Search Results (72)

Intercropping with green manures is an effective practice for increasing agricultural production and reducing environmental issues. However, the effects of green manure type and intercropping patten on soil nutrient availability and microbial communities remains underexplored. In the present study, the impacts of three green manure–maize intercropping patterns on maize yield, rhizosphere nutrient availability, and soil fungal community were evaluated. Four treatments (three replicate plots for each) were involved, including a monoculture treatment (MC) as a control and three intercropping patterns as follows: maize–ryegrass (Lolium perenne L.) (IntL), maize–forage soybean (Fen Dou mulv 2, a hybrid soybean cultivar) (IntF), and maize–ryegrass–forage soybean (IntLF) intercropping. The results showed that all three intercropping patterns significantly increased maize yield and rhizosphere available phosphorus (AP) compared with MC. Intercropping shifted the dominant assembly process of the maize rhizosphere fungal community from stochastic to deterministic processes, shaping a community rich in arbuscular mycorrhizal fungi (AMF) and limited in plant pathogens, primarily Exserohilum turcicum. AP showed significant correlations with fungal community and AMF, while maize yield was negatively correlated with plant pathogens. In addition, the dual-species green manure intercropping pattern (IntLF) had the strongest positive effects on maize yield, AP content, and fungal community compared with single-species patterns (IntL and IntF). These results illustrate the advantages of planting diversification in boosting crop production by improving nutrient availability and soil health in the rhizosphere and suggest that the maize–ryegrass–forage soybean intercropping system is a potential strategy for improving soil fertility and health. Full article

Global food security relies on wheat, maize, and soybean, yet their cultivation faces escalating threats from Fusarium head blight (FHB) pathogens. We demonstrate that agricultural intensification enables cross-kingdom root infections by Fusarium graminearum and F. asiaticum across these crops. Screening of 180 Fusarium strains revealed tripartite host infectivity, with transcriptomics uncovering host-adapted virulence strategies. Transcriptome analysis identified distinct gene expression patterns during the infection of each crop, with F. graminearum employing host-specific genes, such as FgPPDT1 (a pyridoxal phosphate-dependent transferase), for maize root infection. The FgPPDT1 knockout mutant (Δfgppdt1) exhibited severely impaired root colonization. Our findings establish differential gene expression as a regulatory axis for cross-host adaptation, directly linking FHB transmission risks to wheat–maize intercropping and wheat-soybean rotations. Full article

Maize–soybean intercropping is widely practised to improve land use efficiency, but shading from maize often limits soybean growth and productivity. Melatonin, a plant signaling molecule with antioxidant and growth-regulating properties, has shown potential in mitigating various abiotic stresses, including low light. This study investigated the efficacy of applying foliar melatonin (MT) to enhance shade tolerance and yield performance of soybean under intercropping. Four melatonin concentrations (0, 50, 100, and 150 µM) were applied to soybean grown under mono- and intercropping systems. The results showed that intercropping significantly reduced growth, photosynthetic activity, and yield-related traits. However, the MT application, particularly at 100 µM (MT₁₀₀), effectively mitigated these declines. MT₁₀₀ improved plant height (by up to 32%), leaf area (8%), internode length (up to 41%), grain yield (32%), and biomass dry matter (30%) compared to untreated intercropped plants. It also enhanced SPAD chlorophyll values, photosynthetic rate, stomatal conductance, chlorophyll fluorescence parameters such as Photosystem II efficiency (ɸPSII), maximum PSII quantum yield (Fv/Fm), photochemical quenching (qp), electron transport rate (ETR), Rubisco activity, and soluble protein content. These findings suggest that foliar application of melatonin, especially at 100 µM, can improve shade resilience in soybean by enhancing physiological and biochemical performance, offering a practical strategy for optimizing productivity in intercropping systems. Full article

Plant growth regulators (PGRs) enhance crop stress resistance but their roles in microbial-mediated phosphorus cycling within intercropping systems are unclear. Thus, We conducted a two-year field study using corn (Zea mays L. cv. Denghai 605) and soybean (Glycine max L. cv. Hedou 22) in fluvisols and luvisols soil according to World Reference Base for Soil Resources (WRB) standard. Under a 4-row corn and 6-row soybean strip intercropping system, three treatments were applied: a water control (CK), and two plant growth regulators—T1 (EC: ethephon [300 mg/L] + cycocel [2 g/L]) and T2 (ED: ethephon [300 mg/L] + 2-Diethyl aminoethyl hexanoate [10 mg/L]). Foliar applications were administered at the V7 stage (seventh leaf) of intercropped corn plants to assess how foliar-applied PGRs (T1/T2) modulated the soil phosphorus availability, microbial communities, and functional genes in maize intercropping systems. PGRs increased the soil organic phosphorus and available phosphorus contents, and alkaline phosphatase activity, but not total phosphorus. PGRs declined the α-diversity in fluvisols soil but increased the α-diversity in luvisols soil. The major taxa changed from Actinobacteria (CK) to Proteobacteria (T1) and Saccharibacteria (T2) in fluvisols soil, and from Actinobacteria/Gemmatimonadetes (CK) to Saccharibacteria (T1) and Acidobacteria (T2) in luvisols soil. Functional gene dynamics indicated soil-specific regulation, where fluvisols soil harbored more phoD (organic phosphorus mineralization) and relA (polyphosphate degradation) genes, whereas phnP gene dominated in luvisols soil. T1 stimulated organic phosphorus mineralization and inorganic phosphorus solubilization in fluvisols soil, upregulating regulation genes, and T2 enhanced polyphosphate synthesis and transport gene expression in luvisols soil. Proteobacteria, Nitrospirae, and Chloroflexi were positively correlated with organic phosphorus mineralization and polyphosphate cycling genes, whereas Bacteroidetes and Verrucomicrobia correlated with available potassium (AP), total phosphorus (TP), and alkaline phosphatase (ALP) activity. Thus, PGRs activated soil phosphorus by restructuring soil type-dependent microbial functional networks, connecting PGRs-induced shifts with microbial phosphorus cycling mechanisms. These findings facilitate the targeted use of PGRs to optimize microbial-driven phosphorus efficiency in strategies for sustainable phosphorus management in diverse agricultural soils. Full article

The planting area of the maize–soybean strip intercropping system has been increasing annually in the Hexi Corridor oasis irrigation area of China. However, long-term irrational water resource utilization and the excessive mono-application of fertilizers have led to significantly low water and nitrogen use efficiency in this cropping system. To explore the sustainable production model of high yield and high water–nitrogen productivity in maize–soybean strip intercropping, we established three irrigation levels (low: 60%, medium: 80%, and sufficient: 100% of reference crop evapotranspiration) and three nitrogen application levels (low: maize 230 kg ha⁻¹, soybean 29 kg ha⁻¹; medium: maize 340 kg ha⁻¹, soybean 57 kg ha⁻¹; and high: maize 450 kg ha⁻¹, soybean 85 kg ha⁻¹) for maize and soybean, respectively. Three irrigation levels without nitrogen application served as controls. The effects of different water–nitrogen combinations on multiple indicators of the maize–soybean strip intercropping system, including yield, water–nitrogen productivity, and quality, were analyzed. The results showed that the irrigation amount and nitrogen application rate significantly affected the kernel quality of maize. Specifically, the medium nitrogen and sufficient water (N2W3) combination achieved optimal performance in crude fat, starch, and bulk density. However, excessive irrigation and nitrogen application led to a reduction in the content of lysine and crude protein in maize, as well as crude fat and crude starch in soybean. Appropriate irrigation and nitrogen application significantly increased the yield in the maize–soybean strip intercropping system, in which the N2W3 treatment had the highest yield, with maize and soybean yields reaching 14007.02 and 2025.39 kg ha⁻¹, respectively, which increased by 2.52% to 138.85% and 5.37% to 191.44% compared with the other treatments. Taking into account the growing environment of the oasis agricultural area in the Hexi Corridor and the effects of different water and nitrogen supplies on the yield, water–nitrogen productivity, and kernel quality of maize and soybeans in the strip intercropping system, the highest target yield can be achieved when the irrigation quotas for maize and soybeans are set at 100% ET0 (reference crop evapotranspiration), with nitrogen application rates of 354.78~422.51 kg ha⁻¹ and 60.27~71.81 kg ha⁻¹, respectively. This provides guidance for enhancing yield and quality in maize–soybean strip intercropping in the oasis agricultural area of the Hexi Corridor, achieving the dual objectives of high yield and superior quality. Full article

Crop row identification and navigation line extraction are essential components for enabling autonomous operations of agricultural machinery. Aiming at the soybean–maize strip intercropping system, this study proposes a LiDAR-based algorithm for crop row detection and navigation line extraction. The proposed method consists of four primary stages: point cloud preprocessing, crop row region identification, feature point clustering, and navigation line extraction. Specifically, a combination of K-means and Euclidean clustering algorithms is employed to extract feature points representing crop rows. The central lines of the crop rows are then fitted using the least squares method, and a stable navigation path is constructed based on angle bisector principles. Field experiments were conducted under three representative scenarios: broken rows with missing plants, low occlusion, and high occlusion. The results demonstrate that the proposed method exhibits strong adaptability and robustness across various environments, achieving over 80% accuracy in navigation line extraction, with up to 90% in low-occlusion settings. The average navigation angle was controlled within 0.28°, with the minimum reaching 0.17°, and the average processing time remained below 75.62 ms. Moreover, lateral deviation tests confirmed the method’s high precision and consistency in path tracking, validating its feasibility and practicality for application in strip intercropping systems. Full article

Despite growing importance, agricultural landscapes face threats, like fragmentation, shrinkage, and degradation, due to climate change. Although remote sensing and GIS are widely used in monitoring croplands, integrating machine learning, remote sensing, GIS, and landscape metrics for the holistic management of this landscape remains underexplored. Thus, this study monitored crop patterns using random forest (94% accuracy), the role of geographical factors (such as elevation, aspect, slope, maximum and minimum temperature, rainfall, cation exchange capacity, NPK, soil pH, soil organic carbon, soil type, soil water content, proximity to drainage, proximity to market, proximity to road, population density, and profit per hectare production), diversity, combinations, and fragmentation using landscape metrics and a fragmentation index. Findings revealed that slope, rainfall, temperature, and profit per hectare production emerged as significant drivers in shaping crop patterns. However, anthropogenic drivers became deciding factors during spatial overlaps between crop suitability zones. Rice belts were the least fragmented and highly productive with a risk of monoculture. Croplands with a combination of soybean, black grams, and maize were highly fragmented, despite having high diversity with comparatively less production per field. These diverse fields were providing higher profits and low risks of crop failure due to the crop combinations. Equally, intercropping balanced the nutrient uptakes, making the practice sustainable. Thus, it can be suggested that productivity and diversity should be prioritized equally to achieve sustainable land use. The development of the PCA-weighted fragmentation index offers an efficient tool to measure fragmentation across similar agricultural regions, and the integrated approach provides a scalable framework for holistic management, sustainable land use planning, and precision agriculture. Full article

Soybean–maize intercropping is a traditional yet high-yield cultivation model that faces technical challenges in weed management due to the different herbicide requirements of soybean and maize. This study presents the design and experiments of the innovative dual-herbicide direct injection system, which can simultaneously deliver glyphosate and fomesafen through real-time concentration modulation. The system operates by measuring the relationship between the mixing ratio and the conductivity value, mathematical model, and control algorithm. Experimental validation demonstrated that the correlation coefficient of herbicide mixing ratios and measured conductivity values across pressure ranges of 0.1–0.3 MPa are greater than 0.98, which means that measuring the mixing ratio using conductivity is reliable. Optimal operational performance was achieved at 0.2 MPa spraying pressure, characterized by superior mixing uniformity (CV < 5%) and system stability. This technological advancement provides a practical solution for precision agrochemical application in complex cropping models, with potential applications extending to other crop combinations requiring differential herbicide treatments. Full article

Soybean–maize intercropping involves the simultaneous planting of maize and soybean. Compound planting sprayers are equipped with a dual-spraying system, particularly for herbicide application, where isolation between crops is essential. To isolate the spraying, it is necessary to select appropriate nozzles that minimize the interference between spray boundaries while ensuring spray uniformity. This study focuses on soybean–maize intercropping systems and investigates the variation patterns of spray boundary under different nozzle arrangement types. Eccentric nozzles (i.e., spray pattern is asymmetric fan-shaped) and fan-shaped nozzles (i.e., spray pattern is symmetric fan-shaped) were evaluated at a working pressure of 0.3 MPa. The results showed that the eccentric nozzle achieved a coefficient of variation (CV) of 0.57 and a compactness of 0.43, while the fan-shaped nozzle had a CV of 0.50 and a compactness of 0.52. This indicates the eccentric nozzle maintains uniformity with a narrower boundary. In addition, this validation was conducted at 0.4 MPa, having similar observations. In soybean–maize intercropping, the maize row width ranges from 40 to 80 cm and where the maize plants exceed 2 m in height, two-eccentric nozzles are required, tested at spacing intervals of 50 cm, 70 cm, and 90 cm. At 0.3 MPa, the CV reached its minimum value (0.3) at a spacing of 70 cm. Additionally, the spray volume on the eccentric nozzle side decreased as the spacing increased. The soybean row width ranges from 160 to 240 cm, requiring eccentric nozzles on both sides and a fan-shaped nozzle in the middle. The spacing between the eccentric and fan-shaped nozzles is chosen to be 50, 70, and 90 cm. A combination of eccentric and fan-shaped nozzles was tested at the same spacing intervals. The results showed that the CV consistently decreased with increasing spacing, and the spray volume on the eccentric nozzle side also declined. Overall, the optimal nozzle configuration for maize zones is two eccentric nozzles at a spacing of 70 cm, while for soybean zones, combining an eccentric nozzle with a fan-shaped nozzle at a spacing of 90 cm effectively ensures both spray uniformity and boundary compactness when variation in windspeed and direction are ignored. Full article

Solar radiation is crucial for intercropping, while partial shading can protect intercropped soybean leaves from irradiation damage during the pod-ripening period under high solar radiation. This study explored the leaf dynamics and soybean quality for the maize–soybean system, for monoculture soybean (MS), monoculture maize (MM), two-row maize + three-row soybean (IS2-3), and four-row maize + four-row soybean (IS4-4). The results revealed that soybean leaves under IS2-3 and IS4-4 treatments showed increases in Rubisco activity of 59.8% and 12.4% compared with MS, respectively. The antioxidant capacity in soybean leaves in MS was higher than that under intercropping treatments. Soybean leaves under IS2-3 and IS4-4 exhibited higher alpha and beta diversities in their endophytes compared with MS. The relative abundance of pathotrophs under IS2-3 was reduced by 19.1% and 22.6% compared to that of those under MS and IS4-4, respectively. The total land equivalent ratio (LER) under IS2-3 was more than 1.00, and increased by 6.4% and 15.7% compared with IS4-4 in 2023 and 2024, respectively. Soybean seeds under IS2-3 and IS4-4 showed 4.1% and 4.2% increases in crude protein content compared to those of MS, respectively. Among various biosynthesis and metabolism processes, flavone and flavonol biosynthesis exerted a stronger influence on soybean seeds in MS, IS2-3, and IS4-4. Soybean seeds under IS2-3 showed elevated genistein content and reduced daidzein content compared with those of MS. Intercropping soybean treatments, especially IS2-3, maintained leaf health during the pod-ripening period and enhanced the crude protein content compared with sole soybean treatment, thus guiding the design of intercropping in areas with high solar radiation. Full article

The increasing global food demand, the degradation of one-third of agricultural land, and climate change pose significant threats to food production. Maize and soybean intercropping can enhance yields and land use efficiency, yet the year-interval effects of continuous intercropping on yield, yield sustainability, and phosphorus use efficiency (PUE) remain unclear. This study evaluates the effects of continuous maize/soybean intercropping over year intervals on yield, PUE, and sustainability. A seven-year field trial (2017–2023) was conducted on acidic soil, comparing two cropping systems: maize monocropping and maize intercropped with soybean. The results showed that continuous maize/soybean intercropping outperformed maize monocropping across all year intervals. Over the first, third, and seventh year intervals, maize yield increased by 37%, 35%, and 58%, respectively, with a 55% average increase over the seven years. Intercropping also enhanced P use efficiency, as evidenced by AE, RE, PFP, and CPF increases. In the first year, AE, PFP, RE, and CPF increased by 48%, 37%, 27%, and 16%, respectively; after the third year interval, these metrics improved by 40%, 35%, 26%, and 14%; and after the seventh year interval, they rose by 60%, 58%, 24%, and 10.5%. The average AE, RE, and PFP increases over seven years were 53%, 52%, and 27%, respectively, while CPF increased by 13%. The SEM analysis further confirmed the substantial impact of the seventh year intercropping interval on maize yield, sustainability, and PUE. This study demonstrates that continuous maize/soybean intercropping can enhance maize yield, PUE, and sustainability, with the seventh year interval offering the most pronounced benefits. These findings provide valuable insights for improving food security and nutrient management challenges. Full article

Iron (Fe) deficiency is a pervasive agricultural concern on a global scale. Intercropping plays a pivotal role in activating soil nutrient cycling and crop nutrient uptake and utilization. This study integrates plant physiology, soil physicochemical determination, high-throughput sequencing, and metabolomics techniques to conduct pot experiments using field-collected soils with soybean and maize plants. This study aims to investigate the mechanisms through which microorganisms in a soybean–maize intercropping system regulate Fe deficiency adaptation. The results revealed that intercropping enhances the resilience of soybean and maize in Fe-deficient environments, facilitates nutrient absorption by plants, and enriches soil nutrient content. Moreover, intercropping fostered more intricate microbial interactions in comparison to monocropping. The dominant microorganisms in the rhizosphere of intercropped soybean and maize included genera Microbacterium, Sphingomonas, Shinella, and Rhizobium. Microbacterium, Sphingomonas, Shinella, and Rhizobium have the potential to produce Fe chelators or enhance plant Fe absorption. Additionally, intercropping notably modified the composition of root exudates derived from soybean and maize. The soybean and maize rhizosphere exhibited significant enrichment with oleamide, coumestrol, glycitein, and daidzein. Coumestrol may have an effect of promoting Fe absorption, and it is significantly positively correlated with the genus Nakamurella in the maize rhizosphere and the genus Pirellula in the soybean rhizosphere. Consequently, these findings suggested that the rhizosphere of intercropped soybean and maize significantly enriches specific microbial communities and root exudates, thereby enhancing microecosystem stability and improving plant tolerance to Fe deficiency. Full article

While satellite-based remote sensing offers a promising avenue for large-scale LCC estimations, the accuracy of evaluations is often decreased by mixed pixels, attributable to distinct farming practices and diverse soil conditions. To overcome these challenges and to account for maize intercropping with soybeans at different growth stages combined with varying soil backgrounds, a hyperspectral database for maize was set up using a random linear mixed model applied to hyperspectral data recorded by an unmanned aerial vehicle (UAV). Four methods, namely, Euclidean distance, Minkowski distance, Manhattan distance, and Cosine similarity, were used to compare vegetation spectra from Sentinel-2A with the newly constructed database. In a next step, widely used vegetation indices such as NDVI, NAOC, and CAI were tested to find the optimum method for LCC retrieval, validated by field measurements. The results show that the NAOC had the strongest correlation with ground sampling information (R² = 0.83, RMSE = 0.94 μg/cm², and MAE = 0.67 μg/cm²). Additional field measurements sampled at other farming areas were applied to validate the method’s transferability and generalization. Here too, validation results showed a highly precise LCC estimation (R² = 0.93, RMSE = 1.10 μg/cm², and MAE = 1.09 μg/cm²), demonstrating that integrating UAV hyperspectral data with a random linear mixed model significantly improves satellite-based LCC retrievals. Full article

Combining soybeans with grass or biomass maize in silage holds promise in addressing the nutritional limitations of individual crops, providing a roughage with a good energy–protein balance. This study evaluated the effects of replacing urea-treated rice straw (UTRS) with silages made from intercropped maize–soybean and Guinea grass (GG) in calf diets on feed intake and growth performance. Sixteen native Yellow calves (130.7 ± 16.1 kg live weight and 12.8 ± 2.6 months old) were used; the experiment had a randomised complete block design with four dietary treatments: Treatment 1 (70% UTRS + 30% GG); Treatment 2 (40% UTRS + 30% GG + 30% Guinea grass silage); Treatment 3 (40% UTRS + 30% GG + 30% Guinea grass–soybean silage); and Treatment 4 (40% UTRS + 30% GG + 30% maize–soybean silage). The animals were fed 0.5 kg concentrate per 100 kg live weight daily, with unlimited access to forage and clean water, for 12 weeks after a two-week adaptation. The results indicate that silages containing soybean increased total weight gain and average daily gain (ADG) and decreased feed conversion ratio (FCR); however, silage replacements had no impact on dry matter intake and body conformation, suggesting that Guinea grass–soybean or maize–soybean silage can effectively enhance the ADG and decrease the FCR of growing calves fed UTRS-based diets. Full article

Maize–soybean intercropping can increase soybean yields and stabilize maize yields, and this practice has been widely promoted in China. Fluroxypyr is a recommended herbicide for maize seedlings, and its drift will cause phytotoxicity to neighboring soybean seedlings. A laboratory toxicity test was performed on soybeans by using a mobile bioassay spray tower. It showed that both the carrier volume and the drift deposition rate of fluroxypyr significantly influenced soybean fresh weight. The soybean fresh weight inhibition rate increased with the increase in the drift deposition rate, especially in the range of 1% to 6%, and soybean fresh weight decreased rapidly. The lack of fit R² was 0.6875, with a 9% maximum deviation between experimental values and simulated values. The drift deposition rate upper threshold for mild phytotoxicity (10% fresh weight inhibition rate, ED₁₀) was determined to be 3.35%, while the threshold for no phytotoxicity (0% fresh weight inhibition rate, ED₀) was 1.01%. To ensure soybean safety, isolation devices and anti-drift nozzles were installed on the boom sprayer to maintain drift below ED₀ or, at most, ED₁₀. Maize seedling strip weed control field tests showed that the highest drift deposition rate was 0.689% under the carrier volume of 330 L·ha⁻¹. There was no phytotoxicity observed on soybeans after 21 days of application, which was consistent with laboratory research results. In this study, the phytotoxicity risk and safe thresholds for the fluroxypyr drift on soybean seedlings were established, which provide a theoretical basis for the safe production of soybeans. Full article