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Soils with high organic carbon (SOC) have been shown to enhance crop yields while minimizing climate-induced losses. However, the resilience impacts and mechanisms by which high SOC enhances crop performance have not been fully explored. Here, eight-year rotations of winter wheat and summer maize managed with chemical fertilizer input alone (CF) or with cattle manure (OM) or with peat and vermiculite (PV) were conducted, and various soil properties were measured alongside crop growth, nitrogen (N) uptake, and grain yield, with seasons categorized as dry or normal based on precipitation amounts. The OM and PV treatments increased SOC by 57% and 78% relative to the CF, respectively, and improved soil nutrient availability and the soil quality index. Soil moisture content in the 0–30 cm layer increased by 3.5–26.6%, but was less influenced in the 30–90 cm soil layers. Annual yield of wheat plus maize increased by 13% and 12% in OM and PV compared to the CF, and the yield sustainability index increased by 29% and 17%. Yield gains were more pronounced in dry compared to normal seasons, ranging from 19% to 28% and 12–15% for wheat. At least in part, the relative advantages of OM and PV treatments under drying conditions were associated with accelerated growth and N uptake rate from sowing to stem elongation for wheat and maize. Among the factors influencing yield in the present study, soil moisture exerted the greatest positive total effect on yield. Overall, the results highlight that enhanced SOC resulting from combined application of organic amendments and mineral fertilizer was positively associated with yield by promoting soil quality and water availability, with a more pronounced benefit under water-limited conditions. [Display omitted] • Improved soil quality and moisture enhance wheat and maize yield and stability. • Combined inorganic fertilizer and organic amendments increased soil moisture in the 0–30 cm but not in deeper layers. • Better soils with high SOC enhanced wheat and maize yield and stability during dry seasons. • Accelerated vegetative growth and nutrient uptake by high SOC contributed to productivity resilience. [ABSTRACT FROM AUTHOR]

The use of "green manure"—crops that are cultivated specifically to be incorporated into the soil to increase its organic matter content—has been proposed as an alternative to chemical fertilizer because of its benefits in terms of crop yield. Nonetheless, the differential impacts of green manure on ammonia volatilization remains underexplored. In this study, the influence of various green manure management strategies on ammonia volatilization in maize cultivation were examined. Field experiments conducted from 2020 to 2022, the field experiment applied common vetch after the spring wheat harvest, with five distinct treatments: conventional tillage without green manures as a control (CT); tillage with total green manure incorporation (TG); no-tillage with total green manure mulching (NTG); tillage with only root incorporation (T); and no-tillage with removal of aboveground green manure (NT). The results showed that under TG and NTG, the maize yields were 12.3%-33.2% higher than under CT, and 6.8%-18.8% higher than under T and NT. Compared with CT, all four green manure management practices also significantly increased NH 3 emissions in maize fields, and they increased ammonia volatilization by 12.0%-13.7% in NTG and TG compared to root retention patterns, with NTG exhibiting higher rates than TG. NTG significantly increased soil organic matter, total nitrogen, mineral nitrogen, water-filled pore space (WFPS), microbial biomass carbon and nitrogen, and C: N, and it decreased soil pH compared to TG. Regression analysis showed that these factors were correlated with NH 3 volatilization. In addition, soil urease and ammonia-oxidation functional genes (amo A) showed differences under green manure management practices. Structural equation modeling showed that NH 4 +-N had the greatest positive impact on NH 3 , and urease activity and total nitrogen had positive effects on NH 4 +-N. Furthermore, microbial biomass carbon and pH had positive and negative effects on urease activity, respectively, both of which were only related to SOM. At the same time, WFPS had a positive impact on total nitrogen. In summary, no-tillage with total green manure mulching increases maize yield but also increases NH 3 emissions. NH 4 +-N formed by the hydrolysis of urea by soil urease and the conversion of total nitrogen were found to be the main reasons for high NH 3 emissions. In addition, SOM can promote urease activity, increase NH 4 +-N content and NH 3 volatilization by increasing MBC and decreasing soil pH. [Display omitted] • No-tillage combined with total green manure retention can enhance soil quality and crop yield. • NH 3 volatilization is mainly a physicochemical process caused by the control of NH 4 +-N. • Urease activity and total nitrogen have significant effects on NH 4 +-N. • Increasing microbial biomass carbon and decreasing soil pH can promote urease activity. [ABSTRACT FROM AUTHOR]

Evaluating the contribution of diverse nitrogen (N) sources in agricultural systems is pivotal for optimizing sustainable farming practices. While knowledge exists about the roles of various N sources, there's limited comprehensive data on the relative contributions of manure compost, fertilizer, and root residues to subsequent plant uptake. A comprehensive field study was conducted in Shandong Province, China, utilizing 15N labeling techniques to clarify these contributions. Four treatments were established, each incorporating four exogenous nitrogen sources (manure compost + urea + maize root + residual urea) applied concurrently at wheat seeding, with only one source being 15N labeled per treatment. Additional two treatments served as controls, one without 15N labelling and another without manure compost. During a wheat growing season, the N contribution from each individual source to subsequent wheat growth was quantified. Manure contributed 10% of the wheat seed N, while urea contributed 18% and maize root contributed 0.3%. Nitrogen recovery in distinct components of the wheat plant (seeds, straw, and roots) was assessed, revealing urea's superior use efficiency within the total wheat biomass at 55%. In contrast, both manure compost and maize root showed a recovery rate of 29%. Although this study spans only one-year, it offers fresh perspectives on the differential contribution and use efficiency of key N sources under field conditions, emphasizing their role in bolstering crop health and productivity for sustainable agriculture. [Display omitted] • Manure contributes 10% of N in wheat seeds, more than maize root (0.3%), but less than urea (18%). • Soil and other contributes 72% of the seed N, 71% of the straw N, and 65% of the root N. • N use efficiency in wheat biomass is comparable for manure and maize root (29%). • Urea shows superior N use efficiency in wheat total biomass at 55%. • Grains per spike, not spike number or grain weight, influence yield differences. [ABSTRACT FROM AUTHOR]

Cover crops (CCs) are a recognized best management practice to reduce surface water runoff and nutrient loss from agroecosystems. This 4-yr study was conducted in a tile-terraced field to assess the effects of CCs on nutrient loss compared to without CC (no CC) in a corn (Zea mays L.)-soybean (Glycine max L.) rotation. The 3xCCmix (wheat (Triticum aestivum L.), radish (Raphanus raphanistrum subsp. Sativus), and turnip (Brassica rapa subsp. Rapa)) was aerial seeded in soybean at R6 in 2018 and 2020. Cereal rye (Secale cereale) was drill seeded after the corn harvest in 2019 and 2021 (corn-cereal rye-soybean-3xCCmix). Water samples from individual flumes were collected using automated samplers and analyzed for concentrations and loads of nitrate-N (NO 3 -N), total phosphorus (TP), dissolved phosphorus (PO 4 -P), and total suspended solids (TSS). The 3xCCmix and cereal rye had 16% and 12% lower discharge, respectively, than no CC. The 3xCCmix reduced TSS load 50% compared to CC, while cereal rye had no effect. Cover crops reduced NO 3 -N load 20%, 54%, and 68% during the corn, cereal rye, and soybean growing periods, respectively. Over the full rotations, cumulative discharge and nutrient loads were greater during the 2018–20 crop rotation year because of increased precipitation in 2019. The variability in effectiveness of CCs in reducing nutrient losses was likely affected by different climatic and management factors including CC planting and termination dates. This study highlights the benefits of CCs for reducing sediment and nutrient loss over crop rotation, as well as the continued need for enhanced fertilizer management systems to reduce nutrient loss. • On average, CCs reduced NO 3 -N load in discharge by 20%, 54%, and 68% during the corn, cereal rye CC, and soybean seasons, respectively. • The effect of CC on discharge varied with total rainfall and growing season. • Grass cover crops showed potential to reduce sediment losses in runoff. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is the key nutrient for crop growth in most agricultural systems, but excessive N fertilizer applications have led to very large ammonia (NH 3) and greenhouse gas (GHG), especially nitrous oxide (N 2 O), emissions, resulting in severe air pollution and making a major contribution to global warming. To clarify the effects of improved N management on NH 3 and N 2 O emissions and crop production, a 2-year field experiment was carried out in a maize-wheat rotation in the North China Plain (NCP), testing four optimized N management practices including reducing the fertilizer (urea) N rate and using N 'synergists' with the fertilizer. NH 3 emissions were significantly reduced only by the urease inhibitor (UI) LIMUS®, with an average reduction of 66.9 % relative to emissions from the untreated urea. At the same N rate, N 2 O emissions were reduced by 30.8–76.7 % by all the synergists (UI, a nitrification inhibitor DMPP (NI) and urea with a bacterial agent (UB)), and crop yields were improved by 14.4 % and 15.2 % under the UI and UB treatments, respectively. An 15N tracer experiment showed that using N synergists decreased the total N loss by 10.9–58.7 %, and significantly increased the recovery efficiency of N (RE N) by 16.9–44.8 % over the whole rotation. Reducing the N rate reduced the GWP and yield-scaled GWP (GHGI) by 10.6 % and 8.4 %, respectively. Using the N synergists, GHGI was significantly decreased by 19.2–26.7 % (P < 0.05), while GWP was reduced by 13.2–18.1 % only by the application of DMPP or LIMUS®. Overall, the study showed that reducing N 2 O and NH 3 emissions is important for increasing N utilization and mitigating global warming. Reducing N rate and using synergists can address the joint problems of environmental pollution and agricultural efficiency. In particular, the application of the optimal amount of urea (33% reduction over rates typically applied by farmers) amended with the urease inhibitor LIMUS® to maize-wheat rotations in the NCP proved to be the most effective method for the 'green' and sustainable development of agriculture and the mitigation of global warming in that region of China. • Optimizing N rate decreased environmental impact while maintaining crop yield. • Cropland NH 3 emissions were halved by incorporating a urease inhibitor. • A nitrification inhibitor reduced cropland N 2 O emissions. • Both inhibitors increased the recovery efficiency of fertilizer N by 16.9–44.8 %. • Optimizing fertilizer N rate plus appropriate inhibitor mitigated GWP and GHGI. [ABSTRACT FROM AUTHOR]

Highlights • Non-crop habitats increased the abundance of ladybeetles in maize fields. • The smallest scale (0.5 km) was the most predictive spatial scale. • The dominant species Propylaea japonica responded to landscape variables similarly as the whole population. Abstract Ladybeetles are promising contributors of biological control services in agricultural landscapes, potentially providing significant economic gains in agricultural production. In northern China, ladybeetles are the most common predators in the annual double-crop rotation system, where the dominant crops are wheat in the spring and maize and cotton in the summer. Land-use features at the landscape level affect ladybeetle populations in a number of ways, and our previous studies have estimated the effects of landscape composition on ladybeetles abundance in wheat and cotton fields in northern China. However, these landscape effects on ladybeetle abundance in maize remain insufficiently documented in this specific agro-ecosystem. We assessed the relationships between ladybeetle abundance and landscape composition at four spatial scales (0.5, 1.0, 1.5, and 2.0 km) in a summer maize system at the whorl stage (the main period for ladybeetle colonization). We found that both semi-natural habitats (woodlots and grasslands) and vegetation around water bodies increased the abundance of ladybeetles in maize fields, and maize area played a dilution effect on ladybeetle abundance in this crop. These non-crop habitats might serve as source of emigrants that disperse to maize fields. The smallest scale (0.5 km) studied was the most predictive spatial scale in this colonization period for ladybeetles. Propylaea japonica , the dominant ladybeetle, showed response to landscape variables in a similar way as the whole ladybeetle population did. These findings suggest that leaving some non-crop habitats and reducing human disturbance to this vegetation within a landscape will enhance ladybeetle abundance in maize fields. Consistent with our previous studies in wheat and cotton fields in the same system, maintaining the continuity in time and space of functional habitats was essential for the persistence of ladybeetle populations within the landscape. In the future, habitat management and landscape design to ensure resource continuity should be encouraged to maximize the conservation of ladybeetles in agricultural ecosystems in northern China. [ABSTRACT FROM AUTHOR]

Two of the most important agricultural practices aimed at improving soil properties are crop rotations and no-tillage, yet relatively few studies have assessed their long-term impacts on crop yields and soil greenhouse gas (GHG) emissions. The objective of this study was to determine the influence of tillage and crop rotation on soil GHG emissions and yields following 15 years of treatment implementation in a long-term cropping systems experiment in Illinois, USA. The experimental design was a split-plot RCBD with crop rotation as the main plot: (continuous corn [ Zea mays L.] (CCC), corn-soybean [ Glycine max (L.) Merr.] (CS), continuous soybean (SSS), and corn-soybean-wheat [ Triticum aestivum L.] (CSW); with each phase of each crop rotation present every year) and tillage as the subplot: chisel tillage (T) and no-tillage (NT). Tillage increased the yields of corn and soybean. Tillage and crop rotation had no effect on methane (CH 4 ) emissions (p = 0.4738 and p = 0.8494 respectively) and only rotation had an effect on cumulative carbon dioxide (CO 2 ) (p = 0.0137). However, their interaction affected cumulative nitrous oxide (N 2 O) emissions significantly (p = 0.0960); N 2 O emissions from tilled CCC were the greatest at 6.9 kg-N ha −1 -yr −1 ; while emissions from NT CCC (4.0 kg-N ha −1 -yr −1 ) were not different than both T CS or NT CS (3.6 and 3.3 kg-N ha −1− yr −1 , respectively). Utilizing just a CS crop rotation increased corn yields by around 20% while reducing N 2 O emissions by around 35%; soybean yields were 7% greater and N 2 O emissions were not affected. Therefore results from this long-term study indicate that a CS rotation has the ability to increase yields and reduce GHG emissions compared to either CCC or SSS alone, yet moving to a CSW rotation did not further increase yields or reduce N 2 O emissions. [ABSTRACT FROM AUTHOR]

Straw incorporation is increasingly being adopted in wheat (Triticum aestivum L.)–maize (Zea mays L.) rotation systems to improve soil physiochemical properties. To identify the main soil properties influencing infiltration capacity under long-term straw incorporation in a wheat–maize rotation system, the study set four treatments: no straw incorporation and fertilizer application, wheat straw incorporation with 276 kg nitrogen/ha, wheat and maize straw incorporation with 276 kg N/ha, and wheat and maize straw incorporation. The initial, average, and final infiltration rates were calculated to represent soil infiltration capacity. Compared with other treatments, wheat straw incorporation with 276 kg nitrogen/ha treatment significantly decreased soil bulk density, soil aggregate (DMWD) mean weight diameter measured using the dry sieving method, and weight rate of soil aggregates with diameters greater than 0.25 mm measured using the wet sieving method, and significantly increased total soil porosity, soil capillary porosity, field capacity, and weight rate of soil aggregates with diameters less than 0.25 mm measured using the wet sieving method. In contrast, wheat and maize straw incorporation treatment significantly increased soil bulk density and noncapillary porosity, but decreased total soil porosity, capillary porosity, and field capacity. The results of partial least squares regression indicated that the soil moisture content and DMWD were the primary factors influencing initial infiltration rate with positive regression coefficient. Higher total soil porosity, capillary porosity, field capacity, and DMWD contributed to higher final infiltration rate, while higher soil bulk density and noncapillary porosity were correlated with a lower final infiltration rate. The key influencing factors of average infiltration rate were soil bulk density, soil moisture content, total soil porosity, capillary porosity, and DMWD. The wheat straw incorporation with 276 kg nitrogen/ha treatment had higher infiltration rates than no straw incorporation and fertilizer application treatment. However, with an increase in straw amount, the influence of straw on infiltration showed a law of diminishing marginal returns. Therefore, wheat and maize straw incorporation with 276 kg nitrogen/ha treatments had a lower infiltration rate than wheat straw incorporation with 276 kg nitrogen/ha treatment. In addition, wheat and maize straw incorporation treatment had the lowest average and final infiltration rates of all treatments, indicating that excessive straw incorporation without nitrogen fertilizer had adverse effects on infiltration rates. This study furthers understanding of the influence of long-term straw incorporation on soil hydrological processes and helps rationally use straw resources in wheat–maize rotation systems. • Including straw with N fertilizer increases soil infiltration. • Increasing straw amount led to diminishing returns on infiltration rates. • Returning larger straw without N fertilizer increased soil bulk density. [ABSTRACT FROM AUTHOR]

Airport properties often include agricultural land cover that can attract wildlife species hazardous to aircraft, despite recommendations against row crops near air operations areas. However, few studies have directly quantified bird use of corn, wheat, and soybean fields relative to bird-aircraft collision (strike) hazard levels to support land cover recommendations. Therefore, we compared bird use among corn, wheat and soybean fields and predicted that corn and wheat would attract bird species recognized as hazardous to aviation. We also anticipated that soybeans would pose minimal attraction to such birds. Here, hazard ranking (low to extremely high) reflects the percentage of strikes involving a species that resulted in damage to aircraft. We investigated bird use among 22 corn, wheat, and soybean fields near Oak Harbor, OH, using approximately weekly point transects from 2013 to 2014. We used generalized distance sampling models and analysis of variance using distance matrices to determine bird abundance and community responses to row crop land coverages and crop height. We observed 4331 birds of 40 species, with most birds observed in wheat fields ( n = 2555 birds) and standing stubble ( n = 2409 birds). Large flocks occurred more in corn and wheat fields than soybean fields, but soybean fields harbored greater cumulative hazard scores than corn, likely due to consistent detections of small, non-flocking birds in soybean fields. Crop type and height had greater influence on medium- and high-hazard level bird species than other hazard levels. Density of medium- and high-hazard level birds increased with increasing crop height in soybean and wheat fields with wheat fields having slightly greater densities than soybeans. Corn fields also had the greatest bird densities in the tallest crop height categories. Categories of very and extremely high-hazard level bird species were rarely detected, but their abundance peaked in crops 0–15 cm, similar to low-hazard level bird species. However, model selection results included null models for very and extremely high-hazard level bird species suggesting minimal effects. Overall, our results suggest that all three crop types can harbor birds hazardous to aircraft, and crop height can enhance bird use. Although not directly tested in our study, land management surrounding airports may benefit most from alternative land covers (e.g., biofuel crops), but additional research is necessary. [ABSTRACT FROM AUTHOR]

The green development of agriculture, the rational use of pesticides, and soil health are closely related. However, our understanding of them is still limited. Pyraclostrobin (PYRA) is one of the most popular strobilurin fungicides due to its broad-spectrum control of fungal diseases. However, PYRA has been shown to have negative effects on bacterial communities and soil enzyme activities under laboratory conditions. The effects of PYRA on soil microbes (mainly bacteria) in actual field environments still need to be addressed. In the present study, after applying PYRA in a wheat/maize rotation field for 2 years, we determined the level of residual PYRA and assessed the soil bacterial community structure, soil enzyme activity, and ammonia-oxidizing functional gene expression. The results show that the DT 50 of PYRA in agricultural soil was 2.16–38.93 days. The final residual levels of PYRA in wheat/maize grain were less than 0.01 mg kg−1, which is lower than the maximum residue limit (MRL) recommended (0.2 mg kg−1) by China and the European Union. The culturable fungi and bacteria populations were significantly reduced after applying PYRA. The genera's abundance (Sphingomonas and Lysobacter) and urease activity associated with phosphorus cycle were inhibited. The amoA genes abundance of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) showed that the N-cycle function of soil microbes was inhibited. Overall, applying PYRA for 2 years did not increase the negative response of soil microbes. However, in some indicators, such as culturable microorganism populations, more significant reductions in populations were observed in the double recommended dose group than in the recommended dose group. The results obtained in this study reflect the response of soil microbes subjected to pyraclostrobin in an actual field and provide new insights into how agricultural development influences soil health. [Display omitted] • Pyraclostrobin formulation was applied to a wheat/maize rotation field for 2 years. • Soil functions sustaining microbial life and cycling nutrients were negatively affected. • Negative effects of pyraclostrobin on soil fungi and bacteria were observed. • The genus abundance and urease activity associated with P cycle were inhibited. • Expression of functional genes associated with N cycle was downregulated. [ABSTRACT FROM AUTHOR]

The carbon management index (CMI) and labile organic carbon (LOC) pools are postulated as very sensitive indicators of changes in soil organic carbon (SOC) due to land degradation within a short time in response to management practices. To test this hypothesis, we investigated LOC and CMI under a field experiment (2007–2013) in relation to runoff, soil loss, maize and wheat yields on a 2% (1.15°) land slope of the Indian Himalayas. In this study, the impacts of several resource conservation practices, including different combinations of vegetative barriers (VB), minimum tillage (MT), different organic amendments (OA) and weed mulch, were evaluated. Results revealed that the plots under MT + OA with three applications of weed mulch had more SOC, macroaggregate-associated C concentrations and macroaggregates than conventional tillage (CT) + NPK with chemical weed control. Carbon management index varied from 47 to 59 and 42 to 55% with different conservation practices at depths of 0–5 and 5–15 cm depths, respectively. Incorporation of weed mulch along with application of OM, MT and VB (by Palmarosa ) under MT improved CMI by 19.7 and 24.2% compared to CT plots with VB (by Panicum ) and inorganic NPK at depths of 0–5 and 5–15 cm, respectively. Significant positive correlations were observed between CMI and maize yield ( r = 0.948; n = 24; P < 0.01), CMI and wheat yield ( r = 0.872; n = 24; P < 0.01) and CMI and wheat equivalent yield ( r = 0.906; n = 24; P < 0.01). However, significant negative correlations were obtained for CMI and runoff ( r = −0.701; n = 20; P < 0.01) and CMI and soil loss ( r = −0.768; n = 20; P < 0.01). Results established that Palmarosa as VB along with OA plus weed-mulch under MT was the best management practice for decreasing runoff and soil loss and increasing system productivity on a 2% slope in the region. The single value CMI was strongly positively correlated with crop productivity and negatively correlated with soil loss. Hence, this single value CMI could potentially be used for assessment of soil degradation elsewhere. [ABSTRACT FROM AUTHOR]

Highlights: [•] The summer crop of maize was the main contributor to annual N2O emissions. [•] DMPP urea was effective in reducing N2O emissions only in the maize season. [•] Applying DMPP urea did not increase yields. [•] Adjusting N fertiliser rates on estimated residual soil N reduced N2O emissions. [•] Severe yield loss can occur if residual soil N is not estimated correctly. [ABSTRACT FROM AUTHOR]

Highlights: [•] The drought trend in China's semiarid areas has intensified over the past 50 years. [•] This study investigated the effects of climate change on crop water use efficiency. [•] The water use efficiency by crop has significantly increased over the past 50 years. [ABSTRACT FROM AUTHOR]

Grain crops are an important part of the human diet, accounting for a third of the consumed calories. Throughout human history, annual grain crops with high yields have been obtained through domestication. However, the "annual" characteristic brings associated a series of economic and environmental disadvantages, such as soil erosion or low soil resources use, that can be solved if the agriculture of annual varieties evolves towards perenniality. For this reason, there are numerous research groups dedicated to study and obtain perennial varieties of the most cultivated grain crops. In this review article, we have summarized the most important advances related to the subject, focusing on the domestication and hybridization of the most productive grains globally: wheat, rice, maize, rye and sorghum. We highlight their benefits for sustainable agriculture worldwide due to perennial grains may contribute to reducing erosion, acting avoiding carbon losses, reducing nutrient losses to waters or capturing nutrients deeper in soil when they are scarce, reducing farm costs and thus, increasing the effectiveness of agricultural grain crops. Despite perennial grain crops having disadvantages, they possess outstanding characteristics which make them resilient crops to deal with the imminent climate change. However, maintaining the perenniality trait without reducing genetic biodiversity is a great challenge of current scientific importance that must be deeply considered. • Grain crops constitute an important part of the human diet. • Perennial grain crops can reduce environmental problems associated with annual crops. • There are breeding programs to breed perennial varieties of wheat, rice and maize. • The first perennial grain cultivars, such as Kernza, are being introduced in the market. [ABSTRACT FROM AUTHOR]

Water erosion removes soil nutrients, soil carbon, and in extreme cases can remove topsoil altogether. Previous studies have quantified crop yield losses from water erosion using a range of methods, applied mostly to single plots or fields, and cannot be systematically compared. This study assesses the worldwide impact of water erosion on maize and wheat production using a global gridded modeling approach for the first time. The EPIC crop model is used to simulate the global impact of water erosion on maize and wheat yields, from 1980 to 2010, for a range of field management strategies. Maize and wheat yields were reduced by a median of 3% annually in grid cells affected by water erosion, which represent approximately half of global maize and wheat cultivation areas. Water erosion reduces the annual global production of maize and wheat by 8.9 million tonnes and 5.6 million tonnes, with a value of $3.3bn globally. Nitrogen fertilizer necessary to reduce losses is valued at $0.9bn. As cropland most affected by water erosion is outside major maize and wheat production regions, the production losses account for less than 1% of the annual global production by volume. Countries with heavy rainfall, hilly agricultural regions and low fertilizer use are most vulnerable to water erosion. These characteristics are most common in South and Southeast Asia, sub-Saharan Africa and South and Central America. Notable uncertainties remain around large-scale water erosion estimates that will need to be addressed by better integration of models and observations. Yet, an integrated bio-physical modeling framework – considering plant growth, soil processes and input requirements – as presented herein can provide a link between robust water erosion estimates, economics and policy-making so far lacking in global agricultural assessments. • Water erosion reduces maize and wheat yields by 3% on half of the global cropland. • Simulated erosion impacts are mostly driven by slope, precipitation and fertilizer rates. • Highest water erosion impacts are in Asia, sub-Saharan Africa and Latin America. • Maize and wheat losses due to water erosion account for less than 1% of the global production. [ABSTRACT FROM AUTHOR]

Abstract: Intensively cropped agricultural production systems should be managed to improve soil quality and ecological processes and ultimately strengthen system capacity for sustained biological productivity. We examined the long-term changes (>20 years) in soil quality and productivity with incorporation of ecological management principles in a set of intensively managed row crop systems of the upper Midwest, USA. Replicated experimental treatments include corn (maize)–soybean–wheat cropping systems under four different management regimes: (a) conventional tillage and fertilizer/chemical inputs (Conventional), (b) no tillage with conventional fertilizer/chemical inputs (No-till), (c) conventional tillage with ∼30% of conventional fertilizer/chemical inputs and a leguminous cover crop (Reduced Input), and (d) conventional tillage with no fertilizer/chemical input and a leguminous cover crop (Organic). Effects of these treatments on soils were compared by developing a soil quality index (SQI) from 19 selected soil health indicators. An old field community maintained in early succession provided a benchmark for comparison. Reduction in tillage or fertilizer (No-till, Reduced Input and Organic) resulted in increased SQI and improved crop production. The No-till (SQI=1.02) and Reduced Input (SQI=1.01) systems outperformed Conventional management (SQI=0.92) in nitrogen availability and use efficiency, soil stability and structure improvement, and microbial nitrogen processing. Improvements in soil quality corresponded with increased primary production and crop yield in these systems, illustrating the value of an ecologically defined SQI for assessing the long-term effects of fertility and tillage management regimes in agricultural production systems. [Copyright &y& Elsevier]

Abstract: One-year winter wheat–summer maize rotation is the most popular double cropping system in north-central China, and this highly productive system is an important source of nitrous oxide (N2O) and nitric oxide (NO) emissions due to the high fertilizer N and irrigation water inputs. To sustain the high crop production and mitigate the detrimental impacts of N2O and NO emissions, improved management practices are extensively applied. The aim of this study is therefore to evaluate the effects of an improved management practice of irrigation, fertilization and crop straw on grain yield and N2O and NO emissions for a wheat–maize rotation field in northern China. Using automated and manual chamber measuring systems, we monitored N2O and NO fluxes for the conventional (CT, 2007–2008), improved (IT, 2007–2008), straw-amended (WS, 2008–2009), straw-not-amended (NS, 2008–2009), and no N-fertilizer treatments (WS–NN, 2008–2009), respectively, for one rotation-year. The grain yields were determined for CT and IT for three rotation-years (2005–2008) and for WS, NS and WS–NN for one rotation-year (2008–2009). The improved management of irrigation and fertilization reduced the annual N fertilization rate and irrigation amount by 17% and 30%, respectively; increased the maize yield by 7–14%; and significantly decreased the N2O and NO emissions by 7% (p <0.05) and 29% (p <0.01), respectively. The incorporation of wheat straw increased the cumulative N2O and NO emissions in the following maize season by 58% (p <0.01) and 13%, respectively, whereas the effects of maize straw application were not remarkable. The N2O and NO emission factors of applied N were 2.32±2.32% and 0.42±1.69% for wheat straw and 0.67±0.23% and 0.54±0.15% for chemical N-fertilizers, respectively. Compared to conventional management practices using high application rates of irrigation water and chemical N-fertilizer as well as the field burning of crop straw, the improved management strategy presented here has obvious environmentally positive effects on grain yield and mitigation of N2O and NO emissions. [Copyright &y& Elsevier]

The influences of spatial scale, local conditions, and small vertebrate preferences on post-dispersal predation of weed seeds were tested in agricultural ecosystems of the Southern Pampas Region of Argentina. Seeds from different weed species were offered through exclusion experiments at different distances from the weedy field borders, inside maize (2005) and wheat (2006) stubbles with contrasting land use in the neighbor fields (annual crop fields vs. seminatural grasslands), and inside seminatural grasslands adjacent to stubbles. Canopy structure was characterized inside the wheat stubbles, and small mammals were sampled in both stubble crops and grasslands. All weed species were predated in both 2005 and 2006 trials, but predation ratios varied among weed species, partly due to their seed size, with larger ones being more preferred. While in the maize stubbles no distance or neighbor field land use effects, or interactions between the different factors were detected, in the wheat stubbles, influence of neighbor field land use on weed species predation varied according to distance from field border and the height of the stubble canopy. In wheat stubbles adjacent to annual crop fields, predation increased with canopy height at every different distance from the field borders (5m, 30m and 60m). The opposite was found in wheat stubbles adjacent to seminatural grasslands, where seed predation sharply decreased with canopy height, except for the farthest distance to the border. Capture results suggest a predominance of Calomys spp. populations in crop areas (stubbles adjacent to annual crops) which contrasted with the more diverse small mammal’s community of the grasslands. Based on these data, we provide an insight into the hierarchical nature of factors affecting the predation of weed seeds and discuss some implications of land use patterns on the regulation of weed populations by small vertebrates. [Copyright &y& Elsevier]

Decreased agricultural diversity from extensive use of the corn (Zea mays L.)- soybean (Glycine max (L.) Merr.) rotation and occasional inclusion of spring wheat (Triticum aestivum L.), has threatened cropping system sustainability. Using specialty oilseeds crops to extend the corn-soybean rotation might improve yields and promote sustainability. We tested whether corn, soybean, and wheat yields would be improved in a rotation following oilseed crops versus corn or soybean. In Phase 1, replicated blocks of nine different flowering oilseeds and two traditional grain crops (corn and soybean) were grown. In phase 2, corn, soybean, and wheat were planted in replicated blocks perpendicular to the previous year crops. This 2-year rotation was repeated for three site-years, two in Morris, MN and one in Brookings, SD. Soil water balance was evaluated during Phase 1 of the rotation to determine seasonal water use. Potential N mineralization was measured in the spring prior to planting in a subset of phase 1 treatments (spring canola, cuphea, corn, and soybean). Linear mixed models were used to analyze Phase 2 corn, soybean and wheat yield responses to previous crop. N dynamics and water use responses to phase 1 crops were also analyzed with mixed models. Corn yield was higher with any previous crop other than corn. Soybean and wheat yields did not significantly respond to previous crop. Yield patterns were partially explained by N mineralization potential and previous crop water use. Spring canola treatments provided higher potential net nitrification compared to corn. Canola, camelina, borage, and crambe had lower seasonal water use than both corn and soybean in at least one site-year. This short-term study indicated that corn and soybean yields following specialty oilseed crops had similar yields to a traditional corn-soybean rotation. Further, oilseed crops in rotation provided additional environmental benefits. • Extensive use of rotations with few crops threatens cropping system sustainability. • Rotations containing oilseed had no negative effects on common crops. • Patterns in yield were partially explained by N and water availability. • Sunflower and crambe show the most promise of specialty oilseed crops. [ABSTRACT FROM AUTHOR]

Abstract: There is widespread concern about the risk of potentially toxic elements (PTE) soil and crops accumulate but most studies with biosolids have shown different and even contradictory results. Under field conditions we studied: (i) the accumulation of PTE by maize (Zea mays L.) and wheat (Triticum aestivum L.) from biosolid treated soils and (ii) the ability of total or EDTA extraction to represent the availability of PTE. We sampled plots from nine experiments with maize from controls and biosolid doses up to 45t DM/ha and four experiments with wheat to biosolid doses up to 30t DM/ha. The studies were carried out in the Northwest of Buenos Aires province, Argentina. Top soils and plants (shoot and grain) were sampled. Soils were digested with acids or extracted with EDTA. Shoots were digested with acids. Cadmium, chromium, copper, lead, nickel and zinc were determined by ICPES. Boron, cobalt, manganese and molybdenum in maize were also determined in two experiments. The concentrations of PTE in biosolid were below regulatory concentrations but its application increased some PTE concentration in the soil. Crop yields increased when biosolid were applied in high doses and most PTE concentrations were within normal values. Correlations between total manganese and EDTA extractable copper in soils and in maize, and total copper, lead and zinc in soils and in wheat were found. Application of biosolids increased some PTE concentration in soils, but there is no correlative increase in PTE concentration in maize and wheat shoot or grains. The PTE extraction using EDTA does not represent better PTE crop availability than the total extraction. [Copyright &y& Elsevier]

Abstract: Wheat (Triticum aestivum L.) and corn (Zea mays L.) rotation system is important for food security in the Loess Plateau of China. Grain yield and water-use efficiency (WUE: grain yield per unit of water consumed) trends, and changes in soil properties during a 24-year fertilization experiment in Pingliang, Gansu, China, were recorded. Mean yields of wheat for the 16 years started in 1981 ranged from 1.29tha-1 for the unfertilized plots (CK) to 4.71tha-1 for the plots that received manure (M) annually with inorganic nitrogen (N) and phosphorus (P) fertilizers (MNP). Corn yields for the 6 years started in 1979 averaged 2.29 and 5.61tha-1 in the same treatments. Yields and WUEs declined significantly with lapse of time except CK and MNP for wheat. Wheat yields with the N and M declined at rate of 77 and 81kgha-1year-1, but the decline of 57kgha-1year-1 for NP was similar to that of 61ha-1year-1 for straw with N annually and P every second year (SNP). Likewise, the corn yields and WUEs declined from 160 to 250kgha-1year-1 and from 0.01 to 0.03kgm-3year-1 among treatments, respectively. These declines were likely to loss of soil fertility and gradual dry weather. Yields were significantly correlated with seasonal evapotranspiration with slopes ranging from 0.5 to 1.27kgm-3 for wheat and from 1.15 to 2.03kgm-3 for corn. Soil organic carbon (SOC), total N (TN), and total P (TP) gradually built up with time except the CK, in which TN and TP remained unchanged but SOC and available P (AP) decreased. Soil AP decreased in the N. Soil available K declined rapidly without straw or manure. Balanced fertilization should be encouraged to ensure sustainable productivity in this intensive cropping system. The greatest SOC increases of about 160mgha-1year-1 occurred in the SNP and MNP, suggesting that long-term additions of organic materials to soil could increase soil water-holding capacity which, in return, improves water availability to plants and arrests yield declines, and decrease CO2 emission from agricultural soils and sustain land productivity. [Copyright &y& Elsevier]

To prevent or prepare for future food shortages an understanding of the likely magnitude and distribution of future cereal yields is required. To this end, predictions of cereal yields have commonly been made, using various assumptions. However, the employed assumptions, namely, that yields tend to follow a given trend over time, have not been extensively tested. This study presents a test of the applicability of two general models to time series of maize (Zea mays L.), rice (Oryza sativa L.), and wheat (Triticum aestivum L.) yields for 188 nations to characterize past yield trends, to assess the relative importance of various trends on a global scale, and lastly, to determine what factors might be responsible for the presence of slowing yield growth and yield decline in some nations. Results showed that linear growth in yields has been the most common trend over time, occurring in more than half of all nation-crop data sets, and that growth significantly greater than 33.1 kg ha−1 yr−1 (the rate at which global cereal yields must grow to have the current per-capita production in 2050) constituted 20% of the data sets and was the most important trend in terms of global area harvested, production, and population. A trend of slowing yield growth was present in roughly one-sixth of the data sets, and the nations that this subset comprised made a small contribution to global area harvested, production, and population (less than 10%). Nation-crop data sets that showed yield growth greater than 33.1 kg ha−1 yr−1 had much greater yields than those that showed slowing yield growth, demonstrating that yield growth is not being limited by general physiological constraints to crop productivity. The results of a logistic regression procedure showed that the relative frequency of slowing yield growth and yield decline was negatively correlated to per-capita gross domestic product (GDP) for maize and wheat, and to growth in fertilizer rate for maize. In addition to GDP, latitude was negatively correlated with the relative frequency of yield decline. There were no significant predictors for rice. These results suggest that both economic and biophysical factors have played a role in limiting cereal yield growth. [Copyright &y& Elsevier]

Land use change in China is related closely to global environmental change and global food security. In this paper, we analyzed land use change for rice, wheat and maize production in China during 1961–1998 based on long-term historical data. The results indicated that the total land area planted for cereals had both increased and decreased between 1961 and 1998. The total area in cereals increased or remained unchanged during 1961–1978, a period when the “Cultural Revolution” occurred, and also increased during 1986–1990 when the Chinese government increased subsides to agriculture. However, the total area in cereals declined during 1980–1985, a period corresponding to the implementation of the “household responsibility system” policy, and during 1991–1995, when a large proportion of the rural labor force moved to urban areas. The center of cereal production has moved towards northern China although the major area planted for rice, wheat and maize together is still located in southern China. The yield per hectare for all crops has increased from 1.21 t/ha in 1961 to 4.83 t/ha in 1998, but the yield per unit chemical fertilizer use decreased from 164 (rice), 44 (wheat) and 93 (maize) kg/kg in 1961 to 10 (rice), 6 (wheat) and 9 (maize) kg/kg in 1998. The increases in yield per hectare and production per capita appear mostly due to the increased industrial energy inputs, especially the rapid increase in chemical fertilizer use after the “household responsibility system” in late 1970s. The decline of the yield per unit chemical fertilizer use appears as a result of fertilizer saturation, soil degradation, soil and water pollution, the shortage of irrigation in the north, the threat of flooding in the south, and poor and low quality land use, as well as other social, economic and technical issues. With limited reclaimed land resources remaining and a near saturation in the response of crops to fertilizers, increasing food demand from the increasing population will have to come mainly from increased land productivity that will almost certainly continue to lead to the decline of energy (e.g. fertilizer) use efficiency and continued environmental degradation. Alternatively China may begin to import large amounts of food. This situation will generate adverse effects on sustainable development in China, as well as food security in the world, especially if world energy is in short supply. [Copyright &y& Elsevier]

The atmospheric CO2 concentration is increasing, due primarily to fossil-fuel combustion and deforestation. Sequestering atmospheric C in agricultural soils is being advocated as a possibility to partially offset fossil-fuel emissions. Sequestering C in agriculture requires a change in management practices, i.e. efficient use of pesticides, irrigation, and farm machinery. The C emissions associated with a change in practices have not traditionally been incorporated comprehensively into C sequestration analyses. A full C cycle analysis has been completed for agricultural inputs, resulting in estimates of net C flux for three crop types across three tillage intensities. The full C cycle analysis includes estimates of energy use and C emissions for primary fuels, electricity, fertilizers, lime, pesticides, irrigation, seed production, and farm machinery. Total C emissions values were used in conjunction with C sequestration estimates to model net C flux to the atmosphere over time. Based on US average crop inputs, no-till emitted less CO2 from agricultural operations than did conventional tillage, with 137 and 168 kg C ha−1 per year, respectively. Changing from conventional tillage to no-till is therefore estimated to both enhance C sequestration and decrease CO2 emissions. While the enhanced C sequestration will continue for a finite time, the reduction in net CO2 flux to the atmosphere, caused by the reduced fossil-fuel use, can continue indefinitely, as long as the alternative practice is continued. Estimates of net C flux, which are based on US average inputs, will vary across crop type and different climate regimes. The C coefficients calculated for agricultural inputs can be used to estimate C emissions and net C flux on a site-specific basis. [Copyright &y& Elsevier]

• Low-cost biochar was used to ameliorate salt-affected soil. • 12 t ha–1 biochar reduced soil bulk density and increased saturated hydraulic conductivity. • 12 t ha–1 biochar decreased sodium adsorption ratio and increased nitrogen use efficiency. • 6–12 t ha–1 biochar maintained crop yields while fertilizer use was reduced by 25%. Soil salinity and its associated soil compaction and low fertility is a big problem for land management in the arid region or coastal zone. Here, a low-cost and potassium (K)-rich biochar of reed (phragmites communis) was demonstrated effective in alleviating the problem in wheat-maize rotation in the Yellow River Delta region. Adding the biochar at 0, 3, 6, and 12 t ha–1 to a soil with a 2.8‰ salt content via rotary tillage with straw returning, with or without fertilizers, reduced soil bulk density (BD) and increased saturated hydraulic conductivity (K s). At 12 t ha–1 dose and by wheat and maize harvests, respectively, biochar lowered soil BD by 9.1% and 14.5%, increased K s by 82.7% and 91.2%, and reduced sodium adsorption ratio (SAR) by 64.9% and 92.8% in comparison with the control (CK). Further, in comparison with conventional fertilization (CF: 375 kg ha–1 for each crop), biochar use (6 and 12 t ha–1), together with 75% of CF, enhanced the nitrogen use efficiency (NUE) by 20.5%–31.4% for wheat and 15.9%–30.9% for maize. It raised the yields of wheat by 11.3%–17.1% and maize by 9.7%–14.8%. By reducing BD, increasing K s, and decreasing SAR, biochar alleviated soil compaction and salt stress and increased NUE and crop yields. This outcome suggests that the conversion of local bio-waste into biochar as a soil amendment is of agronomic and environmental benefits. [ABSTRACT FROM AUTHOR]

• Regional simulation of nitrate leaching from NCP croplands was done using NLEAP-GIS. • Spatial-temporal variation of nitrate leaching in North China Plain was quantified. • Water input, fertilizer and soil jointly affect N leaching spatial-temporal pattern. • Optimal fertilizer N rates were recommended for winter wheat-summer maize rotation. • Spatial distribution of potential groundwater nitrate pollution risk was implied. Identifying the regional characteristics of nitrate leaching from croplands is of great importance when attempting to assess the groundwater contamination risk due to nitrate leaching from croplands. The regional scale model in the Nitrogen Loss and Environmental Assessment Package with GIS Capabilities (NLEAP-GIS), which takes spatial variations in soil profile properties, meteorological data, and farm practices into account, was adopted in this study to simulate the occurrence dynamics and spatial pattern of nitrate leaching downwards through the crop root zone (0–100 cm) in winter wheat (Triticum aestivum L.)-summer maize (Zea mays L.) rotation croplands during 2011 and 2012 across the Jing-Jin-Ji region on the North China Plain (NCP). The results showed that the monthly nitrate leaching occurrences were driven by rainfall, irrigation, and fertilizer application. The simulated large spatial variation in cumulative nitrate leaching was positively correlated with both rainfall and fertilizer N application rates, whereas it was negatively correlated with N use efficiency. The cumulative nitrate leaching was mostly lower than 10 kg N ha–1 during the winter wheat growing season, whereas nitrate leaching during the summer maize growing season was much higher and mostly ranged from 20 to 100 kg N ha–1. The average cumulative nitrate leaching in the winter wheat-summer maize rotation system was 55.7 ± 33.5 kg N ha–1, accounting for 17.2 ± 10.2 % of the fertilizer N applied (average 176.3 ± 86.2 kg N ha–1 during each crop season). Fertilizer N application rates of 100–200 kg N ha–1 are recommended during each winter wheat and summer maize season to simultaneously achieve higher grain yields, greater N use efficiency, and a lower groundwater nitrate pollution risk on the NCP. The simulated spatial variation in nitrate leaching implied that there was a potential nitrate groundwater contaminant source and the results contributed to the spatial distribution assessment of groundwater nitrate contamination risk caused by fertilizer N inputs. [ABSTRACT FROM AUTHOR]