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Grain or seed number is the dominant component determining yield in major grain crops. Major grain crops differ in the timing of the critical period for grain or seed number determination. Differences between grain crops are related to the flowering phase duration and the proportion of the whole cycle allocated to pre-flowering development. Considering the critical period relative to the onset of grain or seed filling reconciles differences among major field crops. Our findings strengthen the evolutionary basis of the universal plasticity of the number of grains or seeds. Studies across different crops demonstrated that grain or seed number per unit area (GN m–2) is the dominant yield component. Although grains or seeds derive from floret or flower production and survival, the timing of the critical period for GN m–2 determination is known to vary noticeably, from mainly pre-flowering to strongly post-flowering, across major grain crops. Here, we demonstrate that discrepancy between crops in the timing of their critical period is related to the flowering phase duration and the proportion of the whole cycle allocated to pre-flowering development. Changing the perspective, positioning the critical period at the end of the phase when grain abortion occurs instead of flowering, results in the critical period virtually coinciding among contrasting grain crops. [ABSTRACT FROM AUTHOR]

Controlled loss urea (CLU) as a new type of nitrogen fertilizer has attracted much attention due to its significant advantages in saving labor costs, increasing crop yield, improving nitrogen use efficiency (NUE), and protecting ecological environment of farmland. However, there have still been few reports on mechanism of successive controlled loss urea application affecting crop yield, NUE and economic benefits. A six-year field located experiment at the same nitrogen (N) level with 240 kg ha−1 per season from 2015 to 2021 was conducted to systematically study the effect of CLU application on grain yield, soil nutrients, accumulation of soil NO 3 - and economic benefits in wheat and maize rotation farmland in Northern China. The six N treatments have been carried out in the trial including controlled loss urea as once-time basal fertilizer during cultivation, common urea (U) as once-time basal fertilizer during cultivation, 60 % controlled loss urea as basal fertilizer plus 40 % common urea as topdressing fertilizer at jointing stage (CLTU), 60 % common urea as basal fertilizer plus 40 % controlled loss urea as topdressing fertilizer at jointing stage (UTCL), 60 % common urea as basal fertilizer plus 40 % common urea as topdressing fertilizer at jointing stage (i.e. traditional fertilization, UTU), and no N applied as a control (CK). The results showed that, compared with CK, N application across 6 consecutive years markedly increased grain yield of wheat, maize and annual; compared with UTU, the CLU treatment increased grain yield of wheat, maize and annual by 4.7 %-13.7 %, 4.7 %-13.7 % and 2.3 %-11.4 %, respectively. Furthermore, compared with CK, during 8 consecutive years of fertilizer positioning test, each N application treatment increased the content of total N (TN), soil organic matter (SOM) and inorganic nitrogen in 0–20 cm topsoil by 2.44 %-48.14 %, 0.43 %-42.27 % and 0.82 %-79.80 %, respectively, especially in the CLU, UTU and CLTU treatment, UTU treatment performs better than other treatment in 2021–2021 and 2022–2023. In addition, the study also found that soil NO 3 - was mainly accumulated in the 0–120 cm soil layer, and peak value appeared at the 80–100 cm, and the CLU treatment was significantly lower than other treatment. Meanwhile, after 6 years of wheat and maize rotation planting, N agronomic efficiency, N partial factor productivity and economic benefit in the CLU treatment were significantly higher than those of the other N treatment, and the ratio of benefit and cost (B/C) reached 2.50. Therefore, in the current context of traditional N application level and labor shortages in the research area, the CLU application as once-time basal fertilization can not only increase grain yield of wheat and maize, economic benefit and NUE that reduces the carbon footprint in agricultural production, but also improve the soil environment, reduce NO 3 - accumulation in deep soil layer and prevent NO 3 - pollution in groundwater. • Control loss urea (CLU) significantly enhanced Nitrogen use efficiency. • Long-term appropriate CLU application could increase yield and economic benefits. • CLU mainly affected number of wheat spike and maize kernel to improve yield. • CLU reduced carbon footprint and soil NO 3 - leaching to deeper soil layer. [ABSTRACT FROM AUTHOR]

GA 2-oxidases (GA2oxs) are a class of enzymes that inhibit the biosynthesis of bioactive GAs in plants. Although GA2oxs have clear roles in the development and defence responses in Arabidopsis, rice, and wheat, their potential effects on maize remain unclear. This study identified thirteen ZmGA2ox genes in maize and further characterized them using phylogenetic, gene structure, genomic locus, expression pattern analyses and GA content determination. Phylogenetic relationship analysis clearly divided the ZmGA2ox family into three groups—seven in C19-GA2ox class I, three in C19-GA2ox class II, and three in C20-GA2ox class. Evolutionary analysis suggested that ZmGA2ox1;1 and ZmGA2ox1;2 , ZmGA2ox3;1 and ZmGA2ox3;2 , and ZmGA2ox7;1 and ZmGA2ox7;2 are three pairs of segmental duplicated genes. Prediction of cis-regulatory elements in promoters suggested that ZmGA2ox genes were mainly associated with growth, development, hormones, and biotic/abiotic stress. Therefore, their spatial and temporal expression patterns and responses to various stress treatments were analysed on the basis of published RNA-seq data. Moreover, the changes of ZmGA2ox expression in leaves and roots of maize seedlings was detected under salt, alkali, dehydration, and cold stresses by qRT-PCR. The ZmGA2oxs exhibited obvious expression tendencies or characteristics in various organs under different abiotic stresses. The variations in the expression of three ZmGA2ox genes in the C20-GA2ox class in maize seedling roots showed significant regularity and a clear negative correlation with bioactive GA contents under cold and drought conditions, indicating that these three genes might exert key effects on the regulation of GA synthesis and the response to drought and cold stress. Taken together, this study is useful for further dissection of the effect of ZmGA2oxs on abiotic stress responses and might provide potential targets for the genetic improvement of maize. • A set of 13 ZmGA2ox genes were identified in maize via genome-wide screening. • Spatio-temporal specificity of ZmGA2ox gene expression was accurately demonstrated. • C20-GA2ox expressions in roots showed opposite changes under the cold and PEG stress. [ABSTRACT FROM AUTHOR]

The use of anaerobic digestates as fertilizer is proposed as a means to close agricultural nutrient cycles. However, digestates have higher inorganic nitrogen contents than raw manures, which could translate into increased emissions of potent greenhouse gases such as nitrous oxide (N 2 O) and methane (CH 4). To mitigate these emissions, the addition of biochar with high nutrient absorption capacity is suggested. To quantify the effects of anaerobic digestion and biochar amendment on N 2 O and CH 4 emissions, we conducted a study over 33 months with four different crops (silage maize, winter wheat, winter barley, and forage grass). We measured soil parameters such as mineral nitrogen, moisture, and temperature. The N 2 O emissions after application of digestates were generally similar to those observed after cattle slurry or mineral fertilizer application. The highest N 2 O emissions were observed in the first year of the experiment during maize cultivation and were strongly influenced by high soil nitrate concentrations, which were likely linked to enhanced soil organic N mineralization after ley termination. The CH 4 emissions were mostly negative. The addition of biochar to co-digested manure before application at an annual rate of 2 t ha− 1 had no effect on N 2 O emissions but led to short-lived CH 4 peaks from organic fertilizers directly after spreading. We conclude that digestates do not promote larger N 2 O emissions than mineral fertilizers or cattle slurry, and that biochar addition to digestates in small application quantities does not reduce N 2 O emissions but bears the risk of CH 4 release. • N 2 O emissions were strongly affected by crop and position in the rotation. • Highest N 2 O emissions in maize after grass-clover ley. • No consistent effect of mineral vs. liquid organic fertilizers on N 2 O emissions. • Biochar amendment to digested manure did not alter field N 2 O emissions. • Short-lived CH 4 peaks after biochar amendment to digested manure at field application. [ABSTRACT FROM AUTHOR]

The methodology for measuring the frictional force of granular materials of plant origin is complex, since it requires taking into account both variable material factors and the use of available measurement methods in an appropriate way. This article deals with one of the important aspects of the application of a measurement methodology using bottomless containers. The effect of grain pressure on the side walls of the measuring container on the value of grain pressure on the measuring surface was studied. Five different granular materials (wheat, oat, beans, maize, peas) were used as the research material. To analyse the problem, the Janssen model was used as a basis, which describes the normal pressure of the granular material at the bottom of the container depending on certain factors. The tests were carried out for different heights of the material layer and different load values. After analysing the measurement values with calculated values, modifications of the base model were proposed. This modification allowed a high (close to 1) model fit to the measured values. The proposed approach can be useful in carrying out measurements of the friction force of granular materials, since it allows one to estimate the value of the actual pressure of the material on the contact surface. This provides an opportunity to make better use of the horizontal tribometer with a measuring container with support. [Display omitted] • Methodological problems of friction measurement of granular materials are discussed. • The effect of lateral grain pressure on vertical pressure on the surface is shown. • The possibility of using the Janssen model for small containers was studied. [ABSTRACT FROM AUTHOR]

CONTEXT: Climate change increasingly threatens food security, particularly through prolonged phases of drought. It is therefore important to evaluate and develop arable cropping systems with an enhanced capability to withstand severe drought events to ensure food production. However, it is still poorly understood whether specific management strategies, in particular organic farming and conservation tillage that are thought to be more resilient to drought, can enhance the ability of agroecosystem to withstand drought. OBJECTIVE: The main objective of this study was, therefore, to test the ability of organic farming and conservation tillage practices to withstand drought within expected boundaries of climate scenarios for the end of the century. METHODS: This study summarizes the effects of drought (both natural and experimental) on the productivity of three arable crops (maize, pea-barley mixture and winter wheat) assessed in three consecutive years in a long-term cropping system field experiment. We tested whether four relevant cropping systems (i.e., conventional and organic with and without soil conservation tillage) differ in their ability to reduce the impact of drought on plant yield and crop performance. We studied conditions of moderate natural drought (summer 2018) and severe experimental droughts using rainout shelters (3 years) after 8 years of contrasting field management. RESULTS AND CONCLUSIONS: We found pronounced and consistent yield reductions due to experimental drought events for all cropping systems (34% for maize, 23% for pea-barley, and 17% for winter wheat). Drought induced yield reductions were largely similar across the four cropping systems, suggesting very limited capacity of any cropping system to buffer severe drought. Yet, there was an obvious but insignificant trend in maize in 2018 where under moderate and experimental drought conservation tillage resulted in a higher on-average yield compared to the plowed systems. Furthermore, drought resulted in lower nitrogen (N) uptake by the crops and a positive N budget, which could result in higher N losses after a drought period. SIGNIFICANCE: This study demonstrates that drought has consistent and adverse effects on crop productivity under conventional, organic and soil conservation arable cropping. It further demonstrates that it is difficult to find effective adaptation strategies for arable systems under realistic future scenarios and underlines the need to combine all available practices, from soil management to crop and cultivar choice, to mitigate drought impacts on crop productivity. [Display omitted] • Drought was successfully simulated in three years and for three arable crops. • Organic management and conservation tillage alone cannot buffer severe drought. • Drought reduced yields of three crops grown in four common cropping systems. • Drought limits the yield potential of high input cropping systems. • Drought might result in low resource use efficiency and economic performance. [ABSTRACT FROM AUTHOR]

Stalk lodging is the structural failure of crops due to external loading such as wind. Short-stature (i.e., dwarf) varieties of wheat and rice have shown promise in reducing lodging rates. However, similar dwarfing in large gains like maize and sorghum has typically been accompanied by undesirable commercial characteristics, including significantly decreased grain yields. The purpose of this paper is to quantify the relationship between lodging resistance and plant height in maize to better understand the potential impact of short-stature varieties of maize on lodging resistance. Results from both the engineering analysis and the experimental field study indicate a nearly 1:1 relationship between plant height and plant lodging resistance. These data support the validity of the engineering analysis and suggest that there exists a nearly linear relationship between crop lodging incidence and plant height. Plant height has a direct and quantifiable impact on crop lodging resistance as it influences the bending stresses experienced in the plant stem. This study presents the engineering analysis, supported by field experiments, that explains the cause of this nearly linear 1:1 relationship. • Crop lodging has been a persistent problem for more than 100 years. • Plant height has a direct, measurable impact on crop lodging resistance. • Genetic, environment and GxE interactions have direct measurable impacts on lodging. • lodging resistance index = strength ∙ height − 1.14 . • Newly developed short stature maize varieties can mitigate the problem of crop lodging. [ABSTRACT FROM AUTHOR]

Annual crops dominate Argentinean landscapes with a majority of fields dedicated to soybean production. Consecutive years with full-season soybean crops are frequent and this practice is associated with organic carbon losses affecting soil chemical and physical properties. It is proposed that more intensive and diverse cropping sequences coupled with targeted fertilization may allow keeping near-neutral nutrient and carbon balances while improving successive crops performance. We conducted four on–farm experiments along six seasons in the Argentine Pampas where three crop rotations and two fertilization strategies (high and regular rates of N, P, and S) were evaluated. Crop rotations involved were i) soybean monoculture, ii) a typical wheat-soybean/maize/soybean rotation, and iii) a more intensified rotation consisting of wheat-soybean/field pea-maize/soybean. After five years, soil organic carbon was consistently lower under soybean monoculture compared to that under more intensive and diverse rotations. During the sixth and last season, identically managed soybean crops were grown in all treatments to determine the influence of previous management history on soil, plant nutrients, and on crop performance. Results indicate that crop rotation largely influenced soybean seed yield (range from 120 to 690 kg ha−1 yield increase) mainly through changes in water use affecting solar radiation interception and, by a lesser extent, the conversion efficiency of radiation into biomass and partition to seeds. Comparatively, increased fertilization rates in preceding seasons resulted in a lower seed yield response (range from nil to 180 kg ha−1), which indicates that fertilization strategies alone are ineffective to restore productivity levels after years of soybean monoculture. However, in most cases, the high fertilization strategy in previous seasons resulted in greater soybean protein concentration in seeds and in overall protein yield. • Crop rotation modified physical and chemical soil variables after five years. • These changes affected soybean seed yield and its eco-physiological components. • Diverse and intensified crop rotations increased soybean yield up-to 700 kg ha−1. • High fertilization rate in previous years raised soybean protein % in seeds. [ABSTRACT FROM AUTHOR]

• Limited studies are available on the combined use of conservation tillage and AGT in terms of resource conservation. • Conservation tillage + Arundo donax AGT reduced runoff by 24% and soil loss by 8.22 t ha−1 vs. only conservation tillage. • Conservation tillage + AGT were more profitable than only conservation tillage on sloping crop lands. • Three rainfed crops could be raised in a year with conservation tillage + AGT by using green water technology. Despite investigations suggesting that agro-geo-textiles (AGT) could be an effective and inexpensive soil conservation method, limited quantitative data are available on erosion-reducing effects of AGT under field conditions and effects on crop productivity. Field experiments (probably first of its kind) were conducted on two crop rotations during 2015-16 and 2016-17 at Dehradun on a 4% land slope in the Indian Himalayan Region (IHR). Seven treatments were executed to evaluate the conservation effects of AGT prepared from giant-cane (Arundo donax) and maize (Zea mays L.) straw; and comparisons were made with coir-geo-textile, cowpea (Vigna unguiculata), and grass weed vegetative filters (all placed at 1 m vertical intervals, within 100 m length plots in the rainy season maize crop) on crop productivity, profitability, runoff and soil loss reduction, and moisture conservation. During two years of experimentation, a total of 35 runoff events were observed in maize crops in rainy months (June to September). Results revealed that the highest (p < 0.05) maize grain yield (2.8 Mg ha−1) was recorded in Arundo donax AGT treatment (conservation agriculture plus), which was 36% higher than maize crops raised without AGT (conservation agriculture only). This treatment also reduced runoff (24%) and conserved soil losses (8.22 t ha-1 year -1) across 18 runoff events, resulting in more soil moisture conserved in the soil profile than without AGT (35 runoff events). Productivities of succeeding pea (Pisum sativum var. hortense) and wheat (Triticum aestivum L. emend Fiori & Paol.) crops were enhanced by 122 and 36%, respectively, which resulted the higher net return (736 US$ ha−1) than in a maize-pea-wheat system in conservation agriculture only (128 US$ ha−1). In summary, conservation tillage practices along with AGT (conservation agriculture plus) are more profitable than conservation tillage practices alone on 4% land slopes of IHR. [ABSTRACT FROM AUTHOR]

Abstract Untreated industrial sewage and domestic wastewater irrigation has led to agricultural soil-crop system contamination by heavy metals and fluoride in Dongdagou and Xidagou stream basins, Baiyin city, China. A total of 36 pairs of soil and wheat samples (roots, stalks, leaves, husks, and grains) and 42 pairs of soil and maize samples (roots, stalk1, stalk2, stalk3, leaves, husks, corncobs and grains) were collected from Dongdagou and Xidagou stream basins to examine the accumulation, fractionation, correlation of heavy metals and F in soil-crop systems. Risks posed by heavy metals and F in this system to human health was also assessed. The total contents of F and heavy metals (Cd, Cu, Pb, Mn Zn, Cr and Ni), as well as the fraction distribution in soil, were determined. The total contents of F and heavy metals in crop tissues were also determined. The results indicated that the average contents of Cd, Cu, Pb, Mn Zn, F and Cr in Dongdagou and Xidagou stream basins exceeded the soil background value. Heavy metals and F more easily accumulated in the male inflorescence of maize. Correlation analysis showed that content of water soluble F positively were correlated with the contents of Cd, Cu, Pb, Mn Zn, Cr and Ni in exchangeable and carbonate fractions (P < 0.05). Stepwise discriminant analysis showed that the combined stresses of soil total Cu and Ni accounts for 100% effect on water soluble F accumulation in soil and crop roots. The hazard index indicated that noncancerous risk is likely to occur through maize grains and wheat grains consumption by children and adults. Graphical abstract Unlabelled Image Highlights • Water soluble F may increase the bioavailability of Cu, Mn, Zn, Pb, Ni, Cd and Cr. • The combined stresses of Cu and Ni may be the main factor that increases F bioavailability. • Contaminants easily accumulate in male inflorescence of maize except for roots and leaves. • Crop grains and shoots cannot be used for food and feed consumption. [ABSTRACT FROM AUTHOR]

Highlights • Ecological intensification management (EI) was compared with average farmer practice (FP). • We evaluated resource productivity and its components at the crop sequence level. • Water and radiation productivities were higher in EI than in FP. • Resource use efficiencies increased more than resource capture in EI as compared with FP. • The EI management reduced partial factor productivity of applied N but improved the partial N balance. Abstract The challenge to increase agricultural production with a minimum environmental impact requires to reach the maximum efficiency in the capture and use of resources such as photosynthetically active radiation (PAR), water, and nitrogen (N). Such requisites are encompassed in the ecological intensification (EI) concept. The aims of this work were to evaluate at a crop sequence level: i) crops yields, ii) water and radiation productivity and its components, i.e. resource capture and resource use efficiency, and iii) partial factor productivity of applied N (PFPN), partial nutrient balance for N (PNB), N uptake and N utilization efficiency of a two-year, three-crop sequence (wheat [ Triticum aestivum L.]/soybean [ Glycine max (L.) Merr.] double crop – maize [ Zea mays L.]) carried-out under EI principles in comparison with the same crop sequence under current farmer practices (FP) in two contrasting locations of the Argentinean Pampas, i.e. Paraná (-31°50′; -60°31′) at the northern Pampas and Balcarce (-37°45′, -58°18′) at the southern Pampas. Experiments were carried-out during four consecutive years, covering two complete cycles of the crop sequence. For the accumulated grain production of the crop sequence, EI management outyielded FP from 13 to 42%, depending on environmental conditions. Maize yield accounted for most of the variation (41–64%) of the accumulated grain yield of crop sequence, whether in EI as in FP. Average grain yield differences between EI and FP treatments were 274 g m−2 for maize, 69 g m−2 for wheat and -2 g m−2 for soybean. Water and radiation productivities of the sequence were higher in EI than in FP (26% for water and 17% for radiation; P < 0.0001), mainly because of increases in resource use efficiencies. EI reduced partial factor productivity of applied N, but improved partial nutrient balance for N as compared with FP. These reductions in partial factor productivity of applied N were less than proportional than the increases in N rate. Moreover, in spite of the higher N rate in EI respect to FP, N utilization efficiency (N ut E), i.e. grain per unit N uptake, was higher across all situations in EI. Our results showed that the challenge to obtain high grain yields by increasing N rate in a medium-input system could be achieved even with an increase in N ut E. Grain yields improvements, and increases in radiation and water productivity were reached by applying a set of agronomic practices that included improved genetics, crop and fertilizer N management englobed under EI concept. [ABSTRACT FROM AUTHOR]

Highlights • Data were compiled from 212 studies in China, amounting to 1077 observations. • Leaching of NO 3 was significantly correlated with NO 3 accumulation in the soil. • Control-release fertilizer reduced 50% of NO 3 accumulation for maize than urea. • Compared to flood irrigation, sprinkler irrigation increased NO3 leaching potential driven by intensive rainfall. Abstract Application rates of fertilizers in China often exceed crop requirements, resulting in high accumulation of nitrate (NO 3) in the soil. Nitrate that has accumulated in soils is highly prone to leaching, directly threatening the quality of groundwater. A study was conducted to assess the magnitude of NO 3 accumulation and leaching in China, to identify factors controlling NO 3 accumulation and leaching, and to develop strategies that can be used to minimize NO 3 leaching. Data were compiled from 212 studies conducted in China, amounting to 1077 observations of the NO 3 content of the 0–100 cm soil profile in wheat and maize fields after harvest. Leaching of NO 3 was significantly correlated with NO 3 accumulation in the soil. NO 3 leaching increased with 0.058 and 0.34 kg NO 3 -N ha−1 per season for wheat and maize, respectively, for every 1 kg ha-1 increase in NO 3 -N accumulation in 0–100 cm. This mainly related to lower precipitation during the wheat season and intensive rainfall in the maize season. Accumulation of NO 3 in maize systems was 50% lower than for wheat when fertilized at the same rate, due to differences in rainfall between seasons. Soil NO 3 accumulation was higher in heavy textured soils than in freely draining lighter textured soils, as most of NO 3 leached out of 0–100 cm soil in lighter textured soils. Compared to flood irrigation, sprinkler irrigation increased NO 3 accumulation by 17% and 152% for wheat and maize, respectively, due to lower irrigation and leaching rate. The level of nitrate accumulation in Chinese arable soils has become a significant hazard to drinking water, so good agricultural management is essential. Soil NO 3 accumulation and leaching in China can be reduced by source and process control, such as reducing fertilizer application, using slow or controlled release forms of fertilizers, and regulating irrigation. [ABSTRACT FROM AUTHOR]

Abstract Weather observations are essential for crop monitoring and forecasting but they are not always available and in some cases they have limited spatial representativeness. Thus, reanalyses represent an alternative source of information to be explored. In this study, we assess the feasibility of reanalysis-based crop monitoring and forecasting by using the system developed and maintained by the European Commission- Joint Research Centre, its gridded daily meteorological observations, the biased-corrected reanalysis AgMERRA and the ERA-Interim reanalysis. We focus on Europe and on two crops, wheat and maize, in the period 1980–2010 under potential and water-limited conditions. In terms of inter-annual yield correlation at the country scale, the reanalysis-driven systems show a very good performance for both wheat and maize (with correlation values higher than 0.6 in almost all EU28 countries) when compared to the observations-driven system. However, significant yield biases affect both crops. All simulations show similar correlations with respect to the FAO reported yield time series. These findings support the integration of reanalyses in current crop monitoring and forecasting systems and point to the emerging opportunities linked to the coming availability of higher-resolution reanalysis updated at near real time. Highlights • Crop yield monitoring and forecasting systems driven by reanalysis show similar performance to the ones driven by weather observations. • Simulated wheat and maize yields are well correlated with FAO yields. • Significant biases in simulated wheat and maize yields still remain. [ABSTRACT FROM AUTHOR]

Water productivity (WP) is a robust benchmark for crop production in relation to available water supply across spatial scales. Quantifying water-limited potential (WPw) and actual on-farm (WPa) WP to estimate WP gaps is an essential first step to identify the most sensitive factors influencing production capacity with limited water supply. This study combines local weather, soil, and agronomic data, and crop modeling in a spatial framework to determine WPw and WPa at local and regional levels for rainfed cropping systems in 17 (maize) and 18 (wheat) major grain-producing countries representing a wide range of cropping systems, from intensive, high-yield maize in north America and wheat in west Europe to low-input, low-yield maize systems in sub-Saharan Africa and south Asia. WP was calculated as the quotient of either water-limited yield potential or actual yield, and simulated crop evapotranspiration. Estimated WPw upper limits compared well with maximum WP reported for field-grown crops. However, there was large WPw variation across regions with different climate and soil (CV = 29% for maize and 27% for wheat), which cautions against the use of generic WPw benchmarks and highlights the need for region-specific WPw. Differences in simulated evaporative demand, crop evapotranspiration after flowering, soil evaporation, and intensity of water stress around flowering collectively explained two thirds of the variation in WPw. Average WP gaps were 13 (maize) and 10 (wheat) kg ha −1 mm −1 , equivalent to about half of their respective WPw. We found that non-water related factors ( i.e. , management deficiencies, biotic and abiotic stresses, and their interactions) constrained yield more than water supply in ca. half of the regions. These findings highlight the opportunity to produce more food with same amount of water, provided limiting factors other than water supply can be identified and alleviated with improved management practices. Our study provides a consistent protocol for estimating WP at local to regional scale, which can be used to understand WP gaps and their mitigation. [ABSTRACT FROM AUTHOR]

Stakeholders, policy makers, government planners and agricultural market participants in Central Eastern Europe require accurate and timely information about wheat and maize yield and production. The study site, the lowlands (altitude below 200 m) of the Tisza river catchment is by far the most important wheat and corn producing region in the Carpathian basin, and even in Central Eastern Europe. The conventional sampling of on-field data and data processing for crop forecasting requires significant amounts of time before official reports can be released. Several studies have shown that wheat and maize yield can be effectively forecast using satellite remote sensing. In this study, a freely available MODIS NDVI satellite data based wheat and maize yield forecasting methodology was developed and evaluated for estimating yield losses effected by drought. Wheat and maize yield was derived by regressing reported yield values against time series of 15 different peak-season MODIS-derived NDVI. The lowest RMSE values at the river basin level for both wheat and maize yield forecast versus reported yield were found when using at least six or more years of training data. Wheat forecast for the 2000 to 2015 growing seasons were within 0.819% and 19.08% of final reported yield values. Maize forecast at county level for the 2000 to 2015 growing seasons were within 0.299% and 17.14% of final reported yield values. The Nash–Sutcliffe efficiency index (E 1 ) is positive with E 1  = 0.322 in the case of wheat forecast, and with E 1  = 0.401 in the case of maize forecast, which means the developed and evaluated forecasting method performs acceptable forecast efficiency. Nevertheless the occurrence of extreme drought or extreme precipitation can alter the forecasting efficiency resulting over or underestimation. Overall statement, which based on MODIS NDVI, possible yield losses can easily be forecasted 6–8 weeks before harvesting and applying simple threshold levels, yield losses can be mapped simply. [ABSTRACT FROM AUTHOR]

Coloured (black, purple, blue, pink, red, and brown) cereal grains have gained much attention recently due to attractive nutritional values. A major type of pigments responsible for the colours as well as the health benefits of the cereals are anthocyanins. Focusing on the recent updates, this review summarises the chemical composition of the anthocyanins in diverse cereals including maize, rice, wheat, barley, sorghum, millet, and rye. There is a great diversity in anthocyanin composition among various cereals. Special cereal genotypes with much enhanced anthocyanin content ( e.g. , endosperm of rice kernels rich in anthocyanins) have been developed by genetic means. The coloured cereals as potential ingredients for functional food production have been subjected to extensive research for health benefits. Both in vitro and in vivo studies on the health effects of the anthocyanins from the cereals have been summarised. The claimed health benefits include anti-oxidation, anti-cancer, glycemic and bodyweight regulation, neuroprotection, retinal protection, hypolipidemia, hepatoprotection, and anti-ageing. These health effects suggest potential uses of the cereal anthocyanins for positive human nutrition. However, clinical and human studies are needed to confirm these claimed health effects. [ABSTRACT FROM AUTHOR]

The North China Plain (NCP) has a severe water shortage. About 70% groundwater has been exploited for irrigation. Winter wheat – summer maize and pears are typical representative cereal crops and commercial fruit trees in this area, respectively. Water budget for the typical cropland and orchard ecosystems has a significant importance for agricultural production, especially in the NCP. Therefore, evapotranspiration (ET) and water balance were studied in the annual winter wheat – summer maize rotation (cropland) and pear orchard. Latent and sensible heat fluxes were measured by eddy covariance. Annual ET for pear trees was 764 mm and for both crops was 690 mm. The difference of ET between these two ecosystems was about equal to one irrigation. Transpiration was the main loss with the mean proportion of 63% for crops and 76% for pear trees. Wheat growth period is in the dry season and requires much more irrigation than maize. Mainly transpiration (80%) occurred from April through September in the both ecosystems which was also the growing period for pear trees. The annual precipitation was 469 mm and 444 mm in the pear orchard and cropland, respectively, although 80% of it occurred from June to September. Compared with the precipitation, annual mean water deficit was 294 mm for the pear trees and 244 mm for crops. The water shortage was severe in May while surplus water presented in July and August. Energy and ET fluxes were determined by atmospheric demand and the response of plants as controlled by plant phenology and crop selection. As the water shortage situation becomes more serious in the NCP, sustainability of the agricultural ecosystems could be improved by changing crop planting patterns, specifically, increasing the area ratio of maize to pear trees. [ABSTRACT FROM AUTHOR]

In this study, we explored how changing climate conditions in the 20th and 21st century affect summer and winter crop yields the southeast United States. An ensemble of 10 global circulation models (GCMs) were utilized and the uncertainties associated to their estimates were calculated. The objectives of this study were to utilize historical and projected climate data to ( i ) analyse historical and projected precipitation and temperature separately for a winter and a summer crop; ( ii ) evaluate how these climate factors impact the crop yield and the water use; ( iii ) quantify for the two crops, and for vegetative vs. reproductive stages, the impacts of climate extremes on crop yield and water use. The daily weather data for both historical and projected periods were obtained from the Multivariate Adaptive Constructed Analogs (MACA) downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5) datasets. A series of 16 climate extremes indices mostly selected from the Expert Team on Climate Change Detection and Indices (ETCCDI) was calculated using the MACA downscaled CMIP5 data. The Decision Support System for Agrotechnology Transfer (DSSAT) model was used to simulate the effects of climate on a summer crop (maize, using the CERES-Maize model) and a winter crop (wheat, using the CERES-Wheat model) crop on a silty-clay and on a sandy soil during the historical baseline (1950–1999) and the projected (2006–2055) periods. Overall, the decadal crop-specific growing season temperature trend showed warming of the southeast with little variability across the climate models for the baseline and an increase uncertainty for future conditions. For each 1 °C the simulated maize yield would decrease by 4.6% across the different climate projections, while wheat would be reduced by 3.8%. Water use efficiency decreased under future projections by 2.7% on a silty-clay soil, independently of the winter/summer crop, but on a sandy soil the decrease was 4% for maize and 1.7% for wheat. The impacts of projected temperature and rainfall change will be different for a winter than for a summer crop depending on the type of soil on which the crop is grown. [ABSTRACT FROM AUTHOR]

Low and declining soil organic matter contents pose a significant threat to soil fertility, crop productivity and economic returns in arid and semi-arid agroecosystems. Holistic approaches are required to build and sustain soil organic matter in such soils to enhance nutrient use efficiencies and meet food security. Biochar is emerging as an attractive option for multiple benefits to soil-plant systems and carbon sequestration, especially in low fertility soils. We conducted a two-year maize-wheat rotation field experiments during 2015 and 2016 to test the effects of biochar on crop productivity, soil properties and phosphorous use efficiency (PUE) when applied with organic P sources as either farmyard manure (FYM) or poultry manure (PM) and diammonium phosphate (DAP) chemical fertilizer. Biochar was applied at two rates (0 and 10 t ha −1 ) whereas percentage of organic-inorganic P sources were 0, 25, 50 and 100% respectively. Biochar and manures were incorporated only once at the start of the field experiments whereas chemical fertilizers were applied during each crop cycle. Analysis of the two-year data revealed that biochar and P sources significantly and positively changed crop and soil quality attributes. Application of biochar significantly increased biological and grain yields of maize and wheat, soil organic carbon (SOC), and available nitrogen (N) and P contents without any negative effects on soil pH and electrical conductivity (EC). Addition of 50% P each from organic (FYM or PM) and chemical fertilizer increased biological and grain yields of maize, however, wheat biological and grain yields were higher with 100% PM or FYM in the presence of biochar. SOC and P contents were the highest when biochar was integrated with 100% P from FYM under maize crop. Biochar enhanced PUE from organic P sources more than the chemical fertilizer for both crops. Grain and biological yields of both crops correlated positively with SOC, soil N and soil P contents. We also found strong correlations between SOC, PUE and harvest index (HI) suggesting the benefits of increasing SOC contents under biochar-related integrated nutrient management practices. Overall results from these field experiments indicate potential of biochar to enhance plant nutrition, crop productivity and soil quality in nutrient poor alkaline calcareous soil under maize-wheat cropping system. Long-term farmers’ participatory field experiments, however, are required to extrapolate the potential of biochar integrations into current cereal-based cropping systems of Pakistan. [ABSTRACT FROM AUTHOR]

We present work using two long-term climate datasets to show that nitrogen fertiliser is an important aspect of yield projection for three major crops. The ability of linear models using climate variables as predictors to accurately project the yield of maize, rice and wheat over multi-decadal scales is improved with the addition of fertiliser as an input. Highly productive nations including Argentina, India, Poland and South Africa show significant improvement in yield simulations and show that fertiliser use should not be discounted when estimating yield variability. The use of nitrogen fertiliser in the generalised linear models improves yield forecast by 18% using the Princeton climate dataset and 23% using the WFDEI climate dataset. This work therefore supports the use of additional predictors than climate for improving the ability of statistical models to reconstruct yield variability. [ABSTRACT FROM AUTHOR]

Development of semi-dwarf wheat (Triticum aestivum) and rice (Oryza sativa) led to increased yields and agronomic efficiencies with less lodging. While these short-stature cereals have become common in global crop production, commercial maize (Zea mays L.) hybrids remain tall. There is no information currently available on plant N uptake or yield responses to N timing for short stature maize hybrids. We tested three hypotheses on short-stature and tall maize hybrids 1) short-stature maize hybrids would have similar yield response to in-season N application compared to tall hybrids, 2) short-stature maize hybrids would have similar dry matter and N uptake patterns to tall hybrids, and 3) there would be significant partitioning differences between short-stature and tall hybrids in dry matter and N within the plants at multiple growth stages. In ten side-by-side field trials across eight site-years in the Midwestern USA, we tested the yield response and underlying nitrogen physiology of short-stature maize hybrids and tall comparators to split-rate N application. We show that split-rate application of 50% of the total N at mid-vegetative stages (V6) averaged 0.24 t ha−1 more grain yield across 10 field trials (positive yield response in 6 out of 10 trials) compared to a single 100% up-front N application, with the same pattern for short-stature and tall hybrids. In both hybrid statures, V6 N applications showed more frequent improvement in grain yield than V12 N applications. Total N uptake at maturity was not different between short-stature hybrids and their tall counterparts (p = 0.62). N partitioning differed between short-stature and tall hybrids; leaves in short-stature hybrids had 5% higher N concentration and 13% more N content in early vegetative development, stalks had 18–27% less dry matter and 5–25% less N content, depending on growth stage, while R1 ears averaged 18% more dry matter and N accumulation (p < 0.10 in all cases). At maturity short-stature hybrids had 4% higher harvest index and 3% higher N harvest index (p < 0.10). Based on these results, we expect that N management recommendations in short-stature maize hybrids would be similar to their tall counterparts, but that short stature mitigates logistical risk by providing more flexibility for in-season N applications. This study provides a unique, robust dataset on yield and physiological response to split-rate N treatments in commercially relevant maize hybrids. • Short stature in maize simplifies in-season N application and later crop management. • Split-rate N applications at V6 increased hybrid yields 60% of the time, with similar patterns for short-stature and tall hybrids. • Overall, short-stature maize yielded similarly to tall comparators. • Short stature led to greater partitioning of N and dry matter to the grain than tall hybrids. • Greater flexibility for in-season N fertilization in short-stature maize reduces in-season application risks. [ABSTRACT FROM AUTHOR]

No-tillage of summer maize after the harvest of winter wheat is the main agricultural practice on the Huang-Huai-Hai (HHH) Plain of China. However, long-term no-tillage in the absence of deep tillage practices affects soil properties, and this effect is not beneficial for the growth and yield production of summer maize. Field experiments were conducted in 2016 in two agricultural sub-zones (Luancheng and Guoyang) in the HHH Plain. The main objective of this study was to evaluate the effect of deep vertical rotary tillage (DVRT), compared to no-tillage with strip subsoiling (NTSS), on dry matter accumulation (DMA) and yield formation. DVRT significantly reduced the soil bulk density of the top soil layer (0–40 cm), especially for the lime concretion black soil in the Guoyang experimental site. Compared with NTSS, the soil water content in the 20–60 cm soil layer was increased under the condition of DVRT. DVRT also significantly increased root DMA in the 0–30 cm soil layer in Luancheng and in the 0–40 cm soil layer in Guoyang. The total shoot DMA, seed DMA, and harvest index of DVRT were significantly higher than those of NTSS, primarily due to a significant increase in post-anthesis DMA. In addition, DVRT increased the maximum and mean grain filling rate and thus significantly increased the maximum grain weight at harvest. Compared with NTSS, DVRT significantly increased grain yield by 21.3% and 27.8% under the plant density of 6.75 pl m −2 and 9 pl m −2 , respectively, in Luancheng and it increased by 12.3% in Guoyang. The present results indicate that DVRT can be used as a deep tillage practice to improve soil properties and grain yield of summer maize, and this may provide guidance regarding the requirements to cope with a diversity of deep tillage machines and develop sustainable agriculture in the HHH Plain of China. [ABSTRACT FROM AUTHOR]

Excessive use of groundwater in irrigation (mainly for production of winter wheat) in the North China Plain (NCP) has resulted in markedly decreased groundwater levels. Alternative cropping systems may have potential to reduce groundwater use in the region. The APSIM (Agricultural Production System Simulator) farming systems model was used to simulate long-term (1981–2015) water use, net overdraft and crop yield for eight cropping systems. The wheat-maize double cropping system (WW–SM) in the study area resulted in overdrafts of 258 mm yr − 1 , about 100 mm yr − 1 more than estimated groundwater recharge. Although six of eight simulated systems reduced overdrafts below the estimated recharge value of 150 mm yr − 1 , a triple-cropping system consisting of winter wheat/summer maize followed by fallow and early maize (WW–SM/F–EM) in two years appears to be the most viable alternative. Annual grain yield under the triple cropping system was only 13% less than that under the current WW–SM double cropping system. Groundwater overdrafts under triple-cropping system were about equal to lateral recharge from the mountains, water brought in via the South-North Water Transfer (SNWT) project and water from other water-saving measures (e.g. plastic film mulching) in the region. [ABSTRACT FROM AUTHOR]

In the present work changes in polyamine contents were investigated after various hydroponic polyamine treatments (putrescine, spermidine and spermine at 0.1, 0.3 and 0.5 mM concentrations) in two different crop species, wheat and maize. In contrast to putrescine, higher polyamines (spermidine and spermine) induced concentration-dependent oxidative damage in both crops, resulting in decreased biomass. The unfavourable effects of polyamines were more pronounced in the roots, and maize was more sensitive than wheat. The adverse effects of polyamine treatment were proportional to the accumulation of polyamine and the plant hormone salicylic acid in the leaves and roots of both plant species. Changes in polyamine content and catabolism during osmotic stress conditions were also studied after beneficial pre-treatment with putrescine. The greater positive effect of putrescine in wheat than in maize can be explained by differences in the polyamine metabolism under normal and osmotic stress conditions, and by relationship between polyamines and salicylic acid. The results demonstrated that changes in the polyamine pool are important for fine tuning of polyamine signalling, which influences the hormonal balance required if putrescine is to exert a protective effect under stress conditions. [ABSTRACT FROM AUTHOR]

It is not yet clear whether the carbon released from biochar in the soil solution stimulates biological activities. Soluble fractions (AQU) from wheat and maize biochars, whose molecular content was thoroughly characterized by FTIR, 13 C and 1 H NMR, and high-resolution ESI-IT-TOF-MS, were separated in dilute acidic solution to simulate soil rhizospheric conditions and their effects evaluated on maize seeds germination activity. Elongation of maize-seeds coleoptile was significantly promoted by maize biochar AQU, whereas it was inhibited by wheat biochar AQU. Both AQU fractions contained relatively small heterocyclic nitrogen compounds, whose structures were accounted by their spectroscopic properties. Point-of-Zero-Charge (PZC) values and van Krevelen plots of identified masses of soluble components suggested that the dissolved carbon from maize biochar behaved as humic-like supramolecular material capable to adhere to seedlings and deliver bioactive molecules. These findings contribute to understand the biostimulation potential of biochars from crop biomasses when applied in agricultural production. [ABSTRACT FROM AUTHOR]

Standard ISO Life Cycle Assessment methodology was applied to the production of wheat and maize in an Italian farmers' cooperative, with the aim to assess the potential environmental impacts throughout the life cycle of these crops as well as to identify the hotspots in the production chains. The functional units were 1 tonne of wheat and maize, respectively and system boundaries were from cradle to cooperative's gate, including the agricultural production, the transport to the cooperative, and the cleaning as well as storage phases. Specific primary data collected both at farm and cooperative's premises, were used in the study. The results, according to ILCD impact assessment methods, show that the major hotspot for both cereals in all impact categories is the agricultural phase, due to fertilizers and pesticides use. Finally, a sensitivity analysis was performed, using different methods for the calculation of on-field nitrogen and pesticides emissions, in order to assess their effects on LCA results. [ABSTRACT FROM AUTHOR]

Iran is mostly located in arid and semiarid regions which makes agricultural water management considerably important in this country. In this research the concept of ‘water footprint’ (WF) is applied at the regional scale for the first time in the country. The calculation framework of Ababaei and Ramezani Etedali (2014) was adopted and modified to better account for the gray and white WFs. The weighted average of each WF component (green, blue, gray and white) and the national total water footprint (NTWF) of the production of main cereals (wheat, barley and maize) were calculated. The NTWF of wheat, barley and maize production were estimated 36,777, 7975 and 3744 million cubic meters (MCM) per year for the period 2006–2012. The ratio of total green WF of three crops to the aggregated NTWF (i.e. all crops) was 43%, and the ratios of the green WF to the NTWF were 47%, 42% and 2% for wheat, barley and maize, respectively. These results show that wheat and barley production are significantly large consumers of the green water resources (i.e. effective precipitation). This implied that there are great opportunities to improve the green water productivity through increasing yield, especially in wheat and barley rainfed lands. The average national green+blue WFs were estimated 24,628, 5,123 and 1,604 MCM per year for wheat, barley and maize, respectively, and 31,356 MCM per year altogether. The ratios of national gray + white WF to the NTWF were also estimated 33%, 36% and 57% for wheat, barley and maize, respectively. These values show the importance of better irrigation management strategies to reduce the share of gray and white WF which is important in both terms of water resources management and environment conservation. [ABSTRACT FROM AUTHOR]

Intercropping tends to have a higher productivity than traditional sole crops, mainly due to complementary resource use in time and space among different species. Intercropping may become more important in a world that needs to produce 60–70% more food by 2050 with limited land and other agricultural resources. To assess the role of intercropping in agricultural systems and its contribution to future food security, an intercrop model is needed for growth and yield predictions of intercrops under different growing conditions. Strip intercropping is a prevalent intercropping system, but the existing intercrop models are generally built for full mixtures and are less suitable for strip intercrops. Here we describe a simple intercrop model which is developed based on a sole crop model using the radiation use efficiency (RUE) concept and a strip intercrop light partitioning module. The model allows simulating the growth and yield of each intercropped species in relay-strip intercropping under potential growing conditions (only competition for light; other resources are assumed to be non-limiting), and the intercrop could vary in species combination, planting configuration, sowing densities and sowing dates. The daily inputs of the model are temperature and radiation, and crop-specific parameters are required to simulate crop leaf area index (LAI), biomass and final yield. Data collected during two years (2013 and 2014) field experiments were used to calibrate and test the model. The experiments consisted of two sole crop treatments (sole wheat, SW and sole maize, SM) and three intercrop treatments (replacement intercrop, 6:2WM and add-row intercrops, 8:2WM and 6:3WM). The experiments were conducted in Wageningen, the Netherlands. Data of sole crops (SW and SM) and replacement intercrop (6:2WM) treatment were used to calibrate the model, and data of add-row intercrops (8:2WM and 6:3WM) were used to test the model. Bayesian analysis was applied to calibrate RUE of wheat and maize in sole crops and intercrop. This calibration procedure resulted in posterior distributions of RUE for sole crops and intercrop, on the basis of which distributions of biomass and land equivalent ratio (LER) were simulated. Biomass accumulation and yield of each species were simulated adequately but LAI was slightly overestimated compared to observations. The intercrop model allows simulating the contribution of border row effects to the productivity of intercrops. It combines a simple structure with easy calibration and enables growth and yield simulations for a wide range of relay-strip intercrops. The model thus can be of value in exploratory land use studies to assess the role of intercropping. [ABSTRACT FROM AUTHOR]

Two Proficiency Testings (PTs) involving eighteen laboratory participants from 10 Countries have been conducted in 2014 for the simultaneous determination of deoxynivalenol, fumonisins B 1 and B 2 , zearalenone, T-2 and HT-2 toxins, ochratoxin A and aflatoxins B 1 , B 2 , G 1 and G 2 in maize and of deoxynivalenol, zearalenone, T-2 and HT-2 toxins and ochratoxin A in wheat, respectively. The aim of PTs was to check next to the laboratory performance the state-of-art of the LC–MS multi-mycotoxin methods used by participants. In addition, the trend of performances of LC–MS methods for multi-mycotoxin determination in maize together with method-related issues was assessed by comparing three PTs organised over the years 2011–2014. Data showed the improvement of laboratory performances with the overall acceptable z-scores that progressively increased from 59% in 2011 PT to 85% in 2014 PT, while the rate of unacceptable z-score decreased from 25% in 2011 PT to 11% in 2014 PT. [ABSTRACT FROM AUTHOR]

Increasing and maintaining high productivity levels presents a major challenge facing farmers today and will continue into the near future. More integrative and complex approaches to decision-making, besides adopting new technologies, are necessary for redesigning more productive, stable, and sustainable farming systems. Thus, novel crop sequences should be implemented to improve these properties of farming systems. The aim of our research was to characterize how different preceding crops that open recurrent sequences will impact on the productivity and resource use of the following crops, in order to determine the possibilities of increasing the frequency of double crops in rotations. Three field experiments were conducted under rainfed conditions at three sites in the Rolling Pampas of Argentina. The effects of seven cropping systems on the productivity of succeeding crops were evaluated at each location. The seven cropping systems included five double crops (rapeseed/soybean, wheat/soybean, barley/soybean, field pea/soybean, and field pea/maize) and two single crops (maize and soybean). The seven cropping systems were followed by the same crop sequence: wheat/soybean double crop and maize single crop in the first and second growing seasons, respectively. Radiation use and grain yield, water use and nitrogen uptake were evaluated for each crop in the sequence. Results indicate that repeating cereal crops in the cropping sequence reduces their productivities, while well balanced sequences that include legumes resulted in the highest productivities of cereal crops. Our findings highlight that diversifying cropping systems by adopting different double crops are practical options that can contribute to a more sustainable intensification of cropping systems specialized for grain crops. Increasing crop diversity in sequence influenced nitrogen uptake, among other factors, and may explain the enhanced crop yield in such systems. Our research highlights that crop diversification is critical in designing efficient and sustainable intensified crop sequences. [ABSTRACT FROM AUTHOR]

Yield-scaled nitrous oxide (N 2 O) emission (YSNE) has been recognized as a means for developing appropriate nitrogen (N) management strategies to balance food security and mitigating N 2 O emissions. To better understand and use the concept of YSNE, it is essential to be assessed under various field conditions. The main objectives of this study were to assess the relationship between N inputs and YSNE with published results and identify response patterns of YSNE to N inputs. We assessed the relationship between N inputs and YSNE using published results encompassing 1800 observations (published from 1980 to 2020) from maize, rice, and wheat crops worldwide. Background yield-scaled N 2 O emission (BYSNE; a YSNE in the condition of zero N input) was significantly different by crop type. Rice (90.8 ± 12.9 g N 2 O−N Mg−1) had lower BYSNE compared to maize (174.2 ± 30.1 g N 2 O−N Mg−1) and wheat (325.4 ± 41.8 g N 2 O−N Mg−1). BYSNE was positively correlated with annual mean temperature in maize, rice, and wheat fields. BYSNE was negatively correlated with soil total nitrogen contents in rice fields. Over 60% data set showed a positive relationship between N inputs and YSNE in all three crops studied. A small proportion of the dataset had an optimum N rate that minimized YSNE. The results suggest that in general, lower N input rates result in lower YSNE in crop production. YSNE can be reduced in three ways: increasing yields (Type 1), reducing N 2 O emissions (Type 2), and both increasing yields and reducing N 2 O emissions (Type 3). To identify appropriate measures, we suggest a N 2 O emission-yield curve combining responses of yields and N 2 O emissions to N inputs. In type 1, 2, and 3 measures, an N 2 O emission-yield curve is shifted to the right, down, and both right and down, respectively. Through identifying direction and magnitude of the shifting, the effects of applied measures on yields and N 2 O emission in N input levels can be easily compared and recognized. This study provided insights into the nature of YSNE and how YSNE responds to N inputs. It also suggested an N 2 O emission-yield curve, which can be useful to identify how certain measures affect both N 2 O emissions and crop yields. The information can be useful for scientific community and policymakers developing appropriate N management strategies to balance food security and the mitigation of N 2 O emissions. [Display omitted] • Background yield-scaled N 2 O emission (BYSNE) varied by crop type. • BYSNE was positively correlated with annual mean temperature. • Over 60% data sets showed consistently lower yield-scaled N 2 O emission as N input decreased. • N 2 O emission yield curve showed the effects of mitigation measures on both yields and N 2 O emission. [ABSTRACT FROM AUTHOR]

Seasonal climate prediction can potentially contribute to achieving a more resilient cropping system management. This can help alleviate food insecurity and the economical sustainability of farming at large. For this purpose, seasonal climate forecasts are used to generate crop forecasts. This study assesses two methods for linking seasonal climate forecasts with crop models to improve crop yield predictability in the Iberian Peninsula (IP). Crop models usually require daily weather data and therefore, we tested two methods to disaggregate seasonal climate forecasts into daily weather realizations: (1) a conditional stochastic weather generator (predictWTD) and (2) a simple forecast probability resampler (FResampler1).These methods were evaluated under three seasonal rainfall forecasts by analyzing the impacts on rainfed wheat yield and on irrigation requirements and yields of maize crop. In addition, we estimated the gross margins (€ ha − 1 ) and the production risks associated with contrasting scenarios of seasonal rainfall forecasts (dry and wet). Both methods provided comparable predictability and therefore, both seem feasible options for using seasonal forecasts to establish yield forecasts and irrigation requirements. The large impact of crop prices and of irrigation cost on gross margins for both crops suggests that using a combination of information on expected market prices and crop forecast based on seasonal climate forecasts can be an effective tool for farmer's decision-making, especially under dry forecast situation and/or in locations with low annual precipitation. These methods can help to quantify the benefits and risks from the seasonal weather forecasts to farmers in the IP. The anticipation of risks and the opportunity that skillful climate and crop forecast provide allows for windows of opportunity to prepare and pre-empt mitigating actions. [ABSTRACT FROM AUTHOR]

Balancing the nitrogen (N) budgets of agricultural systems is essential for sustaining yields at lower environmental costs. However, it is still rare to find reports on the total N budgets of agricultural systems including all N fluxes in the literature. Here, we conducted a comprehensive study on the effects of different N fertilizers (control, synthetic fertilizer, 60% synthetic fertilizer N plus 40% pig manure N, pig manure N applied at the same rate of 280 kg N ha −1 yr −1 ) on N pools, cycling processes, fluxes and total N balances in a subtropical wheat-maize rotation system in China by monitoring in situ N fluxes combined with field 15 N-tracer and 15 N isotope-dilution techniques. The warm and wet maize season was associated with significantly larger N losses via gaseous and hydrological pathways than the cooler and drier wheat season. Nitrate leaching and NH 3 volatilization were the main N loss pathways, accounting for 78% and 93% of the annual hydrological and gaseous N losses, respectively. The field 15 N tracing experiment showed that the wheat system had a high N retention capacity (∼50% of 15 N application), although the N residence time was short. In the subsequent maize season, 90% of the residual 15 N-labeled fertilizer in the soil that had been applied to the wheat system was utilized by plants or lost to the environment. The combined application of synthetic and organic fertilizers (pig manure) or application of pig manure resulted in significantly higher soil N retention and lower NO 3 − leaching, while yields remained unaffected. However, the application of manure resulted in larger NH 3 volatilization losses compared with the application of synthetic fertilizer alone. Thus, our study suggests that a combination of synthetic and organic N fertilizers is suitable for sustaining agricultural productivity while reducing environmental N losses by fostering interactions between the soil C and N cycles. [ABSTRACT FROM AUTHOR]

MiR396s play important roles in regulating plant growth and stress response, and great potential for crop yield promotion was anticipated. For more comprehensive and precise understanding of miR396s in Poaceae, we analyzed the phylogenetic linkage, gene expression, and chromosomal distribution of miR396s in this study. Although the mature miR396s' sequences were mostly conserved, differential expression patterns and chromosomal distribution were found among Poaceae species including the major cereal crops rice, wheat, and maize. Consistently, in comparison with rice, wheat and maize plants transformed with the target mimicry construct of miR396 (MIM396) exhibited differential effects on grain size and disease resistance. While the TaMIM396 plants showed increased grain size, panicle length and sensitivity to B. graminis , the ZmMIM396 plants didn't show obvious changes in grain size and disease resistance. In Addition, several GROWTH-REGULATING FACTOR (GRF) genes in wheat and maize were repressed by miR396s, which could be reversed by MIM396, confirming the conserved regulatory roles of miR396 on GRFs. While providing new solution to enhance grain yield in wheat and revealing potential regulatory variations of miR396s in controlling grain size and disease resistance in different crops, this study gives clues to further explore miR396s' functions in other Poaceae species. • Poaceae miR396s are divided into three groups and display both conserved and diversified evolutionary characterizations. • Inhibition of miR396s results in increased grain size, panicle length and pathogen sensitivity in wheat but not in maize. • Different GRFs were upregulated in the MIM396 transgenic plants compared to their corresponding wild type in wheat and maize. [ABSTRACT FROM AUTHOR]

In humid plains with shallow water-tables, vegetation and groundwater influence each other through different mechanisms. Therefore, agricultural management decisions, such as the selection of the crop rotation, can affect water-table levels and these, in turn, can affect the crop performance. In this work, we evaluated the effect of different crop rotations on water-table levels and crop yields in the Argentine Pampas, a region that shows rising water-tables in the last decades that challenge agricultural activities. For this purpose, we modeled the dynamic of water-table depth in different topographic positions with Hydrus-1D and we used empirical models to estimate the grain yield. Crop rotations evaluated were wheat/soybean (W/S), wheat/soybean – maize (W/S – M), cover crop/maize – soybean (CC/M – S) and soybean – maize (S – M), and the simulation period extended throughout 41 growing seasons. Simulated water-table levels and crop yields showed a satisfactory matching with field observations, providing enough confidence for modeling exercises. According to modeling results, the crop rotation clearly affected the water-table depth, with the most intense rotation (i.e. W/S) showing the deepest water-table (e.g. W/S = 2.40 m vs. S–M = 1.90 m in the backslope). In the shoulder, the W/S rotation deepened the water-table in such an extent that more than 76 % of the time it was located below 3.5 m. However, with the least intense crop rotation (S – M) the proportion of time that the water-table remained deeper than 3.5 m depth was reduced to only 15 %. In the footslope, the least intense rotation showed the water-table level riskily shallow (< 1 m depth), negatively affecting most crops, almost half the time (48 %), while with the W/S rotation this percentage was reduced to 14 %. Through their influence on water-table depth, crop rotations also affected grain yields as suggested by empirical models. In maize, the predicted yields were maximum in the backslope for all rotations (~11 Mg ha-1), while they fell more strongly in the footslope with the least intense rotation (−28 %) but in the shoulder with the most intense one (−31 %). In soybean, the topographic position for which the highest yields were predicted depended on the crop rotation, being the footslope for W/S and the backslope for the other rotations. Our work provides novel insights on the influence of agricultural management on water-table levels and crop yields, as well as new tools to help in decision-making aimed at a more efficient management of water resources. • Simulations evidenced a strong influence of crop rotation on water-table depth. • More intense crop rotations (e.g. wheat/soybean) deepened the water-table. • Waterlogging effects were higher in less intense crop rotations. • Crop rotation affected crop yields through its effect on water-table depth. [ABSTRACT FROM AUTHOR]

Changes in field management and climate will alter soil organic carbon (SOC) and nitrogen (SN) cycling in the coming decades. This study is to quantify the effects of various fertilisation strategies and climate change scenarios on crop yield, and soil C and N cycling by the end of this century. Data from a long-term experiment with a winter-wheat ( Triticum aestivium L.) and summer maize ( Zea mays L.) rotation in Northern China was used to calibrate and validate the SPACSYS model. Five fertiliser practices were used: control (CK); combined mineral nitrogen, phosphorus and potassium (NPK); NPK plus manure (NPKM); high application rate of NPK fertilisers plus manure (hNPKM) and NPK with straw incorporation (NPKS). Crop yields, and SOC and SN stocks by 2100 were predicted under four climate scenarios (Baseline, RCP2.6, RCP4.5 and RCP4.5). Results showed that the SPACSYS model can adequately simulate the dynamics of SOC and SN stocks and the yields of winter wheat and summer maize. An application of NPK plus manure or straw not only enhanced crop yield, but also substantially increased SOC and SN stocks. The predictions showed the positive effects of fertilisation and climate change on crop yields and SOC stocks compared with those under the baseline. However, SN stock under the RCP8.5 decreased by 3–14% by 2100 for various fertilisation strategies compared with that under the baseline. On the other hand, mineral fertiliser plus manure led to a higher soil respiration rate and nitrogen losses through leaching and surface runoff under all the climate scenarios. Therefore, application of mineral fertilisers plus manure could enhance crop productivity and sustain soil fertility but cause more carbon emitted to the atmosphere and nitrogen losses. More attention should be paid on optimising fertilisation in order to increase crop productivity while minimising environmental risks. [ABSTRACT FROM AUTHOR]

Groundwater levels in the North China Plain (NCP), the bread basket of China, have dropped more than one meter per year over the last 40 years, putting at risk the long term productivity of this region. Groundwater decline is most severe in the Alluvial Fans where our study site is located. Avoiding a foreseeable systems collapse requires region-wide changes in crop systems management, underpinned by sound environmental policies. Here, we explore the potential of crop system adaptation to remedy the excessive water use and quantify the likely yield penalties associated with more sustainable water use practices. Using simulations with the APSIM cropping systems model we explore production opportunities in an area within the NCP with intensive cropping and no access to irrigation from rivers. We estimate the attainable production levels for wheat and maize if agriculture were made groundwater neutral, through changes in crop sequence, irrigation practices and water conservation technologies (e.g. mulching with plastic film). Total grain production would drop by 44% compared to current practice if agriculture were made groundwater neutral. Water conservation by plastic film could limit this reduction to 21–33% but possible environmental impacts of plastic film need attention. This analysis facilitates a much needed debate on alternative agronomic practices and incentives through a quantitative comparison of adaptation options. Our biophysical analysis needs to be complemented with socio-economic considerations and discussions with all stakeholders. Similar analyses in other parts of the NCP are possible but require more accurate modelling of landscape hydrology and (towards the coast) risk of salt water intrusion. [ABSTRACT FROM AUTHOR]

Favorable climate and soils for rainfed crop production, together with a relatively low population density, results in 70–90% of Argentina grain production being exported. No assessment to date has tried to estimate the potential for extra grain production for soybean, wheat and maize, which account for 78% of total harvested area, by yield gap closure on existing cropland area and its impact at a global scale. The objectives of this paper are (i) to estimate how much additional grain could be produced without expanding crop area by closing yield gaps in Argentina, (ii) to investigate how this production and yield gaps varies across regions and years, and (iii) to analyze how these inter-annual variations are related to El Niño—Southern Oscillation phenomenon (ENSO). Production increase on existing crop area was assessed for soybean, wheat and maize by quantifying the yield gap (Yg), that is, the difference between water-limited yield potential (Yw) and actual yield (Ya). A bottom-up approach was followed to estimate Yw and Yg, in which these parameters were first estimated for specific locations in major crop producing areas and subsequently up-scaled to country level based on spatial distribution of crop area and climate zones. Locally-calibrated crop simulation models were used to estimate Yw at each selected location based on long-term weather data and dominant soil types and management practices. For the analyzed period, the national level Yg represented 41% of Yw for both wheat and maize and 32% of the Yw for soybean. If farmers had closed Yg from these levels to 20% of Yw, Argentina could have increased soybean, wheat and maize production by a respective 7.4, 5.2, and 9.2 Mt, without expanding cropland area. This additional production would have represented an increase of 9%, 4%, and 9% of soybean, wheat, and maize global exports. This potential grain surplus was, however, highly variable because of the ENSO phenomenon: attainable soybean production was 12 Mt higher in favorable “El Niño” years compared with unfavorable “La Niña” years. Interestingly, Yg tended to be higher in wet years, suggesting that farmers do not take full advantage of years with favorable conditions for rainfed crop production. Regional variation in Yg was found in Argentina highlighting the usefulness of this work as a framework to target research and, ultimately, reduce gaps in areas where current yields are well below their potential. [ABSTRACT FROM AUTHOR]

Integrated nitrogen (N) management strategies could make significant contributions to improving the efficiency of N use in the northern Corn Belt, particularly for maize, which has high N requirements. Using legume cover crops has been shown to increase both the soil's capacity to supply N and nitrogen use efficiency (NUE), through the reduction in the amount of N fertilizer that must be applied to the following crops. However, the impact of non-legume crops such as winter wheat ( Triticum aestivum L.) on the diminishing return function between crop yield and N supply and its influence on N fertilizer use remains unclear. We hypothesized that maintaining wheat in short maize and soybean- based rotations is instrumental to improve cropping system performance and increase N fertilizer use efficiency while decreasing N requirements for maize. Seven maize and soybean rotations with different frequency of winter wheat with or without underseeded red clover ( Trifolium pratense L. ) were grown in two tillage systems (conventional and zone-tillage) and four long-term N regimes in Ridgetown, ON, Canada (2009–2013). Wheat in the rotation increased maize and soybean yields, negated crop yield lags due to zone-tillage, and decreased maximum economic rates of fertilizer N (MERN). The benefits of wheat in the rotation on maize yield were negated by high N rates; however, similar yields were obtained with lower N levels in rotationally grown maize, resulting in a 17% (conventional till) to 21% (zone-till) increase in partial factor productivity for N fertilizer at MERN (PFP MERN ). While N benefits to crops following wheat alone may be attributed to a higher indigenous plant available soil N, underseeding red clover further increased the agronomic efficiency (AE) of N fertilizer (AE MERN ) up to 32%. Maize yields were also less limited by N supply and less responsive to N fertilization when grown in rotation with wheat, especially in the zone-till system. These results highlight the value of wheat as a system component of dominant maize/soybean short rotations of Ontario and its potential to increase both maize and soybean productivity using less N input. [ABSTRACT FROM AUTHOR]

The North China Plain (NCP) is one of the main grain production regions in China. However, the annual double cropping system of winter wheat and maize consumed a large amount of groundwater, has led to decline in groundwater table. For conservation of groundwater resource, deficit irrigation is promoted to reduce irrigation water use in recent years. This study combined process-based modeling and experimental data together to evaluate the effects of different irrigation strategies on crop production and groundwater table change for the past three decades in NCP. Data from a six year field trial (2006–2012) under four irrigation schedules and 28 year (1984–2012) field experiment under full irrigation was used to test the agricultural production systems simulator (APSIM) to simulate the responses of winter wheat and maize to different irrigation management. The results showed that APSIM model could well simulate the grain yield and water consumption of the double cropping system under the changing climate and management practices. Simulation results with four irrigation scenarios (critical stage irrigation (CI), minimum irrigation (MI), rainfed (RF) and full irrigation (FI)) from 1984 to 2012 showed that irrigation water use efficiency (IWUE) was highest under CI, although changing from FI would lead to reduction in average annual grain yield by 19.5%, 33.7%, and 58.8% under CI, MI and RF, respectively. Even the minimum irrigation strategy (MI—one irrigation for each crop) will result in continuous decline in the groundwater table, implying an inevitable future shift to alternative cropping systems like dryland wheat-maize system, single wheat or maize. Such change will likely result in lower crop productivity and increased inter-annual variability in crop yields, which will demand improved risk management strategies to minimize loss in bad year while maximize return in good years. [ABSTRACT FROM AUTHOR]

The area used for bioenergy feedstock production is increasing because substitution of fossil fuels by bioenergy is promoted as an option to reduce greenhouse gas (GHG) emissions. However, agriculture itself contributes to rising atmospheric nitrous oxide (N 2 O) and methane (CH 4 ) concentrations. In this study we tested whether the net exchanges of N 2 O and CH 4 between soil and atmosphere differ between annual fertilized and perennial unfertilized bioenergy crops. We measured N 2 O and CH 4 soil fluxes from poplar short rotation coppice (SRC), perennial grass-clover and annual bioenergy crops (silage maize, oilseed rape, winter wheat) in two central German regions for two years. In the second year after establishment, the N 2 O emissions were significantly lower in SRC (<0.1 kg N 2 O–N ha −1 yr −1 ) than grassland (0.8 kg N 2 O–N ha −1 yr −1 ) and the annual crop (winter wheat; 1.5 kg N 2 O–N ha −1 yr −1 ) at one regional site (Reiffenhausen). However, a different trend was observed in the first year when contents of mineral nitrogen were still higher in SRC due to former cropland use. At the other regional site (Gierstädt), N 2 O emissions were generally low (<0.5 kg N 2 O–N ha −1 yr −1 ) and no crop-type effects were detected. Net uptake of atmospheric CH 4 varied between 0.4 and 1.2 kg CH 4 –C ha −1 yr −1 with no consistent crop-type effect. The N 2 O emissions related to gross energy in the harvested biomass ranged from 0.07 to 6.22 kg CO 2 equ GJ −1 . In both regions, Gierstädt (low N 2 O emissions) and more distinct Reiffenhausen (medium N 2 O emissions), this energy yield-related N 2 O emission was the lowest for SRC. [ABSTRACT FROM AUTHOR]

Seed number quantification is an essential agronomic parameter conducted mostly manually or by mechanical counters, both with obvious limitations. Digital image analysis provides a reliable and robust alternative to accurately calculate many biological features. This study presents and evaluates the performance of four open-source image-analysis programs i.e. ImageJ, CellProfiler, P-TRAP and SmartGrain to count crop seeds from digital images captured by camera and scanner. It also evaluates ImageJ program for automated seed counting using macro containing RenyiEntropy threshold algorithm. Digital images of cereal crop seeds were acquired i.e. wheat, barley, maize, rye, oat, sorghum, triticale and rice. All images contained 200 seeds per image present in an area of approx. 1400 cm 2 . RenyiEntropy threshold increased the seed count accuracy of ImageJ from digital camera images. Generally, seed counts from digital camera images of all crops were accurate, but software–crop combination had significant ( p < 0.05) difference from reference value. Among image analysis programs, ImageJ produced mostly higher seed count across all observed crops than other programs. Mean seed counts from scanned images of maize were observed only by CellProfiler and P-TRAP, with other programs inappropriate due to high inaccuracy. These results suggest CellProfiler as a reliable image analysis program for seed counting from digital images. Benchmark test was also performed to compare speed of analysis. The automated seed count produced by image analysis programs described here allows faster, reliable and reproducible analysis, compared to standard manual method. To our knowledge this is the first study on using CellProfiler program for crop seed counting from digital images. [ABSTRACT FROM AUTHOR]

With the growth in population over the past decades, China's food demand has been increasing. However, crops are facing greater water stress with the rising temperature and increasing drought in future. Therefore, identifying potential crop yield and its driving factors is necessary to ensure continued food production. In the present study, we estimated the potential yields of maize and wheat in China, with and without water limits, from 1985 to 2015 using a simple generic crop model (SIMPLE). We then investigated how climate factors (temperature, precipitation, and solar radiation) drove the spatial and temporal variation of yield gaps (quantified as the difference between potential yields with and without water limits). We found an increasing trend in the water limited yield gap of maize in northern China (3.9 ± 4.3 kg ha-1 yr-2) and wheat in central China (2.6 ± 2.4 kg ha-1 yr-2). The temporal trends of maize and wheat yield gaps in China were mainly related to precipitation and temperature. However, the spatial variation in maize yield gap trends was mainly related to the variations in precipitation, whereas for wheat it was attributed to changes in temperature or solar radiation. Upgrading irrigation infrastructure and management techniques or spatially adjusting crop types could help closing the yield gap of wheat in some zones. • The change trends of yield gap between maize and wheat are inconsistent. • The maize yield gaps variation was spatially related to variations in precipitation. • For wheat, it was attributed to changes in temperature or solar radiation. • Management techniques should be upgraded or crop types adjusted to close yield gaps. [ABSTRACT FROM AUTHOR]

The definition of LAI (Leaf Area Index) is important when deriving it from reflectance observation for model application and validation. Canopy reflectance and the corresponding quantities of LAI, PAI (Plant Area Index), GAI (Green Area Index) and effective GAI (GAI eff) are first calculated using a 3D radiative transfer model (RTM) applied to 3D wheat and maize architecture models. A range of phenological stages, leaf optical properties, soil reflectance, canopy structure and sun directions is considered. Several retrieval methods are compared, including vegetation indices (VIs) combined with a semi-empirical model, and 1D or 3D RTM combined with a machine learning inversion approach. Results show that GAI eff is best estimated from remote sensing observations. The RTM inversion using a 3D model provides more accurate GAI eff estimates compared with VIs and the 1D PROSAIL model with RMSE = 0.33 for wheat and RMSE= 0.43 for maize. GAI eff offers the advantage to be easily accessible from ground measurements at the decametric resolution. It was therefore concluded that the most efficient retrieval approach would be to use machine learning algorithms trained over paired GAI eff and the corresponding canopy reflectance derived either from realistic 3D canopy models or from experimental measurements. • Wheat and maize canopy reflectance are simulated with realistic 3D model. • Effective GAI is best estimated from remote sensing observations. • 3D model provides the best estimation of effective GAI compared to 1D model and Vis. [ABSTRACT FROM AUTHOR]

This study addresses the role of satellite Earth Observation (EO) indicators within an operational crop yield forecasting system for the European Union (EU) and neighbouring countries, by exploring the correlation between official yield statistics and indicators derived from fAPAR time-series at sub-national level for the period 1999–2012, and by identifying possible differences across agro-climatic conditions in Europe. A significant correlation between fAPAR and official yields ( R 2 > 0.6) was found in water-limited yield agro-climatic conditions (e.g. the Black Sea region and the Mediterranean basin) for all three crops studied. In regions where crops experience frequent water stress, most of the yield inter-annual variability is explained by substantial changes in leaf area from one year to another, and can be well captured by regional fAPAR time-series. By contrast, in regions characterized by high yields (e.g. northern Europe) – where water constraints are generally not frequent and, therefore, fAPAR inter-annual variability is low – the correlation between fAPAR and yield is weaker ( R 2 < 0.5) as yield variations tend to be explained by multiple factors other than green leaf area. These results confirm the reliability of EO time-series for operational crop yield forecasting at regional level, but also suggest that additional meteorological variables (temperature, precipitation, evapotranspiration) need to be taken into account to interpret EO products meaningfully. Moreover, specific issues related to the spatial resolution of the EO-products, and the absence of dynamic crop masks, currently impede access to crop-specific time-series in the fragmented agricultural landscapes of Europe, and restrict the use of 1-km biophysical products to major crops. [ABSTRACT FROM AUTHOR]