of bolting winter beet. The total dry matter yield considerably varied between 4 and 23tha−1. It was predominantly affected by the environment and to a substantially lower extent by plant density. Increasing plant densities increased the total dry matter yield, resulting in a significantly higher total dry matter yield at plant densities ≥300,000plantsha−1 compared with lower plant densities. Genotypic differences in total dry matter yield were negligibly small. Pruning in June substantially increased the total dry matter yield in July by ca. 8tha−1 only in one out of three environments. Final yield in June (without pruning) and July (pruning in June) was positively related with cumulated temperature and global radiation, but also with taproot dry matter yield before winter. The taproot, shoot (1st, 2nd) and total plant yield were positively correlated with maximum taproot diameter. In conclusion, high dry matter yields close to yields of established energy crops grown over winter were obtained with winter beet roots and shoots only under very favorable conditions (climate, single plant size). High yields can be achieved after good pre-winter development. However, for sufficient frost tolerance the taproot size of plants must be rather small. Hence, the cultivation of bolting winter beet under Central European climate conditions has to face a severe conflict of goals concerning winter survival and yield formation.


      PubDate: 2013-12-15T16:25:04Z
       
  • Grapevine bud fertility and number of berries per bunch are determined by
           water and nitrogen stress around flowering in the previous year
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): Nicolas Guilpart , Aurélie Metay , Christian Gary
      Grapevine yield formation extends over two consecutive years (seasons 1 and 2). The inflorescence formation (around flowering in season 1) is crucial as it is involved in the formation of both the bunch number per vine and the berry number per bunch in season 2, that account for about 60% and 30% of year-to-year yield variation of grapevine, respectively. Light, temperature, water and nitrogen availability are known to affect this early stage. The aims of this work were to determine the critical periods during which inflorescence formation is sensitive to water and nitrogen stress and quantify their effects on it. To address these issues, we used a 3-year (2010–2012) field experiment (cv. Shiraz) in combination with a water balance simulation model (WaLIS) and a 6-year field experiment (cv. Aranel). In both experiments, different treatments were applied to create a gradient of water and nitrogen supply (treatments involved cover cropping, irrigation and fertilization). The grapevine yield and its components were recorded. Water and nitrogen status of grapevine were monitored throughout the season. Inflorescence formation was sensitive to water and nitrogen stress during a critical period that occurred between 400 and 700°Cd after budburst in season 1. Bud fertility (number of bunches per shoot) and berry number per bunch in season 2 were significantly correlated with the fraction of transpirable soil water (FTSW), predawn leaf water potential and leaf nitrogen content at that time for both cultivars. Water and nitrogen stress during the critical period of season 1 determined 65–70% of grapevine yield in season 2. Our results show that the maximum yield that can be reached in season 2 is determined during the critical period of season 1 and they provide clues to estimate it. These results may help grape growers to adapt their practices (i) in season 1 to ensure a sufficient maximum yield for season 2 and (ii) to actually obtain the targeted yield in season 2 depending on the maximum yield determined in season 1.


      PubDate: 2013-12-15T16:25:04Z
       
 
 
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