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Trait-based approaches are increasingly used to understand crop yield improvement, although they have not been widely applied to anatomical traits. Little is known about the relationships between root and leaf anatomy and yield in wheat. We selected 20 genotypes that have been widely planted in Luoyang, in the major wheat-producing area of China, to explore these relationships. A field study was performed to measure the yields and yield components of the genotypes. Root and leaf samples were collected at anthesis to measure the anatomical traits relevant to carbon allocation and water transport. Yield was negatively correlated with cross-sectional root cortex area, indicating that reduced root cortical tissue and therefore reduced carbon investment have contributed to yield improvement in this region. Yield was positively correlated with root xylem area, suggesting that a higher water transport capacity has also contributed to increased yields in this study. The area of the leaf veins did not significantly correlate with yield, showing that the high-yield genotypes did not have larger veins, but they may have had a conservative water use strategy, with tight regulation of water loss from the leaves. This study demonstrates that breeding for higher yields in this region has changed wheat's anatomical traits, reducing the roots' cortical tissue and increasing the roots' xylem investment. [ABSTRACT FROM AUTHOR]

The adverse effects of thermal power plants on crop yield have not received adequate attention. Thus, this study aims to evaluate these effects systematically to fill the gap by utilizing county-level wheat yield data from North China spanning from 2005 to 2016. Our findings indicate that the presence of an additional upwind thermal power plant is associated with a 1.4% decline in wheat yield. Notably, these yield losses are more pronounced in regions characterized by lenient environmental regulations or a high density of large-scale thermal power plants. Reduced wheat yield due to thermal power plants results in a decline in social welfare. Furthermore, we confirm that air pollution emitted from thermal power plants is the primary driver behind the decline in wheat yield. [ABSTRACT FROM AUTHOR]

Global gridded crop models (GGCMs) have been broadly applied to assess the impacts of climate and environmental change and adaptation on agricultural production. China is a major grain producing country, but thus far only a few studies have assessed the performance of GGCMs in China, and these studies mainly focused on the average and interannual variability of national and regional yields. Here, a systematic national- and provincial-scale evaluation of the simulations by 13 GGCMs [12 from the GGCM Intercomparison (GGCMI) project, phase 1, and CLM5-crop] of the yields of four crops (wheat, maize, rice, and soybean) in China during 1980–2009 was carried out through comparison with crop yield statistics collected from the National Bureau of Statistics of China. Results showed that GGCMI models generally underestimate the national yield of rice but overestimate it for the other three crops, while CLM5-crop can reproduce the national yields of wheat, maize, and rice well. Most GGCMs struggle to simulate the spatial patterns of crop yields. In terms of temporal variability, GGCMI models generally fail to capture the observed significant increases, but some can skillfully simulate the interannual variability. Conversely, CLM5-crop can represent the increases in wheat, maize, and rice, but works less well in simulating the interannual variability. At least one model can skillfully reproduce the temporal variability of yields in the top-10 producing provinces in China, albeit with a few exceptions. This study, for the first time, provides a complete picture of GGCM performance in China, which is important for GGCM development and understanding the reliability and uncertainty of national- and provincial-scale crop yield prediction in China. [ABSTRACT FROM AUTHOR]

Climate change and water resource shortages have become important problems limiting winter wheat production in the North China Plain (NCP). Understanding the physiological characteristics of different wheat varieties and their relationship with crop growth and yield is of great importance for addressing climate change through a scientific approach, adopting reliable wheat varieties, and ensuring food production. This study was conducted throughout three winter wheat seasons from 2018 to 2021. The crop growth, physiological indicators, crop yields, and water productivity (WP) of 12 wheat varieties widely cultivated in the NCP were measured to investigate the relationships between physiological characteristics and crop yield. The results showed that among the three wheat seasons, the maximum plant height of each wheat variety was relatively stable, while the changes in maximum plant density (PDm), maximum leaf area index (LAIm), and maximum dry matter (DMm) were highly variable. The gas exchange parameters and fluorescence parameters of wheat flag leaves varied with growth stage, and certain varieties were sensitive to water stress. The wheat grain yield, seasonal crop evapotranspiration (ETa), and WP of the 12 varieties were similar in the 2019–2020 and 2020–2011 seasons and were approximately 25%, 7%, and 19% higher than those in the 2018–2019 season, respectively, in which there were consecutive cool events in the winter and spring. Generally, the grain yields were positively correlated with PDm, LAIm, DMm, ETa, the harvest index, and WP, at a significance level of 0.01. The high-yield wheat varieties had higher photosynthetic rates in the middle and late grain-filling stages. Based on these relationships, high-yield wheat varieties may be selected to address climate change in the NCP as well as other regions in the world. Considering the variations in yield and WP in the three different climatic conditions, we recommend Yingbo700, Lunxuan103, Shimai26, Shinong086, Han6172, and Hanong1412 as high-yield and drought-resistant wheat varieties to be used in the NCP. [ABSTRACT FROM AUTHOR]

Winter wheat is a major food source for the inhabitants of North China. However, its yield is affected by drought stress during the growing period. Hence, it is necessary to develop drought-resistant winter wheat varieties. For breeding researchers, yield measurement, a crucial breeding indication, is costly, labor-intensive, and time-consuming. Therefore, in order to breed a drought-resistant variety of winter wheat in a short time, field plot scale crop yield estimation is essential. Unmanned aerial vehicles (UAVs) have developed into a reliable method for gathering crop canopy information in a non-destructive and time-efficient manner in recent years. This study aimed to evaluate strategies for estimating crop yield using multispectral (MS) and hyperspectral (HS) imagery derived from a UAV in single and multiple growth stages of winter wheat. To accomplish our objective, we constructed a simple linear regression model based on the single growth stages of booting, heading, flowering, filling, and maturation and a multiple regression model that combined these five growth stages to estimate winter wheat yield using 36 vegetation indices (VIs) calculated from UAV-based MS and HS imagery, respectively. After comparing these regression models, we came to the following conclusions: (1) the flowering stage of winter wheat showed the highest correlation with crop yield for both MS and HS imagery; (2) the VIs derived from the HS imagery performed better in terms of estimation accuracy than the VIs from the MS imagery; (3) the regression model that combined the information of five growth stages presented better accuracy than the one that considered the growth stages individually. The best estimation regression model for winter wheat yield in this study was the multiple linear regression model constructed by the VI of ' b 1 − b 2 / b 3 − b 4 ' derived from HS imagery, incorporating the five growth stages of booting, heading, flowering, filling, and maturation with r of 0.84 and RMSE of 0.69 t/ha. The corresponding central wavelengths were 782 nm, 874 nm, 762 nm, and 890 nm, respectively. Our study indicates that the multiple temporal VIs derived from UAV-based HS imagery are effective tools for breeding researchers to estimate winter wheat yield on a field plot scale. [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]

Background: Lodging is a major factor contributing to yield loss and constraining the mechanical harvesting of wheat crops. Genetic improvement through breeding effectively reduced the lodging and improved the grain yield, however, the physiological mechanisms involved in providing resistance to lodging are different in the breeding stage and are not clearly understood. The purpose of this study was to compare the differences in the lodging resistance (LR) of the wheat varieties released during the different decades and to explore the effect of the application of nitrogen (N) fertilizer on the plasticity of LR. Results: A field study was conducted during the cultivation seasons of 2019–2020 and 2020–2021, in soil supplemented with three N levels: N0 (0 kg ha–1), N180 (200 kg ha–1), and N360 (360 kg ha–1) using eight varieties of wheat released for commercial cultivation from 1950 to date. The results obtained showed that genetic improvement had significantly enhanced the LR and grain yield in wheat. In the first breeding stage (from 1950 to 1980s) the lodging resistant index increased by 15.0%, which was primarily attributed to a reduced plant height and increased contents of cellulose, Si, and Zn. In the second breeding stage (the 1990s–2020s) it increased by 172.8%, which was mainly attributed to an increase in the stem diameter, wall thickness, and the contents of K, Ca, Fe, Mn, and Cu. The application of N fertilizer improved the grain yield but reduced the LR in wheat. This was mainly due to an increase in plant height resulting in an elevation of the plant center of gravity, a decrease in the contents of cellulose, and a reduction in the area of large-sized vascular bundles in the stems, even if N supplementation increased the concentrations of K, Ca, and Si. Conclusion: Although breeding strategies improved the stem strength, the trade-off between the grain yield and LR was more significantly influenced by the addition of N. Overcoming this peculiar situation will serve as a breakthrough in improving the seed yield in wheat crops in the future. [ABSTRACT FROM AUTHOR]

Accurate predictions of wheat yields are essential to farmers'production plans and to the international trade in wheat. However, only poor approximations of the productivity of wheat crops in China can be obtained using traditional linear regression models based on vegetation indices and observations of the yield. In this study, Sentinel-2 (multispectral data) and ZY-1 02D (hyperspectral data) were used together with 15709 gridded yield data (with a resolution of 5 m × 5 m) to predict the winter wheat yield. These estimates were based on four mainstream data-driven approaches: Long Short-Term Memory (LSTM), Random Forest (RF), Gradient Boosting Decision Tree (GBDT), and Support Vector Regression (SVR). The method that gave the best estimate of the winter wheat yield was determined, and the accuracy of the estimates based on multispectral and hyperspectral data were compared. The results showed that the LSTM model, for which the RMSE of the estimates was 0.201 t/ha, performed better than the RF (RMSE = 0.260 t/ha), GBDT (RMSE = 0.306 t/ha), and SVR (RMSE = 0.489 t/ha) methods. The estimates based on the ZY-1 02D hyperspectral data were more accurate than those based on the 30-m Sentinel-2 data: RMSE = 0.237 t/ha for the ZY-1 02D data, which is about a 5% improvement on the RSME of 0.307 t/ha for the 30-m Sentinel-2 data. However, the 10-m Sentinel-2 data performed even better, giving an RMSE of 0.219 t/ha. In addition, it was found that the greenness vegetation index SR (simple ratio index) outperformed the traditional vegetation indices. The results highlight the potential of the shortwave infrared bands to replace the visible and near-infrared bands for predicting crop yields Our study demonstrates the advantages of the deep learning method LSTM over machine learning methods in terms of its ability to make accurate estimates of the winter wheat yield. [ABSTRACT FROM AUTHOR]

Phosphorous (P) fixation in saline soils is a concern worldwide. To investigate optimization strategies for P fertilizer application that improve P use efficiency (PUE) and crop yield in saline soil, in terms of P sources and rates, we conducted a two year field experiment in the coastal saline area of China to investigate the effects of P rates and sources, including superphosphate (SSP), monoammonium phosphate (MAP) and ammonium polyphosphate (APP) on yield, aboveground P uptake, agronomy efficiency (AEP), and soil available P of winter wheat (Triticum aestivum L.). Wheat yield, under the three P sources, increased with P rates and reached a plateau under 20 kg P ha−1 SSP,18 kg P ha−1 MAP, and 17 kg P ha−1 MAP, respectively. The application of SSP increased the wheat yield by 9–11% compared to MAP and APP. The aboveground P uptake of winter wheat under SSP was 14% and 13% higher than MAP and APP, respectively, under the optimal P application rate. The AEP under SSP was higher than the other two P sources under the same P rate. SSP increased the soil Ca2+ concentration by 20–42%, but decreased the Na+ concentration by 14–18% at the P rate of 26 kg P ha−1 in all soil layers, including 0–20, 20–40, 40–60 cm, compared to CK (0 kg P ha−1). The soil Olsen-P concentration under APP was higher than the other P sources. This study suggests that optimizing P sources and rates can improve wheat yield, PUE, and soil quality in the coastal saline soil. [ABSTRACT FROM AUTHOR]

As one of the important greenhouse gas, nitrous oxide (N2O) has attracted much attention globally under climate change context. Agricultural practices are the main sources of greenhouse gas emissions. Nevertheless, scarcity of literature is available on the effects of different tillage measures on soil N2O emission under spring wheat (Triticum aestivum L.) ecosystem in the semi-arid area of the Loess Plateau. The main objective of the experimental study was to explore the influence of conservation tillage techniques on soil physicochemical properties, nitrous oxide emission and yield in the Northern semi-arid Dingxi region of China. Four treatments viz., conventional tillage (CT), no tillage (NT), straw mulch with conventional tillage (TS) and stubble-return with no-till (NTS) were evaluated under randomized complete block design with three replications. Our results depicted that compared with conventional tillage, bulk density and water content of topsoil was increased and soil pH value was reduced under conservation tillage techniques. Conservation tillage NT, TS and NTS increased organic carbon, TN, MBN and NH4+-N and reduced the accumulation of NO3–N. Additionally, although the N2O emission under NT, TS and NTS was 8.95, 41.90 and 21.05% respectively higher than under T treatment, the corresponding wheat yield was 15.40, 31.97 and 63.21% higher than T treatment. Moreover, correlation analysis showed that soil moisture and temperature were the most significant factors affecting soil N2O emission. The NTS treatment pointedly increased crop yield without significantly increasing soil N2O emission. Consequently, based on economic and environmental benefits and considering N2O emission and crop yield, we suggest that NTS technique is the best conservation tillage strategy in the semi-arid environmental zone of the Loess Plateau of Dingxi China. [ABSTRACT FROM AUTHOR]

To determine the effects of air pollution on crop yields, weather, air pollution, and maize and winter wheat yield data from 331 cities in China from 2014 to 2016 were collected and analysed. Furthermore, support vector regression and the crop growth model were applied to extrapolate the air pollution data of Beijing and Hetian and verify the relationship between air pollution and yield. Precisely, heavy air pollution usually occurred in North China, but less than moderate air pollution levels affected crop yields statistically insignificantly. Moreover, both the winter wheat and maize yields increased in moderate air pollution periods but decreased in heavy air pollution periods in 2014, 2015 and 2016. Importantly, a threshold value was necessary for the heavy air pollution periods to trigger a yield decrease. The threshold values of maize in 2015 and 2016 were 7 days and 5 days, respectively, while that of winter wheat was 10 days in both 2015 and 2016. Once the heavy air pollution periods exceeded the threshold value, both the winter wheat and maize yields decreased linearly with the periods. PM2.5 was the main air pollutant in Beijing in 2014, while PM2.5 and PM10 were the main air pollutants in Hetian in both 2015 and 2016. Regardless of whether the main air pollutant was PM2.5 or PM10, the simulated potential winter wheat yields by the crop growth model with moderate air pollution for the whole growth period were all higher than the yields under observed and heavy air pollution conditions. [ABSTRACT FROM AUTHOR]

Whether photosynthesis has improved with increasing yield in major crops remains controversial. Research in this area has often neglected to account for differences in light intensity experienced by cultivars released in different years. Light intensity is expected to be positively associated with photosynthetic capacity and the resistance of the photosynthetic apparatus to high light but negatively associated with light-utilization efficiency under low light. Here, we analyzed the light environment, photosynthetic activity, and protein components of leaves of 26 winter wheat cultivars released during the past 60 years in China. Over time, light levels on flag leaves significantly decreased due to architectural changes, but photosynthetic rates under high or low light and the resistance of the photosynthetic apparatus to high light remained steady, contrary to expectations. We propose that the difference between the actual and expected trends is due to breeding. Specifically, breeding has optimized photosynthetic performance under high light rather than low light. Moreover, breeding selectivity altered the stoichiometry of several proteins related to dynamic photosynthesis, canopy light distribution, and photoprotection. These results indicate that breeding has significantly altered the photosynthetic mechanism in wheat and its response to the light environment. These changes likely have helped increase wheat yields. [ABSTRACT FROM AUTHOR]

Agricultural system models provide an effective tool for forecasting crop productivity and nutrient budgets under future climate change. This study investigates the potential impacts of climate change on crop failure, grain yield and soil organic carbon (SOC) for both winter wheat (Triticum aestivum L.) and maize (Zea mays L.) in northern China, using the SPACSYS model. The model was calibrated and validated with datasets from 20-year long-term experiments (1985–2004) for the Loess plateau, and then used to forecast production (2020–2049) under six sharing social-economic pathway climate scenarios for both wheat and maize crops with irrigation. Results suggested that warmer climatic scenarios might be favourable for reducing the crop failure rate and increasing the grain yield for winter wheat, while the same climatic scenarios were unfavourable for maize production in the region. Furthermore, future SOC stocks in the topsoil layer (0–30 cm) could increase but in the subsoil layer (30–100 cm) could decrease, regardless of the chosen crop. [ABSTRACT FROM AUTHOR]

Knowledge about the changes in soil organic carbon (SOC) stocks and grain yields under different field management practices is necessary for achieving agricultural sustainability. An 8‐yr experiment for testing different tillage and straw management practices was conducted in a wheat (Triticum aestivum L.)–maize (Zea mays L.) rotation system in the southern Loess Plateau of China. Three tillage methods (control with no‐tillage and straw removal [CK], no‐tillage with straw stubbles 30–40 cm in height [NT], and rotary tillage with straw incorporation [RT]) were applied before maize planting, and two straw treatments (straw return [SR] and no straw return [SR0]) were applied after maize harvest. Over the 8 yr, SOC stocks exhibited similar dynamic changing trends in all treatments but were higher under NT, RT, and SR than under CK‐SR0. Compared with the initial soil, SOC stock increased the most (34.1%) in NT‐SR. Compared with the CK‐SR0, the NT‐SR, RT‐SR, CK‐SR, NT‐SR0, and RT‐SR0 increased wheat grain yields by 47.2, 36.8, 24.9, 25.1, and 20.0%, respectively. Similar trends were found for maize grain yields. The NT, RT, and SR increased crop yield stability with the highest sustainable yield index in NT‐SR for both wheat (.67) and maize (.70). Overall, the combination of no‐tillage with wheat straw stubbles 30–40 cm in height and maize straw return was the best strategy for improving SOC stocks, grain yields, and agricultural sustainability for grain production in dry, sub‐humid areas of northwestern China. Core Ideas: No‐tillage (NT) and rotary tillage (RT) increased SOC stocks compared with control.NT, RT, and straw return (SR) increased crop yield stability.NT‐SR is an optimal strategy for improving agricultural sustainability. [ABSTRACT FROM AUTHOR]

Dual‐purpose winter wheat (Triticum aestivum L.) has been advocated on the Loess Plateau of China to fill feed gap and integrate crop–livestock systems; however, the effects of sowing date on the recovery after cutting and interactions between various management practices are largely unclear. Field experiment was conducted in 2015–2017 in semiarid northwestern China to investigate the effects of sowing date and cutting timing on forage yield, grain yield, and its components of dual‐purpose winter wheat cultivars. The experiment combined four cutting treatments, that is, winter cutting, spring cutting, winter–spring cutting, and control, two sowing dates (22 Sept., 2 Oct.), and two cultivars (early to mid‐maturing Zhongmai and late‐maturing Longyu4). Results showed delayed sowing decreased forage yield by 33.4%, but still had the potential to produce an average of 1.6 t ha−1 of forage, with average protein content of 290 g kg−1. Response of winter wheat grain yield to cutting ranged from −38.9 to 1%, with a delay of 1–7 d in maturity. Delayed sowing induced insignificant yield penalties. More forage and higher kernel protein content were produced if crops were cut in winter–spring, but this came with large reductions (30.1% in Longyu4 and 38.9% in Zhongmai) in grain yield, mainly due to reductions in kernels per spike and kernel weight. This study suggests that Longyu4 and Zhongmai are suitable varieties for dual‐purpose winter wheat in the Loess Plateau. For higher forage and grain yield, Longyu4 is suitable for sowing in middle or late September, whereas Zhongmai is suitable for delaying sowing. Winter cutting or spring cutting is acceptable to maintain the forage and grain yield, whereas winter–spring cutting is disadvantageous to grain yield in our study area. Core Idea: Delayed sowing had the potential to produce an average of 1.6 t ha−1 of forage.Delayed sowing induced insignificant yield penalties.Response of winter wheat grain yield to cutting ranged from −38.9 to 1%.Reductions in grain yield were greatest with winter–spring cutting.Grain yield was unaffected by the interaction between sowing date and variety. [ABSTRACT FROM AUTHOR]

In northern China, precipitation that is primarily concentrated during the fallow period is insufficient for the growth stage, creates a moisture shortage, and leads to low, unstable yields. Yield prediction in the early growth stages significantly informs field management decisions for winter wheat (Triticum aestivum L.). A 10-year field experiment carried out in the Loess Plateau area tested how three tillage practices (deep ploughing (DP), subsoiling (SS), and no tillage (NT)) influenced cultivation and yield across different fallow periods. The experiment used the random forest (RF) algorithm to construct a prediction model of yields and yield components. Our results revealed that tillage during the fallow period was more effective than NT in improving yield in dryland wheat. Under drought condition, DP during the fallow period achieved a higher yield than SS, especially in drought years; DP was 16% higher than SS. RF was deemed fit for yield prediction across different precipitation years. An RF model was developed using meteorological factors for fixed variables and soil water storage after tillage during a fallow period for a control variable. Small error values existed in the prediction yield, spike number, and grains number per spike. Additionally, the relative error of crop yield under fallow tillage (5.24%) was smaller than that of NT (6.49%). The prediction error of relative meteorological yield was minimum and optimal, indicating that the model is suitable to explain the influence of meteorological factors on yield. [ABSTRACT FROM AUTHOR]

Inappropriate water and fertilizer management can lead to unstable crop yields. Excessive fertilization can potentially cause soil degradation and nitrogen (N) leaching. The aim of this study was to explore the optimal N application rate on two wheat varieties with different nitrogen responding under limited water irrigation at three experimental sites in the Piedmont plain of the Taihang Mountains, China. A two-year field experiment was conducted to explore the effects of five N application rates (N0, N120, N180, N240, and N300) on winter wheat growth, leaf area index, aboveground biomass, grain yield, grain N accumulation, and net return. The results showed that N application rate significantly affected leaf area index, aboveground biomass, grain yield, and harvest index. Variety and variety × N rate interactions had a significant effect on few indicators. Compared with N0, N180 improved leaf area index, aboveground biomass, grain yield, and grain N accumulation. Compared with N240 and N300, N180 increased the harvest index and N harvest index, without significantly reducing grain yield or grain N accumulation, while enhancing a higher N use efficiency. Fertilizers applied in the ranges of 144.7–212.9 and 150.3–247.0 kg ha-1 resulted in the highest net return for the KN199 and JM585 varieties, respectively. Our study provides a sound theoretical basis for high-efficiency fertilizer utilization in sustainable winter wheat production in the Piedmont plains of the Taihang Mountains of China. [ABSTRACT FROM AUTHOR]

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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]

To achieve high crop production, long-term field experiments 20 years (1990-2010) were conducted at Urumqi-China. In this study, we investigate the effect of organic and inorganic fertilization treatments on maize, spring wheat, and winter wheat cropping system in Urumqi, Xinjiang China. We investigated the impact of soil fertility, crop yield sustainability index, nutrients balance, carbon sequestration (CSR), and climatic change model through the Agricultural Production Systems Simulator (APSIM). Five treatments were studied: CK (control); NPK (inorganic fertilizers nitrogen, phosphorus, and potassium); NPKM and manure; NPKS & straw and NPKM2 and manure (the rate of manure was double from NPKM. The study showed that the combined application of inorganic and manure application (NPKM2 and NPKM) significantly increased the crop grain yield and soil fertility and sustainable yield index were higher as compared to NPK and CK. The changes of maximum and minimum temperature (+2), decreasing precipitation (-10), and increased CO2 level (350-650 ppm) from observed values, simulated in the climatic model will significantly decrease essential soil water (191.2- 181.1 mm), runoff (0.43-0.40 mm), total NO3- (1444.0 to 1422.5) kg ha-1, and leaching (0.75-0.73) and runoff (0.43 mm to 0.40 mm) while increased total NH4+ (35.1 to 41.72) kg ha-1 . [ABSTRACT FROM AUTHOR]

Global warming has been reported to cause reductions in crop yields. However, it was suggested that warming temperature might benefit crop productivity in some cool areas at high latitude. In this study, we conducted a 17‐year field experiment (2002–2018) on spring wheat in Inner Mongolia. Temperature changes during each growth stage of spring wheat were investigated. Responses of spring wheat yield to temperature changes during the specific growing stages were evaluated. Average annual maximum temperature (Tmax) and minimum temperature (Tmin) significantly increased over the past 17 years. However, Tmax did not show obvious increase trend during spring wheat growing seasons (p = 0.0672). Furthermore, Tmax also had no distinct change before or after anthesis. Tmin significantly increased during the whole growing season, as well as in pre‐ and post‐anthesis stages. Correlation analysis indicated that Tmax in the entire growing season and post‐anthesis did not affect spring wheat yield, but high Tmax during pre‐anthesis can improve grain yield. The Tmin during the life cycle and pre‐anthesis both had positive relationship with grain yield. Moreover, elevated temperature from seedling to stem elongation can benefit tiller formation and thus increasing spike number, which contributed to the significant yield increase (p = 0.0093). Overall, climate warming affect spring wheat yield in cool area, and increasing temperature that was below the optimum temperature can benefit wheat productivity. [ABSTRACT FROM AUTHOR]

The responses of wheat yield to large-scale atmospheric circulation indices (LACI) were explored in Henan province, north China. With using the annual series of climate-driven yield index (CDYI) extracted from winter wheat yield collected in 17 cites and the monthly series of 15 types of LACI during 1988–2017, the main findings were as follows: (1) this province could be divided into four sub-regions (central-east, west, north, and south Henan) with different CDYI variations; (2) the CDYI in central-east, west, south Henan was dominated by a 3-year oscillation, while the CDYI in north Henan presented a notable 7.5-year oscillation; (3) among the four sub-regions, central-east Henan had the most significant CDYI-LACI relationship, and the higher Nino 1 + 2 in December were a key yield reduction signal; (4) during 2008–2017, the stronger increase of Nino1 + 2_in December had caused the yield decrease in central Henan by 6.58%. In summary, linking wheat yield to LACI anomalies should be instrumental in alleviating the adverse effects of climate change on wheat production. [ABSTRACT FROM AUTHOR]

Large areas of crop yields in northern China have faced with cadmium (Cd) contamination problems. Mercapto-modified palygorskite (MP), as a highly efficient immobilization material, could reduce Cd absorption in wheat and alleviate its biotoxicity. However, the molecular mechanism underlying MP-mediated Cd reduction and detoxification processes in wheat is not well understood. This aim of this study was to investigate the biochemical and molecular mechanisms underlying the reduction in Cd accumulation in wheat (Triticum aestivum L.). The results showed that MP application decreased the Cd concentration by 68.91–74.32% (root) and 70.68–77.2% (shoot), and significantly increased the glutathione (GSH) and phytochelatins (PCs) contents in root and shoot. In addition, with the application of MP, the percentage of Cd in the cell walls and organelles of wheat decreased, while that of Cd in soluble components was increased. The content of Cd in all components was significantly reduced. Ultrastructural analysis revealed that MP thickened the cell wall, promoted vesicle formation in the membrane and protected the integrity of intracellular organelles in wheat. Transcriptome analysis further confirmed the above results. MP upregulated the expression of several genes (CCR, CAD COMT and SUS) involved in cell wall component biosynthesis and promoted vesicle formation on cell membranes by upregulating the expression of PLC and IPMK genes. In addition, genes related to antioxidant synthesis (PGD, glnA and GSS) and photosynthesis (Lhca, Lhcb) were altered by MP to alleviate Cd toxicity in wheat. This present work will help to more thoroughly elucidate the molecular mechanism by which wheat defends against Cd contamination under MP application and provide and important research basis for the application of this material in the future. [Display omitted] • MP reduced the Cd content and Cd subcellular distribution in wheat • MP increases the content of sulfhydryl compounds (GSH and PCs) in wheat. • MP increases cell wall thickness and produces extracellular vesicles to reduce Cd toxicity. • MP enhances the transcriptional response of wheat to confer Cd tolerance. [ABSTRACT FROM AUTHOR]

Wheat powdery mildew (Blumeria graminis f. sp. tritici) and stripe rust (Puccinia striiformis Westend f. sp. tritici) restrict wheat production in southwest China. Nitrogen fertilizers may influence outbreaks of these wheat diseases where wheat/faba beans are intercropped. To clarify how intercropping and varying nitrogen levels influence wheat powdery mildew and stripe rust and their relationship with crop yield, two consecutive field experiments were conducted from 2015 to 2017. Three cropping regimens (monocropped wheat, monocropped faba beans, and intercropped wheat/faba beans) and four nitrogen levels [N0 (0 kg⋅ha–1), N1 (90 kg⋅ha–1), N2 (180 kg⋅ha–1), and N3 (270 kg⋅ha–1)] were evaluated. In two consecutive planting seasons, the incidence and disease index of powdery mildew and stripe rust increased, while the disease index was more affected by nitrogen levels than their incidence. Both diseases were most prevalent at the N3 level. Compared with monocropping, intercropping (N0–N3 levels) reduced the incidence of powdery mildew by 2.8–37.0% and disease index by 15.5–47.4%, increased the relative control effect by 10.7–56.2 and 16.3–47.2%, reduced the incidence of stripe rust by 2.9–42.7% and disease index by 8.3–42.2%, and increased the relative control effect by 5.9–43.7 and 8.8–42.1%. The relative control efficacy of intercropping was most affected by N2 level. Intercropping yield increased with increasing nitrogen by 25.0–46.8%, and overall land equivalent ratio (LER) was 1.30–1.39. The correlation coefficient between disease index and wheat yield for both diseases was −0.7429 to −0.9942, a significant negative correlation, most significant at N1. Nitrogen regulation in intercropped wheat/faba beans can control powdery mildew and stripe rust, and optimize wheat yield. Intercropping at 180 kg ha–1 N2 resulted in the highest yield. [ABSTRACT FROM AUTHOR]

Increasing crop yield for 100 million smallholder farmers in China presents a great challenge, although opportunities exist to increase yields based on field observations. We hypothesized that efforts to improve technology transfer to smallholder farmers could increase both yield and N‐use efficiency for wheat (Triticum aestivum L.) production in Quzhou county, China. Among 1,042 farmers surveyed in 2010−2013, average wheat yield was 7.1 Mg ha−1, but yield varied widely depending on management practices (e.g., tillage, variety, sowing date, sowing rate, fertilization) and farm characteristics (e.g., population, labor, land size). On‐farm trials confirmed that adoption of recommended management approaches, and fertilizer rates could increase yield by 7.1−19.7%. We recommended a technology package consisting of wheat varieties, sowing dates and rates, and fertilizer formulations. Local farmers were classified into three groups: those who used local farming practices (FP), received training two times per year (TP), and received training, field guidance, and help purchasing fertilizers and seeds (OTP). In 2010−2013, wheat yield in TP and OTP increased by 4.4 and 20.6% respectively, relative to FP, thereby increasing N‐use efficiency by 10.7% and improving economic profits by 20.6% relative to FP. The adoption rate of the recommended practices by OTP farmers was 83.0%, compared with 64.3 and 55.5% for TP and FP farmers, respectively. In conclusion, continuous increases in wheat yield could be achieved by optimizing local technologies and improving technology transfer for smallholder agricultural production in China. [ABSTRACT FROM AUTHOR]

This paper reinvestigated the climate-crop yield relationship with the statistical model at crops' growing stage scale. Compared to previous studies, our model introduced monthly climate variables in the production function of crops, which enables separating the yield changes induced by climate change and those caused by inputs variation and technique progress, as well as examining different climate effects during each growing stage of crops. By applying the fixed effect regression model with province-level panel data of crop yields, agricultural inputs, and the monthly climate variables of temperature and precipitation from 1985 to 2015, we found that the effects of temperature generally are negative and those of precipitation generally are positive, but they vary among different growth stages for each crop. Specifically, GDDs (i.e., growing degree days) have negative effects on spring maize's yield except for the sowing and ripening stages; the effects of precipitation are negative in September for summer maize. Precipitation in December and the next April is significantly harmful to the yield of winter wheat; while, for the spring wheat, GDDs have positive effects during April and May, and precipitation has negative effects during the ripening period. In addition, we computed climate-induced losses based on the climate-crop yield relationship, which demonstrated a strong tendency for increasing yield losses for all crops, with large interannual fluctuations. Comparatively, the long-term climate effects on yields of spring maize, summer maize, and spring wheat are more noticeable than those of winter wheat. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to evaluate the ability of Bacillus methylotrophicus M4‐1 to protect winter wheat from the harmful effects of soil salinity and alkalinity. Methods and Results: We isolated the halotolerant B. methylotrophicus M4‐1. Two representative soils with different salt contents (S1, 213 μs cm−1; S2, 786 μs cm−1) in the Yellow River delta region of China were selected for experiments. The effects of the M4‐1 strain on the typical wheat variety (Jimai 21) in this environment were proven. In S1 soil, the M4‐1 strain reduced the wheat rhizosphere soil pH (1·61%) and electrical conductivity (EC) (8·01%) and increased the exchangeable K content (11·14%). The uptake of Mg2+ (20·73%) by wheat roots and K+ (8·84%) by leaves was increased, and the content of Na+ (23·62%) in leaves was reduced. In S2 soil, the M4‐1 strain was able to reduce soil EC (2·56%) and increase exchangeable K (11·20%) content. The absorption of K+ (13·28%) in wheat leaves was increased, and the content of Na+ (12·41%) in roots was decreased. Total N and organic matter contents in rhizosphere soil were significantly positively correlated with wheat growth and salt tolerance, whereas EC showed a significant negative correlation. Conclusions: M4‐1 attenuates salt stress injury in wheat under both low and high salt stress. Significance and Impact of the Study: We demonstrated the efficacy and value of plant growth‐promoting rhizobacteria addition to protect winter wheat against salt stress and improve crop yield. We also elucidated the physicochemical and biochemical interactions among M4‐1, the rhizosphere and the host plant. [ABSTRACT FROM AUTHOR]

In agro‐ecosystems, fertilization practices must accomplish high and stable crop productivity, with maximum soil organic carbon (SOC) sequestration to address climate change and food security challenges. However, the impacts of these practices on SOC and crop yields are variable over the long‐term duration, and an improved understanding of the factors influencing SOC sequestration and sustainable productivity is still needed to provide evidence‐based management decisions. Therefore, we conducted a meta‐analysis to evaluate the impact of long‐term (≥10 years) application of different fertilizer management practices adapted across China on crop productivity, yield sustainability, and SOC sequestration. Results indicated that unbalanced mineral fertilizer (UMF), balanced mineral fertilizer (BMF), organic fertilizers (OF), combined unbalanced mineral and OF, and combined balanced mineral and organic fertilizers (BMOF) significantly enhanced the grain yield, and SOC sequestration compared with control (p <.05). For UMF, the increases in SOC and grain yields were least among fertilization practices. Comparing OF, BMF mostly produced more grain yields, but with a slight increase in C sequestration. Highest SOC sequestration rate of 0.43 Mg C ha−1 yr−1 was recorded in BMOF, among all the treatments. The data obtained indicated that SOC sequestration is highly time‐dependent. Irrespective of fertilization mode, SOC gradually increased and attained the peak of sequestration rate in the initial two decades rather than at later stages of fertilizer addition. The linear fitted model indicated that an increase in SOC sequestration benefits sustainable productivity. The available data indicate that crop yields can be improved by 143 kg ha−1 for rice (Oryza sativa), 255 kg ha−1 for maize (Zea mays), and 202 kg ha−1 for wheat (Triticum aestivum) with every 1 Mg ha−1 increase in SOC stock by fertilization in the root zone. In crux, BMOF can maintain and improve soil quality while producing high and stable crop yields. [ABSTRACT FROM AUTHOR]

In northern China, wheat aphids are widespread and pose serious threats to wheat crop yields. As parasitoids are important parasitic natural enemies of wheat aphids, their interactions with wheat aphids have received much attention. Traditional methods commonly cannot provide clear evidence of trophic links between primary parasitoids and hyperparasitoids or multiparasitism. To overcome this problem, we developed a molecular approach including three multiplex PCRs and five singleplex PCRs. With this approach, four wheat aphid species, four primary parasitoid species and eight to nine hyperparasitoid species were detected from aphid samples, which covered all the primary parasitoids and 94.8-98.1% of the hyperparasitoids found in wheat fields of northern China. The trophic interactions between aphids and primary parasitoids and between primary parasitoids and hyperparasitoids were determined, and a quantitative tri-trophic food web was established through molecular detection. The proportion of hyperparasitized samples was 53.36%, and multiparasitism was very common in the hyperparasitoid trophic interactions (22.02%). These results indicate that this approach is effective for revealing the complex wheat aphid-parasitoid-hyperparasitoid networks in northern China. [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]

Optimizing the type and rate of nitrogen (N) fertilizer is an effective approach for achieving food security and minimizing environmental impacts. In this study, a ten-year in situ field experiment was conducted to evaluate the interannual responses of crop yields and greenhouse gas (GHG) emissions to the continuous application of chemical fertilizer (CF) and partial manure application (30 %, CFM) in a paddy rice-upland wheat rotation system. The results indicated that the trends of crop yields and GHG emissions were stable over ten years, and an appropriate N rate (200/150 kg N ha-1 for rice/wheat) in the rice-wheat system had greater potential for maintaining crop yields (9.25/3.32 t ha-1 for rice/wheat) and reducing their net GHG emissions by 20.8–38.7 % in contrast to the high rate (300/225 kg N ha-1 for rice/wheat). Among CF treatments, CH 4 emissions had a negative correlation with the N rate, while N 2 O emissions were positively correlated. The CFM treatments significantly increased CH 4 emissions (37.5–112.2 %) compared to the CF treatments during the rice season, but mitigated N 2 O emissions during both the rice (55.7–58.2 %) and wheat season (32.0–48.2 %). In a comprehensive assessment of the CH 4 and N 2 O emissions in rice-wheat system, 81 % of the net GHG emissions was occurred in the rice season, and there was no significant difference between the CF and CFM at rate of 200/150 kg N ha-1. The study suggests that partial manure application at an optimum rate can effectively mitigate GHG emissions and be beneficial for the sustainability of rice and wheat production in a paddy rice-upland wheat rotation system. • Ten-year in situ trial with optimized fertilization in China. • Partial manure application promoted CH 4 emissions while inhibited N 2 O emissions. • Decreased N 2 O emissions offset increased CH 4 emissions in rice-wheat system. • Appropriate N rate and type benefit for crop productivity, CH 4 and N 2 O reduction. [ABSTRACT FROM AUTHOR]

Responses of wheat yield in different regions to separate and joint changes in mean temperature (T mean), precipitation (Prec), and solar radiation (Rad) are the foundation for sustainable development under climate change; however, these remain uncertain. Here, we quantified the response of wheat yield variation to changes in T mean , Prec, and Rad by building multiple regression models, de-trending analysis, and MK trend tests. Multi-site meteorological data was obtained from different wheat growing areas and corresponding wheat yield data from provinces. Our findings showed that the effects of different climatic elements on wheat yield are spatially heterogeneous by region, and the combined effects of climatic elements are higher than those of single elements. Climate change caused an increase of 1% and 4.52% in winter and winter-spring wheat areas, respectively, and a loss of 3.72% in spring wheat areas. In addition, the effect of single meteorological factors on wheat yield varied depending on their rate of change. Rad and Prec are the main drivers of wheat yield variability; in winter, spring and winter-spring wheat areas, Rad significantly impacted wheat yield by 0.89%, −1.18%, and 2.46%, respectively, and Prec caused changes of −0.18%, −1.54%, and 1.33%, respectively. Considering normal and extreme climate fluctuations, we found that the contribution of climate change to wheat yield changes in different wheat-growing regions reached 26.1%, 18.6%, and 16.7%, respectively. Our results indicate that the overall climatic conditions in the spring wheat region are moving in an unfavourable direction, while Prec variability has become the main limiting factor for wheat production in the current winter and winter-spring wheat regions. These comprehensive and detailed findings provide a reference for the development of more accurate adaptation strategies and management measures in different regions. Going forward, the results of this study can be better applied to the development of region-specific climate-smart agricultural practices and extended to other crops and regions to better understand the broader impacts of climate change on global food security. [Display omitted] • Spatial differences in crop yield responses to different climate drivers at large scales. • We quantified the effects of climate variation on wheat yield variability. • Uniquely illustrates spatial patterns in the relationship between climate variability and wheat yield variability. • Uncovering the main drivers of climate change impact on wheat yield in China. • Light-efficient varieties and effective irrigation may improve China's wheat yield. [ABSTRACT FROM AUTHOR]

This paper takes Gaobeidian City of Hebei Province as the research area. Based on the Landsat TM/OLI data from 1999 to 2001, 2007-2009 and 2015-2017, the CART decision tree classification method is used to extract the distribution of abandoned arable land in the study area. Finally, we analyze its spatial pattern change characteristics and influencing factors. The study draws the following conclusions: 1) Using CART decision tree classification method to interpret remote sensing images in Gaobeidian City and verify the accuracy. The result shows that: 1）the classification accuracy of 18-stage images are between 87.5% and 96.4%, which can meet the accuracy requirements of this study; 2) The type of abandoned arable land in Gaobeidian City is mainly seasonal abandonment. The area of abandoned arable land reached 21 888.42 hm2 in the spring of 2001, and the area of seasonal abandoned arable land and perennial abandoned arable land are gradually decreasing; 3) The analysis of landscape indicators including plaque number (NP), average plaque area (MPS), median plaque area (PSMD), plaque area standard deviation (PSSD), and average shape index (MSI) of the abandoned arable land shows that the main form of the abandonment of arable land has changed from large-scale centralized abandonment to small-scale decentralized abandonment; 4) The development of rural industry is the main driving factor leading to the abandonment of arable land. The result of the buffer analysis shows that the closer the industrial center is, the higher the comprehensive abandonment rate; The traffic conditions and farming radius also affect the abandonment of arable land to a certain extent, but in the flat plains region, its impact gradually weakened; 5) The gap in crop yields leads to seasonal differences in the cultivated land reclamation in Gaobeidian City. The long-term low net income per unit area of wheat is the main factor leading to the large-scale spring abandonment of arable land in Gaobeidian City, and the arable land transfer can effectively inhibit the abandonment of arable land. The results of rural survey show that the arable land transfer rate in the six surveyed villages shows a significant negative correlation with the change of the arable land abandonment rate. Due to the low resolution of remote sensing images used in this study, the interpretation accuracy may be affected. In addition, the selection time of remote sensing images is mainly based on the growth of spring wheat and summer maize, which do not take into account the late planting of summer stubble carrot and other crops in different growth periods. Although the sowing area of such crops is small, it may still cause errors in the interpretation of abandoned arable land. In order to solve the above problems, it is necessary to use Google high-resolution image for manual visual interpretation and correction, but this method will cost a lot of manpower and time. In future research, other remote sensing data sources with higher spatial resolution and richer spectral information can be considered for interpretation in order to solve these problems. The research results can provide reference for the study of abandoned arable land in other similar areas in China, and provide basis for the formulation of national food security and regional sustainable development policies. [ABSTRACT FROM AUTHOR]

Ozone (O3) flux-based indices are considered better than O3 concentration-based indices in assessing the effects of ground O3 on ecosystem and crop yields. However, O3 flux (Fo) measurements are often lacking due to technical reasons and environmental conditions. This hampers the calculation of flux-based indices. In this paper, an artificial neural network (ANN) method was attempted to simulate the relationships between Fo and environmental factors measured over a wheat field in Yucheng, China. The results show that the ANN-modeled Fo values were in good agreement with the measured Fo values. The R2 of an ANN model with 6 routine independent environmental variables exceeded 0.8 for training datasets, and the RMSE and MAE were 3.074 nmol·m−2·s and 2.276 nmol·m−2·s for test dataset, respectively. CO2 flux and water vapor flux have strong correlations with Fo and could improve the fitness of ANN models. Besides the combinations of included variables and selection of training data, the number of neurons is also a source of uncertainties in an ANN model. The fitness of the modeled Fo was sensitive to the neuron number when it ranged from 1 to 10. The ANN model consists of complex arithmetic expressions between Fo and independent variables, and the response analysis shows that the model can reflect their basic physical relationships and importance. O3 concentration, global radiation, and wind speed are the important factors affecting O3 deposition. ANN methods exhibit significant value for filling the gaps of Fo measured with micrometeorological methods. [ABSTRACT FROM AUTHOR]

Understanding the impacts of climate change on crop yield is important for improving crop growth and yield formation in northwestern China. In this study, we evaluated the relationship between meteorological dryness/wetness conditions and spring wheat yield in the Ili river basin (IRB). The climate and yield data from 1961 to 2013 were collected to analyze characteristics and correlations between these two variables using the standardized precipitation evapotranspiration index (SPEI), yield detrending method, modified Mann-Kendall test and Spearman correlation analysis. Main results were as follows: (1) correlations between monthly SPEI values (MSV) and climatic yield of spring wheat indicated that the dryness/wetness condition in May was a key factor affecting yield in the whole region; (2) although the MSV in May and yield fluctuated from negative to positive values in time, the severely and extremely dryness events were in good agreement with the higher yield losses; (3) each increase of 0.5 MSV in May promoted over 3% increase of yield in most part of IRB; however, the larger variability of MSV in May resulted in larger yield fluctuations; and (4) the Tibetan Plateau index in April showed significant correlations with the MSV in May and yield, which provided a precursory signal for decision-makers to better understand potential yield fluctuations. [ABSTRACT FROM AUTHOR]

Yield components play a decisive role in regulating the potential crop grain yields, and their formation is greatly influenced by in-season nitrogen (N) management, as N is essential of optimizing crop growth. To test the applicability of critical N dilution curve based instantaneous N nutrition index (NNI) and integrated NNI (NNI inte) in-season prediction of grain yield and its components in wheat. This study evaluated the applicability of the critical N dilution curve for predicting grain yield and yield components in wheat by establishing the relationships of NNI and NNI inte with relative grain yield (RY), dry matter (RDM), number of spikes (RPN), number of grains per spike (RGN), and grain weight at different growth stages of wheat. Data were acquired from six multi-N rates field experiments conducted in eastern and central China. The RY, RPN, and RDM were estimated by NNI and accumulated NNI inte during different growth stages of wheat. The higher R2 values of relationships observed during the middle to later growth stages compared with early growth stages indicated that the early growth stages might not be suitable for estimating wheat grain yield and yield components. The NNI inte specifically during booting to anthesis stage showed improved accuracy estimating the number of grains per spike compared to other stages. Overall, the estimation performance based on accumulated NNI inte was superior compared to NNI or NNI inte during the single growth stage of wheat. The above models provided comprehensive and accurate estimates dry matter at maturity, grain yield and yield components as early as the anthesis stage. The findings provided valuable insights for predicting grain yield and yield components in intensive wheat cropping systems, and also offer practical guidance for precisely scheduling N management. • Wheat grain yield and yield components were estimated by NNI and integrated NNI (NNI inte) during different growth stages. • Single-stage NNI (booting) allows earlier estimates of dry matter at maturity and spike number. • Single-stage NNI inte (anthesis) only improved the estimation performance of grain number. • NNI inte over multiple consecutive stages could better estimate dry matter at maturity, grain yield, and spike number. • The models can comprehensively and accurately estimate grain yield and yield components as early as the anthesis stage. [ABSTRACT FROM AUTHOR]

The optimization of nitrogen (N) fertilization has become an ever more important global challenge with the aim of achieving high crop yields and high N use efficiency (NUE) with low environmental risks. The North China Plain (NCP) is China's most important wheat (Triticum aestivum Linn.) production region, and a global hotspot for N fertilizer use. How much nitrogen can be saved compared to the farmers' level that would not influence wheat yield, and lead to high NUE with low N surplus? It is still challenging as there are not enough evidences from the long-term experiments. Thus, continuous detailed observations from an ongoing long-term experiment in the NCP since 2010 with five N rates, namely 0 (N0), 60 (N60), 120 (N120), 180 (N180) and 240 (N240) kg N ha−1, were included in the study. Our results indicated that stable high wheat yield cannot be achieved without enough N inputs from the long-term, because of severely depleted N pool in the N0 and N60 treatments seriously influenced root growth and wheat development thus damaged wheat yield. Though highest wheat yield was obtained in the N240 treatment, the high N rate caused lowest NUE and largest N surplus with high soil mineral N (SMN) with the mean value of 143 kg N ha−1 at the 0–60 cm layer at harvest. Besides, both root weight density (RWD) and root length density (RLD) were much lower in the N240 treatment compared to that in the N180 treatment. Our integrative analyses clearly indicate that the optimal N application for achieving high yield, high NUE and low environmental risks in wheat production was 180 kg N ha−1 based on long-term observations. Our results should be beneficial for promoting sustainable wheat production in the NCP and similar regions with wheat-based double cropping over the world. • Long-term low/no N application significantly reduced wheat yield. • Increased N rates caused a high N surplus and low NUE. • The RWD and RLD were largest in 0–60 cm soil layer in the N180 treatment. • The optimal N application for achieving high yields and high WUE with low environmental risks in the NCP were 180 kg N ha−1. [ABSTRACT FROM AUTHOR]

Diagnosing the status of crop nitrogen (N) helps to optimize crop yield, improve N use efficiency, and reduce the risk of environmental pollution. The objectives of the present study were to develop a critical N (Nc) dilution curve for winter wheat (based on spike dry matter [SDM] during the reproductive growth period), to compare this curve with the existing Nc dilution curve (based on plant dry matter [DM] of winter wheat), and to explore its ability to reliably estimate the N status of winter wheat. Four field experiments, using varied N fertilizer rates (0–375 kg ha-1) and six cultivars (Yangmai16, Ningmai13, Ningmai9, Aikang58, Yangmai12, Huaimai 17), were conducted in the Jiangsu province of eastern China. Twenty plants from each plot were sampled to determine the SDM and spike N concentration (SNC) during the reproductive growth period. The spike Nc curve was described by Nc = 2.85×SDM-0.17, with SDM ranging from 0.752 to 7.233 t ha-1. The newly developed curve was lower than the Nc curve based on plant DM. The N nutrition index (NNI) for spike dry matter ranged from 0.62 to 1.1 during the reproductive growth period across the seasons. Relative yield (RY) increased with increasing NNI; however, when NNI was greater than 0.96, RY plateaued and remained stable. The spike Nc dilution curve can be used to correctly identify the N nutrition status of winter wheat to support N management during the reproductive growth period for winter wheat in eastern China. [ABSTRACT FROM AUTHOR]

Concerns about the effects of global warming on crop yields have risen due to stagnating yield progress in recent years. Understanding crop traits and grain yield variations in different climate zones is critical to gain insights into crop response and adaptation mechanisms to ongoing climate change. However, the interactions of genotype, environment and management on crop traits and historical yield progress are lacking. This study is to investigate the variations and trends in wheat traits in different climate zones across China, trade-offs among phenological and yield-related traits, the effects of genotype, environment and management interactions on wheat traits, as well as the contributions of traits, management, climate and genetic changes to grain yield. The genotype, environment and management interactions on wheat traits and grain yield variations were analyzed based on long-term field trials during 2003–2016 at five representative stations across China. And then, a machine learning method was applied to quantify the relative contributions of these factors to wheat traits and grain yield variations. A significant warming trend during the reproductive growth period and a decreasing trend in solar radiation were observed. Significant trends and variations in wheat traits and significant interactions between genotype, station and year were discovered. Compared with fertilization, grain yield under no-fertilization was significantly lower by 80.3% at five representative stations across China. With local farmer's practices, about 3.5–40.9%, 19.6–58.3% and 0.1–8.2% of the yield variations were associated with agricultural management practices, climate change and cultivar shifts, respectively, contradicting some previous studies which highlight the weight of genetic yield improvement. The findings are valuable for understanding the mechanisms underlying crop traits and grain yield variations, for breeders to breed desirable traits, and for agronomists to adopt suitable cultivars and agricultural management practices. [Display omitted] • The interactions of genotype, environment and management throughout the traits on historical yield progress are lacking. • Understanding crop traits and grain yield variations in different climate zones helps to crop response and adaptation mechanisms to ongoing climate change. • A machine learning method and meta-regression analyses were used to distinguish the relative contributions of these factors to grain yield variations based on long-term field trials at five representative stations across China. • Climate and agronomy, especially changes in traits, not genetics, affect wheat yield. [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]

Crop production in the dryland farming areas of northern China is constrained by low and variable rainfall. This article presents the analysis of the relationships between variations in rainfall and yields of winter wheat and spring maize. The analysis is based on data from both several short-term and our ongoing long-term field experiments in dryland farming research projects in Tunliu, Linfen, Shouyang, and Luoyang. Grain yields of wheat and maize ranged from 1,548 to 5,169 and from 2,612 to 8,789 kg ha-1respectively, with differences up to above 200% (between dry and wet years). Wheat yields are sensitive to growing season rainfall but also correlated to water use (ET), whereas maize yields are sensitive to the critical time of water supply (especially June rainfall) but not correlated to ET. The ratio of grain yields to soil water at sowing is an important indicator, showing close relationships between yields and soil water-related ratio within the rainfed crops site. Comparison between the indices of water use efficiency (WUE) and precipitation use efficiency (PUE) suggests that the index WUE is more grain-related indicator than the PUE used for assessing rainfed crop water use by both maize and wheat. The index PUE should be used in caution, especially for wheat crops in dry years. Our results indicate that options to alleviate crop moisture stress must be tailored to the rainfall pattern. This holds especially for conservation tillage with response nutrient management practices that aim at enhancing water use efficiency. [ABSTRACT FROM AUTHOR]

The experiment is to explore the efficient and comprehensive utilization of maize straw resources to achieve the sustainability of the soil fertility under double cropping of winter wheat and summer maize. Summer maize hybrid Denghai 605 (DH605) and winter wheat variety Tainong 18 (TN18) were used as experimental materials. Based on all winter wheat straw returned to the field, the treatment of all summer maize straw (SR) and half of summer maize straw (1/2SR) and summer maize straw not returned to the field (CK) 3 experimental treatments were tested for 8 consecutive years. Under the condition of normal nitrogen application of 210 kg ha−1, two split areas were set to reduce the amount of nitrogen fertilizer by 15% and 30% (SR-15%、SR-30%、1/2SR-15%、1/2SR-30%、CK-15%、CK-30%) at the beginning of the 2016 wheat season. In the first two years of reduced nitrogen application, the yields of SR and 1/2SR treatments were significantly higher than that of CK under the same nitrogen application conditions, while the yields of SR, 1/2SR, SR-15%, and 1/2SR-15% were not significantly different. In the third year of the process of reducing nitrogen fertilizer, compared with SR, 1/2SR, and SR-15% treatments, the yield of 1/2SR-15% were significantly reduced by 9% under winter wheat season. During winter wheat and summer maize season, the nitrogen use efficiency, and nitrogen absorption efficiency of SR and 1/2SR were significantly increased compared with CK treatment under the same nitrogen rate, of which SR-15% treatment was not significantly different from SR and 1/2SR. The pre-anthesis nitrogen transfer rate and nitrogen harvest index of summer maize treated with SR, 1/2SR, SR-15% and 1/2SR-15% were also significantly increased, compared with CK and CK-15% treatments. The win-win situation of ecological and crop yield can be achieved by return half of the straw to the field or reducing the nitrogen fertilizer application by 15% under the condition of straw returned to the field. • Returning the full amount of summer corn to the field can stably replace 15% of the nitrogen fertilizer application. • The yield stability and NUE of SR-15% treatment are not significantly different between with SR and 1/2 SR treatments. • The 1/2SR treatment can achieve a synergistic increase in crop yield and nitrogen utilization under NCP in China. [ABSTRACT FROM AUTHOR]

The reduction in biodiversity owing to agricultural intensification has brought negative effects on sustainable crop production in the agro-environment. Plant diversity can help regulate insect pests; however, research that demonstrates that genotypic diversity of multiple varieties with prominent agroecological practices to suppress insect pests and benefit crop yield at agricultural landscapes is limited. To examine the effects of diversity of wheat varieties on aphids and crop productivity, we performed field experiments by designing plots of single (resistant/susceptible) and cultivar mixtures in 2018–2020. The effects of population abundance of cereal aphids (Sitobion miscanthi and Rhopalosiphum padi) and crop yield on resistant and susceptible wheat varieties and mixture of wheat cultivars were determined to reveal the most dominant mixed broadcasting mode in Kaifeng of China. The results showed that cultivar mixture significantly decreased aphid abundance compared with the single varieties (resistant/susceptible). Cultivar mixture had a higher yield compared with the single varieties (resistant/susceptible). Additionally, cultivar mixture had significantly higher thousand-grain weights than susceptible and resistant wheat varieties in 2019 and 2020. Cultivar mixture enhanced wheat yield by decreasing cereal aphids, indicating a bottom-up or top-down effect from genetic diversity to pest abundance. Our results indicated that appropriate cultivar mixtures could manage insect pests to some extent and stabilize crop yield. [ABSTRACT FROM AUTHOR]

The relationships between crop yield and its selected related impact factors has often been explored using ordinary least squares regression (OLSR). However, this model is non-spatial and non-robust. This study first used stepwise regression to identify the main factors affecting winter wheat yield from twelve potential related factors in Yucheng County, China. Next, robust geographically weighted regression (RGWR) was used to explore the spatially non-stationary relationships between wheat yield and its main impact factors. Then, its modeling effect was compared with that of GWR and OLSR. Last, robust geostatistical analysis was conducted for spatial soil management measures in low-yield areas. Results showed that: (i) three main impact factors on wheat yield were identified by stepwise regression, namely soil organic matter, soil total phosphorus, and pH; (ii) the spatially non-stationary effects of the main impact factors on wheat yield were revealed by RGWR but were ignored by OLSR; (iii) RGWR obtained the best modeling effect (RI = 52.31%); (iv) robust geostatistics obtains a better spatial prediction effect and the low-yield areas are mainly located in the northeast and the middle east of the study area. Therefore, the integrated yield-based methodology effectively improves soil nutrient management at a regional scale. [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]

Global warming and altered precipitation patterns pose a serious threat to crop production in the North China Plain (NCP). Quantifying the frequency of adverse climate events (e.g., frost, heat and drought) under future climates and assessing how those climatic extreme events would affect yield are important to effectively inform and make science-based adaptation options for agriculture in a changing climate. In this study, we evaluated the effects of heat and frost stress during sensitive phenological stages at four representative sites in the NCP using the APSIM-wheat model. climate data included historical and future climates, the latter being informed by projections from 22 Global Climate Models (GCMs) in the Coupled Model Inter-comparison Project phase 6 (CMIP6) for the period 2031–2060 (2050s). Our results show that current projections of future wheat yield potential in the North China Plain may be overestimated; after more accurately accounting for the effects of frost and heat stress in the model, yield projections for 2031-60 decreased from 31% to 9%. Clustering of common drought-stress seasonal patterns into key groups revealed that moderate drought stress environments are likely to be alleviated in the future, although the frequency of severe drought-stress environments would remain similar (25%) to that occurring under the current climate. We highlight the importance of mechanistically accounting for temperature stress on crop physiology, enabling more robust projections of crop yields under future the burgeoning climate crisis. [ABSTRACT FROM AUTHOR]

Understanding the time-course of dry matter (DM) and nitrogen (N) accumulation in terms of yield–trait relationships is essential to simultaneously increase grain yield and synchronize N demand and N supply. We collected 413 data points from 11 field experiments to address patterns of DM and N accumulation with time in relation to grain yield and management of winter wheat in China. Detailed growth analysis was conducted at the Zadok growth stages (GS) 25 (regreening), GS30 (stem elongation), GS60 (anthesis), and GS100 (maturity) in all experiments, including DM and N accumulation. Grain yield averaged 7.3 Mg ha−1, ranging from 2.1 to 11.2 Mg ha−1. The percent N accumulation was consistent prior to DM accumulation, while both DM and N accumulation increased continuously with growing time. Both the highest and fastest DM and N accumulations were observed from stem elongation to the anthesis stage. Significant correlations between grain yield and DM and N accumulation were found at each of the four growth stages, although no positive relationship was observed between grain yield and harvest index or N harvest index. The yield increase from 7–9 Mg ha−1 to >9 Mg ha−1 was mainly attributed to increased DM and N accumulation from stem elongation to anthesis. Although applying more N fertilizer increased N accumulation during this stage, DM accumulation was not improved, indicating that N fertilizer management and related agronomic management should be intensified synchronously across the wheat growing season to simultaneously achieve high yields and match N demand and N supply. [ABSTRACT FROM AUTHOR]

In the North China Plain, the grain yield of irrigated wheat-maize cropping system has been steadily increasing in the past decades under a significant warming climate. This paper combined regional and field data with modeling to analyze the changes in the climate in the last 40 years, and to investigate the influence of changes in crop varieties and management options to crop yield. In particular, we examined the impact of a planned adaptation strategy to climate change -'Double-Delay' technology, i.e., delay both the sowing time of wheat and the harvesting time of maize, on both wheat and maize yield. The results show that improved crop varieties and management options not only compensated some negative impact of reduced crop growth period on crop yield due to the increase in temperature, they have contributed significantly to crop yield increase. The increase in temperature before over-wintering stage enabled late sowing of winter wheat and late harvesting of maize, leading to overall 4-6% increase in total grain yield of the wheat-maize system. Increased use of farming machines and minimum tillage technology also shortened the time for field preparation from harvest time of summer maize to sowing time of winter wheat, which facilitated the later harvest of summer maize. [ABSTRACT FROM AUTHOR]

Abstract: Understanding agronomic and physiological performance of crop high yield is essential to make strategies for breeding and crop management. This study aimed to identify major agronomic and physiological traits associated with high grain yields of rice and wheat in the wheat–rice rotation system in the lower reaches of Yangtze River of China. Two high-yielding cultivars, each for winter wheat and rice, were field-grown from 2008 to 2010 for 3 years. Two crop management treatments, the local farmer''s practice (LFP) and improved high-yielding cultivation (IHC), were used. The IHC adopted two new techniques, i.e., site-specific nitrogen management in both rice and wheat and alternate wetting and moderate drying irrigation in rice and controlled soil drying irrigation in wheat. Across the 3 years, the IHC yielded an average 9.67tha−1 of wheat and 12.55tha−1 of rice with an annual total of 22.2tha−1, an increase of 26.8% when compared with that (17.5tha−1) under the LFP. The increased grain yield under the IHC was mainly attributed to expanded sink size as a result of more kernels per spike or more spikelets per panicle, increased kernel weight of wheat and increased percentage of filled grains of rice. When compared with LFP, IHC showed a greater percentage of productive tillers, more pre-anthesis nonstructural carbohydrate (NSC) storage in the stem, greater leaf photosynthetic rate and concentration of cytokinins in root exudates, higher activities of sucrose synthase and adenosine diphosphoglucose pyrophosphorylase in grains, more dry mater production during the grain filling period, and higher harvest index. We conclude that (1) expanding sink capacity through an increase in kernels per spike or spikelets per panicle, (2) enhancing grain filling efficiency by an increase in pre-anthesis NSC in the stem, and (3) increasing post-anthesis dry mater production by an enhancement in root activity during grain filling should be considered as three major strategies for further increases in grain yields of wheat and rice in the lower reaches of Yangtze River of China. [Copyright &y& Elsevier]

This study examined the effects of long-term K fertilization on crop yields and K use efficiency and balance under a wheat (Triticum aestivum L.)-maize (Zea mays L.) cropping system in the Fluvo-Aquic soil of Yucheng Comprehensive Experiment Station in the North China Plain (NCP). Results showed that the native K supply could maintain annual grain yields at stable levels at 10.7 Mg ha-1 for >19 yr with applications of N and P alone. The application of K alone significantly improved maize yield by 46% but wheat showed no response. The agronomic efficiency, physiological efficiency, and partial factor productivity but not apparent use efficiency of wheat were significantly lower than the average values previously reported. In addition, only 43% of K found in the aboveground biomass of wheat and maize came from an annual application of fertilizer. The application of K caused a large K surplus, even with balanced fertilization, in which 33% of applied K was left: in the soil, mostly in the 0- to 20-cm depth due to its surface application. The data indicated that the native K supply in the NCP might sustain normal wheat yields for about 10 to 30 yr. Generally, in a Fluvo-Aquic soil with a high content of soil available K, soil K can be used. In this study, 471 kg ha-1 yr-1 K input was excessive for the growth of maize and wheat, and at least 120 to 150 kg ha-1 yr-1 K could be saved with the use of balanced fertilization. [ABSTRACT FROM AUTHOR]