Agrosystems, Geosciences & Environment最新文献

Microplastics (MPs), formed from the physical breakdown of larger plastics, have been found across a variety of ecosystems. Much research has been done on the effects of MPs in aquatic ecosystems, but fewer studies have explored their effects in terrestrial environments, particularly in agroecosystems where modern practices contribute strongly to MP soil pollution (e.g., plasticulture, fertilization with contaminated biosolids, and composts). Aquatic pharmaceutical contamination is also considered an emerging pollutant threat. Naproxen, a commonly used drug, has been found in wastewater and natural freshwater bodies globally. Thus, crops may be exposed to multiple pollutants simultaneously through soil and water inputs. Our research provides insight into the individual and interactive effects of soil MP pollution intensity and exposure to naproxen-contaminated water on growth and development of Lactuca sativa (lettuce). Soil abiotic factors (pH, electrical conductivity, and rates of soil moisture loss) are also reported. We found that 7% polyester MP-contaminated soil significantly reduced total aboveground biomass and coarse root biomass, while both 0.03% and 7% polyester MP-contaminated soil significantly reduced leaf count and average leaf size. However, 1 mg/L naproxen had no effect on plant growth or development, and there were no interactive effects of naproxen with MPs. MPs also significantly increased rates of soil moisture loss, but we found no effects of MPs or naproxen on soil pH or electrical conductivity. Predicted global increases in soil MP contamination levels will potentially have negative consequences for food systems.

Remote sensing tools, along with Global Navigation Satellite System cattle collars and digital soil maps, may help elucidate spatiotemporal relationships among soils, terrain, forages, and animals. However, standard computational procedures preclude systems-level evaluations across this continuum due to data inoperability and processing limitations. Deep learning, a subset of neural network, may elucidate efficiency of livestock production and linkages within the livestock-grazing environment. Consequently, we applied deep learning to environmental remote sensing data to (1) develop predictive models for yield and forage nutrition based on vegetation indices and (2) at a pixel-level (per 55 m²), identify how grazing is linked to soil properties, forage growth and nutrition, and terrain attributes in silvopasture and pasture-only systems. Remotely sensed data rapidly and non-destructively estimated herbage mass and nutritive value for enhanced net and primary productivity management in livestock and grazing systems. Cattle grazed big bluestem (Andropogon gerardii ‘Vitman’) with 182% greater frequency than orchardgrass (Dactylis glomerata L.) in the pasture-only system. Real-time estimates of vegetative bands may assist in predicting grazing pressure for more efficient pasture resource management. Cattle grazing followed distinct soil-landscape patterns, namely reduced cattle grazing preference occurred in areas of water accumulation, which highlights linkages among terrain, soil-water movement, soil properties, forage nutrition, and animal grazing response spatially and temporally. Results from this study could be scaled up to improve grazing management among the largest land-use category in the United States, that is, grasslands, which would allow for sustainable intensification of forage-based livestock production to meet growing demands for environmentally responsible protein.

Increasing soybean [Glycine max L. (Merrill)] productivity relies heavily on optimizing crop geometry, encompassing both inter- and intra-row spacing. This crucial agronomic practice directly impacts the productivity of soybean crops, making it vital for farmers to consider soybean maturity group when determining optimal crop geometry. Hence, the study was conducted to determine the effect of inter- and intra-row spacing on yield and yield components of soybean varieties and to determine appropriate plant spacing for each maturity group of soybean varieties to achieve a high yield of soybean in the study area. Two soybean varieties from each maturity group, four inter-row spacing (30, 40, 50, and 60 cm), and two intra-row spacing (5 and 10 cm) were arranged in factorial combinations in randomized complete block design with three replications. The results showed that days to flowering, days to maturity, plant height, number of seeds/pod, number of pods/plant, and 100-seed weight were significantly influenced by the main effect of varieties, inter- and intra-row spacing for each maturity group of soybean varieties. The highest grain yield was recorded from narrow inter-row spacing for early and medium maturity groups regardless of intra-row spacing while the highest grain yield was obtained from 50-cm inter-row spacing for late maturing groups. Thus, it can be concluded that 40-cm inter-row spacing is recommended for early and medium soybean varieties, while 50-cm inter-row spacing is recommended for late-maturing soybean varieties for western parts of Oromia and similar agroecologies.

Adoption of dicamba-tolerant soybeans contributed to widespread reports of chemical trespassing on adjacent, sensitive soybeans. Reports of the impact of dicamba on sensitive soybeans (Glycine max L.) have been well documented; however, the potential for dicamba carryover into harvested beans from sensitive plants has largely been overlooked. Field trials in central Missouri focused on assessing the injury and yield response of sensitive soybeans to concentrations of dicamba as low as 0.25% of the use rate (10 µL L⁻¹ dicamba). In both 2018 and 2019, dicamba-sensitive soybeans were planted in conventional row spacing and treated with 10–300 µL L⁻¹ dicamba at both V3 and R1 soybeans. Dicamba symptoms were visible in less than 7 days after application (DAA); significant injury was observed at 10 µL L⁻¹ and persisted through the duration of the study (28 DAA). Injury levels reached almost 50% with 300 µL L⁻¹ dicamba. Step-wise increases in soybean yield losses occurred with increasing dicamba concentrations and reached 50% with 300 µL L⁻¹ dicamba. Yield losses were up to 10% greater for R1 versus V3 soybeans treated with the same dicamba concentration. Dicamba residues in bean tissue ranged from 0.72 to 0.81 mg kg⁻¹ for 150 to 300 µL L⁻¹ dicamba, and residues were similar for beans at both V3 and R1. Dicamba persisted in beans harvested up to 122 days after plant exposure to dicamba. Although dicamba residues were within limits established by the EPA (10 mg kg⁻¹), residues exceeded that allowed in marketed, organic soybeans (0.5 mg kg⁻¹).

Purple nutsedge (Cyperus rotundus L.) poses a significant challenge to Florida tomato (Solanum lycopersicum L.) producers due to its ability to puncture plastic mulch, resilient tubers, and rapid rhizome proliferation. Preemergence herbicides effectively suppress purple nutsedge in tomatoes under plastic mulch. Although the impact of co-application of herbicides with fertilizers has been studied in row crops, its potential in vegetable plasticulture systems remains unexplored. This study aimed to evaluate the effectiveness and crop safety of the preemergence herbicide S-metolachlor, both as a standalone treatment and in combination with a fertilizer enhancer or chelated iron in tomato plasticulture. Field trials at the University of Florida's Southwest Florida Research and Education Center, Immokalee, FL, involved applying S-metolachlor at the recommended rate of 1 kg a.i. ha⁻¹ on raised beds before installing plastic mulch. The herbicide was applied as a blanket spray alone, mixed with fertilizer enhancer, and coated on chelated iron fertilizer. Results indicate that using S-metolachlor alone effectively reduced purple nutsedge density compared to the nontreated control in both trials I and II. Combining S-metolachlor with fertilizer enhancer or chelated iron resulted in a >30% and 57% reduction in purple nutsedge density, respectively, compared to the nontreated control in trial II. These treatments did not adversely impact chlorophyll content or crop yield (p > 0.05) compared to the nontreated control. Notably, tomato yield significantly (p < 0.05) decreased with increased purple nutsedge density at 4, 8, and 12 weeks after transplanting. Overall, the results from both trials suggest that using S-metolachlor is an effective approach to reduce purple nutsedge infestation in plastic-mulched raised beds without negatively impacting tomato health and productivity.

Biofertilizers can be better alternatives to chemical fertilizers to enhance plant nutrition and productivity as they improve the soil fertility and crop productivity in an eco-friendly and cost-effective manner. A pot experiment was conducted between December 2018 and March 2019 in southern Ethiopia to evaluate the combined inoculation of arbuscular mycorrhizal fungi (AMF) and Meso-rhizobium (MR) on biomass yield, nutrient uptake, and moisture stress tolerance of chickpea (Cicer arietinum L.) (variety: Habru). The experiment was executed as a factorial arrangement using a completely randomized design with three replications. The treatments were control (non-fertilized), sole AM fungi inoculation, AM fungi inoculation with phosphorus fertilizer (20 kg P ha⁻¹) and MR, and sole inorganic fertilizers (20 kg P;10 kg N ha⁻¹) at four different moisture levels (optimum throughout the growing season, stressed at vegetative, flowering, and seed filling stages). The results demonstrated that biomass yields were limited by moisture stress, especially at vegetative and flowering stages of chickpea. Sole and co-application of AMF with MR and inorganic P increased biomass yields on average by 19%, 39%, and 33% under water stress conditions, respectively, compared to the non-inoculated control. The application of AMF with MR and inorganic P also significantly increased nodulation, AMF colonization, and nutrient uptake, but these effects were dependent on soil moisture status. In conclusion, there are potential advantages to be gained from sole and combined AMF application with rhizobium to improve growth and productivity of chickpea through enhanced nutrient and water uptake, though the results of this pot experiment should be validated through field trials.

Field trials were conducted in 2021 and 2022 to evaluate the effects of planting date (mid-March, mid-April, and mid-May) on 11 fiber hemp (Cannabis sativa L. <0.3% total tetrahydrocannabinol) varieties. Trials were conducted in Goldsboro, Kinston, and Salisbury, NC. Each location followed a split-plot randomized complete block design with at least three blocks where planting date was the main-plot and variety the sub-plot. Varieties investigated originated from China and Australia (2021 only). Data collection included flowering time, end of season stand counts, stem height, diameter, and final retted dry straw yield. We found differences among the varieties investigated in both years; however, no distinct trend was observed across years. All varieties investigated flowered at the end of August and beginning of September, allowing for a long growing season and ability to produce abundant biomass. In general, the Chinese genetics yielded higher stem biomass compared to previously reported European genetics. Stem thickness was >7.5 mm, which is generally considered the maximum width for textile-grade fiber production. To achieve thinner stems from the varieties investigated, harvesting prior to male-flower initiation may be required. The crop experienced temperatures below freezing in both years with no signs of damage. Taken together, farmers seeking to plant fiber hemp in North Carolina have a wide planting window from mid-March to mid-May using these Chinese varieties.

Annually, approximately 1.5 million tonnes of sediment are dredged from federal navigational channels in Lake Erie. Recognizing the potential influence of Lake sediments on soil compaction, structure, water retention capacity, and aeration, this research assessed the agronomic performance of selected specialty crops under varying sediment ratios in an open-field production system. The experimental design involved three sediment application rates: 0 tonne (100% farm soil), 0.7 tonne (90% farm soil and 10% sediment), and 7 tonnes per bed (100% sediment). Lettuces (Lactuca sativa L.) were harvested 35 days after planting, with assessments including fresh and dry weights of leaves root biomass and root length measurements. Radishes (Raphanus sativus L.) were evaluated for root length, leaf fresh weight, root fresh weight, and diameter. Tomatoes (Solanum lycopersicum L.) plants were monitored for plant height and stem diameter. Fruit harvest occurred at days 70 and 75 post-transplant. Metrics such as total number of marketable fruits, total fruit weight, number of US grade-1 fruits, and polar and equatorial diameters were recorded. The results revealed significant positive effects of the 7-tonne sediment treatment on lettuce, including increased dry leaf and root biomass, root lengths, and fresh weight. Similarly, radishes exhibited enhanced weight and length when grown in beds with 7 tonnes of sediment. Tomatoes from the 7-tonne sediment treatment displayed higher values in plant measurements and harvested fruits. Overall, the findings indicate that soils treated with Lake Erie sediment positively influence the development and production of lettuce, radishes, and tomatoes compared to untreated soils.

Barley (Hordeum vulgare L.) is a major grain crop farmed in Ethiopia throughout the long rainy season (Meher) and the short rainy season (Belg) of the year. Barley genotypes were subjected to multi-environment experiments in six different settings to identify stable genotypes and estimate the impact of genotype × environment interaction (GEI) on grain production. In each area, the field experiment was conducted from mid-July to January during the primary cropping season of 2021. Three replications of a randomized complete block design were used to set up the trials. According to the additive main effects and multiplicative interaction (AMMI) study, genotype (18.19%), GEI (22.98%), and environment (58.83%) all had an impact on the major treatment sum of squares. The more variance attributed to the environments is a sign of environmental diversity. Given that the two interaction principal component analysis (IPCAs) accounted for 76.94% of the interaction sum of squares, they were sufficient for cross-validation of the grain yield variance explained by GEI. In contrast to the GGE biplot approaches, which indicated genotypes G12, G3, and G9 as stable and high-yielding genotypes throughout the environments, the AMMI stability value identified genotypes G3, G12, and G9 as high yielding with stable performance across environments. In general, the GGE biplot and AMMI analysis models demonstrated that genotypes G12, G3, and G9 were stable and yielded well, making G3 acceptable for cultivation in a wider range of environments and G12 and G9 suitable for release.

Many research findings stated that field pea was phenotypically diverse and symbiotically effective. However, limited studies were conducted on field pea (Pisum sativum var. abysinicum) regarding biological nitrogen fixation with local varieties and races. Therefore, the current study was conducted on the synergetic efficiency of locally available inoculums on yield and yield components of Dekoko. Randomized complete block design with three replications was used at farmers field level as an experimental design. The analysis of variance result revealed that, locally isolated Rhizobium inoculants significantly influence the agronomic parameters such as plant height, number of tillers, number of seeds, grain yield, and 1000-seed weight at p < 0.05. The highest plant height (81.87 and 87.49 cm), pod number (19.53 and 20.93 NP/P), grain yield (633.2 and 790.2 kg ha⁻¹) and 1000-seed weight (97.33 and 92.42 g) were recorded from field condition. The rhizobial population count of the study sites varied, and experimental site number 1 had higher population count (2.33 × 10⁸) compared to the second experimental site (1.23 × 10⁸). Soils having various rhizobial population have different capability to fix atmospheric nitrogen. Since Ethiopian soils harbor rhizobial populations in the soil Rhizosphere. Therefore, the authors concluded that, prior to field experimentation, assessing the microbial diversity of the study area is a primary agenda.