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Precision agriculture manages within-field spatial variability by applying suitable inputs at the appropriate time, place, and amount. Delineation of field-specific management zones (MZs), representing significantly different yield potentials prescribe the rates of a specific crop inputs within-field. This paper examines multiple-year maize grain yield maps (2014, 2015, 2017 and 2018) and their spatial and temporal variability of within-field datasets (soil electrical conductivity [EC], soil organic matter [OM], and elevation) and climate data. The research was undertaken on a non-irrigated field at New Zealand's Foundation for Arable Research (FAR) in the Waikato region, to provide a simple, heuristic method to delineate dynamic MZs for crop inputs. Supervised statistical learning models (stepwise multiple linear regression [SMLR], feedforward neural network (FFNN), classification and regression tree (CART), random forest (RF), extreme gradient boosting (XGBoost) and Cubist regression) were implemented to predict spatial yield. Prediction accuracies of the trained models were evaluated by withholding one subset of data for testing. For internal 'split-sample' validation, CART, random forest and XGBoost produced slightly better statistical predictions (RMSE = 1.9–2.0 and R2 = 0.60–0.63) than Cubist and FFNN (RMSE = 2.1–2.2 and R2 = 0.52–0.57), whereas MLR produced the weakest prediction (RMSE = 2.3 and R2 = 0.51). Spatial yield prediction of individual years, were poor (R2 = 0.07–0.36). Input data used is readily and inexpensive for small arable fields in New Zealand. The methods presented, could be applied to a wider range of arable crops for within-field management inputs, to respond to spatially diverse soil texture distribution and variable rainfall patterns. [ABSTRACT FROM AUTHOR]

Organic grain producers are interested in interseeding cover crops into corn (Zea mays L.) in regions that have a narrow growing season window for post-harvest establishment of cover crops. A field experiment was replicated across 2 years on three commercial organic farms in Pennsylvania to compare the effects of drill- and broadcast-interseeding to standard grower practices, which included post-harvest seeding cereal rye (Secale cereale L.) at the more southern location and winter fallow at the more northern locations. Drill- and broadcast-interseeding treatments occurred just after last cultivation and used a cover crop mixture of annual ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] + orchardgrass (Dactylis glomerata L.) + forage radish (Raphanus sativus L. ssp. longipinnatus). Higher mean fall cover crop biomass and forage radish abundance (% of total) was observed in drill-interseeding treatments compared with broadcast-interseeding. However, corn grain yield and weed suppression and N retention in late-fall and spring were similar among interseeding treatments, which suggests that broadcast-interseeding at last cultivation has the potential to produce similar production and conservation benefits at lower labor and equipment costs in organic systems. Post-harvest seeding cereal rye resulted in greater spring biomass production and N retention compared with interseeded cover crops at the southern location, whereas variable interseeding establishment success and dominance of winter-killed forage radish produced conditions that increased the likelihood of N loss at more northern locations. Additional research is needed to contrast conservation benefits and management tradeoffs between interseeding and post-harvest establishment methods. [ABSTRACT FROM AUTHOR]

No tillage (NT) is often presented as a means to grow crops with positive environmental externalities, such as enhanced carbon sequestration, improved soil quality, reduced soil erosion, and increased biodiversity. However, whether NT systems are as productive as those relying on conventional tillage (CT) is a controversial issue, fraught by a high variability over time and space. Here, we expand existing datasets to include the results of the most recent field experiments, and we produce a global dataset comparing the crop yields obtained under CT and NT systems. In addition to crop yield, our dataset also reports information on crop growing season, management practices, soil characteristics and key climate parameters throughout the experimental year. The final dataset contains 4403 paired yield observations between 1980 and 2017 for eight major staple crops in 50 countries. This dataset can help to gain insight into the main drivers explaining the variability of the productivity of NT and the consequence of its adoption on crop yields. Measurement(s) yield trait • crop Technology Type(s) digital curation Factor Type(s) precipitation balance • temperature • crop species • soil texture • management of crop rotation • management of soil cover • management of field fertilization • management of weed and pest control • management of crop irrigation • geographic location Sample Characteristic - Organism Viridiplantae Sample Characteristic - Environment cultivated environment Sample Characteristic - Location global Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.13303118 [ABSTRACT FROM AUTHOR]

Organic fertilization or conversion to grassland may increase soil organic carbon (SOC) and soil total nitrogen (STN). However, responses of net SOC and STN accumulation are sometimes inconsistent and little is known about temporal patterns when those strategies are stopped. We (a) assessed the effects of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) cover crops (CCs) on SOC and STN during a 4-year "enriching" period (EP), and a following 2-year "depleting" period (DP); (b) compared these strategies with compost application and conversion to permanent fescue (Festuca arundinacea Schreb.); and (c) determined the responses of maize (Zea mays L.), soybean (Glycine max L. Merr.), and sunflower (Helianthus annuus L.) yields. Crop yield increased only in maize with compost and hairy vetch, which downsizes the role of these strategies to support productivity. SOC and STN increased with 4-year compost (+ 10.2 Mg C ha−1; + 0.5 Mg N ha−1), rye (+ 8.8 Mg C ha−1; + 0.6 Mg N ha−1), and hairy vetch (+ 6.9 Mg C ha−1; + 0.6 Mg N ha−1). Afterwards, SOC stock loss during 2-year DP tended to be higher than annual C input where there were CCs, and accounted for about 70% of annual C input where there was compost. High SOC loss highlights the weak effect of CCs for long-term SOC stabilization. Conversely, STN increased even during DP, which indicates a more lasting effect. Green manuring with CCs may be relevant for enhancing SOC and STN, although the beneficial effects are short-lived. Conversion to grassland remains the reference strategy. [ABSTRACT FROM AUTHOR]

In this work, coconut waste was evaluated for its potential for biofuel production via pyrolysis by considering physicochemical properties, kinetics of thermal degradation, and chemical composition of products generated. The kinetic of pyrolysis was investigated based on data obtained in a thermogravimetric analyzer at various heating rates. The independent parallel reactions model was used to describe the decomposition process. The activation energy (Ea) values estimated for extractives, hemicellulose, cellulose, and lignin were 194.7–197.7, 122.8–128.6, 244.1–250.5, and 53.0–64.0 kJ mol−1, respectively. The composition of the pyrolytic vapors was investigated via Py-GC/MS at different temperatures in an inert helium atmosphere. The results show that products of pyrolysis of the coconut waste can be a source of valuable chemicals, such as phenol, 1-hydroxy-2-propanone, furfural, and acetic acid. The increase of the reaction temperature resulted in the formation of hydrocarbons and in an increase in the number of aldehydes and ketones. [ABSTRACT FROM AUTHOR]

Use of seed-applied fungicides has become commonplace in the United States soybean production systems. Although fungicides have the potential to protect seed/seedlings from critical early stage diseases such as damping-off and root/stem rots, results from previous studies are not consistent in terms of seed-applied fungicide's ability to mitigate yield losses. In the current study, the relationship between estimated soybean production losses due to seedling diseases and estimated seed-applied fungicide use was investigated using annual data from 28 soybean growing states in the U.S. over the period of 2006 to 2014. National, regional (northern and southern U.S.), state, and temporal scale trends were explored using mixed effects version of the regression analysis. Mixed modeling allowed computing generalized R2 values for conditional (R2GLMM(c); contains fixed and random effects) and marginal (R2GLMM(m); contains only fixed effects) models. Similar analyses were conducted to investigate how soybean production was related to fungicide use. National and regional scale modeling revealed that R2GLMM(c) values were significantly larger compared to R2GLMM(m) values, meaning fungicide use had limited utility in explaining the national/regional scale variation of yield loss and production. The state scale analysis revealed the usefulness of seed-applied fungicides to mitigate seedling diseases-associated soybean yield losses in Illinois, Indiana, North Carolina, and Ohio. Further, fungicide use positively influenced the soybean production and yield in Illinois and South Dakota. Taken together, use of seed-applied fungicide did not appear to be beneficial to many of the states. Our findings corroborate the observations made by a number of scientists through field scale seed-applied fungicide trials across the U.S and reiterate the importance of need base-use of seed-applied fungicides rather than being a routine practice in soybean production systems. [ABSTRACT FROM AUTHOR]

In precision agriculture, suitable soil moisture and nutrient levels are important for crop production. Therefore, studying the spatial variability in soil moisture and nutrient, and their impact on crop yield is essential. In this study, spatial variability in soil mechanical composition, bulk density, water content and nutrient content in north China along with its impact on crop yield is investigated. Results show that soil mechanical composition and bulk density respectively exhibited moderate and weak spatial variation at the 0–80 cm soil depth. Soil moisture and NH4+-N contents at the 0–80 cm soil depth showed moderate spatial variation, while soil NO3−-N content showed a moderate spatial variation from the seedling stage to the filling stage and a strong spatial variation from the milk-riping stage to the maturing stage. The maximum attainable yield was achieved under the optimum soil moisture, NH4+-N, or NO3−-N contents for the whole growth period and each growth stage. At high soil water condition, both soil NH4+-N and NO3−-N contents were found to be significantly different between the high and low yield areas, while at low soil water condition, only soil NO3−-N content affected the crop yield significantly. At either low or high soil NO3−-N level, soil NH4+-N content in high-producing areas was significantly lower than that in low-producing areas. Excess fertilization was found in the experimental area. This study can provide a scientific basis for developing appropriate crop irrigation and fertilization management practices to obtain high yield. [ABSTRACT FROM AUTHOR]

Integrated crop-livestock systems (ICLS) can be an alternative to increase the productivity of agroecosystems by enhancing nutrient cycling via grazing animals. Despite the holistic approach that bears the designing of ICLS, fertilization practices are proceeded in a conventional crop basis, disregarding nutrient fluxes at the appropriate spatial and temporal dynamics. We argue that fertilization practices in ICLS must follow the same integrated approach. To test this, we compared a conventional crop fertilization strategy versus a system fertilization approach applied to two production systems being a conventional cropping system and ICLS. The conventional cropping system consisted of a soybean crop succeeded by a non-grazed Italian ryegrass cover crop. The ICLS model consisted of a soybean-Italian ryegrass rotation grazed by sheep. In the conventional crop fertilization strategy phosphorus and potassium were applied at soybean sowing and nitrogen at the Italian ryegrass establishment. The system fertilization consisted of the application of all nutrients during the Italian ryegrass establishment. Accordingly, treatments were fertilization strategies in a factorial framework with production systems randomly distributed in a complete block design with four replicates. Results indicated for the first time greater daily herbage accumulation rate (24%; P < 0.01) and total herbage production (18%; P < 0.05) in the system fertilization compared with conventional crop fertilization. Consequently, system fertilization allowed for greater stocking rates in the pasture phase (17%; P < 0.05). The ICLS presented greater equivalent soybean yield (P < 0.001), energy production (P < 0.01), and system productivity (P < 0.05) compared with the cropping system, regardless of fertilization strategies. Soybean yield was not affected by fertilization strategies or grazing. In conclusion, the adoption of system fertilization strategy and crop-livestock integration enhance the production without jeopardizing soybean grain yields, so that land use is optimized by a greater energy production per unit of nutrient applied. [ABSTRACT FROM AUTHOR]

Analysis methods for landscape-scale site-specific agricultural datasets have been adapted from a wide range of quantitative disciplines. Due to spatial effects expected at landscape scales with respect to yield affecting factors, inference from aspatial analyses may lead to inefficient statistical inference. When spatial correlation exists within a random variable e.g. explanatory variables such as elevation or soil characteristics, spatial statistical methods can provide unbiased and efficient estimates on which to base economic analyses and farm management decisions. Simple continuous terrain variables derived from spatially lagged independent variable transformation of relative terrain position allowed models to be estimated using familiar linear aspatial models without introducing the problems associated with interpolated data in inferential spatial statistics. Using site-specific data from three example fields, cross regressive elevation variables complemented topographic attributes, rather than replacing them in a range of statistical models. Results indicated that cross regressive elevation variables, especially relative elevation, reduced estimation problems due to correlation among independent variables and bias arising from spatially interpolated data in statistical analysis. [ABSTRACT FROM AUTHOR]

Feeding 9 billion by 2050 is one of major challenges for researchers. Use of diversified crops, nonconventional water resources and rehabilitation of marginal lands are alternate options to produce more food to face climate change projections. Adaptation to climate change through climate smart agriculture practices, agroecology activities, and crop-based management packages can help transform the marginal lands from environmental burdens into productive and economic blocks. This review discusses the recent advancements on specialty group of alternate crops (oil seeds, legumes, cereals, medicinal, lignocellulose, and fruit crops) which can adapt in the marginal environments. Availability of alternate water resources (saline water, treated wastewater) for irrigation cannot be omitted. Crop diversification systems involving drought and salt-tolerant crops are likely to be the key to future agricultural and economic growth in the regions where salt-affected soils exist and/or saline aquifers are pumped for irrigation. These systems may tackle three main tasks: sustainable management of land resources and enhancement of per unit productivity; intensification of agroecological practices to increase soil fertility; and improving productivity of marginal lands for diversified climate smart crops. This review explores various aspects of marginal lands and selection of tolerant crop genotypes, crop diversification, and agroecological practices to maximize benefits. [ABSTRACT FROM AUTHOR]

Optimal planting speed of vacuum maize planters is usually suggested by planter's manufacturers, while increased planting speed may influence plant spacing and finally yield. Our hypothesis was that by increasing planting speed over the suggested level plant spacing variability will also increase which will result in decrease of silage and grain yield and saving of seed and energy. The field trial consisted of three planting speeds of 7, 9 and 11 km/h in the form of random blocks. The following measurements were taken as follows: plant spacing, silage and grain yield, fuel and energy use at planting. Results in this study show that planting speed did not have significant influence on silage and grain yield of maize, while up to 10% less seed was needed per hectare and fuel and energy use was lower for 15%. By the increase of planting speed the distance between the plants in a row, and in most cases also the plant spacing variability increased. It was noticed that by increasing planting speed plant density decreased. This research established that at higher planting speeds significant increase of the silage yield per individual plant and of the grain yield per individual plant was achieved. The ear parameters also show that the kernel mass per individual ear, the ear mass, and the cob mass, as well as the individual kernel mass, are larger at the planting speed of 11 km/h than at the planting speed of 7 km/h. At the latter planting speed, significantly higher fuel consumption per hectare and higher energy use was achieved than at the other two planting speeds. Overall the main benefits of planting speed of 11 km/h is saving seed and energy at planting while maintaning the same level of silage and grain yield compared to lower planting speeds used in the trial. [ABSTRACT FROM AUTHOR]

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Copyright of Manas Journal of Agriculture Veterinary & Life Sciences is the property of Kyrgyz-Turkish Manas University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Context: Albedo can be used to quantify ecosystem and landscape contributions to local and global climate. Such contributions are conventionally expressed as radiative forcing (RF) and global warming impact (GWI). We contextualize our results within landscape carbon production and storage to highlight the importance of changes in albedo for landscape GWI from multiple causes, including net ecosystem production (NEP) and greenhouse gas (GHG) emissions. Objective: To examine the spatiotemporal changes in albedo (Δα) in contrasting managed landscapes through calculations of albedo-induced RF (RFΔα) and GWI (GWIΔα) under different climatic conditions. Methods: We selected five contrasting landscapes within the Kalamazoo River watershed in southern Michigan USA as proof of concept. The daily MCD43A3 MODIS (V006) product was used to analyze the inter- and intra-annual variations of growing season albedo. In addition, the variations of RFΔα and GWIΔα were computed based on landscape composition and climate. Results: The RFΔα (− 5.6 W m−2) and GWIΔα (− 1.3 CO2eq ha−1 year−1) were high in forest-dominated landscapes, indicating cooling effects and CO2eq mitigation impacts similar to crops. The CO2eq mitigation of cropland-dominated landscapes was on average 52% stronger than forest-dominated landscapes. In the landscape with the highest proportion of forest, under dry and wet conditions CO2eq mitigation was reduced by up to 24% and ~ 30%, respectively; in one cropland-dominated landscape wet conditions reduced CO2eq mitigation by 23%. Conclusions: Findings demonstrate that quantifying spatiotemporal changes in albedo in managed landscapes and under different climatic conditions is essential to understand how landscape modification affects RFΔα and GWIΔα and thereby contributes to ecosystem-level GWI. [ABSTRACT FROM AUTHOR]

Purpose-grown biomass is derived from herbaceous species such as switchgrass (Panicum virgatum), and miscanthus (Miscanthus giganteus) as well as woody species such as poplar (Populus spp.) and willow (Salix spp.). Feedstocks derived from these crops are used in the production of biofuels. Soil microorganisms in biomass cropping systems play important roles in soil fertility, nutrient cycling, and plant productivity. However, they can be influenced by plant species and management practices. This study assessed the distribution and abundance of soil microbial communities (total bacteria, total fungi and arbuscular mycorrhizal fungi (AMF) as influenced by poplar and willow (woody biomass crops) and switchgrass and miscanthus (herbaceous biomass crops) planted in fertilized and unfertilized plots in marginal soils. Soil was sampled in the fall of 2014 and spring of 2015 from biomass crops planted on marginal land in Guelph, Ontario, Canada. DNA was extracted, and quantitative PCR was used to enumerate the total bacteria (16S rRNA), total fungi (ITS), and AMF (AMF SSU rRNA) abundance in the soil. The total fungi and AMF abundance differed significantly across the herbaceous and woody species, with higher fungal abundance in the poplar resulting in higher fungal/bacterial (F/B) ratios compared to switchgrass and miscanthus. However, AMF were more abundant in the herbaceous species than in the woody species. Fertilization had a positive effect on the bacterial and fungal communities but not the AMF community under the different biomass cropping systems assessed in the fall season. These results illustrate that biomass crop species and management practices in biofuel cropping systems strongly influence soil microbial communities. [ABSTRACT FROM AUTHOR]

The herbicide glyphosate is widely used to control weeds in grain crops. The overuse of glyphosate has induced issues such as contamination of surface water, decreased soils fertility, adverse effects on soil microbiota and possible incorporation in food chains. Here we review biochemical, agricultural, microbiological and analytical aspects of glyphosate. We discuss uptake, translocation, toxicity, degradation, complexation behaviour, analytical monitoring techniques and resistance emergence in crops. We provide data of glyphosate toxicity on different ecosystems. Experiments reveal that excessive glyphosate use induces stress on crops and on non-target plants, and is toxic for mammalians, microorganisms and invertebrates. The long half-life period of glyphosate and its metabolites under different environmental conditions is a major concern. Development of analytical methods for the detection of glyphosate is important because glyphosate has no chromophoric or fluorophoric groups. [ABSTRACT FROM AUTHOR]

Winter rye (Secale cereale L.) is a popular cover crop in North Central United States for preventing soil erosion and nutrient losses, among other agronomic and ecosystem benefits. Winter rye can also be a high-quality spring forage option when double-cropped with corn silage (Zea mays L.), thus adding diversity to monocrop rotations. However, these sustainability-promoting benefits have potential trade-offs including soil nutrient immobilization and decreased corn yields. We hypothesized that winter rye would promote sustainable intensification of corn silage, as substantiated by decreased nitrogen budget and soil nitrate without yield loss. We also predicted that winter rye double-cropped and harvested as a forage would maintain total production (corn silage + rye harvest) compared to corn silage alone. This five-season study is representative of continuous corn silage systems in North Central United States, and Wisconsin specifically, distinguished by fall liquid dairy manure applications. Corn was planted after rye termination or harvest, and varying rates of nitrogen were applied to corn. As predicted, rye cover reduced preplant soil nitrate without affecting corn silage yield. Rye harvested as a forage crop reduced preplant and in-season soil nitrate, and total production equaled or exceeded corn silage yields without rye, despite a 13% decrease in corn silage yield. The 5-year nitrogen balance demonstrated almost 40% reduction in excess nitrogen in the rye forage system. This novel study demonstrated no cumulative or single-year agronomic limitations to winter rye implementation in manured, corn silage systems characteristic of North Central United States over a range of seasonal weather conditions. Furthermore, the dual use of rye as a cover crop conservation practice or harvested as a forage double-crop makes it agronomically advantageous and demonstrate potential for sustainable intensification in this system. This research is the first to show that sustainable intensification through double cropping dairy-based systems can increase high-quality biomass production while reducing nitrogen losses to the environment. [ABSTRACT FROM AUTHOR]

The high-resolution and mass accuracy of Fourier transform mass spectrometry (FT-MS) has made it an increasingly popular technique for discerning the composition of soil, plant and aquatic samples containing complex mixtures of proteins, carbohydrates, lipids, lignins, hydrocarbons, phytochemicals and other compounds. Thus, there is a growing demand for informatics tools to analyze FT-MS data that will aid investigators seeking to understand the availability of carbon compounds to biotic and abiotic oxidation and to compare fundamental chemical properties of complex samples across groups. We present ftmsRanalysis, an R package which provides an extensive collection of data formatting and processing, filtering, visualization, and sample and group comparison functionalities. The package provides a suite of plotting methods and enables expedient, flexible and interactive visualization of complex datasets through functions which link to a powerful and interactive visualization user interface, Trelliscope. Example analysis using FT-MS data from a soil microbiology study demonstrates the core functionality of the package and highlights the capabilities for producing interactive visualizations. Author summary: High-resolution mass spectrometry instruments provide a mechanism for researchers to better understand the fundamental chemical composition of materials such as soil, plants, petroleum, and beverages. The large and complex data generated by analysis of these materials has led to a growing demand for software tools to aid researchers in processing, analyzing, and creating informative visualizations of these data. To move beyond existing software tools designed for specific purposes and visualizations of data from an individual sample, we present a software package, ftmsRanalysis, that provides researchers with a large collection of methods for streamlining the downstream processing high-resolution mass spectrometry data.ftmsRanalysis provides methods to compute useful chemical properties, filter data, define groups of samples, statistically compare sample groups, and make visualizations for many samples simultaneously. In this paper, we give an overview of ftmsRanalysis' general structure and capabilities. We then apply ftmsRanalysis to a soil microbiology dataset and present some of the results and visualizations generated by using the software package. [ABSTRACT FROM AUTHOR]

At two sites in the North Central USA (Michigan (KBS) and Wisconsin (ARL)), we evaluated the effect of N fertilization on the yield and quality of five perennial bioenergy feedstock cropping systems: (1) switchgrass (Panicum virgatum L.), (2) giant miscanthus (Miscanthus × giganteus), (3) a native grass mixture (5 species), (4) an early successional field (volunteer herbaceous species), and (5) a restored prairie (18 species). In a randomized complete block design with 5 replicates and 2 split plots, N was applied at 0 and 56 kg ha−1 to split plots for each cropping system from 2010 to 2016. No yield response to N was detected in switchgrass at either location in any year. Giant miscanthus exhibited a positive yield response to N at both sites (11% at KBS and 83% at ARL). Nitrogen fertilizer addition significantly reduced glucose (KBS 12.9 and 13.8 g kg−1 year−1, ARL 11.2 and 9.7 g kg−1 year−1) in the native grass mix and restored prairie systems respectively. Nitrogen fertilizer also reduced xylose at KBS in the switchgrasss, native grass mix, and restored prairie (4.9, 7.5, and 5.0 g kg−1 year−1). At ARL, N fertilization reduced xylose levels in switchgrass, giant miscanthus, and restored prairie (7.4, 6.8, and 6.2 g kg−1 year−1) and increased xylose levels in the early successional system (5.0 g kg−1 year−1). [ABSTRACT FROM AUTHOR]

The development of resilient cropping systems with high yield stability is becoming increasingly important due to future climatic and agronomic challenges. Consequently, it is essential to compare the effects of different agronomic management practices, such as cropping sequences and nutrient supply, on the stability of crop yields. Long-term experiments are a valuable resource for investigating these effects, as they provide enough time to accurately estimate stability parameters. The objective of the current study was to compare the effects of different cropping sequencing (#1: continuous v. rotational), fertilization (#2: mineral v. organic) and straw management techniques (in the case of continuous wheat; #3: removal v. incorporation) on the yield stability of winter wheat; yield risk (the probability of yield falling below a threshold yield level) and inter-annual yield variability were used as stability indicators of the effects. Long-term yield data from the Broadbalk Wheat Experiment (Rothamsted, UK) were analysed using a mixed model. Overall, the results showed that rotational cropping combined with sufficient mineral N fertilizer, with or without organic manure, ensured stable wheat yields while reducing yield risk. In contrast, higher yield risks and inter-annual yield variabilities were found in continuous wheat sections with less mineral N fertilizer or with organic manure only. [ABSTRACT FROM AUTHOR]

Key message: Candidate genes on grain drying rate (GDR) were identified, and drying molecular mechanism of grain was explored by integrating genome-wide association with transcriptomic analysis in maize. Grain drying rate (GDR) is a key determinant of grain moisture at harvest. Here, a genome-wide association study (GWAS) of 309 inbred maize lines was used to identify single-nucleotide polymorphisms (SNPs) associated with drying rates of grain, cob and bract. Out of 217,933 SNPs, seven significant SNPs were repeatedly identified in four environments (P < 10–4). Based on genomic position of significant SNPs, six candidate genes were identified, one of which (Zm00001d047468) was verified by transcriptomic data between inbred lines with high and low GDR, indicating stable and reliable correlation with GDR. To further detect more genes correlated with GDR and explore drying molecular mechanism of grain, expression profile of all GWAS-identified genes (4941) detected from different environments, tissues and developmental stage was evaluated by transcriptomic data of six inbred lines with high or low GDR. Results revealed 162 genes exhibit up-regulated expression and another 123 down-regulated in three higher-GDR inbred lines. Based on GO enrichment, 162 up-regulated genes were significantly enriched into grain primary metabolic process, nitrogen compound metabolic process and macromolecule metabolic process (P < 0.05), which indicated grain filling imposes notable influence on GDR before and after physiological maturity. Our results lay foundation in accelerating development of higher-GDR maize germplasm through marker-assisted selection and clarifying genetic mechanism of GDR in maize. [ABSTRACT FROM AUTHOR]

This study aimed to determine short-term effects of soil tillage and crop residues on soil quality and grain yield of rice in a double-cropping paddy field of southern China. The experiment included four soil tillage treatments: conventional tillage with crop residues incorporation (CT), rotary tillage with crop residues incorporation (RT), no-tillage with crop residues retention (NT), and rotary tillage with crop residues removed as control (RTO). The results showed that the soil bulk density with RTO treatment were higher than with CT and RT treatments. And the soil EC, aggregate mean weight diameter in both wet and dry sieving with NT and RT treatments were higher than that of RTO treatment. CT and RT treatments had the best soil quality and produced the highest rice yield of average 2016–2018. Removing the crop residues gave the lowest yield and less favourable soil physical and chemical characteristics compared to the application of crop residues treatments. It was found that conventional tillage and rotary tillage with crop residues retention is a feasible management technology for farmers producing rice in the double-cropping paddy field of southern China, resulting in a better soil quality and higher yield than with the conventional farmer practice. [ABSTRACT FROM AUTHOR]

Despite the growing need to produce energy crops, information on comprehensive feasibility of growing short-rotation woody crops (SRWCs) on non-contentious and less-utilized lands and lands transitioning from previous uses in the southeastern USA is limited. An assessment model (SRWC-PEAM) was developed and tested for assessing the feasibility of SRWCs on lands targeted for ecosystem-service enhancements based on land conditions, species, and stand and economic variables in the southeastern USA. Productivity and economic returns of sweetgum (Liquidambar styraciflua L.), sycamore (Platanus occidentalis L.), and poplar (Populus) stand differed due to land types, species' adaptability and biomass potential, and optimal land-type-based management schemes. Poplar stands had the greatest biomass and the highest returns on all land types although returns from the three species on most land types were poor using current reported regional delivered prices. Irrigating stands increased yields but returns were poorer than from non-irrigated stands due to high costs of irrigation. Longer rotations resulted in greater biomass and returns and were more crucial for irrigated stands. Significantly higher feedstock prices and productivities are requisite for SRWC viability in the southeastern USA. SRWC-PEAM is a web-based tool and can accommodate other SRWC species and assessment of environmental services associated with SRWCs. [ABSTRACT FROM AUTHOR]

It is unclear if additional inoculation with Bradyrhizobia at varying soybean [Glycine max (L.) Merr.] growth stages can impact biological nitrogen fixation (BNF), increase yield and improve seed composition [protein, oil, and amino acid (AA) concentrations]. The objectives of this study were to evaluate the effect of different soybean inoculation strategies (seed coating and additional soil inoculation at V4 or R1) on: (i) seed yield, (ii) seed composition, and (iii) BNF traits [nodule number and relative abundance of ureides (RAU)]. Soybean field trials were conducted in 11 environments (four states of the US) to evaluate four treatments: (i) control without inoculation, (ii) seed inoculation, (iii) seed inoculation + soil inoculation at V4, and (iv) seed inoculation + soil inoculation at R1. Results demonstrated no effect of seed or additional soil inoculation at V4 or R1 on either soybean seed yield or composition. Also, inoculation strategies produced similar values to the non-inoculated control in terms of nodule number and RAU, a reflection of BNF. Therefore, we conclude that in soils with previous history of soybean and under non-severe stress conditions (e.g. high early-season temperature and/or saturated soils), there is no benefit to implementing additional inoculation on soybean yield and seed composition. [ABSTRACT FROM AUTHOR]

Multifunctional woody polycultures (MWPs) are an alternative agricultural practice gaining interest in the U.S. Corn Belt as an option for combining agricultural production and conservation goals. MWPs integrate fruit, nut, timber, and/or bioenergy crops adjacent to annual crops. Previous studies revealed that landowners lack adequate information to make informed decisions regarding the adoption of MWPs. Following up on that work, this study engaged with 15 rural landowners in the Upper Sangamon River Watershed of Central Illinois to identify their design preferences, their information needs, and the adoption potential for MWPs. Landowner-specific designs were constructed based on three predefined alternative scenarios distinguished by their focus on: (1) production, (2) conservation, or (3) cultural functions. Two semi-structured interviews were conducted with landowners before and after the design process. Results from quantitative analysis and qualitative interpretation showed landowners preferred designs that integrated high levels of edible nuts and berries in an efficient, machine-harvestable arrangement. Nut-producing species, notably northern-adapted varieties of pecan (Carya illinoinensis), were the most preferred. The most influential motivators for the design and adoption of MWPs were utilizing high-value edible crops, improving pollinator and wildlife habitat, and increasing productivity of marginal land. While important, landowners felt these motivators still did not overcome limitations in the practical application of MWPs due to a lack of harvest machinery, of post-harvest processing facilities, and of accessible markets. The study findings demonstrate that a lack of reliable economic, marketing, and management information severely constrains the adoption potential of MWPs despite landowner interest in using MWPs on marginal lands. [ABSTRACT FROM AUTHOR]

Key Message: We investigate the genetic basis of panicle architecture in switchgrass in two mapping populations across a latitudinal gradient, and find many stable, repeatable genetic effects and limited genetic interactions with the environment. Grass species exhibit large diversity in panicle architecture influenced by genes, the environment, and their interaction. The genetic study of panicle architecture in perennial grasses is limited. In this study, we evaluate the genetic basis of panicle architecture including panicle length, primary branching number, and secondary branching number in an outcrossed switchgrass QTL population grown across ten field sites in the central USA through multi-environment mixed QTL analysis. We also evaluate genetic effects in a diversity panel of switchgrass grown at three of the ten field sites using genome-wide association (GWAS) and multivariate adaptive shrinkage. Furthermore, we search for candidate genes underlying panicle traits in both of these independent mapping populations. Overall, 18 QTL were detected in the QTL mapping population for the three panicle traits, and 146 unlinked genomic regions in the diversity panel affected one or more panicle trait. Twelve of the QTL exhibited consistent effects (i.e., no QTL by environment interactions or no QTL × E), and most (four of six) of the effects with QTL × E exhibited site-specific effects. Most (59.3%) significant partially linked diversity panel SNPs had significant effects in all panicle traits and all field sites and showed pervasive pleiotropy and limited environment interactions. Panicle QTL co-localized with significant SNPs found using GWAS, providing additional power to distinguish between true and false associations in the diversity panel., (© 2022. The Author(s).)

Usually, soils utilised for livestock production have similar high spatial variability as those for agricultural or forest use. As a consequence, it is necessary to determine the spatial patterns of the main soil properties as the first stage to implement site-specific management. However, this has to be performed using an inexpensive technique because the profitability in these types of farm are very low, so owners need a cheap, effective, and reliable method to know which zones have similar production potential. Using soil apparent electrical conductivity (ECa) measurements, obtained with a contact sensor at many locations, as the basis to perform a directed soil sampling, 10 samples were taken at two depths (0–0.25 m and 0.25–0.50 m) in a 2.3 ha field in Évora (southern Portugal). Firstly, relationships between ECa and many soil properties were analysed using regression analysis. Six soil properties (clay, silt, fine sand, soil moisture content, pH, and cation exchange capacity) were significantly correlated with ECa. Consequently, spatial distributions of these variables were visualised using map algebra techniques. Later, a fuzzy clustering algorithm was utilised to delineate management zones, resulting in two subfields to be managed separately. Finally, a principal component analysis was conducted to analyse the influence of the soil properties and elevation on the soil variability. It was determined that elevation and clay were the most important contributing properties. Therefore, these can be regarded as key latent variables in this soil. Results showed that low-cost data based on ECa surveys can be used to implement site-specific management in soils with permanent pastures, such as those in the montado or dehesa ecosystems, in the southwest of the Iberian Peninsula. [ABSTRACT FROM AUTHOR]

Aims: Productivity of forest ecosystems is constrained by site resource availability and utilisation at an individual tree level. A better understanding of nitrogen (N) nutrition addition to forest ecosystems is critical for maintaining optimal plantation productivity, given the influence of an environment gradient, genetics, and their interactions. Methods: We studied the aboveground growth response in a plantation setting of ten commercial P. radiata genotypes to N-fertilisation using three different N sources, and also assessed the effect of on-site environmental factors on this response. We compared, on equimolar basis, the effect of N-fertilisation with inorganic N (NH4NO3), organic N (L-arginine), and the two N sources combined (L-arginine:NO3−) to that of unfertilised trees on tree height, diameter, descriptors of microsite variability, and climate and seasonal information. After 2.5 years of fertilisation, genotype-specific variation in aboveground growth response to N sources were measured, and these were significantly influenced by field-scale heterogeneity. Results: Across P. radiata genotypes, trees treated with inorganic N forms showed suppressed growth compared to unfertilised trees, while trees fertilised with organic N (either alone or in combination with inorganic N) were not significantly different than the untreated controls. We provide evidence of significant interactions between N source and genotype, N source and cover as well as genotype and microsite variability affecting temporal trends in tree volume. Conclusions: We conclude that the comprehension of field-scale variability in soil properties and associated environmental variables is essential for understanding genotype performance as they are crucial determinants of intraspecific variation in response to N-fertilisation. [ABSTRACT FROM AUTHOR]

For the first time, Lactobacillus plantarum strains carrying heterologous genes encoding multifunctional glycoside hydrolases were constructed and used as additives for alfalfa silage. The chemical characteristics, nonstructural carbohydrate composition, and fermentation quality of alfalfa silage were examined. The supernatant of L. plantarum expressing CbXyn10C and Bgxg1 (LP11AG) showed activities on xylan, Avicel, and carboxymethylcellulose (CMC), while the supernatant of the wild-type L. plantarum showed no activity. When LP11AG was used as silage additive, the water-soluble carbohydrate content of alfalfa silage increased by 72%, 55%, and 155% compared with control when the silage was stored at 20 °C, 30 °C, and 40 °C, respectively. With LP11AG being used as an additive for the alfalfa silage stored at 20 °C, the hemicellulose, cellulose, and acid detergent ligninin (ADL) contents decreased by 17%, 6%, and 14% compared with the control (p < 0.05), respectively. Compared with the corresponding original contents, the contents of glucose, arabinose, galactose, and fructose detected in silage treated with LP11AG after 45 days of ensiling increased by 55%, 1494%, 68%, and 5% , respectively, when stored at 40 °C. Raffinose and stachyose, originally present in alfalfa, disappeared after ensiling. In conclusion, our results suggest that LP11AG provides a substantial benefit as a silage additive. [ABSTRACT FROM AUTHOR]

Riparian ecosystems provide various ecosystem services including habitat for a variety of plant and animal communities, biofiltering, and stabilizing stream and river systems. Due to their location, riparian zones often share long borders with agricultural fields where herbicides are commonly applied to eliminate unwanted plants. There is a general concern that exposure of riparian vegetation to off‐target drifted herbicides may adversely impact their health and diversity. We utilized the Normalized Difference Vegetation Index (NDVI) to investigate the long‐term (between 1992 and 2011) trend of riparian vegetation health at 17 locations in the Midwest and Great Plains areas of the United States, where herbicide usage was likely most intense. Assessment of NDVI data demonstrated that long‐term vegetation health did not decline for the studied riparian zones located in proximity to croplands during spring months (April and May). During summer (June and July), while the long‐term vegetation health did not decline for the majority of the sites, there were a few cases in Kansas and Nebraska with a decline in vegetation health (negative‐trending NDVI). Cluster analysis of the negative‐trending NDVI pixels showed that the majority of these pixels were randomly distributed throughout these riparian sites, indicating a lack of shared common causing factors. Similarly, proximity analysis suggested that distance from croplands was not associated with the decline of vegetation health found in these sites, suggesting that exposure to herbicide drift may not be a plausible factor because this would have shown higher impact on pixels closer to the cropland. Changes in canopy coverage and vegetation diversity also did not show any dependence on distance from croplands. Finally, the remote‐sensing–based NDVI data sets used provide only an indirect way of assessing the impact of herbicide drift, and therefore, further work based on field survey data is recommended to completely isolate the impacts of herbicides. Integr Environ Assess Manag 2019;15:528–543. © 2019 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC) Key Points: We assessed the riparian vegetation health (VH) of the United States Great Plains for 2 decades.Spring VH remained unchanged or increased at all 17 sites.Summer VH declined at few sites in Kansas and Nebraska.We found no association between decline in VH and distance to croplands. [ABSTRACT FROM AUTHOR]

In agricultural fields, observations near in space share more similarities than observations far apart. This phenomenon of closely related points, the so-called spatial autocorrelation or in that case, the within-field spatial variability, is well-recognized and needs to be characterized to consider site-specific management. Quantifying spatial dependency is fundamental for understanding the underlying factors affecting field productivity. An examination of multiple scientific papers was carried out to assess why and how practitioners were evaluating the spatial variability across their fields. An analysis of the existing descriptors of within-field variability was performed to identify the most relevant indicators to use based on (i) the case studies that practitioners employed, (ii) the different nature of data to which users were confronted, and (iii) the complexity and ease of access to information in support of these available approaches. Finally, this paper provides users with a comprehensive decision tree that should help them select an appropriate index of spatial variability for their work. Results also highlight the needs for further investigation, especially regarding the implementation of more general and standardized approaches that will enable cross-study comparison. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) storage is a critical component of the overall sustainability of bioenergy cropping systems. Predicting the influence of cropping systems on SOC under diverse scenarios requires a mechanistic understanding of the underlying processes driving SOC accumulation and loss. We used a density fractionation technique to isolate three SOC fractions that are conceptualized to vary in SOC protection from decomposition. The free light fraction (FLF) is particulate SOC that is present in the inter-aggregate soil matrix, the occluded light fraction (OLF) is contained within aggregates, and the heavy fraction (HF) is associated with minerals. We evaluated surface (0 to 10 cm depth) SOC fraction changes from baseline conditions 5 years after biofuel cropping system establishment at two temperate sites with contrasting soil textures. The biofuel cropping systems included no-till maize, switchgrass, prairie, and hybrid poplar. The FLF concentration (g fraction C g bulk soil−1) did not change significantly from baseline levels under any of the cropping systems at either site after 5 years. Except for poplar, OLF concentrations were reduced in all systems at the site with coarse-textured soils and maintained at the site with fine-textured soils. In poplar systems, OLF concentrations were maintained on coarse-textured soils and increased on fine-textured soils. The HF concentrations also increased under poplar on the coarse-textured soil. A structural equation model indicated that OLF concentrations increased with lower litter C:N, and HF concentrations increased with greater litter quantity and lower litter C:N mass ratios. C:N increased over time within all SOC fractions, suggesting that all pools are sensitive to land-use change on sub-decadal timescales. In agreement with modern SOC theory, our empirical results indicate that increasing litter input quantity and promoting plant species with low C:N litter may improve SOC storage in aggregate and mineral-associated soil fractions. [ABSTRACT FROM AUTHOR]

Dedicated bioenergy crops, such as perennial grass and short rotation trees, qualify as cellulosic biofuel feedstocks to meet the requirements for advanced biofuel according to the expanded Renewable Fuel Standard. The utilization of dedicated energy crops for cellulosic biofuels is still in the early stage, at pilot scale, and the existing cellulosic biorefineries are yet to be commercialized. This study develops an agent‐based model to simulate the spatial diffusion of switchgrass (Panicum virgatumL.) adoption in Indiana cropland from 2015 to 2027 under various biofuel market scenarios. Results indicate that it would be economically viable to produce 1.1 billion gallons (4.2 billion liters) cellulosic ethanol from switchgrass annually in Indiana until 2023, given an average annual farm‐gate price of $123.93 t−1 for the feedstock. This study also finds that the high productivity of switchgrass can increase the adoption rates of farmers and secure a stable feedstock supply. It also reveals that the high equipment costs required for scaling up production capacity and the high variable operating cost of cellulosic biofuel production will inhibit the viability of commercializing cellulosic biofuels with a stable supply of feedstock. Financial incentives for cellulosic biofuel production have a significant impact on promoting the adoption of dedicated energy crops in Indiana. This paper provides useful insights for biorefinery development and policy making to facilitate the commercialization of cellulosic biofuels by explaining the effects of the decisions of farmers on the adoption of dedicated energy crops. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

BACKGROUND Fatty acids are the major components in extra virgin olive oil, and they are considered as a quality parameter to its authentication. As fraudulent practices are the most important problem in this sector, fast, reliable and cost‐effective techniques, such as Raman spectroscopy, have been successfully applied, in combination with chemometrics, to determine the fatty acid profile of oils. RESULTS: The huge amount of information provided by Raman spectra is reduced in a few orthogonal components of principal component analysis (PCA). The goodness‐of‐fit of the statistical models including only these PCA factors is considerably increased by introducing dummy variables, associated with the harvest, and some agro‐climatic variables (temperature, humidity, wind speed, radiation, precipitation and evapotranspiration). Many of these additional variables are statistically relevant in models using either the global sample or subsamples of Andalusian provinces or olive varieties. CONCLUSIONS: The regression models using only Raman spectral information are clearly improved by the consideration of harvesting time and agro‐climatic data, a useful result as trade standard applying to olive oils limits values for disaggregated fatty acids to authenticate olive oils. Nevertheless, the effect (or the statistical relevance) of these variables depends on the specific type of fatty acid, geographical region (province) or olive variety. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A process consisting of regeneration of crystalline cellulose, dilute-phosphoric acid hydrolysis of regenerated cellulose to soluble oligomers, and enzymatic post-hydrolysis of soluble oligomers in the absence of disturbing solid particles was evaluated as a process alternative for upgrading the obtainable sugar concentration and facilitating the long-term enzymatic hydrolysis of cellulose by utilizing soluble oligomers instead of insoluble particles. Cellulose was regenerated though phosphoric acid-acetone process, i.e., dissolution into 21 g/g acid at 50 °C for 60 min and precipitation by adding 41 g/g acetone. Regenerated cellulose was hydrolyzed at 120, 150 or 180 °C for 30 or 60 min using 0.5 or 1% phosphoric acid. After filtration, the hydrolysates were subjected to 10 or 15 FPU/g cellulase. Dilute-acid hydrolysis of regenerated cellulose with 0.5% acid at 180 °C, 30 min, and 10% solid loading resulted in an "oligomeric hydrolysate" with 44.6 g/L soluble oligomers. Enzymatic post-hydrolysis of soluble oligomers resulted in a "monomeric hydrolysate" containing as high as 47 g/L glucose and cellobiose. In the hydrolysis, 429 g sugar was released at high concentration from one kg crystalline cellulose. The hydrolysates were subjected to fermentation by Clostridium acetobutylicum, where oligomeric hydrolysates showed poor fermentability. The fermentation of monomeric hydrolysates obtained by dilute-acid hydrolysis (120 °C, 60 min, and 0.5% acid) and post-hydrolysis (15 filter paper unit/g) resulted in 6.1 g/L acetone–butanol–ethanol. Besides other potential advantages, this hydrolysis approach resulted in relatively high concentration of glucose which may facilitate cellulosic butanol production. [ABSTRACT FROM AUTHOR]

State and federal policy targets for renewable energy production in the US have prompted investigations into the feasibility of different biomass feedstock types for use in transportation fuels or electricity production. Woody biomass systems can be integrated strategically within agricultural systems for multifunctional benefits while building regional biomass supply capacity. In order to assess the potential for biomass-based bioenergy, it is essential to characterize the interest that potential suppliers have in such an endeavor. In the US Northern Great Plains region (North Dakota, South Dakota, Nebraska and Kansas), this begins with assessing relevant perceptions of farmers and ranchers. Results from a 2014 survey of farm and ranch operators managing agriculturally marginal farmland indicated that 61% of operators have some degree of interest in woody biomass production. An ordered probit regression was utilized to further investigate how farm system attributes, individual farmer/rancher characteristics, relevant attitudes, knowledge, and perceived constraints affect interest. This study highlights attributes of operators who are most likely to be early adopters of a woody biomass crop and has implications for the development of relevant policy initiatives and management practices. [ABSTRACT FROM AUTHOR]

The current study was carried out in Alexandria, Egypt and investigated the effect of sowing date; 1st May, 1st July, and 1st September 2017 and 2018, and age at harvest; 45, 55 and 65 days after sowing (DAS) on yield and quality of maize green forage grown with three plant densities (120, 160, and 200 kg ha-1). Sowing at 1st of May produced the highest significant amount of fresh yield (41.51 t ha-1 in average). Sowing at 1st of July resulted in the production of significantly lower yield (24.54 t ha-1 in average), however, higher dry matter content (175.99 g kg-1 in average), compared to sowing at 1st of May (143.62 g kg-1 in average). A pronounced increase in fresh yield was observed when maize was harvested at 55 DAS (30.89 t ha-1 in average) compared to harvesting at 45 DAS (22.92 t ha-1 in average). Meanwhile, the increase in fresh yield from 55 DAS to 65 DAS was non-significant. The effect of sowing date on quality parameters was greatly dependent on the age of plant at harvest. Harvesting maize green forage at 65 DAS, reflecting an advanced stage of maturity, caused a significant reduction in the crude protein (CP), and a significant increase in the neutral and acid detergent fibre fractions (NDF and ADF), resulting in a decline in the digestible organic matter (DOM). Plant density exerted non-significant influence on the fresh yield and DM content, minimal effect on the CP content, while the effect on the NDF and ADF contents was dependent on the age at harvest. The lignin content (ADL) of the herbage significantly decreased with increasing the plant density. Variations in the DOM were most dependent on the variations in CP content, followed by the variations in ADF and ADL contents. In conclusion, it is recommended to grow green forage maize twice a season on the 1st of May and 1st of July, with intermediate plant density (160 kg ha-1), and harvest it not later than 55 DAS to achieve the optimum balance between herbage productivity and nutritive value. [ABSTRACT FROM AUTHOR]

Soybean (Glycine max. (L.) Merr.) is a symbiotic nitrogen-fixing crop. In order to increase grain yield, it is important to know how soybean plants respond to nitrogen topdressing for the improvement of nitrogen utilisation. We used two soybean cultivars with different grain yield potentials and applied 13 nitrogen topdressing treatments to determine optimal topdressing time and nitrogen metabolism. Nitrogen treatments included a base fertiliser and single topdressings at different times, in 10-day intervals from 10 to 120 days after emergence (DAE). Among the nitrogen treatments, the optimal times for topdressing were at 40 DAE or 90 DAE to increase grain yield, and both soybean cultivars also had higher nitrate reductase (NR) and glutamine synthetase (GS) activities with topdressing at these times. Higher expression of the NR2 gene was associated with upregulated NR activity in leaves of both cultivars at the early-mature stage. With topdressing at 90 DAE, higher GS1 expression and GS activity were found in the leaves of the higher yielding cultivar at the full-seed stage and the early-mature stage. With topdressing at 90 DAE, the higher yielding cultivar had a higher nitrate metabolism capacity at the late reproductive stages than the lower (common) yielding cultivar. By up-regulated soybean nitrogen metabolism, topdressing at 40 DAE and 90 DAE increased soybean grain yield significantly. With topdressing at beginning seed stage (90 DAE), the higher yielding cultivar had a higher nitrate metabolism capacity at the late reproductive stages. [ABSTRACT FROM AUTHOR]

Background and Aims: Studies verify that intercropping increases soil macro-aggregates but the mechanism underlying the increase is poorly understood.Methods: Three long-term field experiments were conducted starting in 2009 at three sites in an oasis in northwest China. The first was a split-plot design: Rhizobium (with or without inoculation) and three cropping systems (faba bean/maize intercropping and corresponding monocultures). The second and third experiments were both single-factorial randomized block designs with nine cropping systems (maize intercropped with faba bean, chickpea, soybean, or oilseed rape, and the corresponding monocultures). Soil aggregates were determined by the wet sieving method. Microbial biomass and community composition in 2015 and 2016 were determined by phospholipid fatty acid (PLFA) and high throughput sequencing analysis of 16S rRNA.Results: Soil macro-aggregates (> 2 mm) in intercropping systems increased by 15.5-58.6% across three sites and two years, an effect derived partly from increased relative abundance of soil Sordariales, from enhanced arbuscular mycorrhizal fungi biomass, or from reduced relative abundance of Nitrospirae, depending on soil type.Conclusions: Intercropping alters soil microbial community composition and further facilitates soil aggregation. These findings provide insights into the mechanisms underlying the maintenance of biodiversity in ecosystem functioning. [ABSTRACT FROM AUTHOR]

The effect of genetic markers and reference databases on analyses of fungal communities were estimated using fungal large subunit (LSU) and internal transcribed spacer (ITS) amplicon datasets in consecutive years of rhizosphere samples from three candidate biofuel crops, corn (Zea mays), switchgrass (Panicum virgatum), and miscanthus (Miscanthus × giganteus). These two marker genes were selected to contrast possible differences in biological conclusions. In addition, two ITS schemes based on two ITS reference databases were used to assess differences due to reference database composition. A taxonomy-supervised method was invoked using the Ribosomal Database Project naïve Bayesian classifier that accesses all three databases. The UNITE classification scheme had the highest number of classified taxa in the raw classification result; however, it also had the highest proportion of unknown taxa (sequences that were classified to "unclassified," "unidentified," incertae sedis or, in the case of Warcup, to matches containing two unique names). After removal of these unknown taxa, LSU had the highest classification rate followed by Warcup and UNITE. As expected, the communities resolved using the two ITS databases, based on the same sequences, were relatively more similar than those from the lower-coverage LSU classification scheme. The choice of marker gene or even the same reads with different classification databases revealed different community patterns due to database coverage, e.g., the relative abundance of the most abundant groups changed or were only detected in one or two of the classification schemes, such as for Mortierella, Fusarium, and Phoma. No marked difference in fungal beta-diversity was identified among the three methods. Differentiation between the three biofuel crops and between the drought and normal rainfall years was apparent, regardless of method. Though classification rates, taxonomic conflicts, and coverage differences within the high-abundance fungal groups varied according to classification scheme, there was no overall impact on beta diversity among the three methods. [ABSTRACT FROM AUTHOR]

Biotransformation of daidzein was performed by using Bacillus amyloliquefaciens KCTC 13588, Lactococcus lactis subsp. lactis KCTC 3769, Leuconostoc citreum KCTC 13186, Kluyveromyces lactis var. lactis KCTC 17704, Pediococcus pentosaceus KCTC 3116, and Lactobacillus sakei KCTC 13416 cells as a biocatalyst. Four derivatives of daidzein such as daidzein-7-O-phosphate, daidzein-7-O-β-D-glucoside, daidzein-7-O-β-(6′′-O-succinyl)-D-glucoside, and 4′-Ethoxy-daidzein-7-O-β-(6′′-O-succinyl)-D-glucoside were isolated from the biotransformation reaction mixture. The structures of the molecules were elucidated by HPLC, HR-QTOF-ESI/MS and 1H-NMR analyses. Among them 4′-Ethoxy-daidzein-7-O-β-(6′′-O-succinyl)-D-glucoside derivative is novel compound and not reported elsewhere till now. [ABSTRACT FROM AUTHOR]

Organic fertilization enhances the global warming potential of the soil, which is primarily attributed to higher CO2 emission from the soil. However, long-term studies under organic fertilization to observe its impact on soil’s warming potential with respect to CO2 efflux are limited in the dry tropical ecosystem. Therefore, we observed the changes in soil organic matter (C, N), soil CO2 efflux (SCE), soil moisture, microbial biomass C, and dehydrogenase activity in the plots under 1, 3, 5, and 10 years of organic fertilization, designated as OM1, OM3, OM5, and OM10, respectively. Also, a nearby native forest was taken as a standard reference system (NF) in the present study for comparative purpose. We observed that organic fertilization significantly (P ≤ 0.05) increased soil organic carbon (SOC), soil organic nitrogen (SON), SCE, moisture, microbial biomass C, and dehydrogenase activity, whereas decreased the SOC/SON ratio after 10 years, which also approached closer to NF. However, only the plots under 10 years of organic fertilization showed SCE significantly (P ≤ 0.05) similar to NF. It indicates that long-term organic fertilization is required for the improvement in soil properties. SCE showed a significantly (P ≤ 0.05) higher value (on average, by 61%) in OM10 site as compared to OM1. However, SCE on unit C basis (SCER) showed no change (P > 0.05). This increase in SCE after 10 years of organic fertilization might be attributed to the significant (P ≤ 0.05) increase in SOC, soil moisture, microbial biomass C, and dehydrogenase activity. However, no change in SCER after 10 years shows that organic fertilization has possibly been misinterpreted with respect to their impact on soil’s global warming potential. It might be attributed to the C protective nature of the organic fertilization. Overall, our results contradict with the often publicized higher warming potential of the organically amended systems. This indicates that organic fertilization does not increase the soil’s global warming potential, which is often misrepresented because SCE is not observed with respect to the existing SOC content. [ABSTRACT FROM AUTHOR]

Research was undertaken to clarify the taxonomic identity of leaf rust (Pucciniales) fungi on bioenergy switchgrass in the Eastern and Central U.S. We integrated internal transcribed spacer 2 (ITS2) and partial 28S ribosomal RNA gene sequence data from collections taken from cultivated switchgrass and herbarium specimens, including purported aecial and telial states of Puccinia graminicola and Puccinia pammelii. Maximum likelihood and Bayesian analyses revealed four monophyletic clades: Puccinia emaculata sensu stricto (s.s.), P. pammelii, P. graminicola, and Puccinia novopanici. Results also indicated that P. emaculata s.s. was not affecting cultivated, bioenergy switchgrass. Aecidium pammelii and P. pammelii were distinct phylogenetically from P. emaculata s.s. and grouped within a well-supported clade, demonstrating aecial-telial host alternation for P. pammelii between Euphorbia corollata and switchgrass. Aecidium stillingiae on queen’s delight (Stillingia sylvatica)—a purported aecial state host for P. graminicola—shared identical sequences with the recently described species Puccinia pascua. The latter fungus, however, was recovered within a subclade of P. graminicola. Hence, queen’s delight likely is not an aecial host to P. graminicola s.s. Additional molecular studies are warranted to determine species boundaries within the P. graminicola complex. The majority of contemporary collections from cultivated switchgrass were recognized as P. novopanici. Collectively, bioenergy switchgrass is host to at least three phylogenetically distinct species, presenting a significant challenge to the future selection and breeding of switchgrass with improved rust resistance. [ABSTRACT FROM AUTHOR]

Key Message: Identifying QTL associated with soybean seed quality traits from a diverse GWAS panel cultivated in Canadian and Ukrainian mega-environments may facilitate future cultivar development for foreign markets. Understanding the complex genetic basis of seed quality traits for soybean in the mega-environments (MEs) is critical for developing a marker-assisted selection program that will lead to breeding superior cultivars adapted to specific regions. This study aimed to analyze the accumulation of 14 soybean seed quality traits in Canadian ME and two seed quality traits in Ukrainian ME and identify associated ME specific quantitative trait loci (QTL SP ) and ME universal QTL (QTL U ) for protein and oil using a genome-wide association study (GWAS) panel consisting of 184 soybean genotypes. The panel was planted in three locations in Canada and two locations in Ukraine in 2018 and 2019. Genotype plus genotype-by-environment biplot analysis was conducted to assess the accumulation of individual seed compounds across different locations. The protein accumulation was high in the Canadian ME and low in the Ukrainian ME, whereas the oil concentration showed the opposite trends between the two MEs. No QTL U were identified across the MEs for protein and oil concentrations. In contrast, nine Canadian QTL SP for protein were identified on various chromosomes, which were co-located with QTL controlling other traits identified in the Canadian ME. The lack of common QTL U for protein and oil suggests that it may be necessary to use QTL SP associated with these traits separately for the Canadian and Ukrainian ME. Additional Ukrainian data for seed compounds other than oil and protein are required to identify novel QTL SP and QTL U for such traits for the individual or combined Canadian and Ukrainian MEs., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The research investigated ways to enhance maize yield in intensive maize cropping system by evaluating the effect of high planting densities combined with foliar fungicide treatments. The considered assessments were fungal leaf disease, biomass and grain yield and methane production through anaerobic fermentation. The experiment was conducted in the years 2012 and 2013. The treatments compared at each location were factorial combinations of two plant densities and three fungicide applications. A standard planting density (StD, 7.5 plants -2 on a 0.75 m inter-row spacing) was compared with the high density (HiD, 10 plants nr2 on narrow 0.5 m inter-row spacing). Two fungicides, pyraclostrobin at 0.2 kg AI ha-1 and a mixture of pyraclostrobin and epoxiconazole at 0.2 and 0.075 kg AI ha-1 respectively, were applied at the tassel emergence stage and compared with an untreated treatment. The HiD system positively increased the silage maize yield (+16%), grain (+17%) and methane yield per hectare (+19%) in comparison to the StD. The fungicide application significantly restrained foliar disease symptoms only in 2012. Fungicide did not affect plant silage composition (protein, starch or fibre content) and methane yield, conversely it significantly increased grain yield for both planting density systems (+5%). The overall boost in yield obtained by combining both strategies in an intensive system, HiD combined with the fungicide, was +24% for methane and +21% for grain yield compared to StD without fungi-cide application. This work proved that an intensive high planting system with up to 10 plants m-2, supported by leaf fungicide treatments, can lead to a real yield enhancement of both maize grain and silage. [ABSTRACT FROM AUTHOR]

Interest and focus on development of renewable biofuels has been increasing over the past decade leading to the introduction of a wide cadre of renewable feedstocks. As a result, numerous perennial warm-season grasses have been introduced and management practices evaluated to determine their suitability as biofuel feedstocks. “Merkeron” napier grass (Pennisetum purpureum) plots were established in 2010 and harvested during crop years 2011 through 2015 adjacent to an on-going peanut (Arachis hypogaea L.), corn (Zea mays L.), and cotton (Gossypium hirsutum L.) cropping systems study conducted at the USDA/ARS Multi-crop Irrigation Research Farm in Shellman, GA (84 36 W, 30 44 N) on a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults). Napier grass was produced in both non-irrigated and two irrigated levels with different levels of nitrogen and potassium fertilizers. Peanut, corn, and cotton were produced in non-irrigated and full irrigation regimes. Breakeven prices for napier grass ranged from $65 to $84 Mg−1 at variable and total costs. The breakeven napier grass price was estimated such that the net returns were equal between napier grass and peanut, cotton, corn cropping systems. At variable production cost, comparative breakeven napier grass prices for non-irrigated, 50% irrigated, and full irrigated regimes were $77, $117, and $112 Mg−1, respectively. Napier grass did not compete economically against traditional irrigated cropping systems. Depending on traditional crop prices and bioenergy feed stock prices, napier grass could offer economic opportunities in non-irrigated production environments, riparian buffer zone edges, or non-cropped marginal production areas. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Winter pea (Pisum sativum L.) grows well in a wide geographic region, both as a forage and cover crop. Understanding the quality constituents of this crop is important for both end uses; however, analysis of quality constituents by conventional wet chemistry methods is laborious, slow and costly. Near infrared reflectance spectroscopy (NIRS) is a precise, accurate, rapid and cheap alternative to using wet chemistry for estimating quality constituents. We developed and validated NIRS calibration models for constituent analysis of this crop. RESULTS: Of the 11 constituent models developed, nine constituents including moisture, dry‐matter, total‐nitrogen, crude protein, acid detergent fiber, neutral detergent fiber, AD‐lignin, cellulose and non‐fibrous carbohydrate had low standard errors and a high coefficient of determination (R2 = 0.88–0.98; 1 – VR, which is the coefficient of determination during cross‐validation = 0.77–0.92) for both calibration and cross‐validation, indicating their potential for quantitative predictability. The calibration models for ash (R2 = 0.65; 1 – VR = 0.46) and hemicellulose (R2 = 0.75; 1 – VR = 0.50) also appeared to be adequate for qualitative screening. Predictions of an independent validation set yielded reliable agreement between the NIRS predicted values and the reference values with low standard error of prediction (SEP), low bias, high coefficient of determination (r2 = 0.82‐0.95), high ratios of performance to deviation (RPD = SD/SEP; 2.30–3.85) and high ratios of performance to interquartile distance (RPIQ = IQ/SEP; 2.57–7.59) for all 11 constituents. CONCLUSION: Precise, accurate and rapid analysis of winter pea for major forage and cover crop quality constituents can be performed at a low cost using the NIRS calibration models developed. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]