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Introduction: To ensure higher productivity, fertilizers have been excessively applied to the fruit greenhouse soil yearly, thus resulting in the increasing risks of residual nitrate leaching in the North China Plain. Methods: In this study, a water and solute transport HYDRUS-1D model was used to evaluate the effects of using sweet corn as a catch crop on deep water drainage and nitrate leaching in a sweet cherry greenhouse soil. A three-year (2019–2021) field experiment was conducted during the rainfall season from July to September in the post-harvest of sweet cherry, when the plastic cover was removed each year. In the experiment, the five treatments were designed. The three nitrate residue levels denoted by CKR, N1R, and N2R, represented nitrate residue amounts in the soil profile of three nitrogen fertilizer levels(0, 280 and 420kg ha-1) before the harvest of sweet cherry(March to June). Two other treatments with and without sweet corn as a catch crop based on the treatments of N1R and N2R were denoted by N1RC and N2RC, respectively. The data of both the spatial and temporal distribution of water and nitrate content during the rainy seasons of 2019, 2020 and 2021 in the field experiment were collected to calibrate and validate the model. Results: The simulated results have showed that using sweet corn as a catch crop increased the evapotranspiration rate, the upward flux of water and nitrate at a 100 cm soil depth reached a maximum of 1.5 mm d-1 and 1.0 kg N ha-1d-1, respectively, and the downward movement of water and nitrate leached to deeper soil layers was reduced. Compared with CKR, the treatments with catch crops (N1RC and N2RC) reduced the amount of water drainage by 16.4% -47.7% in the 0-180cm soil profile. The average amounts of nitrate leaching in the 1.8 m soil profile during the three-year experiment were 88.1, 113.3, and 58.2 kg N ha−1 for the treatment without catch crop (N1R and N2R) and 32.3, 54.8, and 31.4 kg N ha−1 for the treatment with catch crop (N1RC and N2RC), respectively. The treatments (N1RC and N2RC) with catch crops decreased the amount of nitrate leaching by 29.6%-69.1% compared with the treatments without catch crops (N1R and N2R). Discussion: Sweet corn as summer catch crop can reduce nitrate leaching in the sweet cherry greenhouses. Our study has provided an effective method to reduce the risk of nitrate leaching for sweet cherry greenhouses in the North China Plain. [ABSTRACT FROM AUTHOR]

Catch crops are intermediate crops sown between two main crop cycles. Their adoption into the cropping system has increased considerably in the last years due to its numerous benefits, in particular its potential in carbon fixation and preventing nitrogen leaching during winter. The growth period of catch crops in Germany is often marked by dense cloud cover, which limits land surface monitoring through optical remote sensing. In such conditions, synthetic aperture radar (SAR) emerges as a viable option. Despite the known advantages of SAR, the understanding of temporal behavior of radar parameters in relation to catch crops remains largely unexplored. Hence, in this study, we exploited the dense time series of Sentinel-1 data within the Copernicus Space Component to study the temporal characteristics of catch crops over a test site in the center of Germany. Radar parameters such as VV, VH, VH/VV backscatter, dpRVI (dual-pol Radar Vegetation Index) and VV coherence were extracted, and temporal profiles were interpreted for catch crops and preceding main crops along with in situ, temperature, and precipitation data. Additionally, we examined the temporal profiles of winter main crops (winter oilseed rape and winter cereals), that are grown parallel to the catch crop growing cycle. Based on the analyzed temporal patterns, we defined 22 descriptive features from VV, VH, VH/VV and dpRVI, which are specific to catch crop identification. Then, we conducted a Kruskal–Wallis test on the extracted parameters, both crop-wise and group-wise, to assess the significance of statistical differences among different catch crop groups. Our results reveal that there exists a unique temporal pattern for catch crops compared to main crops, and each of these extracted parameters possess a different sensitivity to catch crops. Parameters VV and VH are sensitive to phenological stages and crop structure. On the other hand, VH/VV and dpRVI were found to be highly sensitive to crop biomass. Coherence can be used to detect the sowing and harvest events. The preceding main crop analysis reveals that winter wheat and winter barley are the two dominant main crops grown before catch crops. Moreover, winter main crops (winter oilseed rape, winter cereals) cultivated during the catch crop cycle can be distinguished by exploiting the observed sowing window differences. The extracted descriptive features provide information about sowing, harvest, vigor, biomass, and early/late die-off nature specific to catch crop types. In the Kruskal–Wallis test, the observed high H-statistic and low p-value in several predictors indicates significant variability at 0.001 level. Furthermore, Dunn's post hoc test among catch crop group pairs highlights the substantial differences between cold-sensitive and legume groups (p < 0.001). [ABSTRACT FROM AUTHOR]

ABSTRACTCover crops (CCs) are a diverse group of species that are sown simultaneously or after the cash crop either as monocrops or mixtures. A farmer survey with 1130 respondents was carried out with the aim to gain knowledge on CC species used by Finnish farmers, to understand how experienced farmers were with them, how experiences varied depending on farm and farmer characteristics, and to identify target groups for dissemination and policy measures. The studied groups were conventional and organic farms that had selected CCs as a registered measure in 2020 to receive agricultural payments. Our results show that farmers were experienced with a high number of CCs despite the high-latitude conditions. Only 11% of respondents had plenty of experience with CCs as mixtures. Farmers tended to favour CCs that were familiar to them as cash crops. Organic producers were usually more experienced than conventional farmers. Education increased curiosity towards CCs. Farmers who used more diverse cash crops tended to use more diverse CCs. In conclusion, especially farmers who have cereal-based systems and rotations should be a core group for knowledge sharing to support transition towards increased use of CCs and higher diversity of CC species in the future.

IntroductionTo ensure higher productivity, fertilizers have been excessively applied to the fruit greenhouse soil yearly, thus resulting in the increasing risks of residual nitrate leaching in the North China Plain.MethodsIn this study, a water and solute transport HYDRUS-1D model was used to evaluate the effects of using sweet corn as a catch crop on deep water drainage and nitrate leaching in a sweet cherry greenhouse soil. A three-year (2019–2021) field experiment was conducted during the rainfall season from July to September in the post-harvest of sweet cherry, when the plastic cover was removed each year. In the experiment, the five treatments were designed. The three nitrate residue levels denoted by CKR, N1R, and N2R, represented nitrate residue amounts in the soil profile of three nitrogen fertilizer levels(0, 280 and 420kg ha-1) before the harvest of sweet cherry(March to June). Two other treatments with and without sweet corn as a catch crop based on the treatments of N1R and N2R were denoted by N1RC and N2RC, respectively. The data of both the spatial and temporal distribution of water and nitrate content during the rainy seasons of 2019, 2020 and 2021 in the field experiment were collected to calibrate and validate the model. ResultsThe simulated results have showed that using sweet corn as a catch crop increased the evapotranspiration rate, the upward flux of water and nitrate at a 100 cm soil depth reached a maximum of 1.5 mm d-1 and 1.0 kg N ha-1d-1, respectively, and the downward movement of water and nitrate leached to deeper soil layers was reduced. Compared with CKR, the treatments with catch crops (N1RC and N2RC) reduced the amount of water drainage by 16.4% -47.7% in the 0-180cm soil profile. The average amounts of nitrate leaching in the 1.8 m soil profile during the three-year experiment were 88.1, 113.3, and 58.2 kg N ha−1 for the treatment without catch crop (N1R and N2R) and 32.3, 54.8, and 31.4 kg N ha−1 for the treatment with catch crop (N1RC and N2RC), respectively. The treatments (N1RC and N2RC) with catch crops decreased the amount of nitrate leaching by 29.6%-69.1% compared with the treatments without catch crops (N1R and N2R).DiscussionSweet corn as summer catch crop can reduce nitrate leaching in the sweet cherry greenhouses. Our study has provided an effective method to reduce the risk of nitrate leaching for sweet cherry greenhouses in the North China Plain.

Purpose: Summer catch crop (CC) has been introduced into the vegetable rotating system in greenhouse fields to reduce nitrogen (N) losses through crop uptake and residual N immobilization. However, the effects of planting sorghum with high N uptake and biomass, and biological nitrification inhibition (BNI) potential as a CC on soil N dynamics and subsequent crop yield remain unclear. Methods: In the two-year field experiment, the comprehensive effects of planting sorghum as CC on subsequent eggplant yield, soil mineral N dynamics, ammonia-oxidizing archaea (AOA) and bacteria (AOB) amoA gene abundances were determined, in comparison to the sweet corn and fallow treatments. Results: Compared to the fallow and sweet corn, planting sorghum as CC increased subsequent eggplant yield by 24.88% and 18.94% in the 2014–2015 and 2015–2016 over-winter growing season, respectively. CC planting reduced soil nitrate (NO3−-N) accumulation during the summer fallow season. Sorghum planting could significantly maintain higher level of ammonium (NH4+-N) concentration during the summer fallow season and the first month of succeeding over-winter season. In addition, sorghum planting reduced soil net nitrifying potential, which could be partially attributed to the decreased amoA gene abundance of AOA at the 0–30 and 30–60 cm soil layers and AOB at 0–30 cm soil layer. Conclusion: We conclude that planting sorghum in the summer fallow season is a promising strategy to retain soil NH4+-N, reduce soil NO3−-N accumulation, and enhance subsequent eggplant yield. [ABSTRACT FROM AUTHOR]

In order to control the amount of greenhouse gas emissions from agriculture, it is necessary to select the appropriate crop rotation and tillage intensity depending on the soil type and climatic conditions. However, their implementation in agricultural management methods has been insufficient until now. The main objective of this study was to investigate the changes and dependences in soil net CO2 exchange rate (NCER) and main physico-chemical parameters under different tillage (conventional (CT) and no tillage (NT)) and crop rotation systems. Cropping systems significantly affected the amount of nutrients, but did not affect pH and organic carbon; otherwise, tillage vs. cropping systems had no significant effects on the soil chemical parameters analyzed. The data revealed that in NT treatments, the NCER was 28% higher than in CT. Different crop rotations also revealed a significant effect on NCER from the soil. Carbon dioxide fluxes increased in cropping systems where a higher share of catch crops were included. In NT systems, a comparatively higher soil moisture content was registered. In addition, the rotations with catch crops produced a higher (by 1–3%) soil moisture content. The temperature of the soil surface was not significantly affected by tillage or cropping systems; nevertheless, a trend towards higher soil surface temperatures in CT was determined, which might be affected by enhanced air circulation in the pores. Soil NCER increase correlated negatively with higher soil surface moisture content, while its relationship was positive with soil surface temperature increase. In general, soil surface temperature and moisture were the most significant factors in explaining the fluctuation in NCER from Cambisols in Lithuania under moderate climatic conditions. [ABSTRACT FROM AUTHOR]

Conservation farming practices are known for their capacity to mitigate runoff and erosion, but the magnitude of their effectiveness is highly variable across studies. In order to better understand the contribution of environmental and management factors to their effectiveness, up to 37 studies reporting 271 individual trials were collated for a quantitative review regarding 3 common conservation agriculture‐related practices, at the plot scale and in a Western European context. Two different methods suitable for hierarchically structured data sets were used for the meta‐analyses—hierarchical nonparametric bootstrapping and linear random effects models—, yielding nearly identical average outcomes but differing in terms of confidence intervals. We found that, on average, winter cover crops reduce cumulative seasonal (autumn‐winter) runoff by 68% and soil losses by 72% compared with a bare soil. The occurrence and intensity of stubble tillage on the control plot is a key explanatory variable for the mitigation effect of winter cover crops. In potato crops, tied ridging reduces cumulative seasonal (spring–summer) runoff by a mean of 70% and soil erosion by 92%. Conservation (non‐inversion) tillage techniques alleviate cumulative seasonal overland flow by 27% and associated sediments losses by 66%, but strong evidence of publication bias was detected for this farming practice, probably leading to an overestimation of its effectiveness. These mitigation effects are shown to be much greater for spring crops than for winter crops, and to increase with time since ploughing was stopped. The type of conservation tillage scheme strongly affects the ability to attenuate surface flows. Intensive non‐inversion tillage systems relying on repeated use of (powered) tillage operations appear to be the least effective for reducing both water and sediment losses. The best performing scheme against runoff would be a deep (non‐inversion) tillage (−61%), while against erosion it would be a no‐till system (−82%). Although several explanatory factors were identified, there remains a high (unexplained) variability between trials effect sizes, thus not attributable to pure sampling variability. Meanwhile, this review provides farm advisors or policy makers with guidance on the contexts in which implementation of such conservation practices should be supported so as to maximize expected benefits. [ABSTRACT FROM AUTHOR]

Catch crops are intermediate crops sown between two main crop cycles. Their adoption into the cropping system has increased considerably in the last years due to its numerous benefits, in particular its potential in carbon fixation and preventing nitrogen leaching during winter. The growth period of catch crops in Germany is often marked by dense cloud cover, which limits land surface monitoring through optical remote sensing. In such conditions, synthetic aperture radar (SAR) emerges as a viable option. Despite the known advantages of SAR, the understanding of temporal behavior of radar parameters in relation to catch crops remains largely unexplored. Hence, in this study, we exploited the dense time series of Sentinel-1 data within the Copernicus Space Component to study the temporal characteristics of catch crops over a test site in the center of Germany. Radar parameters such as VV, VH, VH/VV backscatter, dpRVI (dual-pol Radar Vegetation Index) and VV coherence were extracted, and temporal profiles were interpreted for catch crops and preceding main crops along with in situ, temperature, and precipitation data. Additionally, we examined the temporal profiles of winter main crops (winter oilseed rape and winter cereals), that are grown parallel to the catch crop growing cycle. Based on the analyzed temporal patterns, we defined 22 descriptive features from VV, VH, VH/VV and dpRVI, which are specific to catch crop identification. Then, we conducted a Kruskal–Wallis test on the extracted parameters, both crop-wise and group-wise, to assess the significance of statistical differences among different catch crop groups. Our results reveal that there exists a unique temporal pattern for catch crops compared to main crops, and each of these extracted parameters possess a different sensitivity to catch crops. Parameters VV and VH are sensitive to phenological stages and crop structure. On the other hand, VH/VV and dpRVI were found to be highly sensitive to crop biomass. Coherence can be used to detect the sowing and harvest events. The preceding main crop analysis reveals that winter wheat and winter barley are the two dominant main crops grown before catch crops. Moreover, winter main crops (winter oilseed rape, winter cereals) cultivated during the catch crop cycle can be distinguished by exploiting the observed sowing window differences. The extracted descriptive features provide information about sowing, harvest, vigor, biomass, and early/late die-off nature specific to catch crop types. In the Kruskal–Wallis test, the observed high H-statistic and low p-value in several predictors indicates significant variability at 0.001 level. Furthermore, Dunn’s post hoc test among catch crop group pairs highlights the substantial differences between cold-sensitive and legume groups (p < 0.001).

Sugar beet production is highly affected by weeds. The structure of crop rotation, the use of intercrops and different tillage techniques bring several benefits to sugar beet cultivation and create different living conditions for weeds. The response of weed communities in sugar beet stands has not been studied. The experimental plot is in the cadastral area of Ivanovice na Hané (Czech Republic). During an eight-year monitoring period (2013–2020), 46 weed species were identified. The dominant species was Chenopodium album. There were also summer and winter weeds. A more varied crop rotation increased the intensity of weed infestation, with winter weeds being the most common. On the contrary, a higher proportion of cereals in the crop structure favors the presence of summer weeds. The tillage technology and the inclusion of catch crops did not significantly affect the intensity of weed infestation in sugar beet stands or the spectrum of weed species. Current cropping technologies have driven the evolution of weeds. Due to their short life cycles and relatively simple genomes, weeds can respond very quickly to technological measures and, thus, change their harmfulness. [ABSTRACT FROM AUTHOR]

In sustainable cultivation technologies, the method of managing crop residues and the microbiological activity of the soil, supported by the application of effective microorganisms, is of particular importance. Unfortunately, wheat monocultures are still common. Therefore, there is also a need to introduce elements of sustainable agrotechnics to such crops. The aim of the research was to compare the effect of 18 spring wheat (Triticum aestivum L.) cultivation technologies in a monoculture. Therefore, a four-year two-factor experiment was carried out with a spring wheat monoculture. Six ways managing the organic matter before sowing and tillage (first factor) and the application of microbiological preparations (second factor) were tested, leasing to a total of 18 experimental objects. The parameterized weed infestation, chlorophyll index, and leaf area index, elements of the yield structure, and spring wheat yield were determined through tillage technology. In most cases, the application of biopreparations was not found to have a significant impact on the tested features. The highest yields of spring wheat were obtained through the following technologies: application of EM or UGmax microbiological preparations on the shredded straw of the forecrop; mixing the forecrop with the soil using a grubber immediately after harvest; sowing the white mustard catch crop; winter plowing. [ABSTRACT FROM AUTHOR]

Cover crops (CCs) are a diverse group of species that are sown simultaneously or after the cash crop either as monocrops or mixtures. A farmer survey with 1130 respondents was carried out with the aim to gain knowledge on CC species used by Finnish farmers, to understand how experienced farmers were with them, how experiences varied depending on farm and farmer characteristics, and to identify target groups for dissemination and policy measures. The studied groups were conventional and organic farms that had selected CCs as a registered measure in 2020 to receive agricultural payments. Our results show that farmers were experienced with a high number of CCs despite the high-latitude conditions. Only 11% of respondents had plenty of experience with CCs as mixtures. Farmers tended to favour CCs that were familiar to them as cash crops. Organic producers were usually more experienced than conventional farmers. Education increased curiosity towards CCs. Farmers who used more diverse cash crops tended to use more diverse CCs. In conclusion, especially farmers who have cereal-based systems and rotations should be a core group for knowledge sharing to support transition towards increased use of CCs and higher diversity of CC species in the future. [ABSTRACT FROM AUTHOR]

Context: In developing countries there is a preference to grow food crops rather than forage. However, suitable food–fodder based systems ensure year-round green fodder availability for profitable livestock production. Aims: This study aimed to determine whether including single cut Egyptian clover (SEC) in the existing cropping systems could improve system productivity, forage availability and economic returns. Method: Nine SEC based cropping systems were tested in a randomised complete block design with three replications. Key results: Sorghum–SEC–wheat (late sown) cropping system produced 18% greater wheat equivalent yield compared with a popularly adopted sorghum–wheat system (8.9 Mg ha−1). The water productivity (1.80 kg m−3) of this system was also improved in the sorghum–multi-cut Egyptian clover system (1.74 kg m−3). There was a marginal increase in dry matter yield and crude protein content of the succeeding sorghum crop when it was rotated with Egyptian clover. The inclusion of Egyptian clover also improved the soil organic carbon (23%) and available nitrogen (15%) compared with cereal–cereal systems. The findings identify a sustainable intensification option in the sorghum-based cropping system with short duration Egyptian clover (single cut) as an economically feasible and ecologically effective approach. Conclusion: Integration of single cut Egyptian clover in sorghum–wheat rotation as a catch crop recorded greater system productivity, water-use efficiency and economic returns to achieve the sustainable crop intensification. Implication: The SEC can be an effective option for diversification and intensification of cropping systems to improve fodder availability, yield, boost income and improve soil health. Livestock productivity in India is below potential due to scarcity of green fodder. There is very limited scope to expand the acreage under fodder production, because of other demands on existing cultivable land. Integrating Fahli type Egyptian clover in the sorghum–wheat rotation as a catch crop increases fodder availability without affecting the yield of main crops and has potential as a productive system. Clover can diversify and intensify cropping systems, address food and fodder security and improve soil quality. [ABSTRACT FROM AUTHOR]

This study tested prescribed management practices to reduce nitrogen (N) leaching by 20% while maintaining or improving profitability relative to an existing farm management baseline (Control). N leaching and profitability were estimated for a South Canterbury case study dairy farm using Overseer® Nutrient Budgets and FARMAX Dairy. Three practices were used: (1) reducing N in cows’ diets through low-N feed (fodder beet), (2) recapturing N from soils through catch crops (oats) and (3) diluting urinary N by including plantain in cows’ diet. While most treatments reduced N leaching, significant management inputs were required to achieve a 20% reduction from the Control. Plantain was identified as the key forage for reducing N leaching from the milking platform. Fodder beet and oats had little impact, due to the small area cropped on the milking platform and low dietary substitution. However, they increased profitability relative to the Control. Only one scenario, employing all three forages with biannual direct drilling of plantain, achieved the target, reducing N leaching by 27% and increasing profitability by 2% compared with the Control. The implications of this modelling study for real-life application are that a combination of measures will be needed to achieve large environmental and economic targets. [ABSTRACT FROM AUTHOR]

Due to anthropogenic climate change, cover crop water consumption in winter could potentially increase drought stress for a succeeding crop. Simulation of cover crop evapotranspiration (ET) losses could be a tool for farmers to make smart management decisions. In Germany, the model AMBAV is used by the German Meteorological Service (DWD) to advise farmers in irrigation management. We compared measured ET of phacelia (Phacelia tanacetifolia), oilseed radish (Raphanus sativus var. oleiformis) and white mustard (Sinapis alba) cultivated in a container experiment with simulated data and conducted a sensitivity analysis to identify the meteorological and crop‐specific parameters, which had the strongest effect on simulated ET. In general, measured ET exceeded simulated ET. Different statistical criteria showed that AMBAV performed best for the simulation of evaporation from a bare soil surface. Model performance was also strongly influenced by the irrigation regime in the container experiment. However, the sensitivity analysis showed that changes in irrigation hardly influenced simulated ET. We recommend optimization of the model for irrigated agriculture. Furthermore, we identified temperature and humidity as the most important meteorological and leaf area index as the most important crop‐specific parameter for ET simulations with AMBAV. Since farmers' management decisions depend on the accuracy of ET simulations, they should be aware that even small regional deviations of meteorological conditions and soil cover can significantly affect model predictions. [ABSTRACT FROM AUTHOR]

Rising temperatures and disruption of rainfall patterns due to climate change make water a limiting growth factor even in regions of temperate climates. Thus, producing 'more crop per drop' is of utmost importance. While cover crops provide many benefits to cropping systems, their influence on soil water is discussed controversially. While an increase in transpiration can lead to soil water depletion, the reduction of evaporation in combination with possible additional water inputs could provide a water benefit for a succeeding crop. Occult precipitation could be such an additional water input. The objective of this study was to quantify whether cover crops provide a net water benefit over a bare fallow due to the occurrence of occult precipitation. In a 2‐year experiment, seven different cover crops were cultivated in pure stands and as a mixture under semi‐controlled conditions in a container experiment. Water fluxes and meteorological conditions were closely monitored. Although favourable conditions occurred during both vegetation periods, we found no evidence of occult precipitation. In autumn, soil water was depleted by fast‐growing cover crops. In winter, soil water was recharged due to the early preparation of a mulch layer combined with high winter precipitation while in early spring rising temperatures increased transpiration losses of a winter‐hardy cover crop, leading to a reduction of soil water. For middle European conditions, this shows that (1) living cover crops do not provide any water benefits and that (2) soil water recharge in winter is highly dependent on meteorological conditions and cover crop management. From a water budget viewpoint, negative effects on a succeeding cash crop can only be prevented if cover crops are terminated early enough for replenishment of soil water. [ABSTRACT FROM AUTHOR]

Cover crops (CCs) are a promising strategy for maintaining and enhancing agroecosystem sustainability, yet CCs' effects on the subsequent crop yield are highly variable. To quantitatively synthesize the effects of CCs on subsequent crop yield, a meta-analysis of 672 observations collected from 63 recent studies (2015 to 2021) in temperate climates was conducted. Legume CC species increased subsequent crop yield significantly more than grass (by 14%), nonlegume broadleaves (by 7%), and mixtures (by 2%). Incorporation of CC residue into soil increased crop yield by approx. 15% compared to leaving the CC residue on the soil surface. Relative to the no-CC control, the adoption of grass and legume CC species in non-organic vegetable cropping systems enhanced crop yield by 14% and 19%, respectively. Likewise, crop yield with legume CCs in coarse and medium textured soil, and under high precipitation conditions (>700 mm), was significantly greater than the no-CC control by 18%, 4%, and 11%, respectively. Cover crops significantly increased vegetable crop yields and decreased the silage corn yield; however, grain corn, soybean, and winter wheat yield did not decrease with CC. Adoption of CC in no-tillage and plow tillage systems contributed to an increase in crop yield compared to the no-CC control. Our meta-analysis highlights that crop yield response to CC might become more robust when pedo-climatic conditions and agronomic factors are considered. [ABSTRACT FROM AUTHOR]

Sugar beet production is highly affected by weeds. The structure of crop rotation, the use of intercrops and different tillage techniques bring several benefits to sugar beet cultivation and create different living conditions for weeds. The response of weed communities in sugar beet stands has not been studied. The experimental plot is in the cadastral area of Ivanovice na Hané (Czech Republic). During an eight-year monitoring period (2013–2020), 46 weed species were identified. The dominant species was Chenopodium album. There were also summer and winter weeds. A more varied crop rotation increased the intensity of weed infestation, with winter weeds being the most common. On the contrary, a higher proportion of cereals in the crop structure favors the presence of summer weeds. The tillage technology and the inclusion of catch crops did not significantly affect the intensity of weed infestation in sugar beet stands or the spectrum of weed species. Current cropping technologies have driven the evolution of weeds. Due to their short life cycles and relatively simple genomes, weeds can respond very quickly to technological measures and, thus, change their harmfulness.

In sustainable cultivation technologies, the method of managing crop residues and the microbiological activity of the soil, supported by the application of effective microorganisms, is of particular importance. Unfortunately, wheat monocultures are still common. Therefore, there is also a need to introduce elements of sustainable agrotechnics to such crops. The aim of the research was to compare the effect of 18 spring wheat (Triticum aestivum L.) cultivation technologies in a monoculture. Therefore, a four-year two-factor experiment was carried out with a spring wheat monoculture. Six ways managing the organic matter before sowing and tillage (first factor) and the application of microbiological preparations (second factor) were tested, leasing to a total of 18 experimental objects. The parameterized weed infestation, chlorophyll index, and leaf area index, elements of the yield structure, and spring wheat yield were determined through tillage technology. In most cases, the application of biopreparations was not found to have a significant impact on the tested features. The highest yields of spring wheat were obtained through the following technologies: application of EM or UGmax microbiological preparations on the shredded straw of the forecrop; mixing the forecrop with the soil using a grubber immediately after harvest; sowing the white mustard catch crop; winter plowing.

[Display omitted] • Co-ensiling with diverse co-substrates was applied on sunflower and rye. • Effluent retention was proportional with co-substrate's water holding capacity. • Straw, soiled paper and wood chips addition had no impact on fermentation. • Chicken manure increased silage pH, horse manure promoted homolactic fermentation. Cover crops harvested at a low maturity stage generally have a high moisture content, which may generate energy losses during silage storage via effluent production and undesirable fermentations. This paper investigates the use of different waste types as absorbent co-substrates to be added before ensiling. The relation between the absorbent water holding capacity and silage effluent volume was first studied to find an effective parameter to prevent effluent production. Effluent retention was found to be proportional to the absorbent loading and water holding capacity (r2 = 0.98) and up to 90 % of effluent production was avoided when compared to control (295 l.t−1). The impact of different co-substrates (including bio-waste and manures) on overall ensiling performances was then investigated at an optimized absorbent loading. All co-substrates allowed a total effluent retention while a 76 l.t−1 effluent volume was reported for the control. The silage fermentation was modified or mostly unchanged depending on the co-substrate chemical and microbial properties and different metabolic pathways were observed (e.g. homolactic or butyric fermentation). In most conditions, the methane potential of the crop was efficiently preserved over a storage of 60 days. Co-ensiling was shown to be a relevant silage preparation method for biogas production. [ABSTRACT FROM AUTHOR]

Some European countries are exploring the idea of replacing dedicated crops with energy cover crops for biogas production. Indeed, energy cover crops can generate consequential biomass without competing with food crops for land use. However, the potential benefits and impacts of this choice are not fully understood. Here, we review what is known about the consequences of energy cover crop usage by examining management regimes and digestate use, including impacts on the environment and cropping system performance. First, compared to cover crops, energy cover crops are intensively managed to produce more biomass (< 5 t DM/ha vs. up to 16 t DM/ha). Second, nitrogen is conserved during anaerobic digestion and is more readily available to crops in digestate than in cover crops residues. However, ammonia is lost via volatilization, which could reduce nitrogen use efficiency, depending on the storage conditions and application method. Third, 43–80% of the crops' initial carbon is transformed into biogas. That said, levels of soil carbon storage may nonetheless resemble those obtained with cover crops left behind because carbon is stabilized during anaerobic digestion and the energy cover crops' roots and stubble are left behind in the soil. Fourth, energy cover crops can act as multiservice cover crops, reducing nitrate leaching, improving soil microbial activity, and enhancing soil physical properties during the fallow period. Fifth, energy cover crop usage can have certain disservices, such as soil compaction, the need for additional inputs (e.g., irrigation, fertilization, pesticides), reduced groundwater recharge, and reduced following crop yield. In summary, expanding the usage of energy cover crops for biogas production does not seem to be an environmental threat. However, care must be taken to avoid the intensification of irrigation and lengthening growing periods to boost biomass, which could reduce food production. [ABSTRACT FROM AUTHOR]

Common vetch (Vicia sativa L.) is an annual legume, grown as green manure provide rapid soil cover, can increase soil moisture and organic matter content and reduce soil erosion during fall. During the fallow period, legumes grown as catch crops are known by relea sing large amounts of mineral nitrogen (N) for the subsequent crop. By taking advantage of these benefits, it is possible to increase the yield of the next crop in an environmentally friendly and sustainable way. The goal of this study was to determine the value of common vetch as a green manure, considering its effect on soil conditions and the yield of next crops. We examined three different common vetch seed rate as a green manure in a crop rotation with triticale, oat and corn. Next to the green manured treatments, we used fertilized and bare fallow control treatment for comparison. In our study we evaluated the aboveground biomass weight of spring vetch green manure and its effect on the moisture content of the soil. We examined the green manure's effect on the next crops plant height and yield. We found that the moisture content of the green manured plots was significantly higher during summer drought. On the green manured plots, 37.9% higher triticale yield, 50% h igher oat yield and 44% higher corn yield were measured compared to the control plots. The insertion of spring vetch green manuring into crop rotations could be a good alternative to sustainable nutrient replenishment methods. It can be used to reduce the input needs of farming, reduce carbon footprint, contribute to the protection of soils and increase the organic matter content of the soil. [ABSTRACT FROM AUTHOR]

Forage maize is the predominant crop in the intensive dairy farming regions of Europe. This crop, however, is associated with considerable nitrate leaching and decreasing soil organic matter concentrations. Catch crops installed after maize harvest can usually only be sown late in the growing season in North-West Europe to tackle these problems efficiently. Intercropping maize with grass species such as tall fescue has the potential to result in a timely developed grass sward before the winter, capable of assimilating important quantities of carbon and soil residual nitrogen and to buildup soil organic matter. Yet, the intercropped grass might compete with the maize for water and nutrients. Here, we report, for the first time, the effect of (i) herbicide combinations, (ii) tall fescue sowing density and method, (iii) tall fescue morphotype, and (iv) the maize maturity group on the functioning of forage maize intercropped with tall fescue. We assessed maize and intercropped tall fescue yields and studied the N uptake and the effect on soil residual nitrate of the intercropped grass. We found that every kg dry matter ha−1 of tall fescue aboveground dry matter, present at the end of the autumn, came at a cost of 1.4 kg dry matter ha−1 of maize dry matter yield. Herbicide treatments can regulate grass-maize competition, whereas lower sowing densities of the intercropped grass or different sowing methods of the intercropped grass had no effects. Despite the superior winter growth of the Mediterranean tall fescue morphotype compared to the continental tall fescue, the reduction in soil residual nitrate was similar for both morphotypes. We demonstrate that tall fescue intercropped in maize can be an alternative to cover crops installed after the harvest of maize, to reduce nitrate leaching, and to compensate for the soil organic matter losses associated with forage maize production. [ABSTRACT FROM AUTHOR]

Cover crops (CC) can contribute to climate protection as a result of their effects on soil nitrogen (N) cycling and nitrous oxide (N 2 O) emission and by increasing soil organic carbon (SOC) stocks. This study explored the influence of different winter CC (saia oat, winter rye and spring vetch) compared with bare fallow, followed by silage maize on N 2 O emissions and soil mineral N (SMN) dynamics, as well as on SOC stocks in year-round replicated field plot experiments in four fields located at two sites in northern Germany (Kiel, Uelzen) over two consecutive years (2018/19 and 2019/20). Non-legume CC decreased SMN contents in 0–30 cm during the CC period, but this did not result in decreased cumulative N 2 O emissions over that time. Decreased emissions during CC growth were offset by increased emissions during CC mineralisation after frost and incorporation. Higher cumulative N 2 O emissions during the maize period in all CC treatments compared with bare fallow (significant for non-legume CC) indicated that the incorporated CC biomass still boosted N 2 O emissions under the following crop. Overall, including CC in the cropping system increased annual and yield-related N 2 O emissions compared with bare fallow (significant only for non-legumes). The increase in annual N 2 O emissions of 0.84 ± 1.06 kg N 2 O-N ha−1 yr−1 was only partly offset by the estimated mitigation potential for indirect N 2 O emissions of 0.52 ± 0.14 kg N 2 O-N ha−1 yr−1. The mean annual increase in SOC induced by growing CC every fourth year over a 50-year period was 40–60 kg C ha−1 yr−1. In summary, CC had both positive and negative effects on greenhouse gas exchange. Site and crop rotation optimised CC systems, and a more precise and site-specific consideration of fertilising effects might help improve the net greenhouse gas budget of CC. • Non-legume cover crops significantly reduced topsoil mineral N in winter. • Cover crops had no decreasing effect on direct N 2 O emissions in winter. • Non-legume cover crops increased annual and yield-related N 2 O emissions. • Cover crops potentially decreased indirect N 2 O emissions. • Growing cover crops every fourth year increased SOC by 40–60 kg C ha−1 yr−1 [ABSTRACT FROM AUTHOR]

The water demand for cover crops (CC) should be considered to achieve competitive crop stands for weed control also under unfavorable conditions. This study aims to estimate the weed suppressive ability of winter CC, as Sinapis alba L., Phacelia tanacetifolia Benth., Vicia sativa L. and Avena strigosa Schreb., under a water-limited regime. The water deficit tolerance of different CC was determined in a greenhouse experiment by measuring the maximum quantum efficiency of photosystem II. Moreover, soil moisture, CC, and weed establishment were measured in field experiments in Southwest-Germany during two contrasting growing seasons in 2016 and 2017. A. strigosa showed a higher water deficit tolerance than S. alba in the greenhouse. In the field, A. strigosa showed the highest weed cover reduction (98%) in the field, along with an increasing effect on the soil moisture compared to the untreated control. S. alba performed most sensitive to water deficit in the greenhouse but reached the significantly highest weed control efficacy (94%) during the dry field season in 2016. Even though the selected CC showed differing sensitivities to water deficit in the greenhouse, their weed suppression ability was independent of the water supply under field conditions.

Purpose: Significant leaching losses of nitrogen (N) and phosphorus (P) from soil occurred during the summer fallow period of intensive plastic-shed vegetable production systems, which could be resolved by catch crops. Materials and methods: We firstly estimated the economic profits and then evaluated the efficiencies of six catch leafy vegetables on reducing N and P leaching losses. Meanwhile, responses of soil nutrient contents and the yield as well as the quality of subsequent lettuce were observed under plot-scale experiment. Results and discussion: The six leafy vegetables as catch crops can bring approximately 23, 000–43, 000 yuan RMB hm–2 extra economic profits to farmers. There were five catch treatments that reduced the NO3–-N leaching losses from 22.7 kg hm–2 under the control treatment to 4.6–15.8 kg hm–2. The total P leaching losses were lower under all six catch crop treatments (with 10.5–22.3 kg hm–2) than that under the control treatment (with 39.2 kg hm–2). The mitigation efficiency of catch crops on N and P leaching losses was dependent on the vegetable variety. Overall, vegetable crops did not exhaust soil available N but increased soil available P by 42.1% and organic matter content by 16.8%. The catch crop-based vegetable plantation did not influence yield and N and P uptake capacities of subsequent lettuce. As such, the qualities of lettuce (including the soluble protein, sugar, vitamin, and nitrate contents) were also not influenced following the plantation of catch crops. Conclusions: Leafy vegetable as catch crop during the fallow season increased farmer's income while reducing N and P leaching losses. Moreover, there were no negative effects on subsequent vegetable production and qualities. We can also attempt to reduce the input of N and P chemical fertilizers to subsequent vegetable, as increased available P and organic matter were found in the catch crop treatments. [ABSTRACT FROM AUTHOR]

Mitigating nutrient losses from agricultural fields retains these nutrients for subsequent crop production and reduces the risk to downstream water quality. This study evaluated the impact of cover crops, as part of an annual cropping system, on reducing nutrient losses and enhancing water quality. Cover crop literature focusing on water quality was reviewed to determine important factors regarding cover crop performance and cost. Results show that a grass-based cover crop and mixes with grasses tend to increase nitrate loss reduction (40%) compared to legumes (negligible). Biomass growth was also important, with early seeding or growth of a cover crop in areas with increased growing degree days enhancing performance. For phosphorus loss, benefits did not necessarily increase with increasing biomass. Further, dissolved phosphorus concentrations may increase due to freeze-thaw cycles (23%), although overall dissolved phosphorus losses tend to decrease due to less runoff (34%). Cover crop implementation costs ranged from a savings of $25 to $44 ha-1 year-1 before soybeans and corn, respectively, when implementing a cover crop for five straight years to a cost of $193 ha-1 year-1. Including a cover crop in annual crop rotations with adequate time in the fall for germination and growth can reduce nitrogen and phosphorus losses from production agriculture to help meet water quality goals across the U.S. [ABSTRACT FROM AUTHOR]

This article presents a dataset on nitrate, nitrite and dissolved organic carbon (DOC) losses measured for 4 years using lysimeters at the EFELE long-term experimental site (Le Rheu, France). This ongoing long-term study was designed to provide information on effects of organic waste product (OWP) application and soil tillage on crop production, soil properties, biodiversity, greenhouse gas emissions and water quality. Forty wick-fiber lysimeters were installed at depths of 40 and 90 cm to document effects of organic and/or mineral fertilization, vegetation cover and weather conditions on dynamics of nitrate, nitrite and DOC concentrations of water collected during the drainage season (winter). These data help analyze the effects of winter plant cover (wheat vs. mustard catch crop) on these dynamics and fill a knowledge gap on effects of organic waste product supply on DOC losses. These dynamic data over several years are also of great interest for calibrating and evaluating models (e.g. STICS, APSIM, CERES).

Planting a cover crop between the main cropping seasons is an agricultural management measure with multiple potential benefits for sustainable food production. In the maize production system of the Netherlands, an effective establishment of a winter cover crop is important for reducing nitrogen leaching to groundwater. Cover crop establishment after maize cultivation is obliged by law for sandy soils and consequently implemented on nearly all maize fields, but the winter-time vegetative ground cover varies significantly between fields. The objectives of this study are to assess the variability in winter vegetative cover and evaluate to what extent this variability can be explained by the timing of cover crop establishment and weather conditions in two growing seasons (2017–2018). We used Sentinel-2 satellite imagery to construct NDVI time series for fields known to be cultivated with maize within the province of Overijssel. We fitted piecewise logistic functions to the time series in order to estimate cover crop sowing date and retrieve the fitted NDVI value for 1 December (NDVIDec). We used NDVIDec to represent the quality of cover crop establishment at the start of the winter season. The Sentinel-2 estimated sowing dates compared reasonably with ground reference data for eight fields (RMSE = 6.6 days). The two analysed years differed considerably, with 2018 being much drier and warmer during summer. This drought resulted in an earlier estimated cover crop sowing date (on average 19 days) and an NDVIDec value that was 0.2 higher than in 2017. Combining both years and all fields, we found that Sentinel-2 retrieved sowing dates could explain 55% of the NDVIDec variability. This corresponded to a positive relationship (R2 = 0.50) between NDVIDec and the cumulative growing degree days (GDD) between sowing date and 1 December until reaching 400 GDD. Based on cumulative GDD derived from two weather stations within Overijssel, we found that on average for the past three decades a sowing date of 19 September (± 7 days) allowed to attain these 400 GDD; this provides support for the current legislation that states that from 2019 onwards a cover crop should be sown before 1 October. To meet this deadline, while simultaneously ascertaining a harvest-ready main crop, in practice implies that undersowing of the cover crop during spring will gain importance. Our results show that Sentinel-2 NDVI time series can assess the effectiveness and timing of cover crop growth for small agricultural fields, and as such has potential to inform regulatory frameworks as well as farmers with actionable information that may help to reduce nitrogen leaching.

Growing catch crops is one of the possible strategies to decrease erosion and nitrogen loss from soil profiles. Biomass yield and root system size have significant impacts on the soil nitrogen content. a three‑year field experiment with eight varieties of white mustard (Sinapis alba L.) was established to evaluate the effects of genotype and environment on biomass yield, soil nitrogen content and rooting parameters. Significant effects of genotype were found for root length density (RLD), root surface density (RSD) and specific root length (SRL) in the plow layer (0 – 20 cm) and for root system size (RSS), measured by electrical capacitance method, during three phenological phases. Higher biomass yield in varieties with higher RLD and RSD values during ripening and a larger RSS during flowering were found in dry conditions. Relationship of the root system and biomass yield to nitrate and ammonia nitrogen content varied in different environments. We found a significant relation between the RSS and ammonia nitrogen content in more fertile environment on average over the three years. The nitrate nitrogen content was related to the RLD, RSD and SRL in favorable year at shallow soil depths (0 – 20 cm).

One of the major challenges in agriculture is how climate change influences crop production, for different environmental (soil type, topography, groundwater depth, etc.) and agronomic management conditions. Through systems modelling, this study aims to quantify the impact of future climate on yield risk of winter wheat for two common soil types of Eastern Denmark. The agro-ecosystem model DAISY was used to simulate arable, conventional cropping systems (CSs) and the study focused on the three main management factors: cropping sequence, usage of catch crops and cereal straw management. For the case region of Eastern Denmark, the future yield risk of wheat does not necessarily increase under climate change mainly due to lower water stress in the projections; rather, it depends on appropriate management and each CS design. Major management factors affecting the yield risk of wheat were N supply and the amount of organic material added during rotations. If a CS is characterized by straw removal and no catch crop within the rotation, an increased wheat yield risk must be expected in the future. In contrast, more favourable CSs, including catch crops and straw incorporation, maintain their capacity and result in a decreasing yield risk over time. Higher soil organic matter content, higher net nitrogen mineralization rate and higher soil organic nitrogen content were the main underlying causes for these positive effects. Furthermore, the simulation results showed better N recycling and reduced nitrate leaching for the more favourable CSs, which provide benefits for environment-friendly and sustainable crop production. [ABSTRACT FROM AUTHOR]

Catch crops cultivated for green manure play an important role in improving soil quality by maintaining soil organic matter content and returning nutrients to the soil. The effects of field pea used as the catch crop, both incorporated in autumn (AI) or mulched (SI) vs a control on soil phosphatase activity, available phosphorus (PAVAIL) and microbial biomass phosphorus (MBP) content were studied during 3 years in a field, one-factor experiment in a randomized block design with four replications. Soil samples were taken four times a year from the spring barley plots grown between 2009 and 2011. The application of catch crop increased almost twice the soil available P (only in 2009), while the MBP content increased at about 25-35% in the entire study period. The catch crop management enhanced the activities of phosphatases at about 10-16% as compared to the control. The studied properties were not significantly affected by the catch crop management except for the PAVAIL determined in 2009, which was about 25% higher after being mulched than after the autumn incorporation of field pea. The application of a field pea as green manure can be a useful practice to increase the MBP content and enhance the P-related enzymatic activity. [ABSTRACT FROM AUTHOR]

Legume catch crops can enhance soil fertility and promote the N and P supply of the subsequent main crop, especially with low mineral fertilizer use. However, the specific impact of catch crops on arbuscular mycorrhiza formation of the following main crop is unknown. Therefore, the impact of serradella (Ornithopus sativus) vs. bare fallow was tested on mycorrhiza formation, potential soil enzyme activities and plant-available P under subsequently grown barley (Hordeum vulgare) and different fertilization treatments (P-unfertilized—P0; triple superphosphate—TSP; compost—COM; combined—COM + TSP) in a long-term field experiment in northeastern Germany. Catch cropping significantly increased mycorrhiza formation of barley up to 14% compared to bare fallow. The impact of serradella on mycorrhiza formation exceeded that of the fertilization treatment. Serradella led to increased phosphodiesterase activities and decreased ß-glucosidase activities in soil. Plant availability of P was not significantly affected by serradella. These findings provide initial evidence that even serradella as a non-host crop of mycorrhizal fungi can promote the mycorrhiza formation of the subsequent crop and P mobilization in soil. We conclude that the prolonged vegetation cover of arable soils by the use of catch crops can promote P mobilization and transfer from P pools to the following main crops.

Based on the literature amended by some unpublished data and data compilations from the literature, this review identifies the mechanisms of nitrogen (N) losses from arable land and explores the potential of growing catch crops to mitigate N loss risks from the soil-plant system. The nitrate pool in the soil can be regarded as starting point of most of the N losses via gaseous losses and/or leaching from the soil-plant system. Depleting this pool, especially in autumn, lowers the risk of losses and related impairments of the environment. The input into the nitrate pool can be reduced by adjusting the N fertilization to the N demand of the preceding crop, thus decreasing the N surplus. Less intensive soil tillage after the harvest of the preceding crop may lessen N release from the soil organic matter and the crop residues. On the other hand, cover or catch crops and, to a lesser extent, main crops can take up considerable N amounts in autumn and prevent it from being lost. However, in order to reduce N fertilization of the subsequent crop due to an improved N transfer, the big challenge is to harmonize the N demand of the subsequent main crop and the N release from the catch crop residues. Since the latter depends on several factors like accumulated N amount, C:N ratio of the residues, incorporation date and weather conditions, it can hardly be estimated. Another crucial point is the choice of a suitable cover crop because it should not propagate pests or diseases of the main crops.

Catch crop cultivation for green manure is considered to be a sustainable agricultural strategy whose main goal is to mitigate the negative effects of inappropriate plant sequent by increasing the soil biological activity, improving the nutrient content and reducing their loss from soil. Additionally, correct catch crop management is expected to improve the yield of consequent crops as well as their quality parameters. The effects of field pea when used as a catch crop, either incorporated in autumn or mulched and incorporated in spring vs. a control—without a catch crop on the soil chemical properties (total N, organic C, available forms of K and P) and the composition of spring barley grain and straw (total N, P, K, Ca) were studied for three years (2009 to 2011) in two-field, one-factor experiments, which were conducted on two different soil types (Luvisol and Phaeozem). The catch crop had no effect regarding the soil pH, soil organic C or total N content. In turn, applying a catch crop significantly affected the concentration of the available K (in both soils) and available P content (Phaeozem). The effect of a catch crop on the nutrients in the grain and straw of spring barley was associated with the soil type. In Luvisol, a catch crop, independent of its management, increased the total N and P in the grain and straw of spring barley. In Phaeozem, a catch crop that was incorporated in the autumn significantly increased the K content in grain.

The water demand for cover crops (CC) should be considered to achieve competitive crop stands for weed control also under unfavorable conditions. This study aims to estimate the weed suppressive ability of winter CC, as Sinapis alba L., Phacelia tanacetifolia Benth., Vicia sativa L. and Avena strigosa Schreb., under a water-limited regime. The water deficit tolerance of different CC was determined in a greenhouse experiment by measuring the maximum quantum efficiency of photosystem II. Moreover, soil moisture, CC, and weed establishment were measured in field experiments in Southwest-Germany during two contrasting growing seasons in 2016 and 2017. A. strigosa showed a higher water deficit tolerance than S. alba in the greenhouse. In the field, A. strigosa showed the highest weed cover reduction (98%) in the field, along with an increasing effect on the soil moisture compared to the untreated control. S. alba performed most sensitive to water deficit in the greenhouse but reached the significantly highest weed control efficacy (94%) during the dry field season in 2016. Even though the selected CC showed differing sensitivities to water deficit in the greenhouse, their weed suppression ability was independent of the water supply under field conditions. [ABSTRACT FROM AUTHOR]