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Existing agricultural nitrogen datasets in China are mostly developed using coarse national or provincial statistics. A crop‐specific nitrogen rate dataset based on the finest‐scale agricultural nitrogen statistics at the county level remains lacking. Here, we constructed a new dataset (CN‐N), which provides annual nitrogen rates for rice, wheat and maize in China at a 1‐km spatial resolution from 2004 to 2016. This dataset was developed by harmonizing county‐level and provincial agricultural nitrogen statistics with gridded crop distribution maps, resulting in 13 years of nitrogen rate maps for each crop covering 2004–2016. Validation against farmers' surveys by crop indicates CN‐N reliably quantifies average nitrogen rates and trends for each crop over 2004–2016, demonstrating improved spatial heterogeneity compared to previous datasets rasterized using only provincial statistics. Our study provides a crop‐specific, temporally consistent, gridded nitrogen rate dataset based on the finest‐scale county‐level agricultural nitrogen statistics. This can support future process‐based modelling for sustainable agricultural nitrogen management strategies. [ABSTRACT FROM AUTHOR]

The oriental armyworm, Mythimna separata (Walker), an important migratory pest of maize and wheat, is posing a severe threat to maize production in Asian countries. As source areas of spring–summer emigratory populations, the control of M. separata in southwestern China is of great significance for East Asian maize production. To assess the toxicity of Bt maize against the pest, bioassays of Bt-(Cry1Ab+Vip3Aa) maize (event DBN3601T), Bt-Cry1Ab maize (event DBN9936), and Bt-Vip3Aa maize (event DBN9501) were conducted in Yunnan province of southwest China. There were significant differences in insecticidal activity between the three Bt maize events, and DBN3601T presented the highest insecticidal role. The results also indicated that the insecticidal effect of various Bt maize tissues took an order in leaf > kernel > silk, which is highly consistent with the expression amounts of Bt insecticidal protein in leaf (69.69 ± 1.18 μg/g), kernel (11.69 ± 0.75 μg/g), and silk (7.32 ± 0.31 μg/g). In field trials, all larval population densities, plant damage rates, and leaf damage levels of DBN3601T maize were significantly lower than the conventional maize. This research indicated that the DBN3601T event had a high control efficiency against M. separata and could be deployed in southwest China for the management of M. separata. [ABSTRACT FROM AUTHOR]

Chromosome elimination resulting in haploids is achieved by rapid loss of chromosomes from one parent during the zygote stage and is an important procedure to produce doubled haploid (DH) lines in plants. During crosses between an emasculated wheat (Triticum aestivum L.) and maize (Zea mays L.) as pollen donors, the complete loss of maize chromosomes results in wheat haploid embryos. Through embryo rescue and chromosome doubling processes, pure lines with stable traits can be quickly obtained. The technique is called the "Wheat × Maize System". Although this technology is not new, it remains a practical approach to date. In order to optimize and improve this technology and to achieve its maximum potential in the winter wheat area of China, this paper reviews the previous and ongoing research and technical procedures for the production of wheat DH lines via the maize pollen induction and presents outlooks on DH research and its application in wheat breeding. [ABSTRACT FROM AUTHOR]

Drought is a most prevalent environmental stress affecting the productivity of rainfed wheat and maize in the semiarid Loess Plateau of China. Sustainable agricultural practices such as intercropping are important for enhancing crop performance in terms of better physiological and biochemical characteristics under drought conditions. Enzymatic and non-enzymatic antioxidant enzyme activities are associated with improved abiotic tolerance in crop plants, however, its molecular mechanism remains obscure. A 2-year field study was conducted to evaluate the influence of intercropping treatment viz. wheat mono-crop (WMC), maize mono-crop (MMC), intercropping maize (IM) and wheat (IW) crops, and nitrogen (N) application rates viz. control and full-dose of N (basal application at 150 and 235 kg ha−1 for wheat and maize, respectively) on chlorophyll fluorescence, gas exchange traits, lipid peroxidation, antioxidative properties and expression patterns of six tolerance genes in both crops under rainfed conditions. As compared with their respective monocropping treatments, IW and IM increased the Fo/Fm by 18.35 and 14.33%, PS-11 efficiency by 7.90 and 13.44%, photosynthesis by 14.31 and 23.97%, C-capacity by 32.05 and 12.92%, and stomatal conductance by 41.40 and 89.95% under without- and with-N application, respectively. The reductions in instantaneous- and intrinsic-water use efficiency and MDA content in the range of 8.76–26.30% were recorded for IW and IM treatments compared with WMC and MMC, respectively. Compared with the WMC and MMC, IW and IM also triggered better antioxidant activities under both N rates. Moreover, we also noted that intercropping and N addition regulated the transcript levels of six genes encoding non-enzymatic antioxidants cycle enzymes. The better performance of intercropping treatments i.e., IW and IM were also associated with improved osmolytes accumulation under rainfed conditions. As compared with control, N addition significantly improved the chlorophyll fluorescence, gas exchange traits, lipid peroxidation, and antioxidant enzyme activities under all intercropping treatments. Our results increase our understanding of the physiological, biochemical, and molecular mechanisms of intercropping-induced water stress tolerance in wheat and maize crops. [ABSTRACT FROM AUTHOR]

Waterlogging disasters severely restrict crop production. The middle and lower Yangtze River region (MLYRR) is an important grain-producing region in China but suffers from severe waterlogging disasters. In this study, an agriculture-specific index called the accumulative humidity index was introduced to analyze the spatiotemporal characteristics of waterlogging during different wheat and maize growth stages in the MLYRR from 1960 to 2020. Additionally, the relationships between waterlogging intensities and crop yield fluctuations were revealed. The results showed that over the past 60 years, the intensity of wheat and maize waterlogging in the central and eastern MLYRR have increased; crop waterlogging was more intense in the 1990s–2010s than during the 1960s–1980s, and waterlogging intensity peaked in the 1990s. For both crops, waterlogging was more intense during the early growth stages, but its yield-reducing impacts were more significant during middle and late growth stages. The southern MLYRR (especially southern Anhui) was the region where both crops were most prone to waterlogging, but yields in this region were not severely affected by waterlogging. Compared with wheat, maize was more prone to waterlogging, and its yield was more significantly reduced by waterlogging. In conclusion, this study provides guidance for agricultural waterlogging risk reduction in the MLYRR. [ABSTRACT FROM AUTHOR]

Drought is a most prevalent environmental stress affecting the productivity of rainfed wheat and maize in the semiarid Loess Plateau of China. Sustainable agricultural practices such as intercropping are important for enhancing crop performance in terms of better physiological and biochemical characteristics under drought conditions. Enzymatic and non-enzymatic antioxidant enzyme activities are associated with improved abiotic tolerance in crop plants, however, its molecular mechanism remains obscure. A 2-year field study was conducted to evaluate the influence of intercropping treatment viz. wheat mono-crop (WMC), maize mono-crop (MMC), intercropping maize (IM) and wheat (IW) crops, and nitrogen (N) application rates viz. control and full-dose of N (basal application at 150 and 235 kg ha−1 for wheat and maize, respectively) on chlorophyll fluorescence, gas exchange traits, lipid peroxidation, antioxidative properties and expression patterns of six tolerance genes in both crops under rainfed conditions. As compared with their respective monocropping treatments, IW and IM increased the Fo/Fm by 18.35 and 14.33%, PS-11 efficiency by 7.90 and 13.44%, photosynthesis by 14.31 and 23.97%, C-capacity by 32.05 and 12.92%, and stomatal conductance by 41.40 and 89.95% under without- and with-N application, respectively. The reductions in instantaneous- and intrinsic-water use efficiency and MDA content in the range of 8.76–26.30% were recorded for IW and IM treatments compared with WMC and MMC, respectively. Compared with the WMC and MMC, IW and IM also triggered better antioxidant activities under both N rates. Moreover, we also noted that intercropping and N addition regulated the transcript levels of six genes encoding non-enzymatic antioxidants cycle enzymes. The better performance of intercropping treatments i.e., IW and IM were also associated with improved osmolytes accumulation under rainfed conditions. As compared with control, N addition significantly improved the chlorophyll fluorescence, gas exchange traits, lipid peroxidation, and antioxidant enzyme activities under all intercropping treatments. Our results increase our understanding of the physiological, biochemical, and molecular mechanisms of intercropping-induced water stress tolerance in wheat and maize crops. [ABSTRACT FROM AUTHOR]

The fall armyworm (FAW), Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), is a major migratory invasive pest that poses a severe threat to agricultural production and food security in China. In this study, we estimated the effects of six cereal crops on the development, survival, and fecundity of FAW using the age‐stage, two‐sex life table: maize (Zea mays L.), wheat (Triticum aestivum L.), sorghum [Sorghum bicolor (L.) Moench], oats (Avena sativa L.), millet (species, authority) (all Poaceae), and quinoa (Chenopodium quinoa Willd.) (Amaranthaceae). In a six‐choice test using detached leaf material, FAW larvae preferentially occurred on maize, followed by sorghum, within 6–24 h, and occurred the least on millet and quinoa. After 24 h, they had consumed the most leaf material from sorghum and maize, and the least from quinoa. In no‐choice tests using detached leaf material, they performed best on maize in terms of development (e.g., short development time), survival (e.g., high larval survival and pupation rate), and fecundity (e.g., high number of oviposition days and number of eggs laid per female), resulting in the highest predicted population growth (e.g., high intrinsic rate of increase and net reproductive rate). Although maize was found to be the most appropriate host plant, FAW was able to complete its life cycle on all six tested cereals. Our findings can help in predicting population dynamics and deepening our understanding of the potential damage incurred by FAW infestation, especially in regions under maize cultivation. [ABSTRACT FROM AUTHOR]

Background: In areas prone to water erosion, crop selection strategies should be based on assessment of their effects on soil structural properties. Aims: The present study compared the effects of the cultivation of forage maize (Zea mays L.) and forage oat (Avena sativa L.) and their cultivars on soil aggregation relative to potato (Solanum tuberosum L.) or wheat (Triticum aestivum L.) at a hydrothermally limited site on the Loess Plateau, China. Methods: The water‐stable aggregate (WSA) distribution in soil was measured under three cultivars in each of maize, oat, wheat, and potato (a total of 12 cultivars from four crops) in their flowering stage of three cropping seasons, when root biomass was largest. Results: In each year, the water‐stable macroaggregates (>0.25 mm) content and mean weight diameter (MWD) of WSAs in the top 20 cm of soil did not differ between tested cultivars of every crop but increased under maize and oat, compared with those under wheat or potato. The increased soil aggregation under maize and oat, compared with wheat or potato, was consistent with the pattern of change in root biomass but was not consistent with the changes in root length density, root surface area, or root mean diameter across the crops. The water‐stable macroaggregates content and MWD of soil was positively correlated with root biomass across cultivars and crop species within each cropping season. Conclusions: We suggest that increased root biomass under maize and oat relative to potato or wheat resulted in increased soil aggregation in maize and oat cultivated soils. It is demonstrated that, in areas prone to soil water erosion, planting high‐biomass‐yielding crops such as maize and oat is more beneficial for increasing soil aggregation and stability, compared with low‐biomass‐yielding crops such as wheat or potato. [ABSTRACT FROM AUTHOR]

Soil degradation and high environmental costs impede agricultural production in North China. A 6-year field experiment was conducted to determine the effects of tillage practice and nitrogen application rate on changes in soil fertility and wheat yield. Four tillage systems (rotary tillage without maize straw return through 6 years, RT; rotary tillage with maize straw return through 6 years, RS; deep tillage with maize straw return through 6 years, DS; and rotary tillage through 2 years followed by deep tillage next year with maize straw applied for two cycles, RS/DS) and three N levels (HN, 300 kg N ha−1, refers to traditional farming practice; MN, 0.75 × HN, 225 kg N ha−1, to recommended N rate; and LN, 0.5 × HN, 150 kg N ha−1, to reduced N rate) were tested. The soil organic carbon, labile organic carbon, inorganic N, available phosphorus, and available potassium under straw return treatments were significantly higher than RT in the 0–30 cm soil layer (p < 0.05). The microbial diversity, invertase, urease, and alkaline phosphatase activities also increased when maize straw was returned. Tillage practices could distribute maize straw in different depths of the soil and then affect soil nutrients, enzyme activity, and microbial diversity. The RS treatment presented the greatest effects in the 0–10 cm layer, while more significant impacts were observed in DS and RS/DS treatments at the 10–30 cm depths. The levels of soil nutrients and enzyme activity increased with an increased N rate. Compared to that under LN, wheat yields increased under HN and MN treatments, whereas there were no significant differences between HN and MN (p > 0.05). An increasing tendency of grain yield was observed in DS and RS/DS, while conversely so in RS. RS/DS had lower farm costs than DS during the study duration. Thus, RS/DS at 225 kg N ha−1 is the best method for improving soil fertility and wheat yield. [ABSTRACT FROM AUTHOR]

• Cadmium soil pollution and crop accumulation are detectable on national level in China. • Mining activities and sewage irrigation dominate to Cd pollution in China. • Cd pollution in Southwest of China, Middle Yellow River region and North China plain should be taken more seriously. • Cd enrichment models differ with investigated sites and are influenced by pollution sources. Cadmium (Cd) pollution of agricultural soil is of public concern due to its high potential toxicity and mobility. This study aimed to reveal the risk of Cd accumulation in soil and wheat/maize systems, with a specific focus on the source-specific ecological risk, human health risk and Cd enrichment model. For this we investigated more than 6100 paired soil and grain samples with 216 datasets including soil Cd contents, soil pH and grain Cd contents of 85 sites from China. The results showed that mining activities, sewage irrigation, industrial activities and agricultural practices were the critical factors causing Cd accumulation in wheat and maize cultivated sites. Thereinto, mining activities contributed to a higher Cd accumulation risk in the southwest China and Middle Yellow River regions; sewage irrigation influenced the Cd accumulation in the North China Plain. In addition, the investigated sites were classified into different categories by comparing their soil and grain Cd contents with the Chinese soil screening values and food safety values, respectively. Cd enrichment models were developed to predict the Cd levels in wheat and maize grains. The results showed that the models exhibited a good performance for predicting the grain Cd contents among safe and warning sites of wheat (R2 = 0.61 and 0.72, respectively); while the well-fitted model for maize was prone to the overestimated sites (R2 = 0.77). This study will provide national viewpoints for the risk assessments and prediction of Cd accumulation in soil and wheat/maize systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Soil moisture (SM) is a key variable of the regional hydrological cycle and has important applications for water resource and agricultural drought management. Various global soil moisture products have been mostly retrieved from microwave remote sensing data. However, currently there is rarely spatially explicit and time-continuous soil moisture information with a high resolution at the national scale. In this study, we generated a 1 km soil moisture dataset for dryland wheat and maize in China (ChinaCropSM1 km) over 1993–2018 through a random forest (RF) algorithm based on numerous in situ daily observations of soil moisture. We independently used in situ observations (181 327 samples) from the agricultural meteorological stations (AMSs) across China for training (164 202 samples) and others for testing (17 125 samples). An irrigation module was first developed according to crop type (i.e., wheat, maize), soil depth (0–10, 10–20 cm) and phenology. We produced four daily datasets separately by crop type and soil depth, and their accuracies were all satisfactory (wheat r 0.93, ubRMSE 0.033 m 3 m -3 ; maize r 0.93, ubRMSE 0.035 m 3 m -3). The spatiotemporal resolutions and accuracy of ChinaCropSM1 km were significantly better than those of global soil moisture products (e.g., r increased by 116 %, ubRMSE decreased by 64 %), including the global remote-sensing-based surface soil moisture dataset (RSSSM) and the European Space Agency (ESA) Climate Change Initiative (CCI) SM. The approach developed in our study could be applied to other regions and crops in the world, and our improved datasets are very valuable for many studies and field management, such as agricultural drought monitoring and crop yield forecasting. The data are published in Zenodo at https://doi.org/10.5281/zenodo.6834530 (wheat 0–10) (Cheng et al., 2022a), https://doi.org/10.5281/zenodo.6822591 (wheat 10–20) (Cheng et al., 2022b), https://doi/org/10.5281/zenodo.6822581 (maize 0–10) (Cheng et al., 2022c) and https://doi.org/10.5281/zenodo.6820166 (maize 10–20) (Cheng et al., 2022d). [ABSTRACT FROM AUTHOR]

Spring wheat–summer maize (SWSM) annual crop systems were formed to satisfy the maize grain mechanized harvest thermal requirement in the thermal–resource–limited region of the North China Plain. However, the nitrogen (N) application rate effect on SWSM annual yield formation, N accumulation and utilization were barely evaluated. Two–year field experiments were conducted to evaluate the effects of the N application rate on the annual yield of SWSM, observe N accumulation and utilization, and identify the optimized N application. The experiments were conducted under 5 N levels of 0 (N0), 180 (N180), 240 (N240), 300 (N300), and 360 (N360) kg ha−1. The results showed that spring wheat, summer maize and annual cereal yield under the N240 and N480 treatments obtained the highest grain yield (GY) of 5038, 1282 and 16,320 kg ha−1, respectively, and the optimal N application rate was estimated using a linear–plateau model to be 231–307, 222–337 and 463–571 kg ha−1 with maximum GY of 4654–5317, 11,727–12,003 and 16,349–16,658 kg ha−1, respectively. With the increase in the N application rate, the dry matter accumulation (DM) were significantly increased by 16.9–173.5% for spring wheat and 11.1≈–76.8% for summer maize, respectively; and the annual cereal DM was 15.1–179.7% greater than that with N0 treatment, respectively. Spring wheat, summer maize and the annual cereal total N accumulation (TN) under N360 and N720 treatments were significantly increased by 5.4–19.1%, 16.6–32.3% and 11.5–26.2%, respectively, compared to the other treatments; however, N use efficiency for biomass and grain production (NUEbms and NUEg) were decreased significantly by 10.9–13.6% and 8.9–20.7%, 6.8–13.8% and 12.2–15.6%, and 5.5–11.7% and 10.0–16.0%, respectively. Meanwhile, the N partial factor productivity (PFPN), N agronomy use efficiency (ANUE), N recovery efficiency (NRE) and N uptake efficiency (NEupk) under the N240 treatment for spring wheat and summer maize obtained high levels of 20.99 and 47.01 kg−1, 9.27 and 16.35 kg−1, 32.53% and 32.44%, and 0.85 and 0.72 kg−1, respectively. Correlation analysis showed that the N application rate, TN and NEupk played significantly positive roles on GY, spring wheat spilke grain number, summer maize ear grain number and 1000–grain weight, DM LAImax and SPADmax, while NUEbms, NUEg, PFPN and ANUE always played negative effects. These results demonstrate that spring wheat, summer maize and annual cereal obtained the highest GY being 4654–5317, 11,727–12,003 and 16,349–16,658 kg ha−1 with the optimal N application rate 231–307, 222–337 and 463–571 kg ha−1, respectively, which provide N application guidance to farmer for spring wheat–summer maize crop systems to achieve annual mechanical harvesting in the thermal–resource–limited region of the North China Plain. [ABSTRACT FROM AUTHOR]

Because of the effect of nitrogen (N) fertilization on soil-derived N uptake, N difference (FNRDiff) and 15 N tracer (FNR15N) methods may give significantly different estimates of the fertilizer N recovery (FNR) in crops. To better understand quantitative differences in FNR (∆FNR) between the two methods, we evaluated the effect of fertilizer N input rates on ∆FNR and soil-derived N uptake by considering data from field 15 N tracer experiments of cereal crops across China, including N-unfertilized treatments. The FNRDiff was significantly higher than the corresponding FNR15N in wheat (38% vs. 36%), maize (38% vs. 31%), and rice (40% vs. 31%) under fertilizer applications of 40–500 kg N ha−1. Except in wheat at 250–500 kg N ha−1, FNRDiff was higher than FNR15N at various N input rates in the three crops, and ∆FNR decreased with increasing rates of applied N. The ∆FNR apparently occurred because added-N interaction (ANI) increased soil-derived N uptake (by 5% for wheat, 11% for maize, and 24% for rice). For wheat in particular, ANI values decreased significantly as N input rates increased, with a switch from positive to negative above 252 kg N ha−1. This result suggests that the decrease in soil-derived N uptake is mainly caused by the negative rhizosphere N priming and the law of diminishing returns (current-season non-fertilizer N input or previous-season residual fertilizer N) under high N input, but not by the N pool substitution. Finally, we propose a new method for accurately distinguishing direct and indirect pathway contributions to ∆FNR. This study helps to improve understanding of the underlying mechanisms of discrepancies between the N difference method and the 15 N tracer method for estimating the fertilizer N recovery in crops. [ABSTRACT FROM AUTHOR]

Straw mulching farming is currently an effective dry farming technique for improving arid soil environments. Straw mulching technology can increase the infiltration capacity of soil water and improve crop yield and water use efficiency. In this study, the aim is to improve the soil water holding capacity, water retaining capacity, and comprehensive water use efficiency of crops in dry farmland. First, the response surface model is used to study and analyse the optimal parameters of straw returning and its mulching technology, and then, the crop yield, water consumption, and comprehensive water use efficiency of spring corn under different mulching conditions during 2017-2019 are studied. The test results show that the optimized parameters obtained by the response surface model are as follows: film thickness is 0.03 mm, straw returning amount is 4500 kg/hm2, straw particle size is 5 mm, and straw returning depth is 25 mm. At this time, the maximum soil water storage can reach 404.50 mm. The results of the straw mulching test show that under 4500 kg/hm2 mulching, the soil has more water storage, higher soil water content, and a simultaneous increase in water consumption, which is conducive to the efficient use of limited precipitation by crops. The field experiment for three years shows that 4500 kg/hm2 straw (wheat) mulching in the dry farming area of southern Ningxia can better store water and protect soil moisture, promote the virtuous cycle of farmland soil water, and show outstanding performance in improving corn yield and water use efficiency, which can be popularized and implemented in spring corn production in this area. [ABSTRACT FROM AUTHOR]

Rice seedling blight is a globally occurring seedling disease caused by multiple pathogens. It is currently the most common disease affecting rice production in northeast China; hence, determining the causal agents, including its biological characteristics, host range, and fungicide efficacy is vital for its effective management. The present study obtained 45 pathogenic isolates from diseased rice seedlings in Suihua, Heilongjiang Province, China. Of these, five pathogens were identified based on their morphology and molecular identification, while 10 oomycete isolates were identified as Pythium aristosporum—the first to be reported in rice seedling blight. Its optimum growth conditions include a temperature of 25 °C, pH 6, and photoperiod of 24 h. Except for soybean (Glycine max (L.) Merr.), black soybean (Glycine max var.), and cucumber (Cucumis sativus L.), P. aristosporum can potentially infect and cause seedling blight on other hosts, such as wheat (Triticum aestivum L.), maize (Zea mays L.), sorghum (Sorghum bicolor (L.) Moench), alfalfa (Medicago sativa L.), oats (Avena sativa L.), and white clover (Trifolium repens L.). Its isolates were found to be highly sensitive to metalaxyl + propamocarb (EC50 = 0.0138 μg/mL) with 84.1% efficacy at 313 μg/mL. These results can serve as the basis for controlling P. aristosporum. [ABSTRACT FROM AUTHOR]

The fluctuation characteristics of the correlations between China and the US agricultural futures markets have attracted extensive attention from academic circles and government departments. As the main factor that affects the agricultural futures price, the impact of international crude oil futures price on the correlations of the Sino-US agricultural futures markets is also worth discussing. Therefore, this paper adopts the multifractal detrended cross-correlation analysis (MF-X-DFA) and multifractal detrended partial cross-correlation analysis (MF-DPXA) to explore the fluctuation characteristics of cross-correlations for China and the US agricultural futures markets before and after removing the West Texas Intermediate (WTI) crude oil futures price as well as the impact on the cross-correlations. The results show that the fluctuation characteristics of the cross-correlations and partial cross-correlations between the corresponding varieties of China and the US agricultural futures markets as well as among the varieties within the markets are multifractal. The cross-correlation behaviors and the cross-market risks are all affected to varying degrees by the West Texas Intermediate (WTI) crude oil futures. The West Texas Intermediate (WTI) crude oil futures weaken the cross-market risk of the Sino-US soybean futures, while strengthening the cross-market risk of the Sino-US corn and wheat futures. In addition, the impact of the West Texas Intermediate (WTI) crude oil futures on the cross-market risks among China agricultural futures is greater than those among the US corresponding agricultural futures. [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]

Wheat, rice, and maize collectively provide the bulk of energy and protein to the human diet worldwide. Over the last seven decades, China increased 5.8-fold the aggregated production of the three cereals, but further gains are required to meet the predicted demand of 776 Mt. by 2030. Here, we report the rate of genetic gain in yield of 0.65% year-1 for wheat between 1937 and 2012, 0.69% year-1 for rice between 1934 and 2011, and 0.77% year-1 for maize between 1950 and 2014 in China. National farm yield in the same periods increased 1.38% year-1 for wheat, 1.15% year-1 for rice and 1.32% year-1 for maize. Hence, genetic improvement (G) accounted for 47%-60% of the increase in farm yield, with improved management (M) and G × M interaction accounting for the balance. The absolute rate of genetic gain (kg ha-1 year-1) was proportional to environmental potential. Genetic gain in nitrogen utilization efficiency (yield per unit nitrogen uptake) was significant for all three crops and was achieved at the expense in grain N concentration that decreased at 0.19% year-1 in rice and 0.47% year-1 in maize. To guarantee future food security and environmental sustainability, breeding and agronomic efforts need to increase the rate of gain in yield and revert the declining trends in grain protein by improving nitrogen uptake and nitrogen harvest index. [ABSTRACT FROM AUTHOR]

Castor is a cash crop with very wide adaptability in China, and its yield is closely related with its morphological structure. With reference to the research on the relationship between the morphological structure and yield of main cash crops such as rice, wheat and maize, this paper made a review of advances in the research of the relationship between castor variety characteristics, habitat conditions, dry matter distribution, cultivation measures. Finally, it present the research direction, content and route of the relationship between the morphological structure and yield of the castor in the future. [ABSTRACT FROM AUTHOR]

Sustainably feeding the growing population amid a changing climate and dwindling resources is a grand challenge facing mankind. Decades‐long advancement in crop breeding has progressively elevated yield potential, markedly enhancing global food production capacity. However, relevant impact on reactive N (Nr) emissions associated with crop variety improvement has not been explicitly described. Here, we report multitiered evidence that newer and select maize, wheat, and rice varieties developed in China have the capacity to substantially lower Nr losses while producing more grain. First, we pooled studies featuring side‐by‐side comparison of different varieties, totaling 269 paired observations, to demonstrate that collectively, relatively newer varieties of maize, wheat, and rice had less Nr emissions (9.6%–23.5%) while yielding more grains (7.3%–11.2%) compared to older varieties under wide‐ranging conditions. Next, we built an extended database (142 field studies with 833 observations) and comprehensively evaluated the Nr‐loss reduction potential of newer varieties (2000 and after) versus older ones (1985–1999). We found that newer varieties had Nr emission factors (N loss as a percentage of N applied after correcting for background emissions) 18.2%–75.7% less for N2O, 18.3%–75.7% less for NO3-, and −8.5% to 22.8% less for NH3, while producing more grains (16.0%–24.4%). Individual varieties differed markedly in yield‐emission scores. A nationwide farmer survey (2.47 million responses) indicated tremendous opportunities for a new way of management intervention. Coupling variety selection with sound N and other agronomic management can help lower N footprint while producing more grain. [ABSTRACT FROM AUTHOR]

China has a huge resource potential for biomass‐based renewable energy development, but the resources of field residues are still not effectively used. Rice, maize, and wheat made up 89% of staple crop production in China in 2009. A comprehensive assessment of field residues of these three crops is necessary for the development of biomass‐based industries. This research was based on multiyear county‐level data of crop production, area and yield, as well as the crop phenology information from agrometeorological stations. Spatial and temporal analyses were conducted to quantify the spatial patterns, seasonal variations, and temporal trends of the three major field residues. The mean amount of field residue of rice, maize, and wheat was 470.8 Mt/year from 2002 to 2009. Rice residue topped the field residues at 188.5 Mt/year, followed by maize (152.6 Mt/year) and wheat (129.8 Mt/year). The resource supply of field residues varied temporally throughout the season, where peak months are May, June, September, and October. The resources of all three field residues increased from 2002 to 2009, topped by maize residues at a rate of 10.0 Mt/year. Spatially, high production counties had the fast growth rate and a strong positive spatial autocorrelation. The results showed that the intersection area of East and South Central regions has a spatially concentrated residue density and a stable supply for 5 months. The region can be considered as a suitable region for bioenergy development. A better understanding of spatial and temporal distribution of crop residues could facilitate strategic and tactical bioenergy planning. [ABSTRACT FROM AUTHOR]

How to plan crop planting under global warming is a key issue in the context of an emerging global food crisis. Although previous studies have utilized crop potential distribution for crop planting strategies, they overlooked the high and stable crop-yielding areas within the potential distribution zone, which hinders the optimal utilization of these areas. Taking China as a case, this study proposed a high and stable yield index based on crop potential yield using a hybrid model at site scale (i.e., establishing the relationship between the observed crop yield and the outputs of process-based LPJ-GUESS model as well as climate variables using the random forest method) and assessed planting suitability of China's main grain crops (i.e., maize, wheat, and rice) under future climate change using the index. According to the results, (1) the determination coefficients between observed and modeled yield in the hybrid models were 0.71, 0.49, and 0.66 for maize, wheat, and rice, respectively, suggesting that the hybrid model had an acceptable performance. Moreover, the hybrid models had much better performance than the LPJ-GUESS model in crop yield simulation at site scale. (2) Compared with the 2001–2020, future average potential yield of three crops in the actual cultivated land would decline in 2081–2100, where the declined areas for maize, wheat, and rice would account for 83.8–89.2 %, 68.2–70.2 %, and 74.2–80.9 % of cultivated land, respectively. (3) High yield and stable yield areas of each crop do not overlap completely spatially, indicating that establishment of the high and stable yield index for crop planting suitability measurement is necessary. Compared with the 2001–2020, the optimal suitability areas of each crop will decrease under future climate change, implying that future climate change will reduce and shift the high and stable yield area of each crop. (4) Spatial overlay between the actual distribution and the optimal suitability area of each crop demonstrates that the optimal suitability area of each crop has not and will not be occupied completely by actual crop planting, suggesting a large available area for the adjustment of future crop planting area. This work could facilitate spatial optimization of crop planting to adapt to future climate change in China. • A hybrid model was developed to estimate crop yield. • An index of high and stable yield for crop was established for crop planting. • Future climate will reduce potential yield and planting suitability of crops. • Optimal suitability area has not been completely occupied by actual crop planting. • Large space was detected for adjusting and newly developing crop planting. [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]

Northwest China is characterized by a high water deficit and regular water resource shortages. These issues have become limiting factors for agricultural and socioeconomic development. Based on a trend-preserving method of bias correction, we calibrated the maximum temperature and minimum temperature in four CMIP5 GCMs (CNRM, IPSL, BCC, and CMCC). Then, we investigated variations in the regional crop water requirement (CWR) in the total growth stages for five main crops (cotton, spring corn, summer corn, spring wheat, and winter wheat) in the past (1961–2005) and future (2006–2100). The results suggest that the MK test yielded insignificant decreasing CWR trends in the total growth stages of cotton (0.10 mm/year), spring corn (0.13 mm/year), and spring wheat (0.05 mm/year) and insignificant increasing trends for summer corn (0.02 mm/year) and winter wheat (0.32 mm/year) historically. In the future period, for the same type of crops (cotton), the CWRs in all scenarios (RCP 2.6, 4.5, and 8.5 scenarios) for all GCMs exhibited significant positive trends; for the same GCM (BCC), the CWRs projected for five major crops in the RCP 4.5 and 8.5 scenarios all exhibited extremely significant MK trends (99%); in addition, the CWRs' rate increases of the five crops projected in RCP8.5 scenario by BCC exhibited the following order: winter wheat (1.25 mm/year), summer corn (1.15 mm/year), spring corn (1.02 mm/year), cotton (0.97 mm/year), and spring wheat (0.87 mm/year). The maximum CWRs of winter wheat were mainly observed in southeastern Northwest China, while those of the other four crops occurred in southern Xinjiang. [ABSTRACT FROM AUTHOR]

The intensive winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) cropping systems in the North China Plain (NCP) rely on the heavy use of mineral nitrogen (N) fertilizers. As the fertigated area of wheat and maize in the NCP has grown rapidly during recent years, developing N management strategies is required for sustainable wheat and maize production. Field experiments were conducted in Hebei Province during three consecutive growth seasons in 2012–2015 to assess the influence of different N fertigation rates on N uptake, yield, and nitrogen use efficiency [NUE: recovery efficiency (REN) and agronomic efficiency (AEN)]. Five levels of N application, 0 (FN0), 40 (FN40%), 70 (FN70%), 100 (FN100%), and 130% (FN130%) of the farmer practice rate (FP: 250 kg N ha−1 and 205.5 kg N ha−1 for wheat and maize, respectively), corresponding to 0, 182.2, 318.9, 455.5, and 592.2 kg N ha−1 y−1, respectively, were tested. Nitrogen in the form of urea was dissolved in irrigation water and split into six and four applications for wheat and maize, respectively. In addition, the treatment "drip irrigation + 100% N conventional broadcasting" (DN100%) was also conducted. All treatments were arranged in a randomized complete block design with three replications. The results revealed the significant influence of both N fertigation rate and N application method on grain yield and NUE. Compared to DN100%, FN100% significantly increased the 3‐year averaged N recovery efficiency (REN) by 0.09 kg kg−1 and 0.04 kg kg−1, and the 3‐year averaged N agronomic efficiency (AEN) by 2.43 kg kg−1 and 1.62 kg kg−1 for wheat and maize, respectively. Among N fertigation rates, there was no significant increase in grain yield in response to N applied at a greater rate than 70% of FP due to excess N accumulation in vegetative tissues. Compared to FN70%, FN100%, and FN130%, FN40% increased the REN by 0.17–0.57 kg kg−1 and 0.03–0.34 kg kg−1and the AEN by 4.60–27.56 kg kg−1 and 2.40–10.62 kg kg−1 for wheat and maize, respectively. Based on a linear‐response relationship between the N fertigation rate and grain yield over three rotational periods it can be concluded that recommended N rates under drip fertigation with optimum split applications can be reduced to 46% (114.6 kg N ha−1) and 58% (116.6 kg N ha−1) of FP for wheat and maize, respectively, without negatively affecting grain yield, thereby increasing NUE. [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]

Trichothecenes are mycotoxins generated by Fusarium species that are toxic to humans and animals and frequently contaminate cereals. Herein, we present an UHPLC-Q-Orbitrap-HRMS method using one-step pretreatment for simultaneous detection of 16 type A and B trichothecenes in maize and wheat. A calibration strategy based on natural isotopic distribution was adopted and validated to replace traditional time-consuming and laborious multipoint external calibration curves. Various conditions influencing the method were studied. The recoveries of spiked analytes at three different concentrations ranged from 74.2% to 105.3% and the inter-day relative standard deviations were 0.5–15.6%. The limits of quantitation were 4.4–108.8 μg/kg. Moreover, the current methodology was applied to the evaluation of type A and B trichothecenes present in samples from major wheat production areas in China. This study provides a facile methodology for type A and B trichothecenes analysis and presents promising applications for exposure risk assessment of trichothecenes in cereals. [Display omitted] • An UHPLC-Q-Orbitrap-HRMS method was developed for 16 type A and B trichothecenes and their modified mycotoxins. • One-step pretreatment method coupled with a novel isotopic multipoint calibration method was adapted. • The new method was applied to systematically evaluate the type A and B trichothecenes in wheat in China. • DON-3G exhibited a significant linear correlation with DON in wheat. [ABSTRACT FROM AUTHOR]

Soil CO 2 emissions respond differently to different tillage practices. However, limited information is available regarding the impact of conventional tillage (CT) and no-tillage (NT) on soil CO 2 emissions and the primary controlling factors or processes. The goal of this study is to derive the relationship of soil CO 2 emissions with soil physicochemical properties from differently tilled soils in a typical winter wheat summer maize rotation system. We hypothesized that soil tillage practices would impact the soil carbon cycle by modifying soil physical and chemical properties, which would in turn affect the soil CO 2 emissions. The study was conducted from 2018 to 2022 with two tillage practices using a randomized complete block design with three replicates. A leading international real-time monitoring system in situ was used to collect soil CO 2 emission data. Cumulative soil CO 2 emissions were reduced by 28.7% in maize and increased by 9.0% in wheat under NT as compared to CT. On an annual scale, the cumulative CO 2 emissions were decreased by 20.5% in NT as compared to CT. Maize season accounted for 70% 78% of soil CO 2 emissions. NT improved the aboveground biomass by 7.74% and 6.44%, and grain yields by 10.2% and 4.49% for maize and wheat, respectively. The soil CO 2 emission intensity of maize was reduced by 35.9% under NT as compared to CT. No significant differences were discovered under the two tillage practices for soil CO 2 emission intensity of wheat. For maize, NT increased the bulk density, subsequently decreasing soil temperature and increasing soil moisture. NT also led to higher soil organic carbon and total nitrogen content, ultimately resulting in a significant reduction in soil CO 2 emissions. For wheat, NT increased soil bulk density, further increasing soil moisture and lowering soil pH. NT thus resulted in lower soil organic carbon and total nitrogen content, ultimately leading to enhanced soil CO 2 emissions. Some of these observations might not be consistent with theoretical predictions, which indicated that the unconsidered factors of actual field conditions might have much significant effects. Overall, NT can be extensively used as an eco-friendly cropland tillage practice based on its positive effects of reducing CO 2 emissions and increasing crop yields. [Display omitted] • CO 2 emission variations by tillage were evaluated by the structural equation model. • No-tillage (NT) decreased CO 2 emissions by 28.7% in maize and increased by 8.99% in wheat. • Annual CO 2 emissions were decreased by 20.5% under NT than conventional tillage (CT). • Maize season accounted for 70% 78% of soil CO 2 emissions. • CO 2 emission intensity of maize was reduced by 35.9% under NT compared with CT. [ABSTRACT FROM AUTHOR]

Tillage practice can change soil properties, regulate crop root development and nutrient availability, thus affecting crop growth and yield. However, the effect of no tillage (NT) and deep tillage (DT) on crop yield relative to conventional tillage (CT) under varied environmental and management conditions is unclear in China. We assessed the yield response of wheat and maize to NT and DT relative to CT based on collected field data (518 observations) with a meta-analysis. In general, NT led to negative yield response of both crops relative to CT, whereas maize presented a positive yield response (6.0 %) to NT in sandy soil, and crop yield responses to NT were not significantly different among environmental and management factors. DT significantly increased the yield of wheat (8.7 %) and maize (8.2 %) over CT. For wheat, the yield response to DT was similar across soil textures, climate conditions, experiment durations, N fertilizer rates, and residue managements; however, the interval DT every 2–3 years (13.2 %) and monoculture (13.9 %) increased yield response than the continuous DT (8.4 %) and double cropping system (8.9 %), respectively. The yield response of maize to DT was greater in semidry region (16.1 %) and under high N fertilizer rate (>300 kg N ha−1) (16.1 %), interval DT (12.4 %) compared with those in humid (7.5 %) and semi-humid (6.8 %) regions, low N fertilizer rates (<300 kg N ha−1) (6.9 %−7.5 %), and continuous DT (7.8 %), respectively; but other environmental and management factors did not affect its yield response. Overall, NT presented similar yield of wheat and maize to CT, while DT significantly enhanced their yields; this analysis revealed the crucial environmental and management factors influencing yield response to tillage practices in China, we also gave some suggestions on selecting appropriate tillage methods to realize high crop yield or/and agricultural sustainable development. • NT led to negative yield response of wheat and maize relative to CT. • DT significantly enhanced wheat and maize yields over CT. • Interval DT and monoculture presented better effects on crop yield response to DT. • Environmental and management factors should be considered to enhance yield using DT. [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]

Managing reactive nitrogen (Nr) in agricultural production is crucial for addressing the triple challenges of food security, climate change and environmental degradation. Intensive work has been conducted to investigate the effects of mitigation strategies on reducing Nr losses by ammonia emission (Nr-NH 3), nitrous oxide emission (Nr-N 2 O) and nitrate leaching (Nr-NO 3 -) separately. This meta-analysis evaluated the efficiency of each strategy in mitigating Nr losses coupled with grain yield responses. The results indicate that producing one Megagram (Mg) of wheat grains caused higher Nr losses, twice that of rice and 17% that of maize. The Nr-NH 3 and Nr-NO 3 - were the dominant sources of Nr losses of the three crops (96%), while Nr-NH 3 only presented 86% of the total Nr losses for rice. Reducing the N rate strategy decreased the yield by 33% and the Nr losses by 62% compared with the conventional rate (150–250 kg N ha−1) as an average of the three crops. In contrast, increasing the N rate higher than 250 kg N ha−1 amplified the yield by 15% but also caused a 71% increase in Nr losses compared with the conventional rate. Although subsurface application decreased Nr losses by 5%, this study rejected this approach as an effective strategy due to a 4% yield decline on average of the grain crops. Slow-release fertilizers decreased Nr-NH 3 and Nr-N 2 O losses by 41–58% and 54–89%, respectively, of the highest losses under urea in the three crops, but also led to yield reductions. Organic amendments achieved the highest drop in Nr-NO 3 - loss by 66% in maize coupled with yield declines. Biochar increased wheat and maize yields by 0.3 and 0.1 Mg, respectively, coupled with 1 kg reduction in Nr losses. On average, inhibitors augmented the grain yields by 0.2 Mg ha−1 for each 1 kg decline in Nr losses. In conclusion, for sustainable agricultural intensification, biochar (for wheat only) and inhibitors (for the three crops) are strongly recommended as mitigation strategies for Nr losses from grain crop production systems in China. • Changes in grain yields with reactive nitrogen losses in China were assessed. • Wheat reactive nitrogen losses were twice higher than rice and 17% than maize. • Ammonia emission and nitrate leaching were the dominant loss sources by 96%. • Biochar reduced wheat reactive nitrogen losses, while increase grain yield. • Inhibitors reduced losses in the three crops coupled with yield increases. [ABSTRACT FROM AUTHOR]

The current study was to better understand the potential factors affecting aflatoxin B1 (AFB1) accumulation varies between different grains. The nutrient composition and contents of defatted substrates were determined; additionally, according to the nutrient content of the substrates, the effects of starch, soluble sugars, amino acids, and trace elements on AFB1 production and mycelial growth in Czapek-Dox medium were examined. These results verified that removal of lipids from ground substrates significantly reduced the substrate’s potential for AFB1 production by Aspergillus flavus. Maltose, glucose, sucrose, arginine, glutamic acid, aspartic acid, and zinc significantly induced AFB1 production up to 1.7- to 26.6-fold. And stachyose more significantly promoted A. flavus growth than the other nutrients. Thus, this study demonstrated that, combined with the nutrients content of grains, in addition to lipids, sucrose, stachyose, glutamic acid, and zinc might play key roles in various grains that are differentially infected by A. flavus. Particularly, two new nutrients (arginine and stachyose) of the grains we found significantly stimulate AFB1 production and A. flavus growth, respectively. The results provide new concepts for antifungal methods to protect food and animal feed from AFB1 contamination. [ABSTRACT FROM AUTHOR]

This paper summaized the experience in high yield of wheat and com in Jieshou City ad made a further study on the supporting measures for the high yield of wheat ad corn on this basis. [ABSTRACT FROM AUTHOR]

Humans are naturally and frequently exposed to a multitude of mycotoxins, but health risk assessments are usually performed on individual mycotoxins, which may underestimate the total risks. In this study, we assessed for the first time the cumulative health risks of concomitant exposure via dietary intake (DI) to multiple mycotoxins, namely deoxynivalenol (DON) and its acetyl derivatives of 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON), based on the concentration addition (CA) concept. A cross-sectional study was conducted in seven districts in Shanghai, China with 1269 participants and 330 wheat and maize samples analyzed. After probabilistic analysis using Monte Carlo simulation, the results showed no health risks to the population in Shanghai considering individual mycotoxins. However, if the cumulative health risks were calculated based on the combined consideration of DON with either 3-ADON or 15-ADON or both, the DI values in 95th percentile were up to 1087 ng/kg body weight/day, exceeding the Provisional Maximum Tolerable Daily Intake (PMTDI) of 1000 ng/kg body weight/day and hence representing potential health risks to the population in Shanghai. The integrated study proposed here could be a model strategy for cumulative health risk assessment on the co-occurring hazards in the fields of food safety combined with environmental contaminants. [ABSTRACT FROM AUTHOR]

The increases in crop yield in China are linked to massive increases in fertilizer and water input, which have also accelerated the degradation of soil and environmental pollution. Nevertheless, the long-term changes in crop yield and water use efficiency (WUE) of three major cereals (maize, wheat and rice) in response to field management practices are rarely reported. This meta-analysis evaluated the effect of field management (nitrogen input (N), irrigation, fertilizer type, fertilization frequency, and irrigation method) on crop yield and WUE between 1990 and 2020 based on 3152 observations. We found that the N thresholds for maize, wheat, and rice were 150–200 kg ha−1, 140–210 kg ha−1, and 90–135 kg ha−1, respectively. N fertilization within the threshold levels increased the crop yield and WUE of maize (84% and 74%), wheat (47% and 41%), and rice (55% and 30%). The irrigation (mm) thresholds for maize and wheat were 180–240 mm and 300–400 mm and crop yield and WUE were increased by 37% and 13% for maize and by 84% and 41% for wheat. Agricultural management increased yield and WUE (% and %) through drip irrigation (23 and 13 maize; 31 and 14 wheat), alternate wetting and drying (AWD) (26 and 30 rice), split fertilization (31 and 21 maize; 64 and 40 wheat; 33 and 25 rice) and organic–inorganic fertilizer (43 and 39 maize; 68 and 66 wheat; 38 and 34 rice). With the increase in HI (humidity index) from 10 to 30, the contribution of irrigation to WUE decreased, but that of fertilization increased. This study concludes that N fertilizer and irrigation applications between threshold levels along with suitable field management is a win–win strategy to achieve climate-smart agricultural production with minimum damages to soil and environment and at lower dependence on fertilizer and irrigation. [ABSTRACT FROM AUTHOR]

Excessive use of water resources is threatening agriculture, other business and populations in China, India and USA, and crop production is expected to play a critical role in the sustainable use of water. In China, plastic mulching is widely employed in crop production, but its impact on agricultural water footprint has not been properly described. A meta-analysis was performed to examine how plastic mulching influences volumetric water availability (VWA), global stress-weighted water footprint per unit of output energy (WFo), and per unit of net economic return in crop production (WFe). Data extracted from 394 published studies in maize (Zea mays L.), wheat (Triticum aestivum L.), and potato (Solanum tuberosum L.) were used in the meta-analysis on crop production at the regional scale and across a range of N fertilization gradients in China. Plastic mulching reduced VWA by 15.3%, 14.1%, and 16.3% in maize, wheat, and potato, respectively, when compared to non-mulching practice, with corresponding reductions of WFo by 33.3%, 28.1%, and 32.1% and of WFe by 14.8%, 31.1%, and 31.0% in maize, wheat, and potato, respectively. Water footprint for crop production increased first and then decreased over the past four decades in China, and was greater in northwest and north central regions of China than in other regions. Under moderate and high N fertilization (>100 kg N ha−1) in dry regions, plastic mulching increased the impact on VWA, thereby reducing WFo and WFe. Water footprint for the production in potato and maize was lower than that in wheat. The meta-analysis demonstrated that plastic mulching practices reduced water footprint while lowering VWA. Therefore, plastic mulching has potential for saving water resource when appropriate growing region and N fertilizer applications are considered. • Plastic mulching (PM) significantly reduced crop's water footprint. • Under moderate and high N input, PM had greater effect on water footprint. • PM was more effective in reducing water footprint in relatively drought environments. [ABSTRACT FROM AUTHOR]

Various cropping patterns are extensively used on the North China Plain, which greatly alter various soil properties. Although these soil properties respond differently to the different cropping patterns, little is known about the possible effects of cropping patterns on desalinized soils. To assess the effects of the different cropping patterns on soil properties and enzyme activities, a long-term field experiment was conducted at the Nanpi Agro-Ecological Station in Hebei Province, China. The cropping patterns under study were the single-cropping patterns of winter wheat (Triticum aestivum L.), spring maize (Zea mays), and spring cotton (Gossypium hirsutum), and the double-cropping pattern of winter wheat–summer maize (WW–SM), which is the predominant cropping pattern on the North China Plain. Soil samples were collected at a depth of 0–100 cm, depending on the soil properties. Our results indicated that soil available phosphorous (P) and available potassium (K) concentrations at 0–20 cm were greater than those of the subsurfaces. Soil organic matter declined with depth, and WW–SM had the highest amount in the deep levels. The WW–SM cropping pattern also generally showed greater levels of enzyme activities than did the single-cropping patterns, proving that diverse crops can enhance enzyme activities. Soil pH generally increased with depth despite there being no significant differences between the cropping patterns. No significant effects were observed on soil electrical conductivity (EC). However, EC generally increased with depth in spring cotton and winter wheat and declined in spring maize and WW–SM. Winter wheat had a significant aggregate size (<0.053 mm) at 20–40 cm depth and generally showed the lowest amount of nutrients. This study suggests that a fallow period allows the soil to regenerate its structure, whereas WW–SM enhances high soil organic matter in the deep soil layers and promotes increased soil enzyme activities. This indicates that crop rotation could sustainably exploit soil resources without reducing fertility over a long period. There is a need to incorporate different soil management practices for single-cropping patterns to increase their productivity, especially in spring maize, whose organic matter declined the most. Our results also show a need to diversify to different crop rotations to utilize their benefits and enhance soil productivity while increasing crop output. [ABSTRACT FROM AUTHOR]

The Guanzhong Plain is a critical food production area in the Yellow River Basin that frequently suffers from water shortages. In this study, long-term (June 2013 to June 2018) water and energy fluxes were observed, and path analysis was conducted over an irrigated winter wheat (Triticum aestivum L.) / summer maize (Zea mays L.) rotation field to identify the controlling factors of evapotranspiration (ET). Total ET for each crop year ranged from 627 to 775 mm, with an average growing season ET of 398 mm for wheat and 310 mm for maize. There is significant seasonal variation in both ET and surface conductance (G s). Daily ET varied from 0.0 to 6.0 mm d–1 for wheat and 0.0 to 6.7 mm d–1 for maize. The peak daily values of G s were 29.5 mm s–1 for wheat and 19.5 mm s–1 for maize. The direct and indirect effects of environmental and biological factors—net radiation (R n), surface conductance (G s), saturation vapor pressure deficit (VPD), leaf area index (LAI), air temperature (T air), and volumetric soil water content (VWC)—on ET were calculated using the path analysis method. R n was determined to be the primary controlling factor of ET for both the summer maize and winter wheat growing seasons. Also, G s was found to be another controlling factor that has more controlling power in the summer maize growing season than in the winter wheat season. VPD had a significant positive and direct effect on ET for both of the crop seasons, while it had a significant negative and indirect effect on ET through G s in the summer maize season. VWC and T air only directly affected the wheat ET. In addition, VWC had two significant paths that can indirectly affect ET through LAI and G s. The revealed seasonal patterns and controlling factors of evapotranspiration in this agroecosystem provide a theoretical basis for optimizing water resources management of the Yellow River. • A 5-year dataset of energy fluxes in winter wheat/summer maize system is presented. • Seasonal variations in evapotranspiration (ET) and energy partitioning are investigated. • Net radiation and surface conductance (G s) control the ET directly. • Vapor pressure deficit have a significant indirect effect on ET through G s. [ABSTRACT FROM AUTHOR]

The sustainability of winter wheat (Triticum aestivum L.) − summer maize (Zea mays L.) rotation (W − M), which is commonly practiced in the North China Plain (NCP), is threatened by severe groundwater deficits and environmental pollution due to excessive nitrogen (N) applications. Considering the need for protein-rich forages by local livestock operations and the environmental benefits of growing perennial legumes, we propose that an alfalfa (Medicago sativa L.)-based system is worth introducing for field practice in the NCP. An integrated evaluation was used in this four-year study to compare the agronomic, economic, and environmental performances of the following four cropping patterns: alfalfa monoculture (AA), alfalfa and silage maize intercropping with or without N input which is designed for local climate condition, maize monoculture with or without N input which is much-discussed as a resources-saving substitution and commonly practiced W − M. W − M obtained the highest aboveground dry matter (DM) productivity (P < 0.05) based on the highest irrigation water and N fertilizer consumption (P < 0.05) which caused considerable soil mineral N (Nmin) accumulation. The production cost of maize monoculture was the lowest as well as the DM yield, nitrogen accumulation and the net revenue compared with other systems (P < 0.05), moreover, there was a great risk of N losses during the offseason period. The alfalfa and silage maize intercropping with a low N input (120 kg ha−1 which is close to local practice for maize season) achieved 26.6%–34.9% more DM yield compared with AA and maize monoculture, and 12.5%–163.9% more N output compared with W − M and maize monoculture during four experimental years with same total economic revenue as W − M and AA did. The N input in alfalfa and silage maize intercropping dramatically improved the system productivity by assisting intercropped maize growth while did not lead to excessive Nmin accumulation within 0–210 soil layer compared with the intercropping system without N addition. The planting of alfalfa would not affect the water storage in the 0–60 soil layer after maize harvesting each year. For the effects of interspecific competition, the production of the intercropped alfalfa and maize was significantly decreased in 2020 and a three-year period of production is recommended for optimal use of the alfalfa and silage maize intercropping. Alfalfa and silage maize intercropping with an appropriate N input, which acquired comprehensive performances in terms of productivity, environmental impacts as well as economic profits, would be an optimal alternative system in the NCP. The alfalfa and silage maize intercropping with an appropriate N input (A + M), which achieved high dry matter yield, nitrogen uptake and net revenue with the lowest irrigation water and nitrogen fertilizer use, would be an optimal alternative system in the North China Plain. [Display omitted] • The wheat–maize rotation (W – M) in the North China plain is profitable but has inevitable negative environmental impacts. • Alfalfa and maize intercropping (A + M) was proposed for the high protein productivity and the adaptability to climate. • The agronomic, economic, and environmental performances were compared among A + M, W – M, and monoculture systems. • A + M was more productive than monoculture, and consumed lower groundwater and nitrogen than W–M without net revenue loss. • A + M would be an optimal alternative system in the North China Plain for its comprehensive performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nutrient Expert (NE), is designed through adoption of 4R nutrient stewardship. • Results show that NE achieved higher yields, higher profitability, and lower environmental risks. • An outstanding advantage of NE is user-friendly and can be easily acquired by all farmers with smartphones. Fertilizer has revolutionized crop production, but a lack of evidence-based fertilizer usage has resulted in negative economic and environmental ramifications, particularly for smallholder farmers. This study aimed at developing an innovative nutrient recommendation approach, Nutrient Expert (NE), for improving yields of maize, wheat, and rice while optimizing fertilizer input through adoption of 4R (applying the right source of nutrients at the right rate, time and place) nutrient stewardship technologies, and evaluating the large-scale performance on crop productivity and the environmental impact of cropping systems. Thus, we compared NE to current farmers' practice (FP) and soil test-based fertilizer application (ST) for 1,534 farm field experiments in order to validate the benefits of NE on both crop productivity and environmental protection in the main cereal production areas in China. Overall, the NE treatment achieved 4.4 % higher grain yield and 5.8 % more profit over FP, more yield for rice, but no differences for maize and wheat over ST. Nutrient Expert required 29.0 % and 14.7 % less fertilizer N than FP and ST, respectively. The NE recommendations improved the nitrogen (N) recovery efficiency by 10.8–13.4 percent points over FP across the 1,534 sites. Using the NE approach, on average, reactive N losses and greenhouse gas (GHG) emissions were reduced by 36.2 % and 21.5 % over FP, 16.0 % and 9.9 % over ST, respectively. The NE, as a user-friendly tool, is widely applicable across farm types and climatic regions. It could be beneficial for improving fertilizer use efficiency and maintaining strategic food security for smallholder production areas in China where N fertilizer is inappropriate and usually over applied. This approach could potentially be expanded to help reduce N losses and GHG emissions in other regions globally. [ABSTRACT FROM AUTHOR]

• A water-energy-food relative index for cropping systems at the field scale is proposed. • Synergy among water, energy and food in the North China Plain is evaluated. • Sustainable systems can balance crop production while reducing resource depletion. Extreme climate change, rapid population growth and economic development drive a growing demand for resources, which lead to energy, food, water and their intertwined nexus becoming increasingly important. Agricultural decisions considering the interconnections among water, energy, and food are critical. The consumption of large amounts groundwater and non-renewable energy by the predominant traditional wheat-maize cropping system has caused a serious water shortage in the North China Plain (NCP), which is a large food production region in China. This situation has strained the relationship between water/energy consumption and food production. It is important to seek synergy in the water-energy-food nexus. This paper proposed a relative index of water-energy-food (WEF RI) based on different values of resource consumption and use efficiency between treatment systems and control system to analyze the synergy between water utilization, energy consumption and food supply in different cropping systems at the field scale. The goal is to seek a sustainable cropping system to balance crop production while reducing energy consumption and water depletion. In this case, different systems including monocropped maize (Zea mays) (MM), intercropped maize and soybean (Glycine max) (MS), relay cropped of maize with pea (Pisum sativum) (MP) and potato (Solanum tuberosum) (MO), rotation of maize with spinach (Spinacia oleracea) (MI) and ryegrass (Secale cereale) (MR), and using traditional wheat-maize (Triticum aestivum) (MW) as a control. MM, MS, MP and MO were the best systems within a particular range of food supply reduction. The WEF RI of the MM/MS system was the highest (2.96/2.78). Compared to the MW system, the groundwater consumption of MM/MS was reduced by 73.84%/73.84%, and non-renewable energy inputs were reduced by 48.01%/48.30%; however, the food supply decreased by 48.05%/51.70%. The WEF RI of the MP system was 1.98. In comparison with the MW system, the groundwater consumption of the MP system was reduced by 28.46%, and the non-renewable energy inputs were reduced by 42.68%. However, the food supply decreased by 37.13%. The WEF RI of MO system was 1.92. Compared to the MW system, the groundwater consumption of MO was reduced by 11.47%, non-renewable energy inputs were reduced by 32.14%, and the food supply only decreased by 26.27%. In conclusion, we theoretically proposed the following references for cropping systems in the NCP: MM and MS are implemented when the areas has extreme water shortages, MO is implemented when a less than 30% reduction in the food supply capacity is acceptable, and MP is recommended if a 30%–40% reduction in the food supply is acceptable. [ABSTRACT FROM AUTHOR]

• Identify optimized three-band spectral indices for estimating the canopy N uptake of corn and wheat. • The optimized NPDI estimated canopy N uptake of both corn and wheat alone and in combination. • Our algorithm may allow the design of improved N diagnosis systems. Nitrogen (N) fertilization management plays an important role in optimizing crop growth and yield. Concerns over environmental risk require a quick, accurate, non-destructive determination of the N status of crops. Hyperspectral remote sensing allows a timely monitoring of the in-season crop N status. Although many spectral indices for assessing the N status of crops have been proposed, it is still necessary to further optimize the central bands, since they often vary with plant cultivars and species. To improve this, we identified optimized three-band spectral indices for estimating the canopy N uptake of corn and wheat. Experiments were conducted from 2009 to 2011 by evaluating and testing optimized three-band spectral indices for estimating the N status of wheat cultivars grown in Germany and China and corn cultivars grown in China. The indices generally enabled more robust predictions compared to published indices. The central bands suitable for assessing the canopy N uptake were 768, 740, and 548 nm for corn; 876, 736 and 550 nm for wheat; and 846, 732 and 536 nm for corn and wheat combined. Both wheat and corn assessed individually as well as in combination where sharing similar wavebands reflected by the species-specific and interspecies-specific optimized three-band spectral indices, e.g. the wavelengths 740, 736 and 732 nm were identified as optimum for corn, wheat and their combination, respectively. The validation results suggest that predictions using the optimized three-band N planar domain index (NPDI) delivered the highest coefficient of determination (R2 = 0.86) and the lowest root mean square error (RMSE, 20.1 kg N ha–1) and relative error (RE, 18.7 %). The optimized NPDI consistently estimated canopy N uptake of both corn and wheat alone and in combination. Therefore, the optimized three-band algorithm is an attractive tool for optimizing and identifying central bands. Our algorithm may allow the design of improved N diagnosis systems and enhance the application of ground- and satellite-based sensing. [ABSTRACT FROM AUTHOR]

• A comprehensive review on the effects of farming practices on various crops such as wheat, maize and potato • RFFM performed better than RF and FM in increasing crop yield and crop water productivity. • Potato obtained the greatest increases in yield and WP under ridge-furrow planting or film mulching. • For clay soils and high altitude regions, the two film mulching practices (FM and RFFM) attained greater yield increases. • Under the two ridge-furrow treatments (RFFM and RF), it is better to plant crops in the furrow than on the ridge Crop yields are significantly restricted by the shortage of water resources in semi-arid and semi-humid regions around the world. Farming practices like ridge-furrow planting with plastic film mulching (RFFM) can effectively improve crop yield and crop water productivity (WP) by enhancing soil moisture and temperature availability. This meta-analysis study collected and analyzed the data of 964 observations published in 90 peer-reviewed papers to investigate the effects of various farming practices, i.e., RFFM, ridge-furrow planting without film mulching (RF) and flat planting with film mulching (FM) in comparison with conventional flat planting without film mulching (F), on yield and WP of three major crops (wheat, maize and potato) in China, in terms of planting region, climatic condition, altitude, soil type and seeding method. The results showed that RFFM, RF and FM improved mean crop yields by 33.8 %, 16.6 % and 27.0 %, and increased mean WP of crops by 35.8 %, 17.5 % and 27.8 % compared with F, respectively. Increases in crop yields under RFFM, RF and FM were greater in regions with seasonal rainfall <400 mm than in regions with seasonal rainfall>400 mm. RFFM, RF and FM performed better in Northwest China than in North-central and other regions of China. Among the three crops, potato obtained the greatest increases in yield and WP under ridge-furrow planting or film mulching. For clay soils and high altitude regions, the two film mulching practices (FM and RFFM) attained greater yield increases. With regards to the two ridge-furrow practices (RFFM and RF), it is better to plant crops in the furrow than on the ridge. In short, RFFM was most effective to improve yield and WP of wheat, maize and potato among the farming practices. These findings have important implications for choosing appropriate field management practices to improve crop yield and crop water productivity in China. [ABSTRACT FROM AUTHOR]

• Future climate warming led to advance in wheat and maize phenology. • Future climate change had negative impact on maize but positive impact on wheat. • Crop water consumption was largely decreased under future climate scenarios. • Future climate change could mitigate groundwater overdraft across NCP. Climate change has already and will continue to exert a vital impact on crop yield and water use in the North China Plain (NCP). Currently, this plain is facing a dilemma between groundwater depletion and grain production demand. It is urgent to identify the impact of future climate change on crop yield and water consumption and then develop efficient adaptation strategies in the region. In this study, we used statistically downscaled daily climate data from 33 global climate models (GCMs) and two Representative Concentration Pathways (RCP4.5 and RCP8.5) for 61 stations distributed across the NCP and drove the well-validated APSIM model to simulate crop yield and water use for two future periods of 2031–2060 (2040s) and 2071–2100 (2080s). Data from all 33 GCMs show an increase in annual mean temperature and almost all the GCMs also show increases in annual mean solar radiation and annual total precipitation across the NCP. Future climate warming led to an advance in phenology for both winter wheat and summer maize, two typical crops in the NCP. However, the length of the reproductive growth period (RGP) of winter wheat was prolonged while that of summer maize was shortened under future climate scenarios across the NCP. Our simulated results show that future climate change had negative impacts on maize yield but positive impacts on wheat yield across the NCP. Mainly due to the shortening of the whole growth period, crop water consumption was largely decreased under future climate scenarios. The amount of irrigation required was also reduced mainly due to increased precipitation and decreased ET. Although future climate change would likely mitigate groundwater overdraft in most part of NCP, some areas in the northern NCP still had groundwater over-pumping in the future. Therefore, we suggest that it might be a good choice to change cropping system for reducing planting area of water-consuming crop (e.g. winter wheat) in those over-pumping areas to balance groundwater use and crop yield. [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]

China, as one of the largest food consumers in the world, is currently experiencing obvious impacts of climate change. Exploring the impact of climate change on the production potential of maize, wheat, and rice in China is of great significance in adapting to climate change and safeguarding global food security. In this study the Global Agro-Ecological Zone (GAEZ) model and the Extreme-Point Symmetric Mode Decomposition (ESMD) model were used to explore the trends in production potential of China's three major crops in the context of climate change from 1960 to 2010. There was a quasi-3-year and quasi-5-year cycle in changes in maize, wheat, and rice production potential due to climate change in China. Climate change increased maize and rice production potential and reduced wheat production potential. The increase in minimum temperature was the main reason for the increased maize and rice production potential. Reduced wheat production potential was mainly caused by increased maximum temperature. Decreases in precipitation had a substantial negative impact on the production potential of all three crops. These results suggest that priority should be given to adjusting the structure of agricultural cultivation and appropriately expanding the planting area of maize and rice to adapt to climate change. Accelerating the construction of agricultural infrastructure to reduce the negative impact of declining precipitation and increasing daytime temperature on agriculture is also a high priority in order to safeguard food security. • Climate change increased maize and rice production potential of China • Increased minimum temperature was the primary reason for increased yields • Wheat production potential decreased mainly because of maximum temperature stresses • There was a quasi-3&5-year cycle in changes in crop production potentials [ABSTRACT FROM AUTHOR]

• Rainfed wheat/maize intercropping provided land equivalent ratios above 1. • Wheat in first border rows and second border rows showed major yield increase. • The yield components resulted in intercropped wheat yield increase were different. • The SPAD and Pn in border rows of intercropped wheat were significantly improved. • The SPAD and Pn of intercropped maize showed growth recovery after wheat harvest. Intercropping has been widely adopted by farmers for higher yield compared to monoculture, and the border effect was responsible for the yield advantage in irrigated areas. However, few studies have investigated the border effect based on photosynthesis, especially under rainfed conditions. Here, we evaluated the yield in rainfed wheat/maize strip relay intercropping, and explored the associated differences in yield components and physiological process compared to sole crops. A two-year field experiments was conducted including three treatments (sole wheat, sole maize and wheat/maize intercropping) in Yangling, located in the semi-humid region of northwest China. Grain yield, yield components, chlorophyll relative content (SPAD) and photosynthetic parameters in different rows were measured for wheat and maize. Results showed that wheat/maize intercropping increased the land use efficiency and total yield of wheat and maize under rainfed conditions. The yield of intercropped wheat was significantly (p < 0.05) increased by 35% on average over two years, resulting not only from the first border rows but also from the second border rows. The yield improvement in the first border rows relative to sole wheat was attributed to the increase of ear number (56%, p < 0.05), kernel number per ear (14%, p < 0.05) and thousand kernel weight (12%, p < 0.05), but the yield improvement in the second border rows was only attributed to the ear number (22%, p < 0.05). The yield of intercropped maize was not significantly (p > 0.05) decreased (6%), mainly attributed to the border rows (19% lower than in sole maize), in which the kernel number per cob and thousand kernel weight were 14% and 8% (p < 0.05) lower than that in sole maize. This was because that the SPAD and photosynthetic rate of maize in intercropping was suppressed during the co-growth period (about 62 days). Although the two had a partly growth recovery after wheat harvest, the growth recovery was not complete, and this was responsible for the reduction of maize yield in intercropping. This study demonstrates that the importance of yield components and the photosynthesis basis for yield advantage in intercropping systems, and reducing the adverse effect of dominate crop on subordinate crops could better exert the advantages of intercropping. [ABSTRACT FROM AUTHOR]

Deoxynivalenol (DON), along with 3-acetyl-deoxynivalenol (3-ADON) and 15-acetyl-deoxynivalenol (15-ADON), occur in grains and cereal products and is often hazardous to humans and livestock. In this study, 579 wheat samples and 606 maize samples intended for consumption were collected from China in 2017 and analyzed to determine the co-occurrence of type-B trichothecenes (DON, 3-ADON, and 15-ADON). All the wheat samples tested positive for DON, while 99.83% of the maize samples were DON-positive with mean DON concentrations of 165.87 and 175.30 μg/kg, respectively. Per the Chinese standard limits for DON, 3.63% of wheat and 2.97% of the maize samples were above the maximum limit of 1000 μg/kg. The DON derivatives (3-ADON and 15-ADON) were less frequently found and were present at lower levels than DON in wheat. 3-ADON and 15-ADON had incidences of 13.53% and 76.40%, respectively, in maize. By analyzing the distribution ratio of DON and its derivatives in wheat and maize, DON (95.51%) was the predominant toxin detected in wheat samples, followed by 3.97% for the combination of DON + 3-ADON, while DON + 3-ADON + 15-ADON and DON + 15-ADON were only found in 0.17% and 0.35% of wheat samples, respectively. Additionally, a large amount of the maize samples were contaminated with DON + 15-ADON (64.19%) and DON (22.11%). The samples with a combination of DON + 3-ADON and DON + 3-ADON + 15-ADON accounted for 1.32% and 12.21%, respectively. Only one maize sample did not contain all three mycotoxins. Our study shows the necessity of raising awareness of the co-occurrence of mycotoxin contamination in grains from China to protect consumers from the risk of exposure to DON and its derivatives. [ABSTRACT FROM AUTHOR]

• Modeling yield, evapotranspiration and economic profit in different cropping systems using APSIM under projected climate scenarios. • Maize and wheat yield underwent significant reduction in projected scenarios compared with the baseline data. • Plant transpiration have not changed significantly between scenarios, but evaporation decreased in some conditions markedly. • Lucerne-winter wheat rotation presented the greatest potential of the sustainability under projected scenarios. Agriculture in the semiarid region is undergoing radical changes driven by global warming and increasing incidences of extreme weather events. Predicting and evaluating the responses of crop yield and water use patterns of rainfed cropping systems according to future temperature and precipitation changes could provide important information regarding adoption of climate-smart farming systems that could offer great resilience and sustainability. The objective of this study was to evaluate the potential changes in agronomic productivity, hydrological balance and economic profitability of cropping systems with perennial legumes and rotation on the Loess Plateau of China affected by different future temperature and precipitation scenarios using APSIM-based modeling. Five different cropping systems were investigated: (i) continuous maize (Zea mays) (M), (ii) continuous winter wheat (Triticum aestivum) (W), (iii) continuous lucerne (Medicago sativa) (L), (iv) maize-wheat-soybean (Gyleine max) rotation (MWS) and (v) lucerne (4-yr)-winter wheat (2-yr) rotation (LW) in Xifeng, Gansu, China. Five series of temperature and precipitation changes scenarios (no changes in atmospheric CO 2 concentrations were considered) based on RCPs (representative concentration pathways) were integrated into scenario simulations, including the baseline scenario (1980–2010), mid-century scenarios of RCP4.5 (M45) and RCP8.5 (M85), and end-century scenarios of RCP4.5 (E45) and RCP8.5 (E85). The results showed that, compared with baseline simulations, mean maize yield under RCPs decreased by 6.7 %–37.7 %, and the mean wheat yield decreased by 1.7 %–23.6 %. Lucerne yield consistently increased by 7.2 %–12.3 % under M45 and E45. Although different cropping systems affected the yield to a certain extent, only the difference between the wheat yields of W and MWS was significant (P < 0.05). On a cropping system level of every 6-yr (totally five phases for a scenario of 30-yr), the temperature and precipitation changes did not significantly affect plant transpiration (T c) per phase. For all systems except L [which received its highest soil evaporation (E s) per phase in baseline], the greatest E s per phase was found in the E85. L tended to provide greater T c per phase and evapotranspiration (ET) per phase (ranging from 1219 to 1332 mm and 2910–3034 mm, respectively), followed by LW. L and MWS presented the highest and lowest E s per phase (1636–1724 and 1592–1677 mm), respectively. The gross profit (GP per 6-yr phase) and water productivity (WP per 6-yr phase) of L were the greatest among all cropping systems (11.5–13.7 thousand US$ ha−1 per phase and 3.72–4.41 US$ ha-1 mm-1 per phase, respectively), followed by LW and MWS. For M, W and MWS, the GP per phase and the WP per phase were predicted to be greater under the baseline than under any of the RCPs, whereas M45 and E45 scenarios improved the GP per phase and WP per phase of L and LW compared with those of the baseline. In general, we advocate that LW-based systems have the greatest potential for producing acceptable yield and economic profit under future temperature and precipitation scenarios for this local environment. [ABSTRACT FROM AUTHOR]

The production of cereals, including rice, wheat, and maize has increased in China over the past 20 years. However, variations in the production and cultivated area of cereals remains unclear. In this study, we collected and analyzed the cereal production and cultivated area in China from 1998 to 2016. An 85% increase in cereal production was recorded from 1998 to 2016, due to an increase in the maize production along with the increase in the cultivated area. Meanwhile, rice and wheat production have been stable since 2000. No change occurred in the rice cultivated area through 2016, and a 19% decrease in the wheat cultivated area was observed in 2016 relative to 1998. In addition, a significant positive relationship was observed among cereal production, maize production, and cultivated area (p < 0.0001). Together, the increase in cereal production in China over the past two decades has resulted from the increase in maize cultivated area and the consequent increase in maize production. [ABSTRACT FROM AUTHOR]