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Producers utilizing fall manure injection have reported increased growth and greenness in small grains growing on the injection band compared to small grains growing between injection bands. To determine how producers utilizing fall manure injection in small grains should manage potential differential growth, 24 sites under fall manure injection were established. Soil samples were taken in‐band and between‐band 1 month after manure application and at silage harvest for soil NO3‐N. Small grain growth stage was assessed 1 month after planting and at silage harvest, while dry matter (DM) yield and forage nutritive value parameters were assessed at silage harvest. Soil NO3‐N was elevated in‐band compared to between‐band 1 month after manure application (p < 0.05); however, this did not persist until silage harvest. No differences in growth stage were observed 1 month after planting in 2021; however, growth stage means were consistently elevated in‐band in 2022, likely due to earlier planting dates in 2022 compared to 2021. Growth stage at harvest was the same in‐band and between‐band at each site. Small grain DM yield was only increased in‐band compared to between‐band in three of 24 sites. Two of the three sites planted with wheat (Triticum aestivum L.) showed significantly increased DM yield in‐band, suggesting DM yield response could be species dependent. No consistent differences in forage nutritive value parameters were observed. As no consistent differences in small grain DM yield and forage nutritive value were found at harvest, we recommend no changes to management practices for producers utilizing fall manure injection in small grains. Core Ideas: Manure injection consistently elevated soil nitrate in the manure injection band across sites.Some increased small grain tillering observed in the manure injection band 1 month after planting.Soil nitrate concentrations were the same in‐band and between‐band at silage harvest.No differences in small grain maturity, silage yield, and forage quality occurred in‐band versus between‐band.Producers using fall manure injection in small grains do not need to adjust management practices due to banding. [ABSTRACT FROM AUTHOR]

BACKGROUND: Irrigation is used extensively to enhance grain production and ensure food security. Many studies have used crop models and global climate models to study the variation of irrigated crop yield in the context of climate change. But most considered the influence of direct climate change but neglected the influence of irrigation water availability, which is affected by land‐use/cover change (LUCC) and indirect climate change, on irrigated crop yield. This study therefore developed a framework including Patch‐generating Land Use Simulation model, Soil and Water Assessment Tool, Agricultural Production Systems sImulator Model, and global climate models for exploring the impacts of LUCC, direct climate change, and indirect climate change on wheat yield in a typical watershed. RESULTS: Both LUCC and climate change caused increased runoff from October to May, and thus increased the irrigation water availability, by 51.6 and 30.7 mm per growing season under 1.5 and 2.0 °C warming, respectively. The combined influence of LUCC, direct, and indirect climate change increased wheat yield by about 18.5% and 15.5% in the context of 1.5 and 2.0 °C warming, respectively. The relative contribution of LUCC, indirect climate change and direct climate change to yield was 4.7%, 41.2%, and 54.1% under 1.5 °C warming, and 13.1%, 28.7%, and 58.2% under 2.0 °C warming, respectively. CONCLUSION: We suggest that changes in irrigation water availability should be considered from a watershed perspective when simulating the influence of climate change on crop yield, especially regional crop production estimation. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Maintaining or even increasing crop yields while reducing nitrous oxide (N2O) emissions is necessary to reconcile food security and climate change, while the metric of yield‐scaled N2O emission (i.e., N2O emissions per unit of crop yield) is at present poorly understood. Here we conducted a global meta‐analysis with more than 6000 observations to explore the variation patterns and controlling factors of yield‐scaled N2O emissions for maize, wheat and rice and associated potential mitigation options. Our results showed that the average yield‐scaled N2O emissions across all available data followed the order wheat (322 g N Mg−1, with the 95% confidence interval [CI]: 301–346) > maize (211 g N Mg−1, CI: 198–225) > rice (153 g N Mg−1, CI: 144–163). Yield‐scaled N2O emissions for individual crops were generally higher in tropical or subtropical zones than in temperate zones, and also showed a trend towards lower intensities from low to high latitudes. This global variation was better explained by climatic and edaphic factors than by N fertilizer management, while their combined effect predicted more than 70% of the variance. Furthermore, our analysis showed a significant decrease in yield‐scaled N2O emissions with increasing N use efficiency or in N2O emissions for production systems with cereal yields >10 Mg ha−1 (maize), 6.6 Mg ha−1 (wheat) or 6.8 Mg ha−1 (rice), respectively. This highlights that N use efficiency indicators can be used as valuable proxies for reconciling trade‐offs between crop production and N2O mitigation. For all three major staple crops, reducing N fertilization by up to 30%, optimizing the timing and placement of fertilizer application or using enhanced‐efficiency N fertilizers significantly reduced yield‐scaled N2O emissions at similar or even higher cereal yields. Our data‐driven assessment provides some key guidance for developing effective and targeted mitigation and adaptation strategies for the sustainable intensification of cereal production. [ABSTRACT FROM AUTHOR]

Summary: Plant height and grain size are two important agronomic traits that are closely related to crop yield. Numerous dwarf and grain‐shape mutants have been studied to identify genes that can be used to increase crop yield and improve breeding programs.In this study, we characterized a dominant mutant, dwarf and round grain 1 (drg1‐D), in bread wheat (Triticum aestivum L.). drg1‐D plants exhibit multiple phenotypic changes, including dwarfism, round grains, and insensitivity to brassinosteroids (BR). Cell structure observation in drg1‐D mutant plants showed that the reduced organ size is due to irregular cell shape.Using map‐based cloning and verification in transgenic plants, we found that a Glu209Lys substitution in the DRG1 protein is responsible for the irregular cell size and arrangement in the drg1‐D mutant. DRG1/TaACT7 encodes an actin family protein that is essential for polymerization stability and microfilament (MF) formation. In addition, the BR response and vesicular transport were altered by the abnormal actin cytoskeleton in drg1‐D mutant plants.Our study demonstrates that DRG1/TaACT7 plays an important role in wheat cell shape determination by modulating actin organization and intracellular material transport, which could in the longer term provide tools to better understand the polymerization of actin and its assembly into filaments and arrays. [ABSTRACT FROM AUTHOR]

We examine the effects of the federal crop insurance program on crop production under extreme heat using farm‐level data from Kansas. We find that insured dryland corn is 38% more sensitive to extreme heat than uninsured dryland corn. Results also suggest that a uniform +1° C warming scenario leads to yield reductions of 16.7% (11.8%) for insured (uninsured) corn production; and 6.0% (4.4%) for insured (uninsured) wheat production. Warming had a stronger impact with reduced rainfall, especially on insured farms compared with uninsured farms, while altered growing seasons showed potential benefits for wheat but limited improvements for corn. [ABSTRACT FROM AUTHOR]

This article develops a theoretical framework to determine the economically optimal grid size when sampling to guide precision application of inputs. Our theoretical model shows that a finer grid is optimal with increases in output price. A coarser grid is optimal with increased sampling costs and increased spatial correlation. With an exponential variogram, for example, the optimal grid size increases as the range increases. An applied example of lime application for winter wheat is used to demonstrate the framework. Spatial variograms for pH and Buffer pH were estimated using data from nine farmer fields. At the average spatial variability from these fields and using typical Oklahoma wheat yields of 40 bu/ac, grid sampling was economical when prices were above $5.43/bu. The optimal grid sizes were slightly larger than the 2.5‐acre sizes that are typically used by producers. The empirical example verified the theory in that it found that optimal grid size decreased with higher output prices and crop yields and increased with greater spatial correlation. For example, optimal grid size approximately doubled as the range of the exponential correlation function doubled. [ABSTRACT FROM AUTHOR]

SUMMARY: Triticum aestivum L. (bread wheat) is a crop relied upon by billions of people around the world, as a major source of both income and calories. Rising global temperatures, however, pose a genuine threat to the livelihood of these people, as wheat growth and yields are extremely vulnerable to damage by heat stress. Here we present the YoGI wheat landrace panel, comprising 342 accessions that show remarkable phenotypic and genetic diversity thanks to their adaptation to different climates. We quantified the abundance of 110 790 transcripts from the panel and used these data to conduct weighted co‐expression network analysis and to identify hub genes in modules associated with abiotic stress tolerance. We found that the expression of three hub genes, all heat‐shock proteins (HSPs), were significantly correlated with early thermotolerance in a validation panel of landraces. These hub genes belong to the same module, with one (TraesCS4D01G207500.1) being a candidate master‐regulator potentially controlling the expression of the other two hub genes, as well as a suite of other HSPs and heat‐stress transcription factors (HSFs). In this work, therefore, we identify three validated hub genes, the expression of which can serve as markers of thermotolerance during early development, and suggest that TraesCS4D01G207500.1 is a potential master regulator of HSP and HSF expression – presenting the YoGI landrace panel as an invaluable tool for breeders wishing to determine and introduce novel alleles into modern varieties, for the production of climate‐resilient crops. Significance Statement: Global wheat yields and crop growth are vulnerable to damage by heat stress, a threat that is likely to become more common globally in the coming years through climate change. Conducting weighted co‐expression network analysis on 337 diverse landrace accessions, we identified and validated TraesCS4D01G207500.1 as a hub gene that can be used as a marker of early thermotolerance, seemingly via the regulation of the expression of a suite of HSP and HSF genes. [ABSTRACT FROM AUTHOR]

Breeding programs aim to improve crop yield and environmental stability for enhanced food security. The principal methodology in breeding for stable yield gain relies on the indirect selection of beneficial genetics by yield evaluation across diverse environmental conditions. This methodology requires substantial resources while delivering a slow pace of yield gain and environmental adaptation. Alternative methods are required to accelerate gain and adaptation, becoming even more imperative in a changing climate. New molecular tools and approaches can enable accelerated creation and deployment of multiple alleles of genes identified to control key traits. With the advent of tools that enable breeding by targeted allelic selection, identifying gene targets associated with an improved crop performance ideotype will become crucial. Previous studies have shown that altered photoperiod regimes increase yield in wheat (Triticum aestivum). In the current study, we have employed such treatments to study the resulting yield ideotype in five spring wheat cultivars. We found that the photoperiod treatment creates a yield ideotype arising from delayed spike establishment rates that are accompanied by increased early shoot expression of TARGET OF EAT1 (TaTOE1) genes. Genes identified in this way could be used for ideotype‐based improve crop performance through targeted allele creation and selection in relevant environments. [ABSTRACT FROM AUTHOR]

Information on the effect of no‐till crop rotation on a broad range of soil properties and long‐term crop yields is needed to evaluate its benefits on ecosystem services compared with monocropping. The objective of this study was to examine the effects of no‐till crop rotation (barley [Hordeum vulgare L.]/spring wheat [Triticum aestivum L.]–pea [Pisum sativum L.]) and monocropping [continuous barley/spring wheat] on 66 dryland soil physical, chemical, biological, and biochemical properties and long‐term crop yields at two dryland farm sites (14‐ and 36‐yr old) in the northern Great Plains. Soil samples collected to a depth of 15 cm in April 2019 were analyzed for soil properties and crop yields determined. At the long‐term site, crop rotation increased 11 properties, but reduced 16 of 66 soil properties compared with monocropping. At the short‐time site, crop rotation increased 6 properties, but reduced 13 of 66 soil properties compared with monocropping. Longer duration experiments showed more differences in soil properties due to crop rotation than shorter duration experiments. Spring wheat and barley yields were greater following pea than following spring wheat or barley during years with normal or above‐average precipitation at both sites. Pea yield in the crop rotation was also greater during these years. Barley/spring wheat–pea rotation can enhance some soil properties and dryland crop yields compared with continuous barley/spring wheat during wet years in the semiarid region of the northern Great Plains. Core Ideas: Crop rotation had variable effect on soil properties compared with monocropping.Crop rotation increased barley and spring wheat yields compared with monocropping during wet years.Crop rotation can enhance some soil properties and dryland crop yields compared with monocropping. [ABSTRACT FROM AUTHOR]

Understanding the variability in crop yield in relation to the spatial variations in soil properties can help to more efficiently apply agricultural inputs on a site‐specific basis. This study was designed to characterize and quantify the spatial variation in soil properties and wheat yield and to delineate prescription maps for site‐specific fertilization. A wheat field was selected at the research farm of the University of Agriculture, Faisalabad, Pakistan, and a grid pattern (30 m * 30 m) was established at the experimental sites to collect soil and crop yield samples at two sampling depths (0–15 & 15–30 cm). The soil samples were analysed for soil nitrogen (N), phosphorus (P), potassium (K), pH, electrical conductivity (EC), soil organic matter (SOM) and saturation (S) at both sampling depths. The locations of the sampling points and field boundary were marked with a GPS receiver. Results of classical, geo‐statistical and interpolated maps revealed significant spatial variability in soil properties and crop yield, demanding for site‐specific nutrient management. The cluster analysis was performed to group the soil and yield data into five productivity zones termed as 'very low', 'low', 'medium', 'high' and 'very high' without prior knowledge of productivity potential with the internal homogeneity and external heterogeneity at a similarity level of greater than 70%. Results of correlation matrix suggested significant relationships among the crop yield and the soil properties. Results of means comparison in different productivity zones indicated that the crop yield and soil properties were significantly different in developed management zones except 'low' and 'very low' zones. Significant variation of soil nutrients in very low‐to‐very high productivity zones at both sampling depths suggested that the soil nutrients in combination with soil pH and organic matter can be used to develop prescription maps for site‐specific fertilization. Furthermore, the results of this study emphasize the need to predict soil and crop variables using sensors, in future studies, to delineate prescription maps, as soil sampling and analysis is expansive and time consuming. Site‐specific fertilization based on soil and crop needs can improve economic and environmental efficiency. [ABSTRACT FROM AUTHOR]

Plants require zinc (Zn) as an essential cofactor for diverse molecular, cellular and physiological functions. Zn is crucial for crop yield, but is one of the most limiting micronutrients in soils. Grasses like rice, wheat, maize and barley are crucial sources of food and nutrients for humans. Zn deficiency in these species therefore not only reduces annual yield but also directly results in Zn malnutrition of more than two billion people in the world. There has been good progress in understanding Zn homeostasis and Zn deficiency mechanisms in plants. However, our current knowledge of monocots, including grasses, remains insufficient. In this review, we provide a summary of our knowledge of molecular Zn homeostasis mechanisms in monocots, with a focus on important cereal crops. We additionally highlight divergences in Zn homeostasis of monocots and the dicot model Arabidopsis thaliana, as well as important gaps in our knowledge that need to be addressed in future research on Zn homeostasis in cereal monocots. Summary statement: Zinc is an essential nutrient, determining yield and grain quality in monocotyledonous crops. The manuscript reviews our current understanding of the molecular network underlying zinc homeostasis in monocots, highlighting gaps in knowledge and the specificities of monocots compared to Arabidopsis. [ABSTRACT FROM AUTHOR]

Summary: Optimal root system architecture is beneficial for water‐fertilizer use efficiency, stress tolerance and yield improvement of crops. However, because of the complexity of root traits and difficulty in phenotyping deep roots, the study on mechanisms of root development is rarely reported in wheat (Triticum aestivum L.). In this study, we identified that the LBD (LATERAL ORGAN BOUNDARIES DOMAIN) gene TaMOR (MORE ROOT in wheat) determines wheat crown root initiation. The mor mutants exhibited less or even no crown root, dwarfism, less grain number and lodging caused by few roots. The observation of cross sections showed that crown root initiation is inhibited in the mor mutants. Molecular assays revealed that TaMOR interacts with the auxin response factor ARF5 to directly induce the expression of the auxin transporter gene PIN2 (PIN‐FORMED 2) in the root base to regulate crown root initiation. In addition, a 159‐bp MITE (miniature inverted‐repeat transposable element) insertion causing DNA methylation and lower expression of TaMOR‐B was identified in TaMOR‐B promoter, which is associated with lower root dry weight and shorter plant height. The results bring new light into regulation mechanisms of crown root initiation and offer a new target for the improvement of root system architecture in wheat. [ABSTRACT FROM AUTHOR]

Concerns about the effects of global warming on crop yields have been raised due to stagnating yield progress in recent years. However, an understanding of the effects of changes in temperature and rainfall throughout the crop cycle on historical yield progress is lacking in Europe (EU). In this study, positive wheat, barley, rice, and maize yield progress in the EU (1961–2019) was significant, with rates of 0.05, 0.04, 0.05, and 0.07 Tha−1year−1, for the four crops respectively. Much of this progress has been sustained by Eastern European countries (EE), which had the highest yield progress rates. On average, in the case of wheat and barley, a temperature increase of 1°C in the winter resulted in yields increasing by +0.33 Tha−1 in EE. This was potentially due to decreasing cold damage and improved photosynthesis and vegetative growth, supporting positive yield progress. Recent historical (2001–2019) rates of wheat, barley, rice, and maize yield progress were positive in all EU regions except Western Europe (WE), barley in Southern Europe (SE) and wheat in Northern Europe (NE). Stagnated wheat, barley and rice yields in WE were not explained by temperature or rainfall using direct correlations of observed data. However, May and July temperatures were associated with wheat yields in NE (−0.30 Tha−1°C−1), barley in SE (−0.14 Tha−1°C−1) and maize in WE and SE (−0.42 and −0.39 Tha−1°C−1). With increasing temperatures becoming less than optimal for photosynthesis, reducing grain filling duration and increasing drought episodes, crop yields have stagnated for wheat in NE and barley in SE. With consistent increases in temperature and water evaporative demand expected in the future, the interplay among genetic adaptation, increased crop cycle duration, drought tolerance, sowing dates, smart irrigation and sustainable practices may require thorough regional testing to maximise the yields of wheat, barley and maize in Europe. [ABSTRACT FROM AUTHOR]

The rice and wheat agricultural system is the primary source of food for billions across the world. However, the productivity and long‐term sustainability of rice and wheat are threatened by a large number of abiotic stresses, especially salinity stress. Salinity has a significant impact on plant development and productivity and is one of the leading causes of crop yield losses in agricultural soils worldwide. Over the last few decades, several attempts have been undertaken to enhance salinity stress tolerance, most of which have relied on traditional or molecular breeding approaches. These approaches have so far been insufficient in addressing the issues of abiotic stress. However, due to the availability of genome sequences for cereal crops like rice and wheat and the development of genome editing techniques like clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‐associated protein9 (Cas9), it is now possible to "edit" genes and influence key traits. Here, we review the application of the CRISPR/Cas9 system in both rice (Oryza sativa L.) and wheat (Triticum aestivum L.) to develop salinity tolerant cultivars. The CRISPR/Cas genome editing toolkit holds great promise of producing cereal crops tolerant to salt stress to increase agriculture resilience with a strong impact on the environment and public health. [ABSTRACT FROM AUTHOR]

Estimates suggest that a swarm of desert locusts can consume food grains sufficient to feed up to 35,000 people. Despite the potential disaster that these migratory pests can bring about, there is no credible economic estimate of the actual damage caused by locust upsurges to agricultural production. This article takes advantage of plausibly exogenous variation generated by the timing of locust upsurges and geographic variation due to their migration patterns to estimate the impact of an upsurge on crop yields using a large district level panel dataset from India covering more than 200 districts over 45 years. I find that locust upsurges have no impact on rice yields but can lead to a decline of up to 0.2 tons of wheat production per hectare. Given that locusts attack India from the western side and majority of the rice is produced in the east and south, such findings are not surprising. There are two ways to interpret the estimated effect size in terms of how hard the locust upsurges can sting the economy. First, in terms of the economic costs, the magnitude of the effects are around 12% compared to mean per‐hectare production of wheat. Second, in terms of accounting costs, back of the envelope calculations suggest losses up to US$3 billion. Policy implications include recognizing locust upsurges as natural disasters and providing demand‐based market instruments such as locust insurance to help farmers hedge against this risk. Related Content: Monopsonists, Disruptive Innovation and Food Security: The Case of High-Value Commodity [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]

On claypan soils of the eastern Great Plains, yield of no‐till crops often lags yield of crops grown with tillage, especially cereals requiring sound N management. The objective of this 14‐yr study was to determine the yield response of corn (Zea mays L.), winter wheat (Triticum aestivum L.), and double‐crop soybean [Glycine max (L.) Merr.] in a 2‐yr rotation to tillage system and N fertilizer placement. Tillage, N placement, or their interaction affected corn yield in all seven‐corn crop‐years. Corn yields averaged about 25% lower with no‐till than with conventional or reduced tillage and were never greater with no‐till in any year. Nitrogen fertilization increased corn yield by increasing kernels per ear; however, corn yield increase to subsurface band (knife) N applications compared with surface (broadcast or dribble) applications was only about 10%. In the lower‐yielding no‐till system, corn yield increase to knifed N fertilization was greater than in tilled systems and may partially ameliorate the no‐till yield decline. Average wheat yield was unaffected by tillage. Adding N more than doubled wheat yield, but differences in wheat yield between preplant N placements methods were small. Average double‐crop soybean yield was unaffected by tillage with few, inconsistent differences by year. Compared with no‐till, tillage tended to increase soil P and K, but soil organic matter was just redistributed with no net increase with no‐till. Thus, tillage and N placement treatments may affect corn but have lesser effects on wheat and double‐crop soybean and soil properties in this rotation. Core Ideas: Tillage and N fertilization may affect corn–wheat–double‐crop soybean yields in rotation.Corn yield averaged ∼25% lower with no‐till than with conventional or reduced tillage.Corn response to knife N applications may partially ameliorate yield decline due to no‐till.Wheat and double‐crop soybean yields were marginally affected by tillage and N placement.Soil organic matter distribution was affected by tillage, but there was no net increase with no‐till. [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]

BACKGROUND: Plastic film mulch is widely used to improve crop yield and water use efficiency (WUE, yield per unit evapotranspiration) in semi‐arid regions. It is commonly applied as partial‐film mulch (PM: at least 50% soil cover) or full‐film mulch (FM: complete soil cover). The PM has lower economic and environmental cost; hence it would be a superior technology provided it delivers similar gains in yield and WUE in relation to FM. RESULTS: To solve contradictory results from individual studies, we compared FM and PM in a meta‐analysis of 100 studies with 1881 comparisons (685 for wheat; 1196 for maize). Compared with bare ground, FM and PM both increased yield of wheat (20–26%) and maize (37–52%), and WUE of wheat (16–20%) and maize (38–48%), with statistically undistinguishable differences between PM and FM. The increases in crop yield and WUE were stronger at elevation > 1000 m, with annual precipitation<400 mm, and on loess soil, especially for maize. CONCLUSIONS: We concluded that partial‐film mulch could replace full‐film mulch to return similar yield and WUE improvement, with reduced cost and environmental pollution. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Semi‐natural habitats (SNHs) are becoming increasingly scarce in modern agricultural landscapes. This may reduce natural ecosystem services such as pest control with its putatively positive effect on crop production. In agreement with other studies, we recently reported wheat yield reductions at field borders which were linked to the type of SNH and the distance to the border. In this experimental landscape‐wide study, we asked whether these yield losses have a biotic origin while analyzing fungal seed and fungal leaf pathogens, herbivory of cereal leaf beetles, and weed cover as hypothesized mediators between SNHs and yield. We established experimental winter wheat plots of a single variety within conventionally managed wheat fields at fixed distances either to a hedgerow or to an in‐field kettle hole. For each plot, we recorded the fungal infection rate on seeds, fungal infection and herbivory rates on leaves, and weed cover. Using several generalized linear mixed‐effects models as well as a structural equation model, we tested the effects of SNHs at a field scale (SNH type and distance to SNH) and at a landscape scale (percentage and diversity of SNHs within a 1000‐m radius). In the dry year of 2016, we detected one putative biotic culprit: Weed cover was negatively associated with yield values at a 1‐m and 5‐m distance from the field border with a SNH. None of the fungal and insect pests, however, significantly affected yield, neither solely nor depending on type of or distance to a SNH. However, the pest groups themselves responded differently to SNH at the field scale and at the landscape scale. Our findings highlight that crop losses at field borders may be caused by biotic culprits; however, their negative impact seems weak and is putatively reduced by conventional farming practices. [ABSTRACT FROM AUTHOR]

Summary: Efficient phosphate (Pi) uptake and utilisation are essential for promoting crop yield. However, the underlying molecular mechanism is still poorly understood in complex crop species such as hexaploid wheat. Here we report that TaPHT1;9‐4B and its transcriptional regulator TaMYB4‐7D function in Pi acquisition, translocation and plant growth in bread wheat.TaPHT1;9‐4B, a high‐affinity Pi transporter highly upregulated in roots by Pi deficiency, was identified using quantitative proteomics. Disruption of TaPHT1;9‐4B function by BSMV‐VIGS or CRISPR editing impaired wheat tolerance to Pi deprivation, whereas transgenic expression of TaPHT1;9‐4B in rice improved Pi uptake and plant growth. Using yeast‐one‐hybrid assay, we isolated TaMYB4‐7D, a R2R3 MYB transcription factor that could activate TaPHT1;9‐4B expression by binding to its promoter. Silencing TaMYB4‐7D decreased TaPHT1;9‐4B expression, Pi uptake and plant growth.Four promoter haplotypes were identified for TaPHT1;9‐4B, with Hap3 showing significant positive associations with TaPHT1;9‐4B transcript level, growth performance and phosphorus (P) content in wheat plants. A functional marker was therefore developed for tagging Hap3.Collectively, our data shed new light on the molecular mechanism controlling Pi acquisition and utilisation in bread wheat. TaPHT1;9‐4B and TaMYB4‐7D may aid further research towards the development of P efficient crop cultivars. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB) is caused by Fusarium graminearum, which contributes serious economic losses to crop yields, and is an epidemic disease of wheat. The resistance to tebuconazole of 1,118 F. graminearum strains obtained from different areas of Henan Province in 2018–2020 was determined by the discriminatory doses of 5.0 μg/ml. A total of 362 F. graminearum strains resistant to tebuconazole were detected, and the frequency of resistance of F. graminearum strains to tebuconazole was 30.7%. The EC50 and EC90 values of F. graminearum strains to tebuconazole were calculated according to the mycelial growth inhibition of the Henan F. graminearum population. The range of EC50 values of 756 sensitive strains and 362 resistant strains were 0.01–0.69 and 0.02–3.31 μg/ml, and the average ± SD EC50 of sensitive and resistant strains were 0.13 ± 0.01 and 0.40 ± 0.13 μg/ml. The range of EC90 values of 756 sensitive strains and 362 resistant strains were 0.31–4.89 and 0.65–18.69 μg/ml, and the average ± SD EC90 values were 1.13 ± 0.05 and 2.98 ± 0.09 μg/ml. The CYP51A and CYP51B genes of the sensitive and resistant strains were amplified separately by polymerase chain reaction (PCR) and analysed. The results showed that among the 150 resistant strains, only six resistant strains had amino acid mutation, which changed from serine to tyrosine (TCA‐TAT, Ser‐Tyr) at position 169 of CYP51B gene, and no amino acid mutation was found in CYP51B of the other 144 resistant strains. No amino acid mutation was found in the CYP51A gene of 150 resistant strains. These results provide important information to growers for monitoring tebuconazole resistance in F. graminearum field populations from wheat in Henan Province. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Production and heavy application of chemical‐based fertilizers to maintain crop yields is unsustainable due to pollution from run‐off, high CO2 emissions, and diminishing yield returns. Access to fertilizers will be limited in the future due to rising energy costs and dwindling rock phosphate resources. A growing number of companies produce and sell arbuscular mycorrhizal fungal (AMF) inoculants, intended to help reduce fertilizer usage by facilitating crop nutrient uptake through arbuscular mycorrhizas. However, their success has been variable. Here, we present information about the efficacy of a commercially available AMF inoculant in increasing AMF root colonization and fungal contribution to plant nutrient uptake, which are critical considerations within the growing AMF inoculant industry. SummaryArable agriculture needs sustainable solutions to reduce reliance on large inputs of nutrient fertilizers while continuing to improve crop yields. By harnessing arbuscular mycorrhizal symbiosis, there is potential to improve crop nutrient assimilation and growth without additional inputs, although the efficacy of commercially available mycorrhizal inocula in agricultural systems remains controversial.Using stable and radioisotope tracing, carbon‐for‐nutrient exchange between arbuscular mycorrhizal fungi and three modern cultivars of wheat was quantified in a non‐sterile, agricultural soil, with or without the addition of a commercial mycorrhizal inoculant.While there was no effect of inoculum addition on above‐ground plant biomass, there was increased root colonization by arbuscular mycorrhizal fungi and changes in community structure. Inoculation increased phosphorus uptake across all wheat cultivars by up to 30%, although this increase was not directly attributable to mycorrhizal fungi. Carbon‐for‐nutrient exchange between symbionts varied substantially between the wheat cultivars.Plant tissue phosphorus increased in inoculated plants potentially because of changes induced by inoculation in microbial community composition and/or nutrient cycling within the rhizosphere. Our data contribute to the growing consensus that mycorrhizal inoculants could play a role in sustainable food production systems of the future. [ABSTRACT FROM AUTHOR]

The evolution in the definition of crop yield—from the ratio of seed harvested to seed sown to the contemporary measure of mass of seed per unit land area―has favoured less competitive phenotypes. Here we use binary mixtures of cultivars spanning five decades of selection for yield and agronomic adaptation to ask three questions. First, what is the degree of symmetry in the response of yield to neighbour; this is, if an older, more competitive cultivar increases yield by 10% with a less competitive neighbour in comparison to pure stands, would the newer, less competitive cultivar reduce yield by 10% when grown with older neighbour. Lack of symmetry would indicate factors other than competitive ability underly yield improvement. Second, what are the yield components underlying competitive interactions. Third, to what extent are the responses to neighbour mediated by radiation, water and nitrogen. A focus on yield components and resources can help the interpretation of shifts in the crop phenotype in response to selection for yield. The rate of genetic gain in yield over five decades was 24 kg ha−1 year−1 or 0.61% year−1. A strongly symmetrical yield response to neighbour indicates that yield improvement closely associates with a reduction in competitive ability. Response to neighbour was larger for grain number and biomass than for grain weight and allocation of biomass to grain. Under our experimental conditions, competition for radiation was dominant compared to competition of water and nitrogen. High‐yielding phenotypes had lower competitive ability for radiation but compensated with higher radiation use efficiency, a measure of canopy photosynthetic efficiency. Genetic and agronomic manipulation of the crop phenotype to reduce competitive ability could further improve wheat yield to meet the challenge of global food security. [ABSTRACT FROM AUTHOR]

Climate change and future warming will significantly affect crop yield. The capacity of crops to dynamically adjust physiological processes (i.e., acclimate) to warming might improve overall performance. Understanding and quantifying the degree of acclimation in field crops could ensure better parameterization of crop and Earth System models and predictions of crop performance. We hypothesized that for field‐grown wheat, when measured at a common temperature (25°C), crops grown under warmer conditions would exhibit acclimation, leading to enhanced crop performance and yield. Acclimation was defined as (a) decreased rates of net photosynthesis at 25°C (A25) coupled with lower maximum carboxylation capacity (Vcmax25), (b) reduced leaf dark respiration at 25°C (both in terms of O2 consumption Rdark_O225 and CO2 efflux Rdark_CO225) and (c) lower Rdark_CO225 to Vcmax25 ratio. Field experiments were conducted over two seasons with 20 wheat genotypes, sown at three different planting dates, to test these hypotheses. Leaf‐level CO2‐based traits (A25, Rdark_CO225 and Vcmax25) did not show the classic acclimation responses that we hypothesized; by contrast, the hypothesized changes in Rdark_O2 were observed. These findings have implications for predictive crop models that assume similar temperature response among these physiological processes and for predictions of crop performance in a future warmer world. In field‐grown wheat, leaf‐level CO2‐based traits (photosynthesis, carboxylation capacity and respiration measured at 25°C) did not exhibit classic acclimation responses to warming generated by varying time of sowing; by contrast, O2‐based respiration did. [ABSTRACT FROM AUTHOR]

Soil health indicators that link to ecosystem services, such as water and nutrient cycling, crop yield, environmental quality, and biodiversity, are needed. We measured 65 soil physical, chemical, and biological properties as potential soil health indicators from a 36‐yr‐old tillage and cropping system experiment and related these properties to crop yield in eastern Montana. Tillage and cropping systems were fall and spring‐till continuous spring wheat (Triticum aestivum L.) (FSTCW), no‐till continuous spring wheat (NTCW), no‐till spring wheat–barley (Hordeum vulgare L., 1984–1999) replaced by spring wheat–pea (Pisum sativum L., 2000–2019) (NTWP), and spring till spring wheat–fallow (STWF, traditional system). Soil aggregation and stability, Al, Cd, Fe, Mn, P, and Pb concentrations, soil organic matter, water‐extractable C and N, CO2 flush, β‐glucosidase, and autoclaved citrate‐extractable protein (ACEP) were lower, but bulk density was greater with STWF than other treatments. Mean crop yield across years was also lower with STWF than other treatments. Multivariate analysis indicated that most promising soil health indicators that related to crop yield were CO2 flush, KMnO4–extractable C, and Ca, Al, and Fe concentrations. Absence of crops during the fallow period reduced soil health indicators and crop yield with STWF compared to NTCW and NTWP. Because of significant response to management practices and relationship to crop yield, soil biological properties may be used in a routine test to measure soil health in addition to physical and chemical properties. Core Ideas: Measurement of comprehensive soil health indicators in long‐term experiments is lacking. Sixty‐five potential soil health indicators and crop yield were measured in a long‐term experiment. Crop‐fallow reduced 6 physical, 8 chemical, and 15 biological soil properties compared to continuous cropping. Most promising soil health indicators that related to crop yield were CO2 flush, KMnO4‐extractable C, Ca, Al, and Fe concentrations. Biological properties, such as labile C fractions, may be used as robust measurement of soil health indicators in addition to chemical properties. [ABSTRACT FROM AUTHOR]

Summary: Kernel number per spike determined by the spike or inflorescence development is one important agricultural trait for wheat yield that is critical for global food security. While a few important genes for wheat spike development were identified, the genetic regulatory mechanism underlying supernumerary spikelets (SSs) is still unclear. Here, we cloned the wheat FRIZZY PANICLE (WFZP) gene from one local wheat cultivar. WFZP is specifically expressed at the sites where the spikelet meristem and floral meristem are initiated, which differs from the expression patterns of its homologs FZP/BD1 in rice and maize, indicative of its functional divergence during species differentiation. Moreover, WFZP directly activates VERNALIZATION1 (VRN1) and wheat HOMEOBOX4 (TaHOX4) to regulate the initiation and development of spikelet. The haplotypes analysis showed that the favourable alleles of WFZP associated with spikelet number per spike (SNS) were preferentially selected during breeding. Our findings provide insights into the molecular and genetic mechanisms underlying wheat spike development and characterize the WFZP as elite resource for wheat molecular breeding with enhanced crop yield. [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]

Most studies only measure soil biochemical parameters in the surface soil at one growth stage to uncover how fertilization affects crop yield and soil respiration. A field study was conducted in a wheat (Triticum aestivum L.)–maize (Zea mays L.) rotation system to determine whether correlations among soil biochemical parameters, crop yield, and soil respiration vary with growth stage and soil depth. Annual crop yield, seasonal soil respiration, soil biochemical parameters at different growth stages (i.e., soil enzyme activity and available N content), and soil chemical parameters at different soil depths (i.e., soil organic carbon [SOC] and total nitrogen [TN] content) were measured. Stronger positive relationships between crop yield, soil respiration, and soil biochemical parameters were found at the first growth stage relative to other stages during both the 2013 wheat and 2014 maize growing seasons. In addition, the most significant relationship among soil chemical properties, crop yield, and soil respiration was found at 20‐to‐40‐cm soil depth during the 2013 wheat growing season but was found at 0‐to‐20‐cm soil depth during the 2014 maize growing season. Overall, correlations among soil biochemical parameters, crop yield, and soil respiration vary with growth stage and soil depth under fertilization. Our study indicates that single time‐point measurements of only surface soil biochemical parameters are not sufficient to understand fertilization impacts on crop yield and soil respiration. Core Ideas: Correlations among soil biochemical parameters, soil respiration, and yield vary among growth stages.Correlations among soil biochemical parameters, soil respiration, and yield vary among soil depths.Single time‐point measurements of the surface soil biochemical parameters are not sufficient. [ABSTRACT FROM AUTHOR]

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Global dimming reduces incident global radiation but increases the fraction of diffuse radiation, and thus affects crop yields; however, the underlying mechanisms of such an effect have not been revealed. We hypothesized that crop source–sink imbalance of either carbon (C) or nitrogen (N) during grain filling is a key factor underlying the effect of global dimming on yields. We presented a practical framework to assess both C and N source–sink relationships, using data of biomass and N accumulation from periodical sampling conducted in field experiments for wheat and rice from 2013 to 2016. We found a fertilization effect of the increased diffuse radiation fraction under global dimming, which alleviated the negative impact of decreased global radiation on source supply and sink growth, but the source supply and sink growth were still decreased by dimming, for both C and N. In wheat, the C source supply decreased more than the C sink demand, and as a result, crops remobilized more pre‐heading C reserves, in response to dimming. However, these responses were converse in rice, which presumably stemmed from the more increment in radiation use efficiency and the more limited sink size in rice than wheat. The global dimming affected source supply and sink growth of C more significantly than that of N. Therefore, yields in both crops were dependent more on the source–sink imbalance of C than that of N during grain filling. Our revealed source–sink relationships, and their differences and similarities between wheat and rice, provide a basis for designing strategies to alleviate the impact of global dimming on crop productivity. [ABSTRACT FROM AUTHOR]

There has been increasing interest in understanding climate change impacts on crop yield stability, including interannual yield variability and lower yield extremes, in addition to mean yield. In this study, we evaluated these impacts on wheat yield and investigated the contribution of changes in climate mean and variability, and their interaction, on the North China Plain (NCP). Wheat yield simulation experiments with control groups were conducted using the Crop Environment Resource Synthesis (CERES) model, with multiple general circulation model ensembles under two representative concentration pathways (RCPs), namely 4.5 and 8.5. Climate change was projected to reduce mean yield by 15 and 17%, increase yield interannual variability by 5 and 11%, and reduce 10‐year return period lower yield extremes by 31 and 34% under RCPs 4.5 and 8.5, respectively. When analysed, changes in climate mean proved the main cause for changes in mean yield (62–71%), followed by the interactive changes in climate mean and variability (26–33%). As for the impact on yield variability, the interaction of the changes in climate mean and variability proved the main cause (48–54%), followed by changes in climate mean (33–41%). Surprisingly, climate change in variability contributed the least in both cases. Our results pertaining to the decrease in both availability and stability of wheat yield on the NCP presents a greater challenge for building a resilient food system for local areas than before. They also highlighted the importance of separating the impacts of changes in climate mean and variability on crop yield stability in a holistic framework, with particular attention paid to the tangible and interactive effects. [ABSTRACT FROM AUTHOR]

In Northern Europe, inter‐row hoeing has become a popular tactic for controlling weeds in organic cereals. Hoeing is highly effective and can be implemented from crop emergence until stem elongation to maintain a nearly weed‐free inter‐row zone. However, hoeing has a lesser effect on weeds growing in the intra‐row zone, where crop–weed proximity results in heightened competition. In the hoed cereal system, it is investigated whether tall‐growing, competitive, cruciferous weeds in the intra‐row zone affect crop biomass, yield and thousand kernel weight (TKW). An additive experimental design is employed to enable the fitting of rectangular hyperbolas, describing and quantifying the effects of increasing intra‐row surrogate weed density on crop growth parameters. Regressions were studied under the influence of crop (spring barley and spring wheat), row spacing (narrow [12.5 or 15.0 cm] and wide [25.0 cm]) and nitrogen rate (50 and 100 kg NH4‐N/ha). Cruciferous surrogate weeds were found to impact crop yield and quality severely. For example, ten intra‐row plants/m2 of surrogate weed Sinapis alba reduced grains yields by 7%–14% in spring barley and by 7%–32% in spring wheat with yield losses becoming markedly greater in wheat compared to barley as weed density increases. Compared to wheat, barley limited yield and quality losses and suppressed intra‐row weed growth more. Row spacing did not have a consistent effect on crop or weed parameters; in one of six experiments, the 25 cm row spacing reduced yields and increased intra‐row weed biomass in wheat. Nitrogen rate did not affect crop or weed parameters. Results warrant the implementation of additional tactics to control intra‐row weeds and limit crop losses. [ABSTRACT FROM AUTHOR]

Zinc (Zn) concentration in wheat grains is generally low, with an average value of around 28–30 mg/kg. Therefore, increasing wheat grain Zn concentration for better human health is the focus of HarvestPlus global initiatives. Source–sink interactions have been intensively studied for decades to enhance crop yield potential, but less on grain nutritional quality. This review applies concepts of source, sink, and their interactions to the study of wheat grain Zn nutrition and biofortification. Increasing Zn sources to wheat (via soil and foliar application) could directly enlarge available Zn in vegetative tissues and grain Zn sink. Rational nitrogen (N) supply increases grain Zn accumulation (N‐Zn synergism), but phosphorus (P) input generally decreases (P‐Zn antagonism), and the potassium (K) effect is unclear. Conventional and genetic breeding have potential to stimulate Zn flow from source to sink (uptake from soil, root‐to‐shoot translocation, and remobilization). However, a rational manipulation to establish a well‐coordinated source–sink relationship is required to finally realize the grain Zn target (40–50 mg/kg) and increase on‐farm crop yield. Future studies should focus more on fertilization modes adopted by farmers (uses of compound, slow/controlled release, and organic and microbial fertilizers) and develop integrated agronomic and genetic strategies for Zn biofortification. A highly systematic and mechanistic model includes (a) migration paths of Zn (particularly from leaves to different grain parts) using isotopic labeling methods, (b) cross‐talks between Zn and carbon, N, P, K, or other divalent cations, (c) inherent physiological and biochemical processes of enzymes and signaling phytohormones, and (d) complex genetic systems governing Zn homeostasis and their relationships with other nutrients, signaling molecules, and increase or dilution/penalty of yield under different environmental conditions (soil, water, and future climatic changes) and managements (breeding and fertilization). These aspects require further elucidation to fully unravel the "black box" of Zn flow from source to sink. [ABSTRACT FROM AUTHOR]

Pressures of population growth and climate change require the development of resilient higher yielding crops, particularly to drought. A spring wheat diversity panel was developed to combine high‐yield potential with resilience. To assess performance under drought, which in many environments is intermittent and dependent on plant development, 150 lines were grown with drought imposed for 10 days either at jointing or at anthesis stages in Obregon, Mexico. Both drought treatments strongly reduced grain numbers compared with the fully irrigated check. Best performers under drought at jointing had more grain than poor performers, while best performers under drought at anthesis had larger grain than poor performers. Most high‐yielding lines were high yielding in one drought environment only. However, some of the best‐performing lines displayed yield potential and resilience across two environments (28 lines), particularly for yield under well‐watered and drought at jointing, where yield was most related to grain numbers. Strikingly, only three lines were high yielding across all three environments, and interestingly, these lines had high grain numbers. Among parameters measured in leaves and grain, leaf relative water content did not correlate with yield, and proline was negatively correlated with yield; there were small but significant relationships between leaf sugars and yield. This study provides a valuable resource for further crosses and for elucidating genes and mechanisms that may contribute to grain number and grain filling conservation to combine yield potential and drought resilience. [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]

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]

Future crop yield increases are unlikely to keep pace with the dietary needs of a global human population expected to reach nine billion by 2050. This study used United States Department of Agriculture county‐level yield data and autoregressive moving‐average models to examine how changes in maize (Zea mays L.), soybean (Glycine max L.), and winter wheat (Triticum aestivum L.) yields, temporal variability in yields, and yield gaps have varied across space and time from 1970–2017. The majority of county‐level yields have increased linearly, although the increases in wheat lag behind corn and soybean. Where trends were nonlinear, accelerating yields were found in more mesic regions east of the Great Plains, and decelerating yields were found in the drier central and western United States. Mean crop yields were positively correlated with rate of yield increase and negatively correlated with interannual variability. Hotspots were identified in Minnesota, Iowa, Illinois, Nebraska, and some West Coast states where crop yields are currently the largest, have the lowest yield gaps, and since 1970, have had the highest rates of change and/or are experiencing an acceleration of annual yield gains. Across all crop types, the counties with the lowest average yields, highest yield gaps, lowest rates of yield increase over time, and/or deceleration in yield increases were predominantly found in the central United States, including the Dakotas, Kansas, Oklahoma, and Texas. Regions of greatest performance generally have fertile soils, plentiful growing season rainfall, and optimal growing season length and temperatures, or are benefitting from irrigation. [ABSTRACT FROM AUTHOR]

In boundary line analysis a biological response (e.g., crop yield) is assumed to be a function of a variable (e.g., soil nutrient concentration), which limits the response in only some subset of observations because other limiting factors also apply. The response function is therefore expressed by an upper boundary of the plot of the response against the variable. This model has been used in various branches of soil science. In this paper we apply it to the analysis of some large datasets, originating from commercial farms in England and Wales, on the recorded yield of wheat and measured concentrations of soil nutrients in within‐field soil management zones. We considered boundary line models for the effects of potassium (K), phosphorus (P) and magnesium (Mg) on yield, comparing the model with a simple bivariate normal distribution or a bivariate normal censored at a constant maximum yield. We were able to show, using likelihood‐based methods, that the boundary line model was preferable in most cases. The boundary line model suggested that the standard RB209 soil nutrient index values (Agriculture and Horticulture Development Board, nutrient management guide (RB209), 2017) are robust and apply at the within‐field scale. However, there was evidence that wheat yield could respond to additional Mg at concentrations above index 0, contrary to RB209 guidelines. Furthermore, there was evidence that the boundary line model for yield and P differs between soils at different pH and depth intervals, suggesting that shallow soils with larger pH require a larger target P index than others. Highlights: Boundary line analysis is one way to examine how soil variables influence crop yield in large datasets.We showed that boundary line models could be applied to large datasets on soil nutrients and crop yield.The resulting models are consistent with current practice for P and K, but not for Mg.Models suggest that more refined recommendations for P requirement could be based on soil pH and depth. [ABSTRACT FROM AUTHOR]

Northern, Southern and Equatorial Africa have been identified as among the regions most at risk from very high ozone concentrations. Whereas we know that many crop cultivars from Europe, north America and Asia are sensitive to ozone, almost nothing is known about the sensitivity of staple food crops in Africa to the pollutant. In this study cultivars of the African staple food crops, Triticum aestivum (wheat), Eleusine coracana (finger millet), Pennisetum glaucum (pearl millet) and Phaseolus vulgaris (bean) were exposed to an episodic ozone regime in solardomes in order to assess whether African crops are sensitive to ozone pollution. Extensive visible leaf injury due to ozone was shown for many cultivars, indicating high sensitivity to ozone. Reductions in total yield and 1,000‐grain weight were found for T. aestivum and P. vulgaris, whereas there was no effect on yield for E. coracana and P. glaucum. There were differences in sensitivity to ozone for different cultivars of an individual crop, indicating that there could be possibilities for either cultivar selection or selective crop breeding to reduce sensitivity of these crops to ozone. [ABSTRACT FROM AUTHOR]

Global dimming, a decadal decrease in incident global radiation, is often accompanied with an increase in the diffuse radiation fraction, and, therefore, the impact of global dimming on crop production is hard to predict. A popular approach to quantify this impact is the statistical analysis of historical climate and crop data, or use of dynamic crop simulation modelling approach. Here, we show that statistical analysis of historical data did not provide plausible values for the effect of diffuse radiation versus direct radiation on rice or wheat yield. In contrast, our field experimental study of 3 years demonstrated a fertilization effect of increased diffuse radiation fraction, which partly offset yield losses caused by decreased global radiation, in both crops. The fertilization effect was not attributed to any improved canopy light interception but mainly to the increased radiation use efficiency (RUE). The increased RUE was explained not only by the saturating shape of photosynthetic light response curves but also by plant acclimation to dimming that gradually increased leaf nitrogen concentration. Crop harvest index slightly decreased under dimming, thereby discounting the fertilization effect on crop yields. These results challenge existing modelling paradigms, which assume that the fertilization effect on crop yields is mainly attributed to an improved light interception. Further studies on the physiological mechanism of plant acclimation are required to better quantify the global dimming impact on agroecosystem productivity under future climate change. [ABSTRACT FROM AUTHOR]

Cover crops have the potential to increase ecosystem services of cropping systems, although mixed results have been found throughout the U.S. Great Plains. Crop performance and economic returns are often used by producers to gauge the feasibility of adoption. In addition, soil moisture use by cover crops is a concern in semiarid environments. The objective of this research was to determine the impact of cover crops on cotton (Gossypium hirsutum L.) yield and economic return compared with conventional practices in pivot irrigated systems of the southern Great Plains. A 6‐yr study was conducted at the Texas A&M AgriLife Chillicothe Research Station evaluating the following treatments: (i) conventional till (CT); (ii) no‐till (NT); (iii) NT with winter wheat (Triticum aestivum L.) cover crop (NT‐W); and (iv) NT with a multi‐species cover crop mixture (NT‐M). Cotton yields, expenses, and returns were determined over a 6‐yr period (2013–2018). No significant treatment effect was determined for crop yield. Compared to NT, lint yields were increased 9.5% by NT‐M and 9.4% by NT‐W. Cover crop treatments significantly increased total costs compared to NT. However, net returns were 12% greater for NT‐W and 8% greater for NT‐M compared to NT. Over the 6‐yr study, NT‐M did not provide an agronomic or economic advantage over NT‐W. Under irrigated conditions in the southern Great Plains, cover crops were implemented without negatively affecting lint yield or net returns in continuous cotton systems at seeding rates of 34 kg ha–1. [ABSTRACT FROM AUTHOR]

Summary: Seed vigour and early establishment are important factors determining the yield of crops. A wheat nitrate‐inducible NAC transcription factor, TaNAC2, plays a critical role in promoting crop growth and nitrogen use efficiency (NUE), and now its role in seed vigour is revealed. A TaNAC2 regulated gene was identified that is a NRT2‐type nitrate transporter TaNRT2.5 with a key role in seed vigour.Overexpressing TaNAC2‐5A increases grain nitrate concentration and seed vigour by directly binding to the promoter of TaNRT2.5‐3B and positively regulating its expression. TaNRT2.5 is expressed in developing grain, particularly the embryo and husk.In Xenopus oocyte assays TaNRT2.5 requires a partner protein TaNAR2.1 to give nitrate transport activity, and the transporter locates to the tonoplast in a tobacco leaf transient expression system. Furthermore, in the root TaNRT2.5 and TaNRT2.1 function in post‐anthesis acquisition of soil nitrate. Overexpression of TaNRT2.5‐3B increases seed vigour, grain nitrate concentration and yield, whereas RNA interference of TaNRT2.5 has the opposite effects.The TaNAC2‐NRT2.5 module has a key role in regulating grain nitrate accumulation and seed vigour. Both genes can potentially be used to improve grain yield and NUE in wheat. [ABSTRACT FROM AUTHOR]

Summary: Raising crop yield potential is a major goal to ensure food security for the growing global population. Photosynthesis is the primary determinant of crop productivity and any gain in photosynthetic CO2 assimilation per unit of leaf area (A) has the potential to increase yield. Significant intraspecific variation in A is known to exist in various autotrophic organs that represent an unexploited target for crop improvement. However, the large number of factors that influence photosynthetic rates often makes it difficult to measure or estimate A under dynamic field conditions (i.e. fluctuating light intensities or temperatures). This complexity often results in photosynthetic capacity, rather than realized photosynthetic rates being used to assess natural variation in photosynthesis. Here we review the work on natural variation in A, the different factors determining A and their interaction in yield formation. A series of drawbacks and perspectives are presented for the most common analyses generally used to estimate A. The different yield components and their determination based on different photosynthetic organs are discussed with a major focus on potential exploitation of various traits for crop improvement. To conclude, an example of different possibilities to increase yield in wheat through enhancing A is illustrated. Significance Statement: The MS focuses on natural genetic variation in photosynthesis and other physiological processes as possible targets for exploitation for yield improvements. [ABSTRACT FROM AUTHOR]

The assessment of drought characteristics often depends on drought indices, geographic location, hydro‐climatic condition, and timescale. In this study, we examined the spatiotemporal characteristics of drought events using the Standardized Precipitation Evapotranspiration Index (SPEI) and the Multivariate Standardized Drought Index (MSDI). We developed a novel framework using hydro‐climatic variables from a high‐resolution process‐based hydrologic model to understand factors that alter drought indices at various timescales, and their impact on crop yields in a large agricultural region of western Canada. These indices were used to quantify droughts for each month of the year by examining 1–12‐month drought timescales in 2255 sub‐basins, simulated in 17 main river basins across Alberta, for 1981–2017. Temporal variations of the Standardized Yield Residuals Series (SYRS) of three major cereal crops (spring wheat, barley, and canola) were analysed for 1981–2017. Drought characteristics resulting from two indices varied due to differences in the input variables and timescales. The MSDI‐based results showed more frequent droughts during the fall and winter for shorter timescales, while the SPEI‐based results showed more during spring and summer. Comparing drought frequencies at the decadal scale, we found more droughts during 1996–2005 than during 1986–1995 and 2006–2015. The spatial evolution of drought events based on the MSDI showed more sub‐basins with increasing dryness during the study period than did results from the SPEI. The relationship between detrended drought indices and the SYRS varied depending on timescale, geographic location, and growth stage of crops. Overall, both indices performed similarly for agricultural impact assessment; however, the MSDI performed better early in the growing season for wheat and barley, indicating high crop production sensitivity to soil moisture deficiency. [ABSTRACT FROM AUTHOR]

Roots strongly influence the growth and yield of field crops. We characterized root morphological traits of 10 winter wheat varieties in order to determine the extent they were influenced by the environments and impacted grain yield under two irrigation regimes at Bushland (a cooler, drier site with clay loam soil) and Uvalde (a warmer, wetter site with clay soil) in Texas, USA, from 2015 to 2017. Major root traits, including root diameter, specific root length (SRL), root surface area (SSA), tissue mass density (TMD), root length density (RLD), and root weight density, were measured and related to one another and to grain yield. RLD of wheat decreased but SRL and SSA increased with soil depth. Irrigation was second to environment in affecting root traits. Compared with Uvalde, the environment of Bushland promoted deeper root growth, higher TMD, but reduced SRL and SSA. Water deficit inhibited RLD and root: shoot ratio at Bushland, but moderately promoted them at Uvalde. Both SRL and RLD were positively associated with grain yield, with the former relation stronger under drought. The dichotomy of "conservative" versus "acquisitive" root strategy partially explained the variations of root traits of winter wheat in contrasting environments. [ABSTRACT FROM AUTHOR]

Variety mixtures, the cultivation of different genotypes within a field, have been proposed as a way to increase within‐crop diversity, allowing the development of more sustainable agricultural systems with reduced environmental costs. Although mixtures have often been shown to over‐yield the average of component varieties in pure stands, decreased yields in mixtures have also been documented. Kin selection may explain such pattern, whenever plants direct helping behaviors preferentially toward relatives and thus experience stronger competition when grown with less related neighbors, lowering seed production of mixtures. Using varieties of durum wheat originating from traditional Moroccan agrosystems, we designed a greenhouse experiment to address whether plants reduced competition for light by limiting stem elongation when growing with kin and whether such phenotypic response resulted in higher yield of kin groups. Seeds were sown in groups of siblings and nonkin, each group containing a focal plant surrounded by four neighbors. At the group level, mean plant height and yield did not depend upon relatedness among competing plants. At the individual level, plant height was not affected by genetic relatedness to neighbors, after accounting for direct genetic effects that might induce among‐genotype differences in the ability to capture resources that do not depend on relatedness. Moreover, in contrast to our predictions, shorter plants had lower inclusive fitness. Phenotypic plasticity in height was very limited in response to neighbor genotypes. This suggests that human selection in crops may have attenuated shade‐avoidance responses to competition for light. Future research on preferential helping to relatives in crops might thus target social traits that drive competition for other resources than light. Overall, our study illustrates the relevance of tackling agricultural issues from an evolutionary standpoint and calls for extending such approaches to a larger set of crop species. [ABSTRACT FROM AUTHOR]

Perennial crops are increasingly converted to annual cropping systems as Conservation Reserve Program (CRP) contracts expire. We compared crop yields and net returns across 2013-2018 for no-till pulse crop-wheat (Triticum aestivum L.) (P-W) systems, preceded either by 10 yr of P-W or 10 yr of perennial cropping (P-WPer) at Bozeman, MT. The perennial mixed species planting, dominated by alfalfa (Medicago sativa L.), was split into unharvested and annually harvested treatments 2005-2012. The 2013-2018 experimental design included both systems replicated as main plots, with 50 and 100% recommended available N rates as subplots. Precipitation was below average during three of the first four growing seasons, followed by two wetter than average years. The P-WPer system had generally lower soil moisture and equal or greater nitrogen supply than the P-W. 'Haying off' (reduced harvest index) occurred in wheat grown 2 and 4 yr after conversion from perennial to annual cropping, which reduced grain yield, and increased grain protein. Crop yield losses in the P-WPer system averaged 0.84 Mg ha-1 (28%) over 4 yr and two N rates. After adjusting grain prices using historical discounts and premiums for test weight and protein content at Montana grain elevators, P-WPer net returns were reduced for four consecutive years in three economic scenarios, and for 2 yr in a fourth scenario by a 4-yr cumulative average of (USD) $731 ha-1 (45%). We conclude annual crop yield and economic returns were compromised for 4 yr following 10 yr of an alfalfa-dominated perennial cropping system. [ABSTRACT FROM AUTHOR]

Sensor-based approaches to delivering nitrogen (N) fertilizer recommendations often rely on field experimentation to build calibrations between sensor readings and particular crop variables of interest. One important question is the extent to which calibrations derived from specific locations in specific seasons can be confidently extrapolated to other locations in future seasons. In this study, we examined a dataset covering 19 yr of wheat (Triticum aestivum L.) yield potential and crop N response calibrations to help answer two questions. First, what drives the variability in sensor calibration between different years? Second, what are the consequences of seasonal variability for the accuracy of sensor predictions and N recommendations? Deep soil moisture information, measured between 50 and 90 d after sowing, helped to explain the variability in the R² and equation coefficients of yield potential and response index sensor calibrations between years. When data from multiple experimental years were combined to build generalized models, the R2 was quite low (-0.25 for all 19 yr of data). Consequently, the benefit of the N rates recommended by the sensor over a conventional application based on historical optimum N rates was insignificant. We suggest that, rather than increasing experimental years indiscriminately, the relevant seasonal covariates should be incorporated into the sensor predictions in order build holistic sensor models. The results also highlight the likelihood that relevant site-specific information, such as soil moisture status, may also explain between-site variation in sensor calibration and so promote an enhanced ability to extrapolate calibrations from one location to another. [ABSTRACT FROM AUTHOR]

Wheat with a low falling number (FN) has been particularly prevalent in recent years and has resulted in a loss of more than $140 million in a single year in the wheat industry in the Pacific Northwest of the United States. FN measurement is a standard method for the evaluation of grain α‐amylase activity, and a low FN indicates a reduction in hot wholemeal paste viscosity due to sprouting damage. Recent studies show that a low FN may result from a developmental change of starch and adverse effects of non‐α‐amylase macromolecules on wheat. In this review, we describe the principles of FN measurement and the relationship between FN and α‐amylase. We also discuss the isozymes, locations, and inhibitors of wheat α‐amylase. The effects of various aspects of starch, which is the substrate of α‐amylase, on wheat FN are also discussed, including starch structural characteristics (for example, starch granule architecture), starch susceptibility to α‐amylase, and the interaction between starch and nonstarch macromolecules (for example, lipids). Studies on the effects of planting environments (for example, temperature) and agronomic practices (for example, irrigation and fertilization) on both starch paste viscosity and FN are also reviewed. This paper highlights the importance of considering the impacts of starch and the interactions of starch and other macromolecules, including wheat α‐amylase, on wheat FN, which is important for developing strategies to solve the low FN problem. [ABSTRACT FROM AUTHOR]