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The present study was carried out in the period 2006-2008 based on an experiment established in 2005. The study evaluated the effect of conservation and plough tillage as well as of four catch crops on the level of infection by fungal pathogens of the stem base and roots of the spring wheat cultivar ‘Zebra’ grown in monoculture. The species composition of fungi colonizing the stem base and roots of spring wheat was determined. The split-plot design of the experiment set up on rendzina soil included plough tillage and conservation tillage with autumn and spring disking of catch crops. The experiment used four methods for regeneration of the spring wheat monoculture stand using the following: undersown red clover and Westerwolds ryegrass crops as well as lacy phacelia and white mustard stubble crops. Plots without catch crops were the control treatment. Red clover and Westerwolds ryegrass catch crops as well as lacy phacelia and white mustard stubble crops had a significant effect on the decrease in the stem base and root infection index of spring wheat compared to the control without catch crops. The disease indices in the tillage treatments under evaluation did not differ significantly from one another. The stem base and roots of spring wheat were most frequently infected by fungi of the genus Fusarium, with F. culmorum being the dominant pathogen of cereals. Compared to conservation tillage, in plough tillage the pathogenic fungus Bipolaris sorokiniana was not found to occur on the stem base and roots. The Westerwolds ryegrass catch crop promoted the occurrence of F. culmorum, both on the stem base and roots of spring wheat.

Nitrate leaching was measured during 6 years in a crop rotation including oilseed rape (OSR) and winter wheat in two field trials, on two rendzina soils differing by their water content, in Le Magneraud (West of France) and Martincourt (East of France). Results show that nitrate losses are variable within the year and drainage: between 20 and 95 kgN.ha–1.an–1. When the soil remains without cover crop after OSR, losses under wheat following OSR are definitely higher than under OSR following wheat: respectively 54.1 kgN.ha–1.an–1 and 14.8 kgN.ha–1.an–1 during the first three years in Le Magneraud. Results even show that nitrate losses differed according to N strategy management. Among the treatments of nitrogen management, the least losses are observed with optimized fertilization plus OSR volunteers used as cover crop between OSR and wheat; and the highest losses are observed with high fertilization without OSR volunteers as catch crop : respectively in Le Magneraud (second phases of three years) 29.9 and 61.1 kgN.ha–1.an–1, and at Martincourt 43.0 and 61.4 kgN.ha–1.an–1 on average. Simulations realized with LIXIM and DEAC models for new years, soils and regions, show the same trend that experimental results: nitrate losses are higher under wheat after OSR, and the high performance cropping systems are based on optimized N fertilization management of OSR and the catch of nitrate at the end of summer by OSR (after wheat) or its volunteers (before wheat).

This study was focused on modeling soil water, carbon (C), and nitrogen (N) dynamics in soil and crop emphasizing uncertainties in model parameterization and the evaluation of potential water stress for silage maize cultivations on a drained field. The CoupModel was applied on different management systems for silage maize ( Zea mays ) in monoculture and undersown with grass ( Lolium perenne L.) on a sandy-humic soil. Four different fertilization levels with 0, 150 kg of mineral-N, 40 m 3 of cattle slurry (72–148 kg N ha −1 year −1 ), and combined slurry/mineral-N (222–298 kg N ha −1 year −1 ) were simulated over five years. Results were based on most plausible parameter combinations regarding simulated biomass obtained from 10,000 runs by the Generalized Likelihood Uncertainty Estimation (GLUE) approach. The uncertainty in model parameterization was reduced significantly by limiting the number of simulations for each treatment sequentially resulting in quartile coefficients of variation ( CV *) < 25% for 26% and 36% of selected input parameters in bi-cropping and monoculture systems, respectively. Average soil temperatures in upper soil depths, the groundwater level, water potentials, and water contents between 10 and 80 cm of depth were reproduced plausibly with the model as well as plant C and N contents. The CV * values of evapotranspiration and total runoff ranged between 0 and 26% and 8–21%, respectively, on half-yearly basis. Significant differences between the cropping systems were found, even though the soil water balance was positive for all systems, and the potential water stress was only minor in bi-cropping systems. [ABSTRACT FROM AUTHOR]

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Grazing of winter forage crops is a common management option used in the dairy industry of New Zealand, particularly in the South Island, where they are used to feed nonlactating, pregnant dairy cows prior to calving. However, there is concern that the large crop yields per hectare grazed, combined with a high stocking density of cows, lead to large amounts of urinary nitrogen (N) deposited on bare, wet soil that, in turn, could lead to large nitrate leaching losses. We report the results of a simulated winter forage grazing event using field lysimeters planted with a kale ( Brassica oleracea L.) crop. The effect of sowing a 'catch crop' of oat ( Avena sativa L.) following the simulated winter forage grazing on nitrate leaching losses from urine applied at different times throughout the winter was measured. A catch crop sown between 1 and 63 days after the urine deposition in early winter reduced N leaching losses from urine patches by ~34% on average (range: 19-49%) over the winter-spring period compared with no catch crop. Generally, the sooner the catch crop was sown following the crop harvest, the greater the uptake of N by the catch crop and the greater the reduction in nitrate leaching losses. The results indicate that sowing of a catch crop following winter crop grazing could be an effective management strategy to reduce nitrate leaching as well as increase the N-use efficiency of dairy winter forage grazing systems. [ABSTRACT FROM AUTHOR]

Cauliflower ( Brassica oleracea L. var. botrytis ) has high nitrogen (N) demand during growing, but due to its low N use efficiency and N-rich residues, it may cause N losses by leaching after harvest. A field experiment was conducted to investigate the effect of overwintering grass-clover as an intercrop and moderately reduced N fertilization on organic cauliflower yield and risk of nitrate leaching. The experiment tested sole-cropped (S) and intercropped (I) systems using a substitution design and two N fertilizer rates (180 and 230 kg N ha −1 ). To investigate the competition between cauliflower and grass-clover, cauliflower grown alone with empty grass-clover rows (S emp ) and grass-clover grown alone with empty cauliflower rows (GC emp ) were included. The results showed that marketable yield was maintained in the I system compared to in the S system when calculated per meter crop row, and when N fertilization was moderately reduced. The Relative Competition Index (RCI) values in the I system were lower than 0, indicating that cauliflower growth was not interfered in the I system. The ability for aboveground N accumulation in the S and I systems was similar, but the N content of cauliflower residues in the S system was 33 and 23 kg ha −1 higher than in the I system in 2012 and 2013, respectively. The S system had 168 kg N inorg ha −1 in the soil layer of 0–1.5 m at the start of leaching in 2013, which was 40 kg N ha −1 higher than the I system. Reduced N fertilizer level led to 22 kg ha −1 lower soil N inorg at the end of leaching. However, the effect of system and N level on soil residual N inorg per unit marketable yield was not significantly different. Intercropping cauliflower with overwintering grass-clover and moderately reduced N fertilization was feasible in organic cauliflower production, with regard to maintaining marketable yield and reducing the risk of nitrate leaching in the agroecosystem. [ABSTRACT FROM AUTHOR]

Background and aims: During the fallow period, non-legume cover crop species can capture mineral nitrogen (N) and thus decrease nitrate leaching, whereas legume cover crop species can provide a green manuring service that increases N availability for the subsequent crop. The aim of our study was to investigate the ability of bispecific mixtures to simultaneously produce these two services of N management in relation to their interspecific interactions. Methods: Three field experiments were conducted at contrasting sites from summer to autumn to evaluate 25 mixtures and 10 sole crops. We measured biomass, N acquisition, C:N ratio and soil mineral N. Ecosystem services were assessed using both experimental data and simulation model predictions. Results: Overall, prediction of N mineralized from cover crop residues was significantly higher for mixtures than for non-legume sole crops. Predictions of nitrate leached after mixtures did not differ significantly from those after non-legume sole crops and remained significantly lower than those under bare soil, especially for mixtures with turnip rape which benefitted greatly from being in mixtures. Conclusions: Some of the mixtures provided a choice of compromises between the two ecosystem services, which helps define solutions for adapting mixture choice according to the site's soil and climate characteristics and to fallow period management. [ABSTRACT FROM AUTHOR]

Fermentation of lignocellulosic biomass requires auxiliary materials, including nutrients, to ensure the proliferation of microorganisms. Nutrients are usually inexpensive, but their contribution to the cost is considerable because of the very low prices of fermentation products, such as bio-ethanol. Using substances present in native lignocellulosic biomass as nutrients for fermentation was proposed and demonstrated. Leaves and stalks of corn plants were used as biomass, and nutrients were recovered as a nutrient solution by soaking them in water before alkaline peroxide pretreatment. Pretreated biomass and the nutrient solution derived from the same lot were used for non-sterile simultaneous enzymatic saccharification and thermophilic l-lactic acid fermentation (SSF). Using the nutrient solution in the saccharification step did not impact sugar recovery, and instead improved sugar yields because of the presence of eluted sugars in the solution. The l-lactic acid yield of 0.33 g g based on native biomass weight indicated that the nutrient solution functioned as a source of nutrients and sugars, especially as a source of essential phosphorus. Comparatively, autoclaved SSF yielded less or no l-lactic acid, indicating an apparent inhibitive effect derived from the nutrient solution on bacterial growth. [ABSTRACT FROM AUTHOR]

The export of winter wheat straw for bioenergy may reduce soil C stocks and affect N losses. Establishing fast-growing catch crops between successive wheat crops could potentially offset some of the C and N losses. Another option is to sow wheat earlier, increasing biomass production during the autumn. The effects of straw export, oil radish catch crop and early sowing of wheat on soil C storage, N leaching losses and N 2 O emissions were simulated by applying the Daisy model to winter wheat grown continuously for a period of 100 years on a sandy loam soil in a Danish climate. The simulations included five levels of initial soil C content (1–3% C), three levels of straw incorporation (0, 50 and 100%), +/− catch crop (oil radish) and two sowing dates (1 and 22 September). Exporting the entire straw production reduced soil C stocks by 1.2 to 14% after 100 years, depending on the initial C content. Inclusion of the oil radish catch crop could offset this loss by 2–3 percentage points. Earlier sowing of wheat increased straw production by 18% and reduced loss of soil C by 3–5 percentage points compared to normal sowing time with full straw export. Catch crops and early sowing also reduced N-leaching losses compared to a scenario with full straw export. Early sowing of wheat performed better than the oil radish catch crop in reducing N leaching and N 2 O emissions. Sensitivity analyses showed that a wetter climate had little effect on soil C storage, but increased N leaching losses by up to 48%. Loss of soil C and leaching of N increased when early-sown wheat was subject to winter-kill and when sandy loam soil was replaced by a sand soil. When wheat is grown continuously, losses of C are mainly defined by the initial soil C content (reflecting the management and land-use history of the soil) and by the level of straw export. The use of oil radish catch crops and early sowing of wheat may offset some of the adverse effects of straw export. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the effect of the catch crop used as green manure on magnesium content in soil and in the grain and straw of spring barley cultivated afterward in different soil conditions. The fi eld study was carried out in 2008-11 in two different soils: lessive soil (location 1) and typical black earth (location 2). The experimental factor was the catch crop (fi eld pea) used as green manure for spring barley cultivated in the following year. Three treatments were assessed: I) catch crop ploughed in autumn, II) catch crop left over winter as mulch (uncut), and III) control - without the catch crop. Mg content in spring barley grain and straw was determined using the colorimetric method with titanium yellow. Mg content in spring barley grain was not dependent on the catch crop used as green manure. This factor had a better effect on Mg concentration in straw. In both locations it was significantly higher in the control than after the catch crop. Ploughing in the catch crop resulted in a significant decrease in Mg content in straw of barley cultivated in lessive soil as compared with mulch. The content of this element in straw of barley cultivated in the typical black earth was significantly higher in the treatment with ploughed-in catch crop than with mulch. Mg content in spring barley grain was not correlated or negatively correlated with soil abundance in this element. However, a positive correlation between Mg content in soil before spring barley sowing and in straw of this plant was found. [ABSTRACT FROM AUTHOR]

Accurate estimation of animal manure nitrogen (N) availability is required to maximize crop N use efficiency and reduce environmental N losses. Many field and laboratory experiments have shown that first-year net mineralization of manure organic N is often negligible, which often causes crop available N to approximate the ammonium N content of the manure. Anaerobic digestion increases the ammonium share and reduces the C to organic N ratio of animal manures, potentially increasing their N fertilizer value. In 2011, we undertook a three-year field experiment in Northern Italy to estimate the N fertilizer value of four manures: undigested cattle slurry, digested cattle slurry-maize mix, and liquid and solid fractions of the digested slurry-maize mix. The experiment also allowed us to test if ammonium recovery was similar among manures, and between manures and ammonium sulphate. Fertilizers were applied annually to plots before silage maize cultivation that was followed by an unfertilized Italian ryegrass crop. Results showed that the recovery of ammonium from manure in maize did not differ significantly compared to ammonium sulphate among all the fertilizers in 2013; however, in 2011 and 2012 it was significantly lower for all manures except digested slurry-maize mix and its liquid fraction in 2011. The increased recovery of applied N in 2012 and 2013 for solid fraction and undigested manure were likely due to the residual effect of previously applied organic N. [ABSTRACT FROM AUTHOR]

Numerous pesticide fate models are available, but few of them are able to take into account specific agricultural practices, such as catch crop, mixing crops or tillage in their predictions. In order to better integrate crop management and crop growth in the simulation of diffuse agricultural pollutions, and to manage both pesticide and nitrogen pollution, a pesticide fate module was implemented in the crop model STICS. The objectives of the study were: (i) to implement a pesticide fate module in the crop model STICS; (ii) to evaluate the model performance using experimental data from three sites with different pedoclimatic contexts, one in The Netherlands and two in northern France; (iii) to compare the simulations with several pesticide fate models; and (iv) to test the impact of specific agricultural practices on the transfer of the dissolved fraction of pesticides. The evaluations were carried out with three herbicides: bentazone, isoproturon, and atrazine. The strategy applied in this study relies on a noncalibration approach and sensitivity test to assess the operating limits of the model. To this end, the evaluation was performed with default values found in the literature and completed by sensitivity tests. The extended version of the STICS named STICS-Pest, shows similar results with other pesticide fate models widely used in the literature. Moreover, STICS-Pest was able to estimate realistic crop growth and catch crop dynamic, which thus illustrate agricultural practices leading to a reduction of nitrate and a change in pesticide leaching. The dynamic plot-scale model, STICS-Pest is able to simulate nitrogen and pesticide fluxes, when the hydrologic context is in the validity range of the reservoir (or capacity) model. According to these initial results, the model may be a relevant tool for studying the effect of long-term agricultural practices on pesticide residue dynamics in soil and the associated diffuse pollution transfer. [ABSTRACT FROM AUTHOR]

When grass-clover leys have been ploughed nitrate leaching may increase. However, management of leys before or after ploughing may affect the leaching risk. We examined the effect of cultivating a six year ley, which the last two years had been treated differently (grazing only; spring cut followed by grazing, and spring and autumn cuts with grazing during the summer season only) on nitrate leaching in maize with/without a catch crop (per. ryegrass) and with/without slurry application (135 kg total-N ha −1 ). An unfertilized barley harvested for silage with a catch crop of Italian ryegrass was used as reference. Shortening the grazing season in the grass-clover ley phase did not affect leaching after ploughing. In the following maize, the use of a perennial ryegrass catch crop in a high-yielding maize crop was not able to reduce nitrate leaching significantly, although leaching and maize yield tended to be lower with the catch crop. In unfertilized treatments both maize yields and nitrate leaching were significantly lower compared with treatments with slurry application. The unfertilized barley undersown with Italian ryegrass reduced leaching much more than unfertilized maize with perennial ryegrass as an undersown catch crop, despite yields of barley and ryegrass being less than half of the dry matter yields of unfertilized maize. The experiment illustrates that growing maize after ploughing of grass-clover leys without environmental consequences is difficult. [ABSTRACT FROM AUTHOR]

Broomrapes are obligate root parasitic weeds and major constraint to many dicotyledon crops especially in Mediterranean agricultural lands. Due to the fact that no single control measure is able to control broomrapes in the field satisfactorily, integrated management is recommended in general. The use of of trap crops or catch crops is an important strategy for controlling the weeds; and allelopathic plants are also utilized for the control. Trap crops, also called false hosts, are plants which stimulate the germination of the parasite seed but cannot be infested and thus reduce the seed population in the soil. On the other hand, catch crops stimulate the germination of the parasite seeds at a high frequency and allow the development of the parasite. Seed bank of the broomrapes are decreased by destroying the catch crops before the seed creating period of broomrape begins (Sauerborn, 1991). Field trials were conducted using flax (Linum usitatissimum L.) as a trap plant; lentil (Lens culinaris L.) as a catch plant; members of the Brassicaceae species, such as cabbage (Brassica oleracea L.), Brussels sprouts (Brassica oleracea var. gemmifera (DC.) Thell.), broccoli (Brassica oleracea L. var. italica Plenck), cauliflower (Brassica oleracea var. botrytis L.), canola (Brassica napus L.) and turnip (Brassica rapa var. rapa L.) as allelopathic plant in the Adana province (Turkey) in 2007-2009. Flax was the most effective treatment by decreasing 52% and 71% in shoot number and 55% and 26% in dry weight of O. crenata in the first and second year, respectively. Broccoli of the Brassicaceae family, was found to reduce the number of O. crenata shoots by 48% and 39% in two years. Regarding the effect of Brassicaceae family on O. crenata, broccoli was found to reduce the number of O. crenata shoots by 39%. It is concluded that growing flax as a trap plant or lentil as a catch crop two months before the sowing of lentil as a crop is can be a main element of integrated broomrape managament, which cause to reduce the soil seed bank of crenata broomrape. [ABSTRACT FROM AUTHOR]

For more than a decade, studies have aimed to adapt the agronomy of organic no-till systems for the environmental conditions of Eastern Canada. Most research on organic no-till practices in Eastern Canada has been conducted in the province of Québec, where 4% of farms are certified organic, and results from these trials have been published in technical reports available in French. The objective of this review was to revisit previous research work on organic farming in Eastern Canada—the majority of which has been published as technical reports in the French language—in order to highlight important findings and to identify information gaps. Cover crop-based rotational no-till systems for organic grain and horticultural cropping systems will be the main focus of this review. Overall, a few trials have demonstrated that organic rotational no-till can be successful and profitable in warmer and more productive regions of Eastern Canada, but its success can vary over years. The variability in the success of organic rotational no-till systems is the reason for the slow adoption of the system by organic farmers. On-going research focuses on breeding early-maturing fall rye, and terminating cover crops and weeds with the use of bioherbicides.

Diversification of crop rotations is considered an option to increase the resilience of European crop production under climate change. So far, however, many crop simulation studies have focused on predicting single crops in separate one-year simulations. Here, we compared the capability of fifteen crop growth simulation models to predict yields in crop rotations at five sites across Europe under minimal calibration. Crop rotations encompassed 301 seasons of ten crop types common to European agriculture and a diverse set of treatments (irrigation, fertilisation, CO 2 concentration, soil types, tillage, residues, intermediate or catch crops). We found that the continuous simulation of multi-year crop rotations yielded results of slightly higher quality compared to the simulation of single years and single crops. Intermediate crops (oilseed radish and grass vegetation) were simulated less accurately than main crops (cereals). The majority of models performed better for the treatments of increased CO 2 and nitrogen fertilisation than for irrigation and soil-related treatments. The yield simulation of the multi-model ensemble reduced the error compared to single-model simulations. The low degree of superiority of continuous simulations over single year simulation was caused by (a) insufficiently parameterised crops, which affect the performance of the following crop, and (b) the lack of growth-limiting water and/or nitrogen in the crop rotations under investigation. In order to achieve a sound representation of crop rotations, further research is required to synthesise existing knowledge of the physiology of intermediate crops and of carry-over effects from the preceding to the following crop, and to implement/improve the modelling of processes that condition these effects. [ABSTRACT FROM AUTHOR]

Cover crops can be an efficient agricultural practice to reduce nitrate leaching during the fallow period and decrease nitrate pollution of aquifers. For maximum reduction of nitrate leaching, cover-crop management must be adapted to the pedoclimatic context. We used the soil–crop model STICS to assess optimal emergence dates in summer and destruction dates in autumn and winter for three species of cover crops (mustard, ryegrass and vetch) at a large scale in France. We first calibrated and validated STICS’s predictions of soil and crop dynamics under a wide range of conditions, including bare soil and cover crops. Since predictions were sufficiently accurate, we then predicted the impact of several emergence and destruction dates of cover crops on nitrate leaching in 24 contrasting climatic sites over 20 years. These sites represented a wide range of conditions found in France and much of Europe. Using generalized linear model (GLM), we extrapolated to the vulnerable nitrate zones in France the optimal dates predicted for the 24 sites. We defined optimal emergence date as the date allowing the higher nitrate leaching decrease in drained water and optimal destruction dates as those for which a high reduction of nitrate leaching was predicted and that also avoided negative effects on the subsequent main crop and water resources. STICS accurately predicted mineral N and water dynamics from both calibration and validation datasets, despite lower accuracy for vetch simulations. Over the 20-year simulations, optimal dates varied, depending mainly on site, cover crop and year. Optimal emergence dates for cover crops were earlier for vetch (late July) than for ryegrass (early August) and mustard (late August) and earlier in the north (cold and rainy) than in the south of France (warm and dry). Optimal destruction dates, as defined in this paper, were frequently between October and December. Mean optimal dates by site and species were strongly correlated with climatic characteristics of the 24 sites tested, which enabled us to extrapolate them to a larger scale and identify areas with similar optimal emergence and destruction dates according to cover-crop species. Later optimal emergence dates occurred in southeastern France in late August and September, while the earliest dates occurred in late July and early August in the north and east of France. The extrapolated optimal destruction dates occurred in autumn (October–December), with later destruction dates located in zones with higher temperature in the western coastal zones of the Atlantic Ocean and in southeastern France. [ABSTRACT FROM AUTHOR]

Background: Agricultural activities are estimated to contribute 70% of nitrates, 28% of phosphates and 76% of sediments measured in UK rivers. Catchments dominated by agriculture also have elevated levels of pesticides and bacterial pathogens. European member states have a policy commitment to tackle this pollution through the water framework directive. Here we report on the results of a systematic map to investigate and describe the nature and coverage of research pertaining to the effectiveness of 6 on-farm mitigation measures, slurry storage, cover/catch crops, woodland creation; controlled trafficking, subsoiling and vegetated buffer strips for delivering an improved water environment in terms of a reduction in nitrogen (N), phosphorus (P), sediment, pesticides and faecal indicator organisms (FIOs) or pathogens from faecal material. Methods: Research evidence for the effectiveness of the 6 on-farm mitigation measures for delivering an improved water environment (as detailed above) was collated using English language search terms for temperate farming systems in Europe, Canada, New Zealand and northern states of the United States of America. Searches for literature were made from online publication databases, search engines, specialist websites and bibliographies of topic specific reviews. Recognised experts, authors and practitioners were also contacted to identify unpublished literature. Articles were screened for relevance at title, abstract and full text using predefined inclusion criteria set out in an a priori published protocol. All relevant articles were mapped in a searchable database using pre-defined coding and critically appraised for relevance and reliability. Articles reporting the same study were removed. All full text studies without confounding factors were identified and coded for in a separate searchable database. Results: A total of 718 articles were included in the database. Buffer strips were the most commonly studied intervention followed by cover crops and slurry storage. Little evidence was found for woodland creation and sub-soiling. No studies were found for controlled trafficking on grassland. Nitrogen was most frequently measured, followed by P, sediment, pesticides and FIOs or pathogens from faecal material. Conclusions: The majority of the evidence collated in this map investigated the effectiveness of buffer strips and cover crops for improving water quality. This evidence was predominantly focussed on reducing N pollution. An evidence gap exists for the impact of cover/catch crops in reducing leaching of pesticides, FIOs and pathogens, and for organic forms of N and P. There was limited research investigating the effectiveness of buffer strips for reducing leaching of organic forms of N or P, or for pesticides that are currently authorised for use/commonly used in UK agriculture. Further, long term studies across different seasons with controls, pre and post water quality measurements and multiple sampling points from both field and rivers would improve the evidence base. Evidence gaps exist for woodland creation, subsoiling and controlled trafficking on grassland. [ABSTRACT FROM AUTHOR]

[Objective] The aim was to identify changes in a nematode community in response to crop rotation and to determine the appropriate catch crop for a greenhouse. [Method] The experiment was carried out in a typical 6-year-old greenhouse, in which cucumber crops were cultivated twice each year (in spring and autumn), and catch crops were planted in summer. The total number of nematodes was counted and nematode community indices were calculated after collecting soil samples in different stages. [Result] Total nematode abundance was decreased in the soils of catch crop in contrast with former crops (cucumber crops). The abundance of the nematode community was reduced in the treatment of crop rotation compared to the soils of catch crop. In addition, the number of nematode taxa was significantly reduced by the treatment of crown daisy compared to the treatments of following crops. Crop rotation regulated the functional composition of the nematode community by increasing the omnivores-predators functional group and decreasing the relative abundance of root herbivores. [Conclusion] These results indicate that crop rotation affects the nematode community in abundance, diversity and functional composition of the nematode community and crown daisy can be served as the most appropriate catch crop in the greenhouse. [ABSTRACT FROM AUTHOR]

Fermentation of lignocellulosic biomass requires auxiliary materials such as nutrients for fermentation. Because of the low prices of fermentation products such as bioethanol, the costs of nutrients are not negligible. We have developed the concept of using substances natively present in lignocellulosic biomass as nutrients for the downstream fermentation. The leaves and stalks of young dent corn plants were used as biomass and the nutrients were recovered by soaking them in water before alkaline pretreatment, followed by enzymatic saccharification and fermentation. Performing thermophilic l -lactic acid fermentation using these recovered nutrients support their use as commercially feasible alternatives. A level of recovered nutrients of 40% was sufficient to support the fermentation of recovered sugars derived from the same corn biomass. However, the amount of recovered nutrients required for fermentation was almost double that when using yeast extract based on the amounts of nitrogen and/or phosphorus added. The nitrogen and phosphorus balances in the process indicated that adding nutrients was crucial for promoting fermentation based on the amounts of nitrogen and phosphorus. The nutrients proposed were considered to be effective for fermenting biomass pretreated by alkaline, dilute acid, and hydrothermal methods. [ABSTRACT FROM AUTHOR]

CO2 emissions to the atmosphere were studied in a fertilized sandy agricultural soil with and without a catch crop sown into the main crop. The catch crop was grown primarily with the purpose to decrease N-leaching but this study also wanted to find out if the catch crop could have an effect in a climate change perspective. Plots with catch crop showed decreased CO2 emissions from the soil. Since previous results have shown that catch crops effectively decrease N-leaching we recommend growing catch crops as an effective measure for helping both the climate and the eutrophication issue. Seasonal variations in CO2 emissions were pronounced with maximum emissions from the fertilized agricultural soil in June and from an adjacent unmanaged grassland in August. From the plot with catch crop emissions decreased in July and August but somewhat increased later in the autumn. Fertilized agricultural soil showed a within-soil CO2 sink after harvest, i.e. within-soil CO2 uptake. Availability of NH4+ or NO3- in the soil seems to influence the within-soil CO2 sink, with NH4+ enforcing the sink while the same amount of NO3- instead increased CO2 emissions. [ABSTRACT FROM AUTHOR]

Cover crop selection should be oriented to the achievement of specific agrosystem benefits. The cover crop, catch crop, green manure and fodder uses were identified as possible targets for selection. The objective was to apply multi-criteria decision analysis to evaluate different species ( Hordeum vulgare L., Secale cereale L., × Triticosecale Whim, Sinapis alba L., Vicia sativa L.) and cultivars according to their suitability to be used as cover crops in each of the uses. A field trial with 20 cultivars of the five species was conducted in Central Spain during two seasons (October–April). Measurements of ground cover, crop biomass, N uptake, N derived from the atmosphere, C/N, dietary fiber content and residue quality were collected. Aggregation of these variables through utility functions allowed ranking species and cultivars for each usage. Grasses were the most suitable for the cover crop, catch crop and fodder uses, while the vetches were the best as green manures. The mustard attained high ranks as cover and catch crop the first season, but the second decayed due to low performance in cold winters. Mustard and vetches obtained worse rankings than grasses as fodder. Hispanic was the most suitable barley cultivar as cover and catch crop, and Albacete as fodder. The triticale Titania attained the highest rank as cover and catch crop and fodder. Vetches Aitana and BGE014897 showed good aptitudes as green manures and catch crops. This analysis allowed comparison among species and cultivars and might provide relevant information for cover crops selection and management. [ABSTRACT FROM AUTHOR]