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This study is to understand the fate and ecological consequences of pyroxasulfone in aridisols of Punjab, a detailed dissipation study in soil, its influence on soil enzymes, microbial count and succeeding crops was evaluated. Half-lives (DT50) increased with an increase in the application rate of pyroxasulfone. Dissipation of pyroxasulfone decreased with increase in organic matter content of soil and was slower in clay loam soil (DT50 12.50 to 24.89) followed by sandy loam (DT50 8.91 to 17.78) and loamy sand soil (DT50 6.45 to 14.89). Faster dissipation was observed under submerged conditions (DT50 2.9 to 20.99 days) than under field capacity conditions (DT50 6.45 to 24.89 days). Dissipation increased with increase in temperature with DT50 varying from 6.46 to 24.88, 4.87 to 22.89 and 2.97 to 20.99 days at 25 ± 2, 35 ± 2 and 45 ± 2 °C, respectively. Dissipation was slower under sterile conditions and about 23.87- to 33.74-fold increase in DT50 was observed under sterile conditions as compared to non-sterile conditions. The application of pyroxasulfone showed short-lived transitory effect on dehydrogenase, alkaline phosphatase and soil microbial activity while herbicide has non-significant effect on soil urease activity. PCA suggested that dehydrogenase and bacteria were most sensitive among enzymatic and microbial activities. In efficacy study, pyroxasulfone effectively controlled Phalaris minor germination, with higher efficacy in loamy sand soil (GR50 2.46 µg mL−1) as compared to clay loam soil (GR50 5.19 µg mL−1). [ABSTRACT FROM AUTHOR]

Soil-borne fungal plant pathogens lead to worldwide economic yield losses. However, despite the agricultural importance of the North China Plain (NCP), little is known about the occurrence and severity of soil-borne fungal pathogens that could potentially affect the yields of three main crops in this area: wheat, maize and soybean. By combining searches in public databases, we identified a set of main soil-borne fungal pathogen species potentially affecting crop production in the NCP. We investigated their distribution patterns at three scales: globally, in China and in the NCP, and evaluated how these patterns were determined by a range of variables related to climate, spatial drivers and crop area density of the three crop species. We found 25 main soil-borne fungal pathogens that could potentially affect the yields of wheat, maize and soybean in the NCP. Twenty of these fungal pathogens were prevalent across the globe, and 13 were very frequent in the NCP. Significant positive relationships between pathogen prevalence and crop area density were only found for two specialist pathogens. Our work provides an overview of the main soil-borne fungal pathogens in one of China's most intensively cultivated regions, shedding light on potential, previously overlooked, fungal threats for agricultural production in the area. This baseline information may contribute to the development of sustainable management strategies aimed at mitigating disease outbreaks caused by soil-borne pathogens in the future. [ABSTRACT FROM AUTHOR]

The fall armyworm, Spodoptera frugiperda, is one of the most notorious insect pests, and a major threat to maize (Zea mays) and other important crops, such as wheat (Triticum aestivum). Although the push–pull strategy based on intercropping has been reported to effectively prevent damage caused to maize, the potential of wheat-based intercropping systems for S. frugiperda management has rarely been assessed. In this study, the offspring performance, oviposition, and feeding preferences of S. frugiperda on four commonly planted crops—maize, pea (Pisum sativum), faba bean (Vicia faba), and alfalfa (Medicago sativa)—in wheat-based intercropping system were investigated to evaluate the roles of those host plants in the pest management. The results showed that S. frugiperda larvae performed poorly on pea and faba bean plants, as indicated by the longest duration for larval developmental, total pre-oviposition period, and mean generation time as well as the lowest pupal weight and larval survival rate. Lower offspring performance on pea and faba bean leaves coincided with lower efficiency of larval consumption. Preference tests revealed that female adults and larvae exhibited a stronger oviposition on, and feeding preference for maize than wheat, whereas no-preference was observed for faba bean plants. This study revealed the adaptability of S. frugiperda and its preference for wheat and its four common intercropped host plants and provided an insight into the management of S. frugiperda through the establishment of a push–pull strategy in wheat-based intercropping systems. [ABSTRACT FROM AUTHOR]

There is an urgent need to increase cereal yields in the Ethiopian Highlands to ensure national food security. A major crop response-to-fertilizer program was set up in 2017–2019 as part of the CASCAPE project in the Ethiopian Highlands. It covered 33 experiments on maize, teff and wheat in five reference soil groups (Nitisols, Luvisols, Vertisols, Leptosols and Andosols). Five levels of multi-nutrient fertilizer (50–300 kg NPSZnB ha− 1 and 100 kg urea ha− 1) were applied. At the lower fertilizer level, average yields were 5500, 1500 and 3300 kg ha− 1 for maize, teff and wheat, respectively. At the highest rate, yields were 7900, 2100 and 5000 kg ha− 1. Maize and wheat yields were strongly correlated to the reference soil groups, but not to rainfall differences. Wheat yields were also positively correlated to soil organic carbon levels, underpinning the need to apply integrated soil fertility management. Comparing NPSZnB fertilizers with NPS and DAP fertilizers revealed a lack of statistically significant advantage for the fertilizers including Zn and B. As B was present in fine-granular form in the fertilizer bags, being prone to segregation, firm conclusions on the need for this micronutrient cannot be drawn. The use of 'recommendation windows' is suggested to group results into concrete packages at district levels and below, preferably combined with soil maps since soil types were correlated with maize and wheat yields. The windows could then be the starting point to develop 'last mile' fertilizer use policies, relevant to farmers and the way they manage their fields in the landscape. [ABSTRACT FROM AUTHOR]

Balanced nutrition is imperative for efficient nutrient management and has a considerable role in enhancing crop yield. To study the effect of various nitrogen sources at various sulfur levels on maize–wheat yield and N/S uptake under different climatic conditions, field experiments were conducted at Agronomy Research Farm, The University of Agriculture Peshawar, and Research Station Buner during 2018–2019. Nitrogen was applied at 150 kg ha−1 for maize and 120 kg ha−1 for wheat from inorganic (urea) and organic farm yard manure (FYM) sources at ratios of 100:0, 75:25, 50:50, 25:75, and 0:100, and sulfur levels from elemental sulfur of 0, 20, 40, and 60 kg ha−1. The study was carried out with a randomized complete block design with two-factorial arrangement and three replicates. Results shows that maximum 1000-grain weight, grain yield, biological yield, nitrogen uptake, and sulfur uptake were recorded at 50% organic and 50% inorganic nitrogen application for maize and wheat at both locations. Results regarding sulfur levels, maximum 1000-grain weight, grain yield, biological yield, and nitrogen uptake were recorded in the treatment group receiving 20 kg S ha−1 in Peshawar, and 40 kg S ha−1 in Buner; however, sulfur uptake increases with increase sulfur levels. The interaction between nitrogen sources and sulfur levels was significant; maximum grain yield and uptake of nitrogen and sulfur were recorded in the treatment group receiving 150 kg N ha−1 for maize and 120 kg N ha−1 for wheat along with 20 kg S ha−1 for Peshawar and 40 kg S ha−1 for Buner. Hence, it is recommended that 150 kg N ha−1 for maize and 120 kg N ha−1 for wheat (50% inorganic and 50% organic) along with 20 kg S ha−1 for Peshawar and 40 kg S ha−1 for Buner as a source of elemental sulfur be used for optimum grain yield and N/S uptake. [ABSTRACT FROM AUTHOR]

People are focusing more on gluten free food products with minimal production costs. Maize is one of the major cereal crops and provides up to 30 per cent of food calories to 4.5 billion people in the world. Maize was the first plant cultivated by farmers 7000–10,000 years ago in Mexico and later spread to various parts of the world. Maize is generally classified according to its colour, which ranges from white to yellow to red to black. Another major categorization is based on the size and composition of the endosperm containing an appreciable amount of carbohydrates (66.2%), lipids (3.6%), proteins (11.1%) and vitamins and minerals (3.6%) along with fibres (2.7%). Unfortunately, maize is deficient in two major amino acids, namely tryptophan and lysine and also minerals like iron and zinc and vitamin B12. Due to a good nutritional profile, a high proportion of maize grains is processed industrially for transforming into value-added products by three basic methods:- wet milling, dry milling and nixtamalization that enhance shelf stability of the product by preventing the hydrolysis of lipids. This review hopes to facilitate the feasibility of maize incorporation in various food products prepared from other cereal crops and its impact on quality and shelf life with a prime objective to spread awareness regarding nutritional qualities as an alternative to wheat or rice. [ABSTRACT FROM AUTHOR]

The influence of growing season rainfall on agricultural production is indisputable. In Morocco, the production of crops such as barley, maize, and wheat is impacted by growing season rainfall. Due to persistent gaps in growing season rainfall and other drivers of crop yield, crops have experienced observed yields that are often below projected or potential yields. However, there are currently no studies that have quantified these gaps in yield and growing season rainfall in Morocco. To achieve this objective, time-series crop yield for all three crops and growing season rainfall data for the period 1991–2020 were collected from FAOSTAT and the World Bank climate portal, respectively. Growing season rainfall and crop yield data for the spatial variations were culled from System National de Suivi Agrometeorologique (GCMS) and the yield gaps atlas, respectively, for the same historical period. The data were subjected to bias correction to handle uncertainty. The projected/simulated crop yields and growing season rainfall were computed by regression analysis. Crop yield and growing season rainfall gaps were determined by establishing the difference between the projected and observed crop yields and rainfall data. The results show that observed and simulated wheat have a stronger relationship when compared to the other crops. Also, most years with crop yield gaps are associated with growing season rainfall gaps. Wheat records the lowest number of years with yield gaps and the highest number of years with growing season rainfall gaps during the entire data series. Therefore, even though yield gaps are strongly tied to growing season rainfall gaps, it is not the case for wheat, and therefore other drivers might be important because wheat has the lowest number of years with crop yield gaps and the highest number of years with growing season rainfall gaps. Spatially, yield and growing season rainfall gaps decline with increased latitude. The broader perspective and policy implication here is that a better understanding of yield and growing season rainfall gaps mandates an understanding of growing season rainfall and other drivers of yield. As a way forward, potential research should focus on identifying the drivers of yield gaps, sub-national experimentation at the plot level as well as on closing yield gaps through water and nutrient management. [ABSTRACT FROM AUTHOR]

Increasing water consumption in agriculture due to global climate change has posed considerable challenges to food security, thus improving the efficiency of water production is the key to sustainable agricultural development. Deficit irrigation uses limited water resources to achieve stable crop yield according to the migration law of production parameters during crop growth. This study uses meta-analysis to quantitatively analyze the yield and water effects on winter wheat and summer maize under deficit irrigation in northern China based on previously published studies. The result shows that deficit irrigation results in an average yield reduction of 7.10% for wheat and an average yield reduction of 18.71% for maize, while the average water use efficiency (WUE) increases by 9.25% and 6.38% for wheat and maize, respectively. This research reveals the differences and effectiveness of deficit irrigation of wheat and maize in different regions and hydrological years and proposes appropriate water deficit levels and irrigation strategies. The optimal deficit irrigation schedule in different regions involves irrigating twice during the wheat growth with irrigation quotas of 100–200 mm. Generally, supplementary irrigation is carried out during the critical water demand period. When supplemental water (the sum of irrigation and precipitation) is 80% of full irrigation (FI), maize can obtain higher yield and WUE. This study provides a reference for irrigation strategies for winter wheat and summer maize in the major agricultural producing areas in northern China to mitigate the adverse effects of increased agricultural water use and extreme climates. [ABSTRACT FROM AUTHOR]

The study aimed to measure soil-atmosphere N2O fluxes and their controlling factors, as well as NH3 emissions and yields for two soils (silt loam and clay loam) in three management systems over two years under subsequent wheat and maize cultivation. The management systems were characterized as follows: (1) cash crop (C) with mineral fertilizer and conventional tillage; (2) livestock (L) with biogas residue fertilization and its incorporation prior to sowing in maize and reduced tillage; and (3) climate optimized (O) with minimum tillage, 8-year crop rotation, with biogas residue fertilization, in maize without incorporation in clay loam soil or incorporation by strip-tillage prior to seeding in silt loam soil. Stable isotope ratios of N2O and mineral N were determined to identify N2O processes. Within the organically fertilized maize treatments, cumulative N2O fluxes were highest in the O-system treatments of both sites (4.0 to 9.4 kg N ha− 1 a− 1), i.e. more than twice as high as in the L-system (1.5 to 3.1 kg N ha− 1 a− 1). Below root-strip till fertilizer application did not enhance N2O fluxes. Fluxes with mineral fertilization of wheat (1.1 to 3.1 kg N ha− 1 a− 1) were not different from those with organic fertilization. Isotopic values of emitted N2O revealed that bacterial denitrification dominated most of the peak flux events, while the N2O/(N2 + N2O) ratio of denitrification was mostly between 0.1 and 0.5. It can be concluded that, contrary to the intention to lower greenhouse gas fluxes by the O-system management, the highest N2O fluxes occurred in the O-system without biogas digestate incorporation in maize. With respect to NH3 fluxes, we could confirm that the application of digestate application in growing crops without incorporation or late incorporation in fertilization before sowing induces high fluxes. The beneficial aspects of the O-system including more stable soil structure and resource conservation, are thus potentially counteracted by increased N2O and NH3 emissions. [ABSTRACT FROM AUTHOR]

Background: The advent of high-throughput epigenome mapping techniques has ushered in a new era of multiomics with powerful tools now available to map and record genomic output at different levels. Integrating the different components of the epigenome from these multiomics measures allows investigations of cis-regulatory elements on a genome-scale. Mapping of chromatin state, chromatin accessibility dynamics, and higher-order chromatin structure enables a new level of understanding of cell fate determination, identity and function in normal growth and development, disease resistance, and yield. Objective: In this paper, the recent advances in epigenomics research of rice, maize, and wheat are reviewed, and the development trends of epigenomics of major crops in the coming years are projected. Methods: We highlight the role of epigenomics in regulating growth and development and identifying potential distal cis-regulatory elements in three major crops, and discuss the prospects and challenges for new epigenetics-mediated breeding technologies in crop improvement. Conclusion: In this review, we summarize and analyze recent epigenomic advances in three major crops epigenomics and discuss possibilities and challenges for future research in the field. [ABSTRACT FROM AUTHOR]

Genome-editing technologies offer unprecedented opportunities for crop improvement with superior precision and speed. This review presents an analysis of the current state of genome editing in the major cereal crops- rice, maize, wheat and barley. Genome editing has been used to achieve important agronomic and quality traits in cereals. These include adaptive traits to mitigate the effects of climate change, tolerance to biotic stresses, higher yields, more optimal plant architecture, improved grain quality and nutritional content, and safer products. Not all traits can be achieved through genome editing, and several technical and regulatory challenges need to be overcome for the technology to realize its full potential. Genome editing, however, has already revolutionized cereal crop improvement and is poised to shape future agricultural practices in conjunction with other breeding innovations. [ABSTRACT FROM AUTHOR]

In the agroecosystem, titanium dioxide nanoparticles are used in fertilisers, pesticides, remediation and bio-sensors. These applications lead to a pervasive and inevitable distribution of TiO2 NPs in the agroecosystem. It is very important to understand the behaviour of TiO2 NPs in the soil and to assess their impact on the agroecosystem. This review aims to provide an overview of the fate and behaviour of TiO2 NPs in the soil and their impact on staple food crops. The first part of this review deals with the application, and release of TiO2 NPs followed by their fate and behaviour of TiO2 NPs in the soil. Furthermore, the dual (beneficial and toxic) impact of TiO2 NPs on staple food crops such as wheat, rice and maize has been discussed. We also address the mechanism of impact of TiO2 NPs. The second part deals with the beneficial impact of TiO2 NPs followed by their critical assessment. The final section of the review deals with the existing knowledge gaps and future research directions. This review is to deliver information on the safer application of nanoparticles in agriculture. [ABSTRACT FROM AUTHOR]

Background and Aim: Success in agronomic biofortification of maize and wheat is highly variable. This study aimed to elucidate the differences in uptake and translocation of foliar-applied zinc (Zn) in maize (Zea mays L.) and wheat (Triticum aestivum L.) using different experimental approaches. Methods: Old leaves of plants cultured with low or adequate Zn supply in soil were treated with natural Zn (as ZnSO4) or enriched stable isotope 70Zn as SO4 salt. Treated leaves, and the remaining untreated shoot and roots were analyzed for Zn using quantitative (ICP-OES and ICP-MS after acid digestion) and qualitative (fluorescence microscopy after Zinpyr-1 staining) techniques. Results: Application of Zn to a single old leaf resulted in significantly higher increments in Zn concentration of the treated leaf, remaining untreated shoot and roots in wheat than in maize, particularly under low Zn supply. The relative Zn uptake (i.e., the portion of 70Zn taken up by the treated leaf) was also estimated to be significantly higher in wheat than maize, irrespective of the rate of Zn supply to plants. Higher uptake and translocation of Zn in wheat compared to maize was also visualized and demonstrated by using Zinpyr-1 fluorescent dye. Conclusions: Our results conclude that wheat is superior to maize in terms of leaf penetration and uptake, as well as subsequent translocation of foliar-applied Zn, therefore, the agronomic biofortification potential is better for wheat than for maize. [ABSTRACT FROM AUTHOR]

Long-term effects of integrated application of organics and chemical fertilizers on transformation of copper (Cu) into various chemical pools and their availability under maize–wheat cropping system were investigated in the ongoing long-term fertilizer experiment initiated in 1972 at the research farm of Chaudhary Sarwan Kumar Himachal Pradesh Agricultural University on an acidic soil in the Western Himalayas of India. The continuous use of chemical fertilizers alone for 36 years brought about marked depletion in all forms of copper except organically bound Cu (Cu-III) compared to buffer plots. Integrated use of organics and chemical fertilizers gave higher content of Cu forms over chemically treated plots except Cu occluded by free oxides (Cu-IV). Residual Cu was the most dominant form of copper contributing about 62% of the total Cu. Organically bound Cu (Cu-III) was the most important fraction of copper contributing toward DTPA (diethylene triamine pentaacetic acid) extractable Cu. Content of DTPA-extractable Cu increased over control when chemical fertilizers were applied in conjunction with different organics, whereas DTPA-Cu content declined over control with application of chemical fertilizers alone for the last 36 years. [ABSTRACT FROM AUTHOR]

The land surface characteristic influences climatic environments by controlling the land surface energy and water fluxes. Although large progresses have been made in coupling detailed crop models into land surface models, there is much room left for improved estimates of surface fluxes in double cropping system, such as the winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) system under intensive influences of climate change and human activities in the North China Plain (NCP). Here, we modeled the growth and surface fluxes in winter wheat–summer maize double cropping system in the NCP through modified SiBcrop model. The parameters related with the crop growth in winter wheat and maize sub-models were emphasized to better simulate the seasonal dynamics of phenology phase, leaf area index (LAI), and latent (LH) and sensible (SH) heat fluxes. Observational data for phenology, LAI, and energy fluxes were compiled from Yucheng and Guantao stations, to calibrate and validate the SiBcrop model. The results showed that the adjusted SiBcrop captured better the seasonal dynamics of phenology, LAI, LH, and SH, relative to the original code. The largest biases in model results were in SH when horizontal advection prevails and in LH when there is summer maize senescence. Sensitivity analysis illustrated that growth duration, emergence date, LH, SH, and Bowen ratio were quite sensitive to sowing date of wheat, and growth duration and emergence and harvest dates to sowing of maize. The calibrated SiBcrop also simulated the LH and SH well at Guantao station. The adjusted SiBcrop is capable of assessing the responses of surface biophysical processes to the changes of human management and climate change in the double cropping system in the NCP. [ABSTRACT FROM AUTHOR]

India is one of the largest landmasses under crop cultivation with staple consumption of food security crops. Post green revolution (since 1967), there has been a steady March towards self-sustainability in food production. Though the general trends speak of an increase in crop yields, the detailed study on decade wise trends and fast approaching state of stagnation in crop yields is largely missing. The present manuscript is the first study examining the crop yield trends of three major food crops—wheat, rice, and maize across Indian states. The four types of regression models were fitted on the annual yield data from all the 29 Indian states over the period 1967–2017. The best-fit statistical models were chosen using the Akaike information criterion. Our results suggest that (1) Wheat yields in 13 Indian states, rice yields in eleven Indian states, and maize yields in six Indian states are now not improving. (2) The yields in ~ 76% of wheat harvested area (~ 18.5 million hectares), ~ 47% of rice harvested area (~ 19.5 million hectares), and ~ 18% of maize harvested area (~ 1.2 million hectares) are not improving for the recent decade. The detailed mapping of current crop yield trends across Indian states is the first step towards achieving a bigger goal of identifying the responsible factors affecting current crop yield trends and then identifying and recommending appropriate mitigation strategies. [ABSTRACT FROM AUTHOR]

Background: A significant source of greenhouse gas (GHG) emissions comes from the manufacture of synthetic nitrogen (N) fertilizers consumed in crop production processes. And the application of synthetic N fertilizers is recognized as the most important factor contributing to direct N2O emissions from agricultural soils. Based on statistical data and relevant literature, the GHG emissions associated with synthetic N manufacture and fertilization for wheat and maize in different provinces and agricultural regions of China were quantitatively evaluated in the present study. Results: During the 2015–2017 period, the average application rates of synthetic N for wheat and maize in upland fields of China were 222 and 197 kg ha−1, respectively. The total consumption of synthetic N on wheat and maize was 12.63 Mt year−1. At the national scale, the GHG emissions associated with the manufacture of synthetic N fertilizers were estimated to be 41.44 and 59.71 Mt CO2-eq year−1 for wheat and maize in China, respectively. And the direct N2O emissions derived from synthetic N fertilization were estimated to be 35.82 and 69.44 Gg N2O year−1 for wheat and maize, respectively. In the main wheat-cultivating regions of China, area-scaled GHG emissions were higher for Inner Mongolia, Jiangsu and Xinjiang provinces. And for maize, Gansu, Xinjiang, Yunnan, Shannxi and Jiangsu provinces had higher area-scaled GHG emissions. Higher yield-scaled GHG emissions for wheat and maize mainly occured in Yunnan and Gansu provinces. Conclusions: The manufacture and application of synthetic N fertilizers for wheat and maize in Chinese croplands is an important source of agricultural GHG emissions. The current study could provide a scientific basis for establishing an inventory of upland GHG emissions in China and developing appropriate mitigation strategies. [ABSTRACT FROM AUTHOR]

Phosphorus (P) research still lacks techniques for rapid imaging of P use and allocation in different soil, sediment, and biological systems in a quantitative manner. In this study, we describe a time-saving and cost-efficient digital autoradiographic method for in situ quantitative imaging of 33P radioisotopes in plant materials. Our method combines autoradiography of the radiotracer applications with additions of commercially available 14C polymer references to obtain 33P activities in a quantitative manner up to 2000 Bq cm−2. Our data show that linear standard regressions for both radioisotopes are obtained, allowing the establishment of photostimulated luminescence equivalence between both radioisotopes with a factor of 9.73. Validating experiments revealed a good agreement between the calculated and applied 33P activity (R2 = 0.96). This finding was also valid for the co-exposure of 14C polymer references and 33P radioisotope specific activities in excised plant leaves for both maize (R2 = 0.99) and wheat (R2 = 0.99). The outlined autoradiographic quantification procedure retrieved 100% ± 12% of the 33P activity in the plant leaves, irrespective of plant tissue density. The simplicity of this methodology opens up new perspectives for fast quantitative imaging of 33P in biological systems and likely, thus, also for other environmental compartments. [ABSTRACT FROM AUTHOR]

Key message: Overview of current understanding of epigenetic alterations after abiotic stresses during reproductive development in cereals.Abstract: Abiotic stresses, including heat, drought, cold, flooding, and salinity, negatively impact crop productivity. Various stages during reproductive development are especially sensitive to environmental stresses, which may lead to complete sterility and severe yield losses. Plants exhibit diverse responses to ameliorate stress damage. Changes in DNA methylation, histone modification as well as regulation of small RNA and long noncoding RNA pathways have been shown to represent key modulators in plant stress responses. During reproductive development in cereals, various protein complexes controlling histone and DNA methylation have been identified, revealing conserved and novel mechanisms regulating abiotic stress responses in cereals and other plant species. New findings highlight the role of transposable elements during stress periods. Here, we review our current understanding of epigenetic stress responses during male and female gametophyte formation (germline development), fertilization, early seed devolvement, and seed maturation in cereals. An integrative model of epigenetic responses during reproductive development in cereals is proposed, emphasizing the role of DNA methylation and histone modifications during abiotic stresses. [ABSTRACT FROM AUTHOR]

Background and aims: Cereals are the main dietary source of cadmium (Cd). Rice grains often contain higher levels of Cd than other cereals, but the reasons are unknown. The aims of this study were to compare Cd uptake, translocation and influx kinetics between rice, wheat and maize and to investigate whether the expression and functionality of Nramp5 genes differ between the three crop species.Methods: Two cultivars each of rice, wheat and maize were grown hydroponically and exposed to a range of Cd concentrations. Nramp5 genes were cloned from the three plants and their expression levels determined. The Cd transport activities of Nramp5 proteins were tested in yeast.Results: Under hydroponic conditions, Cd uptake in rice was 2.5-8.1 and 1.1-3.6 times that of wheat and maize, respectively. The maximum Cd influx velocity of rice was 6.5 and 2.2 times that in wheat and maize, respectively. Wheat showed the lowest Cd uptake but the highest Cd root-to-shoot translocation. The absolute expression level of OsNramp5 in rice roots was 4-5 times that of TaNramp5A and TaNramp5D in wheat or ZmNramp5 in maize. All Nramp5 proteins were localized to the plasma membrane. When expressed in yeast, OsNramp5 showed a greater Cd transport activity than wheat or maize Nramp5.Conclusions: Rice has a greater Cd uptake ability than wheat or maize, likely because OsNramp5 is more highly expressed and the protein has a higher Cd transport activity than wheat or maize Nramp5. [ABSTRACT FROM AUTHOR]

Spatial distribution changes in major crops can reveal important information about cropping systems. Here, a new centroid method that applies physics and mathematics to spatial pattern analysis in agriculture is proposed to quantitatively describe the historical centroids of rice, maize and wheat in China from 1949 to 2014. The geographical centroids of the rice area moved 413.39 km in a 34.32° northeasterly (latitude 3.08°N, longitude 2.10°E) direction at a speed of 6.36 km/year from central Hunan province to Hubei province, while the geographical centroids of rice production moved 509.26 km in the direction of 45.44° northeasterly (latitude 3.22°N, longitude 3.27°E) at a speed of 7.83 km/year from central Hunan province to Henan province. The geographical centroids of the maize area and production moved 307.15 km in the direction of 34.33° northeasterly (latitude 2.29°N, longitude 1.56°E) and 308.16 km in the direction of 30.79° northeasterly (latitude 2.39°N, longitude 1.42°E), respectively. However, the geographical centroids of the wheat area and production were randomly distributed along the border of Shanxi and Henan provinces. We divided the wheat into spring wheat and winter wheat and found that the geographical centroids of the spring wheat area and production were distributed within Inner Mongolia, while the geographical centroids of winter wheat were distributed in Shanxi and Henan provinces. We found that the hotspots of crop cultivation area and production do not always change concordantly at a larger, regional scale, suggesting that the changing amplitude and rate of each crops’ yield differ between different regions in China. Thus, relevant adaptation measures should be taken at a regional level to prevent production damage in those with increasing area but decreasing production. [ABSTRACT FROM AUTHOR]

The primary objective of the present study was to assess the level of selenium and toxic trace elements in wheat, rice, maize, and mustard from seleniferous areas of Punjab, India. The content of selenium (Se) and toxic trace elements, including aluminum (Al), arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), lead (Pb), and tin (Sn), in crop samples was assessed using inductively coupled plasma mass-spectrometry after microwave digestion of the samples. The obtained data demonstrate that cultivation of crops on seleniferous soils significantly increased Se level in wheat, mustard, rice, and maize by a factor of more than 590, 111, 85, and 64, respectively. The study also showed that Se exposure affected toxic metal content in crops. In particular, Se-rich wheat was characterized by a significant decrease in Al, As, Ni, Pb, and Sn levels. The level of As, Cd, Ni, Pb, and Sn was significantly decreased in Se-rich rice, whereas As content was increased. In turn, the decrease in Al, As, Cd, Ni, Pb, and Sn levels in Se-rich maize was associated with a significant elevation of Hg content. Finally, Se-rich mustard was characterized by a significant increase in Al, As, and Hg levels, while the content of Ni, Pb, and Sn was significantly lower than the control levels. These findings should be taken into account while developing the nutritional strategies for correction of Se status. At the same time, the exact mechanisms underlying the observed differences are to be estimated. [ABSTRACT FROM AUTHOR]

Fungal disease of grain crops is a concern for the agricultural industry, resulting in economic losses. Aside from severe yield losses, mycotoxigenic fungi such as Penicillium and Fusarium can produce harmful mycotoxins, including deoxynivalenol (DON), zearalenone (ZEN), and ochratoxin A (OTA). This proof-of-concept study explored the feasibility and effects of ultraviolet (UV) C light at 253.7 nm to reduce fungal and mycotoxin loads on model surfaces as well as on maize and wheat kernels using benchtop 2D and 3D illumination strategies. Reduction of Penicillium verrucosum (98.6%) and Fusarium graminearum (88.8%) on agar was achieved using a UV-C dose of 100 mJ cm−2. Naturally occurring fungal growth resembling P. verrucosum on maize was reduced by 79% after exposure to 5000 mJ cm−2. Similarly, fungal growth resembling F. graminearum on maize was reduced by 60% with 1000 mJ cm−2. On wheat, significant reduction of fungal growth was not observed. Maximal reduction of DON (97.3%), ZEN (75.4%), and OTA (91.2%) on filter paper was obtained using 15,000 mJ cm−2. The overall reduction of DON (30%; 14%), ZEN (52%; 42%), and OTA (17%; 6%) on maize and wheat, respectively, was lower than on filter paper. Moisture and crude protein content as well as percent germination of maize kernels were not affected by UV-C treatment up to 5000 mJ cm−2. This study has shown that 3D UV-C treatment is a feasible option for reducing Fusarium and Penicillium growth on maize kernels and, at higher doses, decreasing ZEN by ~ 50%. [ABSTRACT FROM AUTHOR]

Background: Differences in cropping systems and their impacts on plant growth and carbon (C) uptake as well as soil C release pose a major challenge in projecting agroecosystem C balance. Methods: A four-year (2012-2015) field experiment was conducted to examine crop C uptake and soil respiration in two conventional (wheat-cotton and wheat-maize) and two legume-based (wheat-soybean and alfalfa-maize) double-season cropping systems in North China Plain. Results: During the 4 experimental years, crop C uptake was greater in the two conventional systems than the two legume-based systems. However, soil respiration was higher in the two systems with C (i.e. maize) than C crops (i.e. cotton and soybean) planted in summer. As consequences, cropland C balance was positive in the two conventional cropping systems, with greater value in the wheat-maize comparing to wheat-cotton system. However, the two legume-based cropping systems showed negative cropland C balance. Conclusions: Our findings indicate that, although more CO-C is emitted in maize-related cropping systems, the conventional agricultural activities may sequestrate more C in comparison with the legume-based farming in North China Plain due to higher C uptake, and highlight the importance of management strategy in improving agroecosystem C storage. [ABSTRACT FROM AUTHOR]

The present study evaluated the effect of untreated wastewater irrigation and its health risks in Triticum aestivum (wheat) and Zea mays (maize) cultivated at south Cairo, Egypt. Morphological measurements (stem and root lengths, number of leaves per plant, and dry weights of main organs) as well as soil, irrigation water, and plant analyses for nutrients and heavy metals were conducted in polluted and unpolluted sites. Wastewater irrigations leads to reduction in the morphological traits of the plants and reduced its vegetative biomass and yield production, with more negative impacts on maize than wheat. The concentrations of Pb, Cd, Cr, and Fe in roots and leaves of wheat were above the phytotoxic limits. Conversely, Pb, Cd, and Fe were significantly high and at phytotoxic concentrations in the leaves of maize at polluted site. The present study indicated that wheat plants tend to phytostabilize heavy metals in their roots, while maize accumulates it more in their leaves. Maize and wheat had toxic concentrations of Pb and Cd in their grains under wastewater irrigation. The health risk index showed values > 1 for Pb and Cd in polluted site for both crops, in addition to maize in unpolluted site. Consequently, this will have greatest potential to pose health risk to the consumers. [ABSTRACT FROM AUTHOR]

A straightforward analytical method was developed and validated to determine the mycotoxin moniliformin in cereal-based foods. Moniliformin is extracted with water and quantified with liquid chromatography tandem mass spectrometry, and its presence confirmed with liquid chromatography-Orbitrap-high-resolution mass spectrometry. The method was validated for flour, bread, pasta and maize samples in terms of linearity, matrix effect, recovery, repeatability and limit of quantification. Quantification was conducted by matrix-matched calibration. Positive samples were confirmed by standard addition. Recovery ranged from 77 to 114% and repeatability from 1 to 14%. The limit of quantification, defined as the lowest concentration tested at which the validation criteria of recovery and repeatability were fulfilled, was 10 μg/kg. The method was applied to 102 cereal-based food samples collected in the Netherlands and Germany. Moniliformin was not detected in bread samples. One of 22 flour samples contained moniliformin at 10.6 μg/kg. Moniliformin occurred in seven out of 25 pasta samples at levels around 10 μg/kg. Moniliformin (MON) was present in eight out of 23 maize products at levels ranging from 12 to 207 μg/kg. [ABSTRACT FROM AUTHOR]

Aim: Iodine (I) deficiency is distinct from other micronutrient deficiencies in human populations in having a high endemic prevalence both in well-developed and in developing countries. The very low concentration of iodine in agricultural soils and cereal-based foods is widely believed to be the main reason of iodine deficiency in humans, especially in developing countries. In the present study, the possibility of using iodine containing fertilizers for agronomic biofortification of cereal grains with iodine was studied. The aim was to establish the best application method (to the soil or as foliar spray), the best form of iodine (potassium iodate or potassium iodide) and the optimal dose of iodine. Additionally, experiments were conducted to study transport of iodine in plants and localization of iodine within the grains. Materials and methods: Experiments were conducted both under greenhouse conditions and in the field on wheat ( Triticum aestivum) grown in Turkey and Pakistan, on rice ( Oryza sativa) grown in Brazil, Thailand and Turkey and on maize ( Zea mays) grown in Turkey. The iodine concentration in the grain, localization of iodine in different grain fractions of wheat (i.e., endosperm, bran and embryo) and iodine concentration of both brown rice and polished rice was analyzed. In short-term experiments, the translocation of iodine from older into younger leaves was also studied. Inductively coupled plasma mass spectrometry (ICP-MS) was used for analysis of iodine in plant and soil samples. Results: In greenhouse experiments on wheat, soil-applied potassium iodide (KI) and potassium iodate (KIO) at increasing rates (i.e., 0, 0.1, 0.25, 1, 2.5, 5, 10 and 20 mg I kg soil) both iodine forms substantially increased iodine concentration in the shoot, with the highest shoot iodine resulting from the KI treatments. However, these soil treatments did not affect iodine concentrations in the wheat grain, with the exception of the highest iodine rates (i. e., 10 and 20 mg I kg soil) which also depressed the grain yield. In contrast to the soil applications, foliar spray of KI and KIO at increasing rates during heading and early milk stages did enhance grain iodine concentrations up to 5- to 10-fold without affecting grain yield. Including KNO or a surfactant to the iodine containing foliar spray further increased the grain iodine concentration. In a short-term experiment using young wheat plants, it was found that iodine is translocated from older into younger leaves after immersion of the older leaves in solutions containing KI or KIO. Adding KNO or a surfactant in the immersion solution also promoted leaf absorption and translocation of iodine into younger leaves. Field experiments conducted in different countries confirmed that foliar application with increasing rates of iodine significantly increased grain iodine concentrations in wheat, brown rice and maize. This increase was also found in the iodine concentration of the endosperm part of wheat grains and in polished rice. Conclusions: The results of the present study clearly show that foliar application of iodine containing fertilizers is highly effective in increasing grain iodine concentrations in wheat, rice and maize. Presented results suggest that iodine is translocated from shoot to grain by transport in the phloem. Spraying KIO up to the rate of 0.05% w/ v is suggested as the optimal form and rate to be used in agronomic biofortification with iodine. The substantial increase in grain iodine concentrations could contribute to the prevention of iodine deficiency in human populations with low dietary iodine intake. The reasons behind the higher effectiveness of foliar-applications compared to the soil applications of iodine fertilizers in improving grain iodine concentration are discussed. [ABSTRACT FROM AUTHOR]

China's large population and deteriorating environment have created great concern related to the sustainability of food production, especially since details related to this topic remain poorly studied. Thus, an integrated analysis of both crop yield and cultivated area is essential for gaining a better understanding of cereal grain production in China and for making corresponding policies designed to achieve food security. In this study, we adopt trend analysis of both provincial yield and cultivated area to assess the subsequent provincial-level cereal production sustainability between 1980 and 2011 with the goal of providing a better understanding of regional agricultural development. The results indicate that while maize shows the most promise for yield improvement, rice and wheat production is experiencing substantial yield stagnation among most provinces across mainland China. In addition, the trends in spatial patterns are prominently different from those of yields. The sizes of the main rice- and wheat-growing areas in China have declined greatly, suggesting that the related production of these cereals should attract more attention from land management planners and farmers. Specifically, the south-eastern coastal provinces have largely failed to sustain both crop yield and area, while the north-eastern provinces have witnessed thriving agricultural production during the last three decades. Moreover, we find that cereal production in China is significantly affected by governmental policies related to the agricultural sector. Thus, this analysis of food production in China will help policymakers to better understand how the potential implications of food security in China may be applicable to countries worldwide. [ABSTRACT FROM AUTHOR]

Background and aims: Intercropping often produces more biomass than the average of the corresponding monocultures, particularly in sustainable, low-input agriculture. Characterizing plant-plant interactions is fundamental for a better understanding of the ecological functioning of intercropping. However, there is little information on whether mycorrhizal networks exhibit different effects upon intra- and interspecific plant interactions in intercropping systems. Methods: Microcosms with one inner and three outer compartments were used. The inner compartment was separated from the outer compartments by a 30-μm nylon mesh or a solid barrier or remained open to allow full interactions between plants grown in the different compartments, creating three treatments, namely −Roots−CMNs (solid barrier), −Roots+CMNs (mesh), and +Roots+CMNs (no barrier). Either faba bean ( Vicia faba) or maize ( Zea mays) was grown as the donor plant in the inner compartment. Maize was combined with maize, wheat ( Triticum aestivum) or the weed species foxtail ( Setaria viridis) as the neighboring plant species. Faba bean was combined with faba bean, maize, or foxtail. The low-P soil was inoculated with the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae or remained uninoculated. Results: In the absence of AMF, plant growth was restricted by P deficiency and root interactions did not significantly affect plant-plant interactions. The presence of AMF enhanced plant biomass (maize by 104.5 %, faba bean by 61.6 %) and nutrient (N and P) uptake. Significant overyielding occurred in treatments where roots and hyphal networks of all plant species intermingled. The weed (foxtail) was suppressed by interspecific interactions while maize and faba bean benefitted from a mycorrhizal network and the presence of intermingling roots. Conclusions: In low-P soils, mycorrhizal networks contribute to overyielding in intercropping by enhancing the biomass and nutrient uptake of the mycorrhiza-dependent plant species. The biomass depression of weed species by AMF and/or root interactions may have ecological implications in weed control in intercropping systems. [ABSTRACT FROM AUTHOR]

The intensification of agriculture has increased production at the cost of environment and biodiversity worldwide. To increase crop yield in dry cereal systems, vast farmland areas of high conservation value are being converted into irrigation, especially in Mediterranean countries. We analyze the effect of irrigation-driven changes on the farm biota by comparing species diversity, community composition, and species traits of arable plants within crop fields from two contrasting farming systems (dry and irrigated) in Spain. We sampled plant species within 80 fields of dry wheat, irrigated wheat, and maize (only cultivated under irrigation). Wheat crops held higher landscape and per field species richness, and beta diversity than maize. Within the same type of crop, irrigated wheat hosted lower plant diversity than dry wheat at both field and landscape scales. Floristic composition differed between crop types, with higher frequencies of perennials, cosmopolitan, exotic, wind-pollinated and C species in maize. Our results suggest that irrigation projects, that transform large areas of dry cereal agro-ecosystems into irrigated crop systems dominated by maize, erode plant diversity. An adequate planning on the type and proportion of crops used in the irrigated agro-ecosystems is needed in order to balance agriculture production and biodiversity conservation. [ABSTRACT FROM AUTHOR]

Reducing the carbon footprint and increasing energy use efficiency of crop rotations are the two most important sustainability issues of the modern agriculture. Present study was undertaken to assess economics, energy, and environmental parameters of common diversified crop rotations (maize-tomato, and maize-toriawheat) vis-a-vis traditional crop rotations like maizewheat, maize + ginger and rice-wheat of the northwestern Himalayan region of India. Results revealed that maize-tomato and maize + ginger crop rotations being on par with each other produced significantly higher system productivity in terms of maize equivalent yield (30.2–36.2 t/ha) than other crop rotations (5.04–7.68 t/ha). But interestingly in terms of energy efficiencies, traditional maize-wheat system (energy efficiency 7.9, human energy profitability of 177.8 and energy profitability of 6.9 MJ/ha) was significantly superior over other systems. Maize + ginger rotation showed greater competitive advantage over other rotations because of less consumption of non-renewable energy resources. Similarly, maize-tomato rotation had ability of the production process to exploit natural resources due to 14–38 % less use of commercial or purchased energy sources over other crop rotations. Vegetable-based crop rotations (maize + ginger and maize-tomato) maintained significantly the least carbon footprint (0.008 and 0.019 kg CO2 eq./kg grain, respectively) and the highest profitability (154,322 and 274,161 Rs./ha net return, respectively) over other crop rotations. As the greatest inputs of energy and carbon across the five crop rotations were nitrogen fertilizer (15–29 % and 17–28 %, respectively), diesel (14–24 % and 8–19 %, respectively) and irrigation (10–27 % and 11–44 %, respectively), therefore, alternative sources like organic farming, conservation agriculture practices, soil and water conservation measures, rain water harvesting etc. should be encouraged to reduce dependency of direct energy and external carbon inputs particularly in sub- Himalayas of India. [ABSTRACT FROM AUTHOR]

Different stresses include nutrient deficiency, pathogen attack, exposure to toxic chemicals etc. Transcriptomic studies have been mainly applied to only a few plant species including the model plant, Arabidopsis thaliana. These studies have provided valuable insights into the genetic networks of plant stress responses. Transcriptomics applied to cash crops including barley, rice, sugarcane, wheat and maize have further helped in understanding physiological and molecular responses in terms of genome sequence, gene regulation, gene differentiation, posttranscriptional modifications and gene splicing. On the other hand, comparative transcriptomics has provided more information about plant's response to diverse stresses. Thus, transcriptomics, together with other biotechnological approaches helps in development of stress tolerance in crops against the climate change. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is one of the toxic metals that adversely affect plant growth. Organic amendments may not only enhance nutrient status of soil, but they may also form complexes with Cd and reduce its availability to plants. This experiment was conducted to determine whether organic amendments (compost and biogas slurry) could stabilize/extract Cd and alleviate the adverse effects of Cd on the growth of two cereals, wheat and maize. Organic amendments along with four varying levels of Cd (0, 5, 20, 50 mg kg soil) were prepared with soil. Effect of these amendments on tolerance indices, root/shoot dry biomass, tissue Cd concentration, Cd uptake and translocation were studied. Biogas slurry caused maximum increase in tolerance indices of wheat and maize (100-112 and 117-133 %, respectively, as compared to control), whereas compost caused significant increase in their dry biomass. Negative correlation between root dry biomass of wheat ( r = −0.37) and maize ( r = −0.53) to Cd revealed its suppressive effects. Dry biomass of plant correlated with organic amendments in wheat ( r = 0.83-0.98), whereas weak correlation was observed in maize ( r = 0.30-0.40). Compost significantly reduced Cd uptake in wheat and maize; however, it increased Cd translocation in plants. Based on the results of this study, root was the major sink of Cd when soil was amended with or without organic amendments. Biogas slurry removed 97 % Cd from artificially polluted water after 13 h at pH 6. The additions of compost in soil and biogas slurry in wastewater are recommended to stabilize/extract Cd. [ABSTRACT FROM AUTHOR]

A critical assessment of three previously published indirect methods based on acidic hydrolysis using superacids for the determination of 'free' and 'total' deoxynivalenol (DON) was carried out. The modified mycotoxins DON-3-glucoside (D3G), 3-acetyl-DON (3ADON), and 15-acetyl-DON (15ADON) were chosen as model analytes. The initial experiments focused on the stability/degradation of DON under hydrolytic conditions and the ability to release DON from the modified forms. Acidic conditions that were capable of cleaving D3G, 3ADON, and 15ADON to DON were not found, raising doubts over the efficacy of previously published indirect methods for total DON determination. Validation of these indirect methods for wheat, maize, and barley using UHPLC-MS/MS was performed in order to test the accuracy of the generated results. Validation data for DON, D3G, 3ADON, and 15ADON in nonhydrolyzed and hydrolyzed matrices were obtained. Under the tested conditions, DON was not released from D3G, 3ADON, or 15ADON after hydrolysis and thus none of the published methods were able to cleave the modified forms of DON. In addition to acids, alkaline hydrolysis with KOH for an extended time and at elevated temperatures was also tested. 3ADON and 15ADON were cleaved under the alkaline pH caused by the addition of KOH or aqueous KCO to 'neutralize' the acidic sample extracts in the published studies. The published additional DON increase after hydrolysis may have been caused by huge differences in matrix effects and the recovery of DON in nonhydrolyzed and hydrolyzed matrices as well as by the alkaline cleavage of 3ADON or 15ADON after the neutralization of hydrolyzed extracts. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the antioxidant responses of wheat and maize growing in Zn-treated soils (200, 450 and 900 mg kg) at different exposure times (7, 14, 21 and 35 days). The Zn concentration in the plants increased with an increase in the Zn concentration in the soil, thereby causing an increase in the accumulation of Mg and Mn. The emergence of wheat and the growth of maize were inhibited by Zn. The chlorophyll levels increased in wheat, whereas the opposite effect was observed in maize. Regarding enzymatic activities, Zn only provoked pronounced increases in the ascorbate peroxidase activity in maize at the early exposure times and occasionally in the superoxide dismutase (14 days) and catalase (7 and 35 days) activities in wheat. The most notable effect of the exposure of plants to Zn was an inhibition of antioxidative activities after 35 days in both plant species. The reduced glutathione levels increased in wheat and maize after 35 days and the protein levels in wheat after 7 and 35 days. The only significant alteration of lipid peroxidation was a decrease in the malondialdehyde level in wheat after 35 days. Results of this work suggest that Zn may generate oxidative stress by interfering with the plant antioxidant defence system (peroxidases, catalases and superoxide dismutase) responsible for free radical detoxification. The enzymatic activities, particularly ascorbate peroxidase, and the content of reduced glutathione could be considered good biomarkers of serious stress by Zn in soils. [ABSTRACT FROM AUTHOR]

The response of the carbon and hydrological cycles of irrigated agro-ecosystems in semi-arid regions to changes in temperature and increasing levels of atmospheric carbon dioxide concentrations is unclear. Furthermore, the extent to which these systems contribute to the carbon cycle as net sources or sinks of carbon dioxide remains relatively unknown. In this study, eddy covariance methodologies were employed to quantify mass and energy exchange of maize, rice and wheat grown in an Australian semi-arid irrigation-dependent agricultural region. It was found that there was a distinct seasonal difference in the magnitude of energy balance components. The latent heat exchange observed during the summer growing season was almost twice that observed during winter. Irrigation management practices significantly influenced the distribution of turbulent fluxes. Over the permanently flooded rice crop, the energy balance was predominately driven by latent heat flux, which accounted for ~99 % of the energy balance. For the crops irrigated intermittently (i.e. maize and wheat), latent heat flux represented ~80 % of the energy balance. In addition, all three crops acted as a net carbon sink over the growing season. The rate of carbon assimilation was impacted by the nature of the photosynthetic pathway of the plant and seasonality. Maize, a C4 plant, exhibited the greatest capacity for carbon uptake (−1,327 g C/m) during the summer months, and winter wheat, a C3 plant, exhibited the least (−388 g C/m). [ABSTRACT FROM AUTHOR]

There is a growing concern that greenhouse gas (GHG) emissions during agricultural energy crop production might negate GHG emission savings which was not intended when promoting the use of renewable energy. Nitrous oxide (NO) is a major GHG, and in addition, it is the most powerful ozone-depleting compound that is emitted by human activity. The use of N fertilizers and animal manures is the main anthropogenic source of NO emissions. In spite of their high relevance, we still have limited understanding of the complex underlying microbial processes that consume or produce NO and their interactions with soil types, fertilizers (rate and types), plants, and other environmental variables. In a 2-year field experiment, we compared two important biogas crops in two different agro-ecological regions of northern Germany for their productivity and GHG emissions, using the closed-chamber technique and high time-resolution sampling. Silage maize, which is currently the most widespread crop grown for biogas fermentation purposes in Germany, was compared with an alternative bioenergy crop at each site. The three forms of nitrogen fertilizers/manures were given: calcium ammonium nitrate, cattle/pig slurry, and biogas residue. The greatest NO flux activity occurred in the period of May-July in all crops and at both sites. Flux patterns indicated pronounced effects of soil moisture-soil mineral-N interactions which were also seen as causation of the higher NO fluxes in the bioenergy crop maize compared to the other tested energy crops. However, the NO emission per unit methane production (specific NO emission) was clearly lower in soils planted with maize due to significantly higher methane hectare yield of maize. Our data suggest a linear relationship between increasing N input and increases in NO emission in both years at site with sandy loam texture where highest NO fluxes were measured. At sandy loam site, the percentage of applied N being emitted as NO was 1.9 and 1.1 % in soils cropped with maize and 0.9 and 0.8 % in soils cropped with wheat during the investigation period 2007-2008 and 2008-2009, respectively. In contrast, at site with sandy soil texture, the percentage of applied N emitted as NO was only 0.6 and 0.7 % in maize soils and 0.4 and 0.3 % in grassland during 2007-2008 and 2008-2009 period, respectively. Higher daily and annual NO emissions at the sandy loam site were attributed to the finer soil texture and higher denitrification activity. The present study provides a very good basis for the assessment of direct emissions of greenhouse gases from relevant biogas crops in North-West Europe. [ABSTRACT FROM AUTHOR]

The technique of diffusive gradients in thin film (DGT) has been shown to be a promising tool to assess zinc (Zn) bioavailability in soils, but there exists considerable debate on its suitability. In this study, Zn bioavailability was systematically investigated in wheat- and maize-grown soils using this technique and seven traditional methods, including soil solution concentration and six widely used single-step extraction methods (HAc, EDTA, NaAc, NHAc, CaCl, and MgCl). The concentrations of Zn in the shoots and roots of these two plant species increased continuously with increasing additions of Zn to the soils, accompanied by significant decreases in shoot biomass and root biomass at Zn concentrations greater than 400 mg kg for maize and 800 mg kg for wheat. Zinc uptake and accumulation was higher in maize roots than in wheat roots. Both the concentrations of bioavailable Zn measured by DGT ( C) and soil solutions ( C) increased linearly with increasing additions of Zn to the soils, while no strong linear relationships were observed for the extraction methods. Higher concentrations of extractable Zn, lower values of C, and larger values of R (i.e., the ratio of C to C) were observed in maize-grown soils compared with those of wheat-grown soils, while the values of C between the two plants were similar. These findings demonstrate that there likely exists a stronger resupply of Zn from the soil solid phases in maize-grown soils to satisfy a higher Zn uptake and accumulation in this plant. Linear correlation analyses showed that C had the highest correlation coefficients with plant Zn concentrations compared with other traditional methods, implying that the DGT technique is more sensitive and robust in reflecting Zn bioavailability in soils to plants. [ABSTRACT FROM AUTHOR]

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Aims and background: Soil fertility quality index is a useful indicator that helps to improve sustainable land use management and achieve economical yield in agriculture production. The objectives of this study were to evaluate the changes of soil fertility quality between the 1980s and 2000s in different cropping systems and its significance to crop productivity and sustainability. Methods: We collected all published data on crop yields and soil parameters from 58 long-term experiments in three typical double-cropping systems in China, including maize-wheat (M-W), rice-rice (R-R) and rice-wheat (R-W) cropping systems, and selected seven fertilizer treatments in each experiment, including inorganic fertilizer [nitrogen and phosphorus fertilizer (NP), nitrogen and potassium fertilizer (NK), phosphorus and potassium fertilizer (PK) and balanced mineral fertilizer (NPK)], combined NPK with farmyard manure (NPKM) or crop straw (NPKS), and no fertilizer application (served as control). For comparison, an integrated fertility quality index (IFQI) was used to estimate the variations in soil fertility in different cropping systems. Moreover, the mean production variability index (PVI, %) in each cropping system was calculated to evaluate the stability of crop production. Results: Over cropping systems, the averaged relative yields of PK, NK and NP ranged from 38.0 to 97.4 %, while the mean yields can be increased by 2.4-5.1 % in NPKM, compared to NPK. The mean yields were similar between NPK and NPKS for maize and wheat crops, but the yield was increased by 4.3-10.0 % in NPKS. Among the different treatments, the highest variability of cereal productivity was obtained in NK, PK or Control, while the lowest value was mostly recorded in NPKM or NPKS in these three cropping systems. Relative to the control, the IFQIs in fertilization treatments were increased by 9.4-150.0 %, 6.2-41.5 % and 1.3-17.5 % in M-W, R-W and R-R systems, respectively (except for PK treatment in R-R system). However, changes of IFQI in topsoil differed among fertilizer treatments, and greater increases existed in the treatments receiving organic residues (NPKM and NPKS). Conclusions: The increase in crop yield is exponentially correlated with the increased IFQI over treatments in three cropping systems. Over the treatments and systems, production variability among years is shown to be negatively, linearly related to IFQI ( P < 0.001). Therefore, the high grain yield and low production variability can be simultaneously achieved by increasing soil fertility in all three cropping systems. [ABSTRACT FROM AUTHOR]

Many untargeted LC-ESI-HRMS based metabolomics studies are still hampered by the large proportion of non-biological sample derived signals included in the generated raw data. Here, a novel, powerful stable isotope labelling (SIL)-based metabolomics workflow is presented, which facilitates global metabolome extraction, improved metabolite annotation and metabolome wide internal standardisation (IS). The general concept is exemplified with two different cultivation variants, (1) co-cultivation of the plant pathogenic fungi Fusarium graminearum on non-labelled and highly C enriched culture medium and (2) experimental cultivation under native conditions and use of globally U-C labelled biological reference samples as exemplified with maize and wheat. Subsequent to LC-HRMS analysis of mixtures of labelled and non-labelled samples, two-dimensional data filtering of SIL specific isotopic patterns is performed to better extract truly biological derived signals together with the corresponding number of carbon atoms of each metabolite ion. Finally, feature pairs are convoluted to feature groups each representing a single metabolite. Moreover, the correction of unequal matrix effects in different sample types and the improvement of relative metabolite quantification with metabolome wide IS are demonstrated for the F. graminearum experiment. Data processing employing the presented workflow revealed about 300 SIL derived feature pairs corresponding to 87-135 metabolites in F. graminearum samples and around 800 feature pairs corresponding to roughly 350 metabolites in wheat samples. SIL assisted IS, by the use of globally U-C labelled biological samples, reduced the median CV value from 7.1 to 3.6 % for technical replicates and from 15.1 to 10.8 % for biological replicates in the respective F. graminearum samples. [ABSTRACT FROM AUTHOR]

Reliability of crop production data has implications for yield gap analysis, production time trends, trading and policy decisions. In this paper, we compared databases of major grain crops estimated by a pair of independent organisations in Nebraska, USA (USDA-NASS, of USDA vs NRD, Natural Resources Districts of Nebraska) and a pair of independent organisations in Argentina (MA, Ministerio de Agricultura vs. BC, Bolsa de Cereales de Buenos Aires). The comparisons involved the yield of irrigated and rainfed maize and soybean reported by USDA-NASS and NRD, and the yield, acreage and production of maize, soybean and wheat reported by MA and BC. The comparison between NASS-USDA and NRD yield data included 127 paired observations for maize and 87 for soybean. For the pooled data involving irrigated and rainfed crops, the average difference in yield between the two sources was small (<5 %). In both crops, however, the yield difference between sources increased with increasing yield suggesting that NRD reported higher yields than NASS-USDA in high-yielding, irrigated crops and lower yields in rainfed crops. For maize, NRD returned lower yield than NASS-USDA for average yield below 10 t ha, and higher yield above this threshold. For soybean, NRD returned lower yield than NASS-USDA for average yield below 3 t ha, and higher yield above this threshold. For the pooled data comprising 13 regions and 9-10 cropping seasons per region in Argentina, differences between yield reported by MA and BC were larger and more scattered for maize than for soybean and wheat. The differences in acreage between the two sources increased with increasing acreage for soybean and wheat, and the same pattern was found for total production. Differences in production were more closely related to differences in acreage than to differences in yield, thus highlighting the need to improve the accuracy of crop acreage estimates. Disaggregation of data showed compensation between regions where positive differences (BC > MA) compensated negative differences (BC < MA). For both Nebraska and Argentina, relative differences between sources generally declined with larger regional cropping area and/or number of reporting fields. All four organisations providing cropping statistics involved experienced professionals using rigorous methods; hence comparisons did not seek to establish the 'right' estimate. The conclusions from these comparisons are thus asymmetric: where the two sources show statistical agreement, we can have some confidence on the reliability of the data, but where the sources disagree, we cannot tell which one is more reliable; we can, however, highlight the mismatch and recommend caution in the use and interpretation of crop yield and production data, particularly at regional level. [ABSTRACT FROM AUTHOR]

Background: Understanding the abundance of adverse environmental conditions e.g. frost, drought, and heat during critical crop growth stages, which are assumed to be altered by climate change, is crucial for an accurate risk assessment for cropping systems. While a lengthening of the vegetation period may be beneficial, higher frequencies of heat or frost events and drought spells are generally regarded as harmful. The objective of the present study was to quantify shifts in maize and wheat phenology and the occurrence of adverse environmental conditions during critical growth stages for four regions located in the North German Plain. First, a statistical analysis of phenological development was conducted based on recent data (1981-2010). Next, these data were used to calibrate the DSSAT-CERES wheat and maize models, which were then used to run three climate projections representing the maximum, intermediate and minimum courses of climate development within the RCP 8.5 continuum during the years 2021-2050. By means of model simulation runs and statistical analysis, the climate data were evaluated for the abundance of adverse environmental conditions during critical development stages, i.e. the stages of early crop development, anthesis, sowing and harvest.Results: Proxies for adverse environmental conditions included thresholds of low and high temperatures as well as soil moisture. The comparison of the baseline climate and future climate projections showed a significant increase in the abundance of adverse environmental conditions during critical growth stages in the future. The lengthening of the vegetation period in spring did not compensate for the increased abundance of high temperatures, e.g. during anthesis.Conclusions: The results of this study indicate the need to develop adaptation strategies, such as implementing changes in cropping calendars. An increase in frost risk during early development, however, reveals the limited feasibility of early sowing as a mitigation strategy. In addition, the abundance of low soil water contents that hamper important production processes such as sowing and harvest were found to increase locally. [ABSTRACT FROM AUTHOR]