for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> AGRICULTURE (Total: 653 journals)
    - AGRICULTURAL ECONOMICS (70 journals)
    - AGRICULTURE (438 journals)
    - CROP PRODUCTION AND SOIL (84 journals)
    - DAIRYING AND DAIRY PRODUCTS (24 journals)
    - POULTRY AND LIVESTOCK (37 journals)

AGRICULTURE (438 journals)            First | 1 2 3 4 5     

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

  First | 1 2 3 4 5     

European Journal of Agronomy    [9 followers]  Follow    
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1161-0301
     Published by Elsevier Homepage  [2556 journals]   [SJR: 1.191]   [H-I: 53]
  • 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
       
  • Responses to temperature of fruit dry weight, oil concentration, and oil
           fatty acid composition in olive (Olea europaea L. var.
           ‘Arauco’)
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): G.P. García-Inza , D.N. Castro , A.J. Hall , M.C. Rousseaux
      Correlative studies in olive using data from different locations or years suggest that temperature can modulate crop oil yield and oil composition. However, there are no published studies of manipulative experiments that demonstrate a direct role for temperature as a regulator of oil yield and oil quality in olive. The objectives of this study were to: i) elucidate the effect of temperature during the fruit oil accumulation phase on fruit dry weight, oil concentration and fatty acid composition; and ii) identify the developmental window within the oil accumulation phase exhibiting the greatest sensitivity to temperature and that with the highest fruit capacity to recover from the temperature treatments. Two branch-level experiments were conducted in a commercial orchard at Los Molinos (La Rioja, Argentina) using var. ‘Arauco’. Both experiments were conducted during the oil accumulation phase by enclosing fruiting branches in transparent plastic chambers with individualized temperature control. The first experiment; known as the four month long experiment, employed four temperature treatments that were applied for a single period of four months: a control at ambient temperature, two heating levels (5°C and 10°C warmer than the control), and a cooling level (5°C cooler than the control). The second experiment consisted of four separate successive one month long treatment periods, in each of which two temperature treatments were applied: control and heating (ca. 7°C higher than control). In the four month long experiment, fruit dry weight was not affected by average temperatures in the 16–25°C range, but it was reduced with further increases in temperature. Oil concentration decreased linearly at 1.1% °C−1 across the whole range (16–32°C) of average seasonal temperatures explored, while oleic acid concentration decreased 0.7% °C−1 over the same range. In the one month long experiment, 30 days of temperatures ca. 7°C above ambient had a permanent negative effect on oil concentration at final harvest, particularly when the exposure to high temperature took place at the beginning of oil accumulation. By contrast, oleic acid concentration at the end of the treatment interval fell with increasing temperature but it could recover after treatment was removed in all periods except the first one. These results show that high temperatures during the oil accumulation phase may negatively affect olive oil yield and quality in warm regions, particularly if the high-temperature event occurs early in the phase. Additionally, the response of oleic acid concentration (%) to temperature under our experimental conditions was found to be opposite to that of many annual oil-seed crops.
      Graphical abstract image

      PubDate: 2014-01-13T04:25:17Z
       
  • Response of soil biological activity to common herbicide strategies in
           sugar beet cultivation
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): Andreas Marwitz , Erwin Ladewig , Bernward Märländer
      Agricultural intensification is strongly related to the application of pesticides which may substantially affect agroecosystems. It is recognized that the effect of pesticides on agroecosystems is associated with the application of multi-component mixtures rather than from individual pesticides. In sugar beet (Beta vulgaris L.) cultivation, the most used pesticides are herbicides. Herbicides are commonly applied with varying intensities depending on their amount of active ingredients and dosages to coincide with weed species-specific occurrence. Research on their ecotoxicological effects on functional attributes of agroecosystems has not received adequate attention. This study aims to determine the impact of three common sugar beet herbicide strategies (HS) on the biological activity of the edaphic community, proposed as a functional indicator for potential decomposition capability. The strategies compared were: HS1: two herbicides, 100% of authorized application rate; HS2: three herbicides, <50% of authorized application rate; HS3: six herbicides, ≤35% of authorized application rate. To discern anticipated small differences, different tillage intensities (ploughing and mulching) and comprehensive field trials at 19 environments (site×year) distributed throughout Germany were compared. Feeding activity on bait substrate and the mass loss of wheat straw were measured to quantify the effect of HS on the decomposition activity of the edaphic community. Overall, this study demonstrated that no consistent significant differences in biological activity were found among herbicides strategies. Environment and tillage intensity were the main factors influencing the biological activity of the edaphic community. Biological activity was highly variable among environments and was reduced by differences in tillage. Furthermore, temperature was observed to be an important factor for the biological activity. Moreover, soil parameters resulting from reduced tillage intensity in the mulching system enhanced biological activity. In conclusion, clear and direct effects of changing herbicide strategies on the functional integrity of the edaphic community could not be discerned. These results were quantified for the first time through considering multiple influencing factors in situ.


      PubDate: 2014-01-08T16:33:05Z
       
  • Assessing innovative sowing patterns for integrated weed management with a
           3D crop:weed competition model
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      Author(s): Nathalie Colbach , Alban Collard , Sébastien H.M. Guyot , Delphine Mézière , Nicolas Munier-Jolain
      Weed dynamics models are needed to design innovative weed management strategies. Here, we developed a 3D individual-based model called FlorSys predicting growth and development of annual weeds and crops as a function of daily weather and cropping practices: (1) crop emergence is driven by temperature, and emerged plants are placed onto the 3D field map, depending on sowing pattern, density, and emergence rate; plants are described as cylinders with their leaf area distributed according to height; (2) weed emergence is predicted by an existing submodel, emerged weed seedlings are placed randomly; (3) plant phenology depends on temperature; (4) a previously developed submodel predicts available light in each voxel of the canopy; after emergence, plant growth is driven by temperature; when shaded, biomass accumulation results from the difference between photosynthesis and respiration; shading causes etiolation; (5) frost reduces biomass and destroys plants, (6) at plant maturity, the newly produced seeds are added to the soil seed bank. The model was used to test different sowing scenarios in an oilseed rape/winter wheat/winter barley rotation with sixteen weed annuals, showing that (1) crop yield loss was negatively correlated to weed biomass averaged over the cropping season; (2) weed biomass was decreased by scenarios allowing early and homogenous crop canopy closure (e.g. reduced interrows, increased sowing density, associated or undersown crops), increased summer fatal weed seed germination (e.g. delayed sowing) or, to a lesser degree, cleaner fields at cash crop sowing (e.g. sowing a temporary cover crop for “catching” nitrogen); (3) the scenario effect depended on weed species (e.g. climbing species were little affected by increased crop competition), and the result thus varied with the initial weed community (e.g. communities dominated by small weed species were hindered by the faster emergence of broadcast-sown crops whereas taller species profited by the more frequent gap canopies); (4) the effect on weed biomass of sowing scenarios applied to one year was still visible up to ten years later, and the beneficial effect during the test year could be followed by detrimental effects later (e.g. the changed tillage dates accompanying catch crops reduced weed emergence in the immediately following cash crop but increased seed survival and thus infestation of the subsequent crops). This simulation showed FlorSys to predict realistic potential crop yields, and the simulated impact of crop scenarios was consistent with literature reports.
      Graphical abstract image

      PubDate: 2014-01-04T22:20:46Z
       
  • Prediction of sunflower grain oil concentration as a function of variety,
           crop management and environment using statistical models
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): Fety Nambinina Andrianasolo , Pierre Casadebaig , Elie Maza , Luc Champolivier , Pierre Maury , Philippe Debaeke
      Sunflower (Helianthus annuus L.) raises as a competitive oilseed crop in the current environmentally friendly context. To help targeting adequate management strategies, we explored statistical models as tools to understand and predict sunflower oil concentration. A trials database was built upon experiments carried out on a total of 61 varieties over the 2000–2011 period, grown in different locations in France under contrasting management conditions (nitrogen fertilization, water regime, plant density). 25 literature-based predictors of seed oil concentration were used to build 3 statistical models (multiple linear regression, generalized additive model (GAM), regression tree (RT)) and compared to the reference simple one of Pereyra-Irujo and Aguirrezábal (2007) based on 3 variables. Performance of models was assessed by means of statistical indicators, including root mean squared error of prediction (RMSEP) and model efficiency (EF). GAM-based model performed best (RMSEP=1.95%; EF=0.71) while the simple model led to poor results in our database (RMSEP=3.33%; EF=0.09). We computed hierarchical contribution of predictors in each model by means of R 2 and concluded to the leading determination of potential oil concentration (OC), followed by post-flowering canopy functioning indicators (LAD2 and MRUE2), plant nitrogen and water status and high temperatures effect. Diagnosis of error in the 4 statistical models and their domains of applicability are discussed. An improved statistical model (GAM-based) was proposed for sunflower oil prediction on a large panel of genotypes grown in contrasting environments.


      PubDate: 2013-12-31T16:26:10Z
       
  • The effect of tillage system and residue management on grain yield and
           nitrogen use efficiency in winter wheat in a cool Atlantic climate
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): J. Brennan , R. Hackett , T. McCabe , J. Grant , R.A. Fortune , P.D. Forristal
      The effects of soil tillage and straw management systems on the grain yield and nitrogen use efficiency of winter wheat (Triticum aestivum L. em. Thell.) were evaluated in a cool Atlantic climate, in central Ireland between 2009 and 2011. Two tillage systems, conventional tillage (CT) and reduced tillage (RT) each with and without incorporation of the straw of the preceding crop, were compared at five levels of fertiliser N (0, 140, 180, 220 and 260kgNha−1). CT had a significantly higher mean grain yield over the three years but the effect of tillage varied between years. Yields did not differ in 2009 (Year 1), while CT produced significantly higher grain yields in 2010 (Year 2), while RT produced the highest yields in 2011 (Year 3). Straw incorporation had no significant effect in any year. Nitrogen application significantly increased the grain yields of all establishment treatment combinations. Nitrogen use efficiency (NUE) ranged from 14.6 to 62.4kg grain (85% DM)kgNha−1 and decreased as N fertiliser rate was increased. The CT system had a significantly higher mean NUE over the three years but the effect of tillage varied with years. While there was no tillage effect in years 1 and 3, CT had a significantly higher NUE than RT in year 2. Straw management system had minimal effect on NUE in any year. The effect of tillage and N rate on soil mineral N content also varied between years. While there was no tillage effect in years 1 and 3, RT had significantly larger soil N contents than CT in the spring before N application, and post-harvest in year 2. N application rates had no effect on soil N in year 1, increased residual N content in year 2 and had an inconsistent effect in year 3. Straw management had no significant effect on soil mineral N content. These results indicate that RT establishment systems can be used to produce similar winter wheat yields to CT systems in a cool Atlantic climate, providing weather conditions at establishment are favourable. The response to nitrogen is similar with both tillage systems where the crop is successfully established. Straw management system has very little effect on crop performance or nitrogen uptake.


      PubDate: 2013-12-28T04:28:13Z
       
  • Rice reproductive growth duration increased despite of negative impacts of
           climate warming across China during 1981–2009
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): Shuai Zhang , Fulu Tao , Zhao Zhang
      Changes in rice phenology during 1981–2009 were investigated using observed phenological data from hundreds of agro-meteorological stations across China. Spatiotemporal changes of rice phenology across China, as well as the relations to temperature, day length and cultivars shifts were analyzed and presented. We found that major rice phenological dates generally advanced while rice growing period changed diversely for different rice cultivation systems in different agro-ecological zones. Length of vegetative growth period (VGP) increased at 59 (67.0%) stations for single-rice, however, decreased at 36 (54.5%) and 35 (51.5%) stations for early-rice, and late-rice, respectively. Length of reproductive growth period (RGP) increased at 71 (70.3%) and 49 (55.7%) stations for single-rice and early-rice, respectively, however, decreased at 46 (54.8%) stations for late-rice. The changes were ascribed to the combined effects of changes in temperature, photoperiod and cultivar thermal characteristics. Increase in temperature had negative impacts on the lengths of VGP and RGP. Day length slightly counterbalanced the roles of temperature in affecting the duration of VGP. Furthermore, we found that during 1981–2009 cultivars with longer growth duration of VGP were adopted for single-rice, but cultivars with shorter growth duration of VGP were adopted for early-rice and late-rice. Cultivars with longer growth durations of RGP were adopted for single-rice and early-rice, as well as late-rice at the middle and lower reaches of Yangtze River. However, in the southwestern China and southern China, cultivars with shorter or almost same growth duration of RGP were adopted for late rice.


      PubDate: 2013-12-28T04:28:13Z
       
  • The effect of a sandy soil amendment with municipal solid waste (MSW)
           compost on nitrogen uptake efficiency by plants
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): Jerzy Weber , Andrzej Kocowicz , Jakub Bekier , Elzbieta Jamroz , Rafal Tyszka , Magdalena Debicka , Danuta Parylak , Leszek Kordas
      The purpose of this work was to determine the influence of municipal solid waste (MSW) compost application on soil properties, nitrogen availability to plants and its uptake efficiency. The paper deals with results of a three-year field experiment where two different MSW composts were non-recurrently applied to sandy soil at rates of 18, 36 and 72tha−1 (dry mass). Plots without fertilisation as well as plots fertilised each year with mineral forms of NPK were the controls, and spring triticale was cultivated in a monoculture on all plots as a test plant. Soil properties, plant yield and nitrogen content in grain and straw were determined at harvest, and on this basis the applied nitrogen uptake efficiency was calculated. During the first year, only the plots with the highest dose of the better-quality compost had yields similar to the plots fertilised with mineral NPK. Following the years of the experiment, all the plots treated with compost had distinctly lower yields than the plots fertilised with mineral NPK. That decrease was accompanied by a decrease in the nitrogen content in straw and grain, in spite of the fact that the soil material indicated a similar content of total nitrogen to those fertilised with NPK. This indicates that organic matter brought into the soil with MSW compost was intensively mineralised, releasing a considerable amount of nitrogen. However, the plant response indicated a shortage of the plant-available forms of this element. The efficiency of compost-originated nitrogen uptake by plants was very low, at less than 7% of the applied nitrogen. This indicates that plants can take up only a limited amount of nitrogen released from the compost, while considerable amounts are emitted into the atmosphere.


      PubDate: 2013-12-23T15:15:12Z
       
  • 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
       
  • Italian ryegrass establishment by self-seeding in integrated
           crop-livestock systems: Effects of grazing management and crop rotation
           strategies
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      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: 2013-12-15T16:25:04Z
       
  • Field experiments and simulation to evaluate rice cultivar adaptation to
           elevated carbon dioxide and temperature in sub-tropical India
    • Abstract: Publication date: March 2014
      Source:European Journal of Agronomy, Volume 54
      Author(s): Sushree Sagarika Satapathy , Dillip Kumar Swain , Srikantha Herath
      Location specific adaptation option is required to minimize adverse impact of climate change on rice production. In the present investigation, we calibrated genotype coefficients of four cultivars in the CERES-Rice model for simulation of rice yield under elevated CO2 environment and evaluation of the cultivar adaptation in subtropical India. The four cultivars (IR 36, Swarna, Swarn sub1, and Badshabhog) were grown in open field and in Open Top Chamber (OTC) of ambient CO2 (≈390ppm) and elevated CO2 environment (25% higher than the ambient) during wet season (June–November) of the years 2011 and 2012 at Kharagpur, India. The genotype coefficients; P1 (basic vegetative phase), P2R (photoperiod sensitivity) and P5 (grain filling phase) were higher, but G1 (potential spikelet number) was lower under the elevated CO2 environment as compared to their open field value in all the four cultivars. Use of the calibrated model of elevated CO2 environment simulated the changes in grain yield of −13%, −17%, −4%, and +7% for the cultivars IR 36, Swarna, Swarna sub1, and Badshabhog, respectively, with increasing CO2 level of 100ppm and rising temperature of 1°C as compared to the ambient CO2 level and temperature and they were comparable with observed yield changes from the OTC experiment. Potential impacts of climate change were simulated for climate change scenarios developed from HadCM3 global climate model under the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (A2 and B2) for the years 2020, 2050, and 2080. Use of the future climate data simulated a continuous decline in rice grain yield from present years to the years 2020, 2050 and 2080 for the cultivars IR 36 and Swarna in A2 as well as B2 scenario with rising temperature of ≥0.8°C. Whereas, the cultivar Swarna sub1 was least affected and Badshabhog was favoured under elevated CO2 with rising temperature up to 2°C in the sub-tropical climate of India.


      PubDate: 2013-12-15T16:25:04Z
       
  • Long-term phytomanagement of metal-contaminated land with field crops:
           Integrated remediation and biofortification
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      Author(s): Teofilo Vamerali , Marianna Bandiera , Paola Lucchini , Nicholas M. Dickinson , Giuliano Mosca
      Several studies on the phytomanagement of mixed-metal-contaminated land were carried out over a period of 10 years in an agricultural soil at Carpiano (Milan, Italy) and in pyrite waste at Torviscosa (Udine, Italy), in order to investigate the practicability of using various field crops for this purpose. Here we demonstrate that seed germination and initial growth are never critical steps under high levels of Cd or Cr, whereas poor plant productivity limits metal removal rates from contaminated waste. Phytoextraction alone was rarely an efficient remediation technology and, if the process was not chemically assisted, only Zn and Mn were accumulated above-ground in considerable amounts. A maximum of 8kgha−1 of metals with rapeseed and only 0.33kgha−1 with fodder radish were removed from soil. Cultivation of metal-contaminated land did provide some limited opportunity for natural biofortification of crops with Zn and Cu, with no apparent risk of toxic metals in the seeds of only a few crops. Improvements in tissue metal rates achieved with auxins, humic acids or chelators were largely detrimental to biomass yield. We conclude that the efficient use of crop species in phytoremediation requires the achievement of high productivity by appropriate agricultural management involving tillage, fertilisation and perhaps also capping or dilution with clean soil. The considerable metal stock in roots suggests exploring the effectiveness of long-term stabilisation, particularly in non-tillage systems.


      PubDate: 2013-12-11T11:39:40Z
       
  • California processing tomatoes: Morphological, physiological and
           phenological traits associated with crop improvement during the last 80
           years
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      Author(s): Felipe H. Barrios-Masias , Louise E. Jackson
      Breeding has greatly increased yields of many crops, but the contributions of particular morphological, phenological and physiological traits to these higher yields are rarely well understood. In the past 50 years, California processing tomato yields per hectare have more than doubled. This study evaluated a group of important processing tomato cultivars released over the past 80 years in California. The objective was to assess how a suite of traits might be associated with genetic improvement for yield gains. A wide array of morphological, physiological and phenological traits and relevant environmental variables was evaluated in the field for a discrete set of eight cultivars originating from a common ancestor. Multivariate statistics were used to analyze the set of 95 variables to understand how cultivars became adapted to a more mechanized agronomic management while also producing higher yields. No single trait seems to have driven yield increases. Instead, distinct assemblies of traits characterize the processing tomato cultivars in different eras. For instance, certain phenological traits (early flowering and concentrated fruit set) were associated with a set of morphological traits (smaller canopies and low vegetative biomass), along with gains in physiological traits (biomass N concentration and photosynthetic rates) in modern varieties. These results provide a platform to examine new suites of traits that could be relevant for future breeding and crop improvement.


      PubDate: 2013-12-11T11:39:40Z
       
  • Considering cost accountancy items in crop production simulations under
           climate change
    • Abstract: Publication date: January 2014
      Source:European Journal of Agronomy, Volume 52, Part A
      Author(s): T. Münch , M. Berg , W. Mirschel , R. Wieland , C. Nendel
      A Farm Economy Coefficient Generator (FECG) is presented as a post-processing tool for agro-ecological simulation models (ASMs) that deliver yields and consumption figures for nitrogen fertiliser and irrigation water use. The FECG carries out simple cost accountancy calculations using typical production techniques, costs and prices for the selected area. The default settings can be adjusted by the user to specifically describe local farm management. Together with various ASMs, the FECG is embedded in a web-based, geo-referenced decision support system to enable users to extract information on future yields and net returns on a regional or farm-level basis. Using the example of a winter wheat–winter barley–silage maize crop rotation in Germany and downscaled A1B climate data it was demonstrated how the ASM–FECG tandem can be used to analyse the cost and benefit of irrigation. In this example the irrigation costs would still outweigh the yield increase today, while in around 2070 the increased difference between potential and water-limited yield is likely to make irrigation profitable, provided that costs and price levels remain constant. The susceptibility of these results to changing market conditions is discussed.


      PubDate: 2013-12-07T22:43:52Z
       
  • Testing farm management options as climate change adaptation strategies
           using the MONICA model
    • Abstract: Publication date: January 2014
      Source:European Journal of Agronomy, Volume 52, Part A
      Author(s): C. Nendel , K.C. Kersebaum , W. Mirschel , K.O. Wenkel
      Adaptation of agriculture to climate change will be driven at the farm level in first place. The MONICA model was employed in four different modelling exercises for demonstration and testing different management options for farmers in Germany to adjust their production system. 30-Year simulations were run for the periods 1996–2025 and 2056–2085 using future climate data generated by a statistical method on the basis of measured data from 1961 to 2000 and the A1B scenario of the IPCC (2007a). Crop rotation designs that are expected to become possible in the future due to a prolonged vegetation period and at the same time shortened cereal growth period were tested for their likely success. The model suggested that a spring barley succeeding a winter barley may be successfully grown in the second half of the century, allowing for a larger yields by intensification of the cropping cycle. Growing a winter wheat after a sugar beet may lead to future problems as late sowing makes the winter wheat grow into periods prone to drought. Irrigation is projected to considerably improve and stabilise the yields of late cereals and of shallow rooting crops (maize and pea) on sandy soils in the continental climate part of Germany, but not in the humid West. Nitrogen fertiliser management needs to be adjusted to increasing or decreasing yield expectations and for decreasing soil moisture. On soils containing sufficient amounts of moisture and soil organic matter, enhanced mineralisation is expected to compensate for a greater N demand.


      PubDate: 2013-12-07T22:43:52Z
       
  • YIELDSTAT – A spatial yield model for agricultural crops
    • Abstract: Publication date: January 2014
      Source:European Journal of Agronomy, Volume 52, Part A
      Author(s): Wilfried Mirschel , Ralf Wieland , Karl-Otto Wenkel , Claas Nendel , Christian Guddat
      The YIELDSTAT model for crop yields, an advanced hybrid of traditional non-linear regression approaches and expert knowledge databases, was developed to predict the spatial distribution of yields for a range of arable crops (winter wheat, winter barley, winter rye, winter triticale, spring barley, oats, potato, sugar beet, winter oil-seed rape, silage maize, clover, clover/grass mix, lucerne, lucerne/grass mix, fodder grass) and two grassland types (intensive, extensive) in eastern Germany across different scales up to the regional scale. YIELDSTAT accounts for a wide range of yield-influencing factors derived from weather, soil, relief and management data, as well as for the long-term changing atmospheric CO2 concentration and for the trend owing to progress in breeding and agro-technology. YIELDSTAT regression modules were derived from several hundred farm data sets from 1975 to 1990 and tested against recent yield observations from the Federal State of Thuringia, Germany. The model test was performed at three different spatial scales. YIELDSTAT successfully reproduced the observed data at all three scales, with a normalised mean bias error of 3.02% across all crops and scales. Model testing also revealed a number of weaknesses in the model, identifying yield-reducing factors that had not been considered previously. All in all, the model proved fitness-for-purpose for simulating spatial yields, also under assumed future climate conditions.


      PubDate: 2013-12-07T22:43:52Z
       
  • Site-specific impacts of climate change on wheat production across regions
           of Germany using different CO2 response functions
    • Abstract: Publication date: January 2014
      Source:European Journal of Agronomy, Volume 52, Part A
      Author(s): K.C. Kersebaum , C. Nendel
      Impact of climate change on crop growth, groundwater recharge and nitrogen leaching in winter wheat production in Germany was assessed using the agro-ecosystem model HERMES with a downscaled (WETTREG) climate change scenario A1B from the ECHAM5 global circulation model. Three alternative algorithms describing the impact of atmospheric CO2 concentration on crop growth (a simple Farquhar-type algorithm, a combined light-use efficiency – maximum assimilation approach and a simple scaling of the maximum assimilation rate) in combination with a Penman–Monteith approach which includes a simple stomata conduction model for evapotranspiration under changing CO2 concentrations were compared within the framework of the HERMES model. The effect of differences in regional climate change, site conditions and different CO2 algorithms on winter wheat yield, groundwater recharge and nitrogen leaching was assessed in 22 regional simulation case studies across Germany. Results indicate that the effects of climate change on wheat production will vary across Germany due to different regional expressions of climate change projection. Predicted yield changes between the reference period (1961–1990) and a future period (2021–2050) range from −0.4tha−1, −0.8tha−1 and −0.6tha−1 at sites in southern Germany to +0.8tha−1, +0.6tha−1 and +0.8tha−1 at coastal regions for the three CO2 algorithms, respectively. On average across all regions, a relative yield change of +0.9%, +3.0%, and +6.0%, respectively, was predicted for Germany. In contrast, a decrease of −11.6% was predicted without the consideration of a CO2 effect. However, simulated yield changes differed even within regions as site conditions had a strong influence on crop growth. Particularly, groundwater-affected sites showed a lower vulnerability to increasing drought risk. Groundwater recharge was estimated to change correspondingly to changes in precipitation. The consideration of the CO2 effect on transpiration in the model led to a prediction of higher rates of annual deep percolation (+16mm on average across all sites), which was due to higher water-use efficiency of the crops. In contrast to groundwater recharge, simulated nitrogen leaching varied with the choice of the photosynthesis algorithm, predicting a slight reduction in most of the areas. The results underline the necessity of high-resolution data for model-based regional climate change impact assessment and development of adaptation measures.


      PubDate: 2013-12-07T22:43:52Z
       
  • Interactive effects of free-air CO2 enrichment and drought stress on maize
           growth
    • Abstract: Publication date: January 2014
      Source:European Journal of Agronomy, Volume 52, Part A
      Author(s): Remy Manderscheid , Martin Erbs , Hans-Joachim Weigel
      Predicting future maize yields requires quantifying anticipated climate change impacts on maize growth and yield. In the present study, maize was grown over 2 years (2007 and 2008) under sufficient (WET) and reduced water supply (DRY) and under ambient (378μll−1, AMB) and elevated (550μll−1, FACE) atmospheric CO2 concentration ([CO2]) using free air CO2 enrichment (FACE). The objective of the present study was to test the hypothesis that maize growth does not respond to elevated [CO2] under WET but under DRY conditions due to an increase of water use efficiency (WUE) of biomass production realized through reduced transpiration. Moreover, in 2008 soil cover was varied to test whether mitigation of evaporation by straw mulch increases the CO2 effect on WUE. The DRY treatment received 12% and 48% less water than the WET treatment in 2007 and 2008, respectively, which was achieved with the aid of rainout shelters. In the first year, drought stress was insignificant and crop growth was similar among the two watering regimes. CO2 enrichment did not affect crop growth in 2007 and also in the WET treatment of 2008. In the second year, a pronounced drought stress decreased green leaf index, accumulated seasonal radiation absorption and radiation use efficiency (RUE) significantly. However, these effects were mitigated by CO2 enrichment and the decrease of RUE was higher under AMB (−18%) than under FACE (−2%) conditions. In the DRY treatment in 2008, CO2 enrichment significantly increased final biomass (+24%) and grain yield (+41%) as compared to the DRY AMB treatment. CO2 enrichment significantly increased soil water content under WET and DRY conditions but did not affect the soil water exploitation. There was a significant interaction of [CO2] and water supply on WUE with no (2007) or a small CO2-response (+10% in 2008) under WET and a strong effect under DRY conditions in 2008 (+25%). Soil cover did not intensify the CO2 effect on WUE. It is concluded that maize will benefit from the increase in [CO2] only under drought but not under sufficient water supply.
      Highlights ► We combined the free air CO2 enrichment technique with rain shelters. ► The system was used to study the interaction of CO2 and water supply on maize growth. ► CO2 enrichment (from 380 to 550μll−1) increased crop growth only under drought. ► And this was due to an increase of water use efficiency (+25%).

      PubDate: 2013-12-07T22:43:52Z
       
  • Integrating regional climatology, ecology, and agronomy for impact
           analysis and climate change adaptation of German agriculture: An
           introduction to the LandCaRe2020 project
    • Abstract: Publication date: January 2014
      Source:European Journal of Agronomy, Volume 52, Part A
      Author(s): B. Köstner , K.-O. Wenkel , M. Berg , Ch. Bernhofer , H. Gömann , H.-J. Weigel
      One of the most decisive natural framework conditions of agriculture – the regional climate – is in transition. This requires considering climate change and climate change impact for decision making. Although this knowledge is uncertain and depends on future green-house gas emission, it is rapidly expanding and improving. Therefore, it is important to create flexible systems with adaptable data bases and analytical tools to integrate knowledge of future climate change in agronomy for impact studies and adaptation planning. The joint project LandCaRe (Land, Climate, and Resources) 2020 aimed at developing a conceptual framework and prototype of a model-based decision support system (DSS) based on improved process knowledge and stakeholder communication. The final product, the LandCaRe DSS should combine grid-based information on regional climate and land surface, robust climate impact models and socio-economic boundary conditions to develop spatially explicit climate impact scenarios. Emphasis was put on the integration of different knowledge from science and practice. Climate projections had to be adapted to the needs of impact modelling of agricultural and ecological processes at regional and farm scale. Impact modelling included new process knowledge, especially related to the CO2 fertilisation effect on crop rotations. A new Free Air Carbon Dioxide Enrichment Experiment (FACE) on the C4 plant maize was conducted during the project. A new agro-ecosystem model was developed which integrates soil–plant–atmosphere exchange and plant production to predict crop yield as well as water, carbon and nitrogen fluxes. Stakeholders included representatives of agricultural and environmental administrations, managers of agro-enterprises and large farms as well as organisations for regional planning and nature conservation. Their central common interests were future land use, water availability and management. Stakeholders from agriculture requested not only to assess potential impacts of regional climate change on yield but also to interpret climate impact on farm economy. This required the design of a farm-economy module linking effects of management and adaptation on crop yield with scenarios of costs and prices. Here an introduction to the project, components of the DSS and its further perspectives are presented.


      PubDate: 2013-12-07T22:43:52Z
       
  • Comparing an empirical crop model with a functional structural plant model
           to account for individual variability
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      Author(s): Lu Feng , Jean-Claude Mailhol , Hervé Rey , Sébastien Griffon , Daniel Auclair , Philippe De Reffye
      Individual variability generally exists in crop fields. It increases with an increase in plant population density, water or nutrient deficiency, or spatio-temporal irregularity, and often results in a reduction in yield. As individual variability exists in a community but is expressed through individuals, we studied it by applying two models, one at the stand level and the other at the individual level. The crop model PILOTE and the functional structural plant model (FSPM) GreenLab were applied to a field of maize (Zea mays L.) to provide a numerical description of the crop at different levels. The delay and slower increase in LAI and in total dry matter at stand level compared to individual level, led us to hypothesize that uneven emergence could have an effect on variability. We derived a theoretical distribution of germination dates, which supported this hypothesis. In parallel, we used GreenLab to analyze possible sources of variability in accumulated biomass within a dynamic system, and to estimate possible parameters from experimental data. Using PILOTE and GreenLab, we successfully identified two typical types of individual variability in the maize field: variability in development over time and variability in competition for space during growth. Our method could be used in future research on the cause and influence of individual variability on performance, and to identify the link between an FSPM based on individual plants and a crop model at stand level.


      PubDate: 2013-12-03T21:10:45Z
       
  • Effect of elevated carbon dioxide and temperature on phosphorus uptake in
           tropical flooded rice (Oryza sativa L.)
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      Author(s): P. Bhattacharyya , K.S. Roy , P.K. Dash , S. Neogi , Md. Shahid , A.K. Nayak , R. Raja , S. Karthikeyan , D. Balachandar , K.S. Rao
      A field experiment was carried out to assess the impact of elevated carbon dioxide (CO2) and temperature on phosphorous (P) nutrition in relation to organic acids exudation, soil microbial biomass P (MBP) and phosphatase activities in tropical flooded rice. Rice (cv. Naveen) was grown under chambered control (CC), elevated CO2 (EC, 550μmolmol−1) and elevated CO2 +elevated temperature (ECT, 550μmolmol−1 and 2°C more than CC) in a tropical flooded soil under open top chambers (OTCs) along with unchambered control (UC) for three years. Root exudates were analyzed at different growth stages of rice followed by organic acids determination. Rhizospheric soil was used for analysis of soil phosphatase, MBP and available P. The total organic carbon (TOC) in root exudates was increased by 27.5% and 30.2% under EC and ECT, respectively over CC. Four different types of organic acids viz. acetic acid (AA), tartaric acid (TA), malic acid (MA) and citric acid (CA) were identified and quantified as dominant in root exudates, concentration of these was in the order of TA>MA>AA>CA. The TA, MA, AA and CA content were increased by 34.4, 31.1, 38.7 and 58.3% under ECT compared to that of UC over the period of 3 years. The P uptake in shoot, root and grain under elevated CO2 increased significantly by 29, 28 and 22%, respectively than CC. Soil MBP, acid and alkaline phosphatase activity was significantly higher under elevated CO2 by 35.1%, 27 and 36%, respectively, compared to the CC. Significant positive relationship exists among the organic acid exudation, MBP, phosphatase activities and P uptake by rice. The enhanced organic acid in root exudates coupled with higher soil phosphatase activities under elevated CO2 resulted in increased rate of soil P solubilization leading to higher plant P uptake.


      PubDate: 2013-12-03T21:10:45Z
       
  • Impact of biochar application on plant water relations in Vitis vinifera
           (L.)
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      Author(s): S. Baronti , F.P. Vaccari , F. Miglietta , C. Calzolari , E. Lugato , S. Orlandini , R. Pini , C. Zulian , L. Genesio
      Soil water status plays an important role in growth-yield and grape quality of Vitis vinifera (L.). In some cases, periods of moderate water stress have been indicated to exert a positive effect on the quality of grape production. However, prolonged water stress may have a strong negative affect grapevine photosynthesis and grape yield, especially in dry Mediterranean environments. Biochar is a co-product of a thermochemical conversion of biomass that is recognized to be a beneficial soil amendment, which when incorporated into the soil increases soil water retention. We investigated the effect of two rates of biochar application (22 and 44tonha−1) on plant water relations of V. vinifera in a field experiment in central Italy. Biochar obtained from the carbonization of orchard pruning waste was applied to the soil over two consecutive growing seasons. The treatments did not show a significant increase in soil hydrophobicity. Moreover, soil analysis and ecophysiological measurements indicated a substantial relative increases in available soil water content compared to control soils (from 3.2% to 45% in the 22 and 44tonha−1 application rates, respectively) and in leaf water potential (24–37%) during droughts.


      PubDate: 2013-12-03T21:10:45Z
       
  • Phytolith carbon sequestration in China's croplands
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      Author(s): Zhaoliang Song , Hailong Wang , Peter James Strong , Fengshan Guo
      A relatively recent found persistent component of the carbon (C) sink is C occluded within plant phytoliths. We constructed a silica–phytolith content transfer function and used crop production data to explore the phytolith C sink within China's croplands. The purposes of the study are to offer references for agricultural management and contribute to mitigating climate change. The Chinese cropland phytolith sink represented approximately 18% of world's croplands (24.39±8.67Tgyr−1) and sequestered 4.39±1.56Tgyr−1 of carbon dioxide (CO2); more than the USA or India. The predominant crop species were rice (Oryza sativa L., 40%), wheat (Triticum sp., 18%) and corn (Zea mays, 30%), while the main contributing areas were the midsouthern (28%) and eastern (26%) Chinese regions. The sink has doubled since 1978 owing to fertilizer application and irrigation. Therefore, fertilizer application and irrigation in conjunction with other management practices (such as crop pattern optimization) may further enhance the cropland phytolith C sink and thereby mitigate climate change.


      PubDate: 2013-12-03T21:10:45Z
       
  • Performance of winter cereals grown on field-stored soil moisture only
    • Abstract: Publication date: January 2014
      Source:European Journal of Agronomy, Volume 52, Part B
      Author(s): Siegfried Schittenhelm , Martin Kraft , Klaus-Peter Wittich
      According to climate change projections, winter cereal production will likely be exposed to increasing air temperatures and prolonged summer droughts. During the 2009/10 and 2010/11 growing seasons at Braunschweig, Germany, four cultivars each of barley (Hordeum vulgare L.), rye (Secale cereale L.), triticale (Triticosecale Wittmack), and wheat (Triticum aestivum L.) were grown in a mobile rain-out shelter with a nearby irrigated control to determine the maximal impact of water shortage on phenology, physiology, and yield. The rain-out shelter plots were subjected to severe drought stress by withholding rain during tillering to harvest. Permanent prevention of water supply caused an average 2 day earlier heading and flowering and a 19 day earlier loss of green leaves. Midday thermal images revealed consistently higher canopy temperatures under drought stress than under well-watered conditions. The drought related temperature increase was 3.7K across crops and years. Contrary to canopy temperature, the spectral moisture stress index and the normalized difference water index did not clearly separate the dry from the wet environment. The drought-induced yield loss averaged 5.9tha−1 (63%) for grain dry matter and 9.2tha−1 (51%) for above-ground dry matter. Among the four cereal species, rye produced the highest grain and above-ground dry matter under both dry and wet conditions, and also had the coolest canopy. Based on the results of the present study, it is expected that rye will cope best, and barley second-best with the drier conditions of the changing climate.


      PubDate: 2013-11-29T13:21:08Z
       
  • Organic fertilizer effects on growth, crop yield, and soil microbial
           biomass indices in sole and intercropped peas and oats under organic
           farming conditions
    • Abstract: Publication date: January 2014
      Source:European Journal of Agronomy, Volume 52, Part B
      Author(s): Ramia Jannoura , Rainer Georg Joergensen , Christian Bruns
      In a field experiment, peas (Pisum sativum L.) and oats (Avena sativa L.) were grown as sole crops and intercrops, fertilized with horse manure and yard-waste compost derived from shrub and garden cuttings at 10tCha−1 each. The objectives were to compare the effects of these organic fertilizer and cropping system in organic farming on (a) yield of peas and oats, grown as the sole crop or intercropped, as well as N2 fixation and photosynthetic rates, (b) the yield of wheat as a succeeding crop, (c) microbial biomass indices in soil and roots, and (d) microbial activity estimated by the CO2 evolution rate in the field and the amount of organic fertilizers, recovered as particulate organic matter (POM). In general, organic fertilizer application improved nodule dry weight (DW), photosynthetic rates, N2 fixation, and N accumulation of peas as well as N concentration in oat grain. Averaged across fertilizer treatments, pea/oat intercropping significantly decreased nodule DW, N2 fixation and photosynthetic rate of peas by 14, 17, and 12%, respectively, and significantly increased the photosynthetic rate of oats by 20%. However, the land equivalent ratio (LER) of intercropped peas and oats exceeded 1.0, indicating a yield advantage over sole cropping. Soil microbial biomass was positively correlated with pea dry matter yields both in sole and intercropped systems. Organic fertilizers increased the contents of microbial biomass C, N, P, and fungal ergosterol in soil and CO2 production, whereas the cropping system had no effects on these microbial indices. According to the organic fertilizer recovered as POM, 70% (manure) and 64% (compost) of added C were decomposed, but only 39% (manure) and 13% (compost) could be attributed to CO2–C during a 101-day period. This indicated that horse manure was more readily available to soil microorganisms than compost, leading to increased grain yields of the succeeding winter wheat.


      PubDate: 2013-11-29T13:21:08Z
       
  • Reflectance estimation of canopy nitrogen content in winter wheat using
           optimised hyperspectral spectral indices and partial least squares
           regression
    • Abstract: Publication date: Available online 1 October 2013
      Source:European Journal of Agronomy
      Author(s): Fei Li , Bodo Mistele , Yuncai Hu , Xinping Chen , Urs Schmidhalter
      Many spectral indices have been proposed to derive plant nitrogen (N) nutrient indicators based on different algorithms. However, the relationships between selected spectral indices and the canopy N content of crops are often inconsistent. The goals of this study were to test the performance of spectral indices and partial least square regression (PLSR) and to compare their use for predicting canopy N content of winter wheat. The study was conducted in cool and wet southeastern Germany and the hot and dry North China Plain for three winter wheat growing seasons. The canopy N content of winter wheat varied from 0.54% to 5.55% in German cultivars and from 0.57% to 4.84% in Chinese cultivars across growth stages and years. The best performing spectral indices and their band combinations varied across growth stages, cultivars, sites and years. Compared with the best performing spectral indices, the average value of the R 2 for the PLSR models increased by 76.8% and 75.5% in the calibration and validation datasets, respectively. The results indicate that PLSR is a potentially useful approach to derive canopy N content of winter wheat across growth stages, cultivars, sites and years under field conditions when a broad set of canopy reflectance data are included in the calibration models. PLSR will be useful for real-time estimation of N status of winter wheat in the fields and for guiding farmers in the accurate application of their N fertilisation strategies.


      PubDate: 2013-11-22T00:42:24Z
       
  • Assessing climate change and associated socio-economic scenarios for
           arable farming in the Netherlands: An application of benchmarking and
           bio-economic farm modelling
    • Abstract: Publication date: Available online 14 November 2013
      Source:European Journal of Agronomy
      Author(s): A. Kanellopoulos , P. Reidsma , J. Wolf , M.K. van Ittersum
      Future farming systems are challenged to adapt to the changing socio-economic and bio-physical environment in order to remain competitive and to meet the increasing requirements for food and fibres. The scientific challenge is to evaluate the consequences of predefined scenarios, identify current “best” practices and explore future adaptation strategies at farm level. The objective of this article is to assess the impact of different climate change and socio-economic scenarios on arable farming systems in Flevoland (the Netherlands) and to explore possible adaptation strategies. Data Envelopment Analysis was used to identify these current “best” practices while bio-economic modelling was used to calculate a number of important economic and environmental indicators in scenarios for 2050. Relative differences between yields with and without climate change and technological change were simulated with a crop bio-physical model and used as a correction factors for the observed crop yields of current “best” practices. We demonstrated the capacity of the proposed methodology to explore multiple scenarios by analysing the importance of drivers of change, while accounting for variation between individual farms. It was found that farmers in Flevoland are in general technically efficient and a substantial share of the arable land is currently under profit maximization. We found that climate change increased productivity in all tested scenarios. However, the effects of different socio-economic scenarios (globalized and regionalized economies) on the economic and environmental performance of the farms were variable. Scenarios of a globalized economy where the prices of outputs were simulated to increase substantially might result in increased average gross margin and lower average (per ha) applications of crop protection and fertilizers. However, the effects might differ between different farm types. It was found that, the abolishment of sugar beet quota and changes of future prices of agricultural inputs and outputs in such socio-economic scenario (i.e. globalized economy) caused a decrease in gross margins of smaller (in terms of economic size) farms, while gross margin of larger farms increased. In scenarios where more regionalized economies and a moderate climate change are assumed, the future price ratios between inputs and outputs are shown to be the key factors for the viability of arable farms in our simulations.


      PubDate: 2013-11-18T00:46:04Z
       
  • Effects of controlled irrigation and drainage on growth, grain yield and
           water use in paddy rice
    • Abstract: Publication date: February 2014
      Source:European Journal of Agronomy, Volume 53
      Author(s): Guang-Cheng Shao , Sheng Deng , Na Liu , Shuang-En Yu , Ming-Hui Wang , Dong-Li She
      Rice is subjected to excessive waterlogging and flash-flooding on large areas in south China. A study on water use, growth and yield effects of controlled irrigation and drainage (CID) of paddy rice at four stages was conducted in specially designed experimental tanks. The treatments were (1) CID during Stage I of tillering stage (CID-Stage I), (2) CID during Stage II of booting stage (CID-Stage II), (3) CID during Stage III of heading to flowering stage (CID-Stage III), (4) CID during Stage IV of milky stage (CID-Stage IV), (5) alternate wetting and drying irrigation during the whole stage (CK). Compared with CK, CID reduced drainage volume with 15.8–31.3% in 2008, and 13.5–28.3% in 2009, and increased the efficiency of available rainfall and irrigation by 1.98–3.46% in both years. Irrigation water application during the whole growing season across the 2 years, on average, was only 81.8%, 91.1%, 93.9%, and 94.5%, respectively, of that applied to CK. A strong reduction in root length, root weight, root-shoot ratio and harvest index were observed, however, shoot weight and total dry mass is increased from the treatments of CID-Stage II, CID-Stage III and CID-Stage IV. The highest radiation use efficiency values were for CID-Stage IV. The responses of CID from vegetative plants at Stage I and Stage II were greater than in generative plants at the latter two stages. CID-Stage II had only a small effect on subsequent development and grain yield. This decrease in grain yield to less than 7.88% and 5.72% of CK was due to reduced number of spikelets per panicle in one trial, and reduced panicle number per unit area in another. The CID-Stage I treatment showed the lowest grain yield among the treatments and reduced it by 23.3% in 2008 and by 17.3% in 2009, due to the decreases in the percentage of filled grains and total number of panicles. The effect of stress was associated with low dry matter production during the flooding stress period as well as during the stress withdrawal period following the stress. With regards to irrigation water use efficiency, it was increased under the first two treatments, and by from a minimum of 101% to a maximum of 110%.


      PubDate: 2013-11-18T00:46:04Z
       
  • Effects of green manure herbage management and its digestate from biogas
           production on barley yield, N recovery, soil structure and earthworm
           populations
    • Abstract: Publication date: Available online 13 November 2013
      Source:European Journal of Agronomy
      Author(s): Randi Berland Frøseth , Anne Kjersti Bakken , Marina Azzaroli Bleken , Hugh Riley , Reidun Pommeresche , Kristian Thorup-Kristensen , Sissel Hansen
      In repeatedly mown and mulched green manure leys, the mulched herbage contains substantial amounts of nitrogen (N), which may only slightly contribute to the following crops’ nutrient demand. The objective of the present work was to evaluate the effect of alternative strategies for green manure management on the yield and N recovery of a subsequent spring barley crop, and their short term effects on soil structure and earthworm populations. A field trial was run from 2008 to 2011 at four sites with contrasting soils under cold climate conditions. We compared several options for on-site herbage management and the application of anaerobically digested green manure herbage. Depending on the site, removal of green manure herbage reduced the barley grain yield by 0% to 33% compared to leaving it on-site. Applying digestate, containing 45% of the N in harvested herbage, as fertilizer for barley gave the same yields as when all herbage was mulched the preceding season. Overall, the apparent N recovery was enhanced from 7% when all herbage was mulched, to 16% when returned as digestate. A positive effect on earthworm density and biomass was seen after one season of retaining mulch material, rather than removing it. Digestate did not affect the earthworm population, but contributed to higher soil aggregate stability. In conclusion, for spring barley production after green manure ley, the digestate strategy increased N recovery and reduced the risk of N losses. The yield of the succeeding barley crop yield was reduced when N in herbage was not returned as mulch or digestate.


      PubDate: 2013-11-13T23:59:32Z
       
  • Maize yield and water balance is affected by nitrogen application in a
           film-mulching ridge–furrow system in a semiarid region of China
    • Abstract: Publication date: Available online 2 November 2013
      Source:European Journal of Agronomy
      Author(s): Chang-An Liu , Li-Min Zhou , Ju-Jie Jia , Li-Jun Wang , Jian-Ting Si , Xin Li , Cheng-Chen Pan , Kadambot H.M. Siddique , Feng-Min Li
      Poor soil and drought stress are common in semiarid areas of China, but maize has a high demand for nitrogen (N) and water. Maize production using the technique of double ridges and furrows mulched with plastic film are being rapidly adopted due to significant increases in yield and water use efficiency (WUE) in these areas. This paper studied N use and water balance of maize crops under double ridges and furrows mulched with plastic-film systems in a semiarid environment over four growing seasons from 2007 to 2010. To improve precipitation storage in the non-growing season, the whole-year plastic-film mulching technique was used. There were six treatments which had 0, 70, 140, 280, 420 or 560kgNha−1 applied in every year for maize. In April 2011, spring wheat was planted in flat plots without fertilizer or mulch following four years of maize cultivation. After four years, all treatments not only maintained soil water balance in the 0–200cm soil layer but soil water content also increased in the 0–160cm soil layer compared to values before maize sowing in April 2007. However, under similar precipitation and only one season of spring wheat, soil water content in the 0–160cm soil layer sharply decreased in all treatments compared to values before sowing in April 2011. Over the four years of maize cultivation, average yield in all treatments ranged from 4071 to 6676kgha−1 and WUE ranged from 18.2 to 28.2kgha−1 mm−1. In 2011, the yield of spring wheat in all treatments ranged from 763 to 1260kgha−1 and WUE from 3.5 to 6.5kgha−1 mm−1. The potential maximum grain yield for maize was 6784kgha−1 with 360kgNha−1 applied for four years, but considerable NO3 N accumulated in the soil profile. A lesser application (110kgNha−1) to this tillage system yielded in 82% of the maximum, increased nitrogen use efficiency and mitigated the risk of nitrogen loss from the system. This study suggests that double ridge–furrow and whole-year plastic-film mulching could sustain high grain yields in maize with approximately 110kgNha−1 and maintain soil water balance when annual precipitation is >273mm in this semiarid environment.


      PubDate: 2013-11-05T11:32:52Z
       
  • First or second generation biofuel crops in Brandenburg, Germany? A
           model-based comparison of their production-ecological sustainability
    • Abstract: Publication date: Available online 5 November 2013
      Source:European Journal of Agronomy
      Author(s): Sander C. de Vries , Gerrie W.J. van de Ven , Martin K. van Ittersum
      We assessed and compared the production-ecological sustainability of first and second generation biofuel production systems in the state of Brandenburg, Germany. Production ecological sustainability was defined by a limited set of sustainability indicators including net energy yield per hectare, GHG emissions, N leaching, soil organic carbon and soil erosion, and several resource use efficiencies. The assessed first generation fuels are biodiesel and bioethanol produced from rapeseed (Brassica napus L.) and sugarbeet (Beta vulgaris L.) feedstock, respectively. Assessed second generation systems are based on feedstock from Miscanthus (Miscanthus × giganteus Greef et. Deu. ex Hodkinson et Renvoize) and black locust (Robinia pseudoacacia L.); for both crops conversion into cellulosic ethanol and Fischer Tropsch Diesel was assessed. In the assessment, computer models were used for simulating crop growth, soil organic carbon dynamics and several other relevant biophysical processes. Second generation biofuel production systems based on Miscanthus and black locust perform substantially better than first generation systems based on rapeseed and sugarbeet. They contribute much more to GHG emission reduction, had much higher net energy yields and better resource use efficiencies; soil erosion and N leaching were also lower. Miscanthus performed better than black locust, except for its N use efficiency; it is the most water-efficient species, which is important in a region with declining groundwater tables. However, in Brandenburg, low temperatures during winter and early spring are often threatening to survival of first-year Miscanthus plantings; there have been disastrous experiences in the past. The drawback of black locust is that it has invasive characteristics; this risk may be controllable however (cf. Motta et al., 2009). Of the first generation systems, rapeseed has low net energy yields and large N requirements per unit of energy produced; it also performed poorly for N leaching. Erosion hazard in rapeseed is especially present after the seedbed has been prepared at the end of summer. Greatest erosion risk was calculated for sugarbeet however, due to its late canopy closure.


      PubDate: 2013-11-05T11:32:52Z
       
  • Combining input uncertainty and residual error in crop model predictions:
           A case study on vineyards
    • Abstract: Publication date: Available online 28 October 2013
      Source:European Journal of Agronomy
      Author(s): Sébastien Roux , François Brun , Daniel Wallach
      As crop modelling has matured and been proposed as a tool for many practical applications, there is increased need to evaluate the uncertainty in model predictions. A particular case of interest that has not been treated before is that where one takes into account both uncertainty in the model explanatory variables and model residual error (the uncertainty in model predictions even when the explanatory variables are perfectly known). The specific case we consider is that of a model for predicting water stress of a vineyard. For many of the model explanatory variables, the vine grower (or the farmer advisor) has a choice between approximate values which are easily obtainable and more precise values that are more difficult (and more expensive) to obtain. We specifically discuss the explanatory variable “initial water stress” which is directly based on the initial soil water content and can be estimated or measured (precise but expensive). The vine grower is interested in the decrease in uncertainty that would result from measuring initial water stress, but it is the decrease in total uncertainty, including model residual error, that is of importance. We propose using accurate measurements of water stress over time in multiple vineyards, to estimate model residual error. The uncertainty in initial water stress can be estimated if one has approximate and precise values of initial water stress in several vineyards. We then combine the two sources of error by simulation thanks to an independence hypothesis; the model is run multiple times with a distribution of values for initial water stress, and on each day a distribution of model residual errors is added to the result. The results show that the resulting uncertainty is quite different in different fields. In some cases, uncertainty in initial water stress becomes negligible a short time after the start of simulations, in other cases that uncertainty remains important, compared to model residual error, throughout the growing season. In all cases, residual error is a substantial percentage of overall error and thus should be taken into account.


      PubDate: 2013-11-01T16:16:51Z
       
  • Designing resilient and sustainable grasslands for a drier future:
           Adaptive strategies, functional traits and biotic interactions
    • Abstract: Publication date: Available online 1 November 2013
      Source:European Journal of Agronomy
      Author(s): Florence Volaire , Karim Barkaoui , Mark Norton
      In many regions of the world, such as Southern Europe and most Mediterranean areas, the frequency and magnitude of droughts and heat waves are expected to increase under global warming and will challenge the sustainability of both native and sown grasslands. To analyze the adaptive strategies of species, genotypes and cultivars, we aim both (i) to understand the composition and functioning of natural grasslands and (ii) to propose ideotypes of cultivars and optimal composition for mixtures of species/genotypes under water deficit and high temperatures. This review presents a conceptual framework to analyze adaptive responses of perennial herbaceous species, starting from resistance to moderate drought with growth maintenance (dehydration avoidance and tolerance of lamina) to growth cessation and survival of plants under severe stress (dehydration avoidance and tolerance of meristems). The most discriminating functional traits vary according to these contrasting strategies because of a trade-off between resistance to moderate moisture deficit and survival of intense drought. Consequently it is crucial to measure the traits of interest in the right organs and as a function of soil water use, in order to avoid misleading interpretations of plant responses. Furthermore, collaboration between ecologists, eco-physiologists, and agronomists is required to study the combination of plant strategies in natural grasslands as only this will provide the necessary rules for species and cultivars or ecotypes assemblage. This ‘agro-ecological’ approach aims to identify and enhance functional complementarity and limit competition within the multi-specific or multi-genotypic material associated in mixtures since using plant biodiversity should contribute to improving grassland resistance and resilience.


      PubDate: 2013-11-01T16:16:51Z
       
  • Climate change impacts and potential benefits of drought and heat
           tolerance in chickpea in South Asia and East Africa
    • Abstract: Publication date: Available online 25 October 2013
      Source:European Journal of Agronomy
      Author(s): Piara Singh , S. Nedumaran , K.J. Boote , P.M. Gaur , K. Srinivas , M.C.S. Bantilan
      Using CROPGRO-Chickpea model (revised version), we investigated the impacts of climate change on the productivity of chickpea (Cicer arietinum L.) at selected sites in South Asia (Hisar, Indore and Nandhyal in India and Zaloke in Myanmar) and East Africa (Debre Zeit in Ethiopia, Kabete in Kenya and Ukiriguru in Tanzania). We also investigated the potential benefits of incorporating drought and heat tolerance traits in chickpea using the chickpea model and the virtual cultivars approach. As compared to the baseline climate, the climate change by 2050 (including CO2) increased the yield of chickpea by 17% both at Hisar and Indore, 18% at Zaloke, 25% at Debre Zeit and 18% at Kabete; whereas the yields decreased by 16% at Nandhyal and 7% at Ukiriguru. The yield benefit due to increased CO2 by 2050 ranged from 7 to 20% across sites as compared to the yields under current atmospheric CO2 concentration; while the changes in temperature and rainfall had either positive or negative impact on yield at the sites. Yield potential traits (maximum leaf photosynthesis rate, partitioning of daily growth to pods and seed-filling duration each increased by 10%) increased the yield of virtual cultivars up to 12%. Yield benefit due to drought tolerance across sites was up to 22% under both baseline and climate change scenarios. Heat tolerance increased the yield of chickpea up to 9% at Hisar and Indore under baseline climate, and up to 13% at Hisar, Indore, Nandhyal and Ukiriguru under climate change. At other sites (Zaloke, Debre Zeit and Kabete) the incorporation of heat tolerance under climate change had no beneficial effect on yield. Considering varied crop responses to each plant trait across sites, this study was useful in prioritizing the plant traits for location-specific breeding of chickpea cultivars for higher yields under climate change at the selected sites in South Asia and East Africa.


      PubDate: 2013-10-28T21:07:58Z
       
  • Agronomic performance, carbon storage and nitrogen utilisation of
           long-term organic and conventional stockless arable systems in
           Mediterranean area
    • Abstract: Publication date: Available online 26 October 2013
      Source:European Journal of Agronomy
      Author(s): Paola Migliorini , Valentina Moschini , Fabio Tittarelli , Corrado Ciaccia , Stefano Benedettelli , Concetta Vazzana , Stefano Canali
      The Montepaldi Long Term Experiment (MOLTE) trial in central Italy has been comparing three agroecosystems with different management: two organic (Old Organic since 1992 and Young Organic since 2001) and one conventional. After sixteen years of comparison, the agronomic performance and environmental sustainability of the three agro-ecosystems were assessed. Crops grain yield, total C inputs and N budget at field level were evaluated. N use efficiency (NUE) at micro-agroecosystem level was determined. Soil samples were collected from the three agroecosystems in order to quantify soil C and N pools. Results showed comparable grain yields in the three agro-ecosystems. The conventional system showed a larger N surplus and a lower crop N use efficiency in comparison with the organic ones. Moreover, the organic systems presented a lower potential risk of N losses with respect to the conventional one. The Young Organic agro-ecosystem was the most effective in terms of long term soil C (13% higher than conventional) and the oldest organic agro-ecosystem was the most effective in terms of soil N storage (9% higher than conventional). The results obtained demonstrated that the application of the organic farming method could increase the environmental sustainability in stockless arable systems under Mediterranean type of climate.


      PubDate: 2013-10-28T21:07:58Z
       
  • Evaluation of the Agro-Ecological Zone methods for the study of climate
           change with micro farming decisions in sub-Saharan Africa
    • Abstract: Publication date: Available online 25 October 2013
      Source:European Journal of Agronomy
      Author(s): S. Niggol Seo
      This paper evaluates the Agro-Ecological Zone (AEZ) methods for understanding agriculture and measuring the impacts of climate change on agriculture with the observed farming decisions in sub-Saharan Africa. The Agro-Ecological Zone (AEZ) method is explained using the concept of the Length of Growing Period (LGP) and the AEZ classification of the African continent. Farmers’ decisions are obtained from the World Bank household surveys of around 8000 farms across 9 sub-Saharan countries. The AEZ results are compared with the observed behavioral decisions of the farmers as well as future predictions of behaviors. Observed choices of agricultural systems, crop net revenues, distributions of livestock species, and grain yields are compared with the AEZ classification. This paper finds that the AEZ/LGP classification identifies the land's suitability for crop farming well, but is a poor indicator of livestock systems, both specialized and diversified. It also does a poor job of identifying nonmajor grains such as forest activities. Besides these identification issues, adaptive decisions such as diversification and risk management are difficult to capture by the AEZ methods. These problems become evident when the AEZ method is applied to measure the impacts of future climate changes since the shifts of farming behaviors are hard to measure. Future research is needed to improve the classification of agro eco-systems and to develop an improved integrated analysis of ecological sciences and economics.


      PubDate: 2013-10-28T21:07:58Z
       
  • Prediction of winter wheat cultivar performance in Germany: At national,
           regional and location scale
    • Abstract: Publication date: Available online 28 October 2013
      Source:European Journal of Agronomy
      Author(s): Donghui Ma , Hartmut Stützel
      Winter wheat cultivar recommendation is usually based on the cultivar performance observed in post-registration trials. In Germany, official recommendations are based on state cultivar trials, which are conducted individually by the federal states, usually over a period of three years. In each predefined winter wheat cultivation region a subset of registered cultivars is tested. The recommendation in a particular region is mainly based on the yields from trials on several locations in this region. Practically, the farmer's interest is a prediction of the yielding ability of cultivars on his own farm in the following growing season. This prediction can be made based on data from different scales, and with one year or multiple-year data. Here, we evaluated the prediction ability with the data from national, regional and location scales per se, and tried to find the optimal information source (scale and number of years) to predict the relative yield of a specific cultivar for a specific location. For this purpose, data from the country wide value testing trials from 1991 to 2001 carried out by the Federal Office of Plant Varieties (Bundessortenamt) were used. Winter wheat cultivation regions were adopted according to the German convention which gives the chance of further dividing the data into regional subgroups. The results of the analyses indicate that for a given location, the two years regional data have the highest predictive power for superior cultivars. Two years’ data from that specific location give the highest predictive power for intermediate and inferior cultivars. In general, the predictive power of single year data is much lower than of two years data. The results confirm the merit of the definition of different cultivation regions. By proper definition of regions, the multiple year data collected within the region have high predictive power for the cultivar performance for the locations within that region.


      PubDate: 2013-10-28T21:07:58Z
       
  • Contributions of cultivars, management and climate change to winter wheat
           yield in the North China Plain in the past three decades
    • Abstract: Publication date: Available online 23 October 2013
      Source:European Journal of Agronomy
      Author(s): Dengpan Xiao , Fulu Tao
      The detailed field experiment data from 1980 to 2009 at four stations in the North China Plain (NCP), together with a crop simulation model, were used to disentangle the relative contributions of cultivars renewal, fertilization management and climate change to winter wheat yield, as well as the relative impacts of different climate variables on winter wheat yield, in the past three decades. We found that during 1980–2009 cultivars renewal contributed to yield increase by 12.2–22.6%; fertilization management contributed to yield increase by 2.1–3.6%; and climate change contributed to yield generally by −3.0–3.0%, however by −15.0% for rainfed wheat in southern part of the NCP. Modern cultivars and agronomic management played dominant roles in yield increase in the past three decades, nevertheless the estimated impacts of climate change on yield accounted for as large as −23.8–25.0% of observed yield trends. During the study period, increase in temperature increased winter wheat yield by 3.0–6.0% in northern part of the NCP, however reduced rainfed winter wheat yield by 9.0–12.0% in southern part of the NCP. Decrease in solar radiation reduced wheat yield by 3.0–12.0% across the stations. The impact of precipitation change on winter wheat yield was slight because there were no pronounced trends in precipitation. Our findings highlight that modern cultivars and agronomic management contributed dominantly to yield increase in the past three decades, nevertheless the impacts of climate change were large enough in some areas to affect a significant portion of observed yield trends in the NCP.


      PubDate: 2013-10-25T00:36:11Z
       
  • Assessment of breeding progress in sugar beet by testing old and new
           varieties under greenhouse and field conditions
    • Abstract: Publication date: Available online 24 October 2013
      Source:European Journal of Agronomy
      Author(s): Jens Loel , Christine Kenter , Bernward Märländer , Christa M. Hoffmann
      Breeding has led to a continuous increase of the performance of sugar beet varieties and thereby contributes to meet the global needs for food and biomass. This study aimed to analyze the extent of the breeding progress in sugar beet and to determine which parameters and traits were modified by breeding. In 2007 and 2008 sugar beet varieties registered between 1964 and 2003 were cultivated in field trials and in greenhouse experiments to exclude effects from changes in agronomic operations and climatic conditions. Differences in white sugar yield related to the reference variety registered in 1964 were regarded as breeding progress. The results showed an increase in the white sugar yield of 0.6–0.9% a−1 from 1964 to 2003 due to breeding. This was achieved by an improved biomass partitioning (higher root to leaf ratio and higher sugar to marc ratio), better technical quality (decreased concentration of K, Na, and amino N combined as standard molasses loss) and enhanced assimilation (higher chlorophyll content, higher assimilation rates). No changes were observed in leaf development and cambium ring formation. A principle component analysis pointed out that breeding targets have shifted with time from “yield” to “biomass quality”. To continue the breeding progress in future it is essential to integrate multiple resistances and tolerances against biotic and abiotic stress.


      PubDate: 2013-10-25T00:36:11Z
       
  • Modelling early growth under different sowing conditions: A tool to
           predict variations in intercrop early stages
    • Abstract: Publication date: Available online 18 October 2013
      Source:European Journal of Agronomy
      Author(s): Benoit Fayaud , Françoise Coste , Guénaëlle Corre-Hellou , Antoine Gardarin , Carolyne Dürr
      Early growth is a critical phase of the crop cycle, which lasts from emergence to the beginning of competition between plants and is sensitive to sowing conditions and species characteristics. Providing tools to improve the management of this critical phase in intercrops is a challenge for agroecology as these cropping systems are the subject of renewed interest for their ability to maintain yields while requiring fewer inputs. The aim of the present study was to investigate variations in early growth under different sowing conditions in different species with contrasted seed and seedling characteristics (seed mass, hypogeal or epigeal emergence, and legume and non-legume species), especially species used as intercrops. Experiments were carried out in glasshouses using different sowing depths and levels of mineral nutrition, first for each species separately, then in mixed sowings. In the first set of experiments, biomass at emergence and relative growth rate after emergence were measured and then modelled as a function of seed mass, mineral nutrition, and time to emergence. Predictive equations were tested by comparing simulations with biomass measured in the second set of experiments, for two intercrops grown under varied sowing conditions. Finally, simulations were run to analyse variations in the early growth of two intercrops (durum wheat/pea or alfalfa) under a wider range of sowing conditions (seed mass, sowing depth, and with or without mineral nutrition). Biomass at emergence was positively correlated with seed mass, and in epigeal species, was also negatively impacted by time to emergence. Relative growth rate was highly stimulated by mineral nutrition whereas its response to time to emergence varied among species. The amount of seminal reserves at emergence (in hypogeal species) and the cotyledon specific mass (in epigeal species) were correlated with the establishment of the relative growth rate. When evaluated, the model was shown to satisfactorily predict the early growth of two intercrops. Used as a simulation tool, the model indicated that all the sowing techniques tested can have a major influence on total biomass and on the proportion of each component species when competition begins. This model can thus contribute to the management of sowing techniques for sole as well as combined crops whose effects are difficult to predict and are also difficult to analyse from field experiments alone because of the number of possible combinations and interactions.


      PubDate: 2013-10-21T02:02:47Z
       
  • Mechanical wounding under field conditions: A potential tool to increase
           the allelopathic inhibitory effect of cover crops on weeds?
    • Abstract: Publication date: Available online 7 October 2013
      Source:European Journal of Agronomy
      Author(s): H. Marjolein Kruidhof , Nicole M. van Dam , Christian Ritz , Lambertus A.P. Lotz , Martin J. Kropff , Lammert Bastiaans
      To increase the inhibitory effect of soil-incorporated cover crop residues on germination and early growth of weeds, the allelochemical content of the cover crop at the time of soil incorporation should be maximal. We investigated whether mechanical damaging in spring induced the production of allelochemicals in late-summer sown lucerne, winter rye and winter oilseed rape. Allelopathic activity and biomass of intact cover crop plants were determined throughout spring, and mechanically damaged plants were monitored till 14 days after wounding. Allelopathic activity was determined directly by lettuce seedling bioassays (lucerne and winter rye) or indirectly by glucosinolate quantification (winter oilseed rape). During spring, the allelopathic activity per unit biomass of intact plants showed a gradual decline for winter rye and lucerne, and a steep decline at the onset of flowering for winter oilseed rape. All cover crop species attained the highest allelopathic activity per unit area at the end of the sampling period as the increase in biomass surpassed the decline in allelopathic activity per unit biomass. Although mechanical wounding enhanced the allelopathic activity per unit biomass of all three species, the effect was only minor and often just sufficient to compensate for the loss in biomass resulting from wounding. This study therefore indicates that the best option for maximizing the inhibitory effect is to incorporate residues of intact cover crops as late as possible.


      PubDate: 2013-10-09T00:40:43Z
       
  • Contrasting patterns of fatty acid composition and oil accumulation during
           fruit growth in several olive varieties and locations in a
           non-Mediterranean region
    • Abstract: Publication date: Available online 7 October 2013
      Source:European Journal of Agronomy
      Author(s): Déborah P. Rondanini , Diego N. Castro , Peter S. Searles , M. Cecilia Rousseaux
      Olive growing has expanded considerably in the last few decades outside of the Mediterranean Basin to non-traditional regions in the Southern Hemisphere. When growing olive genotypes (i.e., varieties) outside of their area of origin, the importance of environmental factors such as temperature and genotype×environment interactions in determining olive oil production and oil quality has been suggested. In several Mediterranean varieties and one South American variety, we assessed the dynamics of fruit growth and oil accumulation along with the evolution of fatty acid composition at multiple locations over two growing seasons. Oleic acid content (%), the principal fatty acid present in olive oil, showed four contrasting patterns during fruit growth when modeled against thermal time from flowering using linear and bilinear regressions: (1) a sharp linear decrease for the varieties ‘Arauco’ and ‘Arbequina’; (2) a plateau followed by a late linear decrease of moderate slope for ‘Barnea’ and ‘Manzanilla Fina’; (3) a slow linear decrease for ‘Frantoio’; and (4) no decrease in ‘Coratina’. Linoleic acid (%) showed linear increases in ‘Arauco’ and ‘Arbequina’ that appear to be inversely related to the decreases in oleic acid, while bilinear patterns were found for many other varieties. Both the rates of fruit growth and of oil accumulation were more important in determining maximum fruit dry weight and oil concentration (%), respectively, than duration when expressed on a thermal time basis. Temperature during oil synthesis was negatively related to final oil concentration. Experiments under controlled conditions would greatly contribute to our understanding of how fruit growth as well as oil quantity and quality are influenced by environmental factors.
      Graphical abstract image

      PubDate: 2013-10-09T00:40:43Z
       
  • A trait-based characterization of cover plants to assess their potential
           to provide a set of ecological services in banana cropping systems
    • Abstract: Publication date: Available online 3 October 2013
      Source:European Journal of Agronomy
      Author(s): Gaëlle Damour , Marc Dorel , Hoa Tran Quoc , Charles Meynard , Jean-Michel Risède
      Cover plants are one of the means to increase the functional biodiversity of fields and to enhance the ecological functions of the communities. However, the design of cropping systems including cover plants relies largely on expert knowledge. There is a lack of methods to select the best suited cover plants according to their role in the agrosystem. We propose to use functional traits to select cover plants suited to sustain ecological services in the banana agrosystems of the French West Indies. Our objectives were (i) to characterize a collection of cover plants on a trait basis, according to their potential to provide the services expected in a banana agrosystem and (ii) to discuss the potential use of this characterization for the design of innovative multi-species banana cropping systems. In these systems, four main services are targeted, i.e. controlling weeds, controlling plant-parasitic nematodes, improving soil fertility and particularly N availability, and avoiding competition with banana for resource acquisition. Three experiments were conducted, under field and controlled conditions, to evaluate the potential of a collection of 28 tropical cover plants to achieve the functions related to these services. For each cover plant, a functional profile was constructed from a combination of plant traits that are easy to assess experimentally. It described plants’ potential to achieve the functions expected in a banana agrosystem. Functional profiles required for cover plant usages were also identified. The comparison of the plant functional profiles and the functional profiles required for their usages enabled us to select the best suited plants for each usage. However, these functional profiles rarely corresponded, meaning that a cover plant is rarely sufficient to achieve all the functions required for a usage. Functional complementarities obtained by the mixture of different species of cover plants are thus often required. Compared to classical approaches of innovative cropping system design based on the experimental testing of spatial and temporal plant combinations, such a trait-based approach saves time by focusing on a shortlist of cover plants best suited according to their functions in the agrosystem.


      PubDate: 2013-10-05T03:47:04Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2014