Search Results (1,469)

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

Foliar fertilization is an effective practice that improves both the yield and quality of maize, a crop with high and specific micronutrient demands. This study hypothesized that foliar application of Fe, Cu, Mn, Mo, Zn and B would improve grain size and quality in GS210 maize compared to the control. The single-factor field experiment was conducted in 2023–2024 on Haplic Cambisol (Eutric) soil, under a variety of meteorological conditions. The application of Zn and B fertilizers significantly increased the soil plant analysis development (SPAD) index. Yield components (number of grains per ear, thousand-grain weight) and grain yield increased significantly following Zn foliar application compared to the control. Zn application increased grain yield by 0.59 t ha⁻¹ and 0.49 t ha⁻¹ in 2023 and 2024, respectively. Smaller but beneficial effects were observed with Cu and B applications. In contrast, the effects of fertilization with other micronutrients (Fe, Mn, Mo) were less pronounced than anticipated. Biochemical analyses revealed that foliar fertilization with Fe, Cu and Mo increased total phenolic content and antioxidant capacity, while Fe and Mo enhanced carotenoid accumulation, and Cu and B significantly influenced grain color parameters. The study highlights the potential of foliar fertilization to improve maize performance and grain quality, despite possible antagonisms between micronutrients. Full article

Maize is a key crop in Ecuador for both human and animal consumption. Its vulnerability to fungal contamination and mycotoxins poses risks to food safety. The aim of this study was to analyze the occurrence of fungi and mycotoxins in maize grown in different regions of Ecuador (29 localities) and postharvest factors influencing contamination. Fungal identification was performed through culturing and morphological analysis. Analysis of multi-toxins was carried out using liquid chromatography coupled with mass spectrometry (LC-MS/MS). Statistical analyses included PCA and linear regression models. Fungal contamination was found in 93.3% of samples; mycotoxins were present in 90%. Fusarium and Aspergillus were dominant. Fumonisins (66.6%), zearalenone (30%), aflatoxins (16.7%), and trichothecenes B (13.3%) were the most prevalent. Co-occurrence of up to three mycotoxins per sample was observed, more frequent on the coast. Grain moisture and temperature were strongly correlated with contamination levels. The study reveals widespread contamination of Ecuadorian maize, with environmental and postharvest factors playing key roles. This poses a food safety concern, highlighting the need for improved storage and monitoring systems. Full article

Simulation is an important technical tool in corn threshing operations, and the establishment of the corn kernel model is the core part of the simulation process. The existing modeling method is to treat the whole kernel as a rigid body, which cannot be crushed during the simulation process, and the calculation of the crushing rate needs to be considered through multiple criteria such as the contact force, the number of collisions, and so on. Aiming at the issue that kernel crushing during maize threshing cannot be accurately modeled in discrete element simulations, in this study, a sub-area crushing model was constructed; representative samples with 26%, 30% and 34% moisture content were selected from a double-season maturing region in China; based on the physical dimensions and biological structure of the maize kernel, three stress regions were defined; and mechanical property tests were conducted on each of the three stress regions using a texturometer as a way to determine the different crushing forces due to the heterogeneity of the maize structure. The correctness of the model was verified by stacking angle and mechanical property experiments. A discrete element model of corn kernels was established using the Bonding V2 method and sub-area modeling. Bonding parameters were calculated by combining stacking angle tests and mechanical property tests. The flattened corn kernel was used as a prototype, and the bonding parameters were determined through size and mechanical property tests. A 22-ball bonding model was developed using dimensional parameters, and the kernel density was recalculated. Results showed that the relative error between the stacking angle test and the measured mean value was 0.31%. The maximum deviation of axial compression simulation results from the measured mean value was 22.8 N, and the minimum deviation was 3.67 N. The errors between simulated and actual rupture forces at the three force areas were 5%, 10%, and 0.6%, respectively. The decreasing trend of the maximum rupture force for the three moisture levels in the simulation matched that of the actual rupture force. The discrete element model can accurately reflect the rupture force, energy relationship, and rupture process on both sides, top, and bottom of the grain, and it can solve the error problem caused by the contact between the threshing element and the grain line in the actual threshing process to achieve the design optimization of the threshing drum. The modeling method provided in this study can also be applied to breakable discrete element models for wheat and soybean, and it provides a reference for optimizing the design of subsequent threshing devices. Full article

Soil pH strongly influences phosphorus (P) availability and, consequently, plant response to P fertilization. This study aimed to assess how soil pH affects P availability, uptake, and fertilizer use efficiency in maize (Zea mays L.) grown under controlled conditions. A pot experiment was conducted using three soil pH_KCl levels (4.2, 5.2, and 6.4) and five P application doses (0, 0.5, 1, 1.5, and 2 g P pot⁻¹). Each pot contained 10 kg of soil. Results showed that soil P concentration after harvest increased with both P dose and pH, with the highest values recorded at pH 6.4. Maize grain and straw yields responded differently to P fertilization depending on pH. At pH 5.2, the highest grain yield and agronomic efficiency (AE) were observed at the 0.5 g P dose, while higher doses led to yield reductions. At pH 4.2, P fertilization significantly increased both grain yield and P uptake, but excessive doses reduced yields. In contrast, at pH 6.4, yield increased steadily with rising P doses, though AE and apparent phosphorus recovery (APR) were lowest. The highest APR was observed at pH 4.2 and the lowest at pH 6.4. Overall, the results suggest that optimal maize response to P fertilization occurs near pH 5.2, where both yield and efficiency indices peak. Full article

This study investigated the effects of reduced nitrogen combined with an organic fertilizer on maize yield, soil microbial communities, and enzyme activities to optimize fertilization strategies. A field experiment on cinnamon soil in Yuncheng, Shanxi, was conducted and included six treatments: no fertilizer (CK), conventional N (NC0, 180 kg N/ha), sole organic fertilizer (CN0, 3000 kg/ha), and reduced-N + organic fertilizer (CN1: 90 kg N/ha + 3000 kg/ha; CN2: 135 kg N/ha + 3000 kg/ha; and CN3: 180 kg N/ha + 3000 kg/ha). We analyzed yield components, soil nutrients, urease and invertase activities, and bacterial community structure (16S rRNA sequencing). The key results are as follows: CN1 achieved the highest yield (9764.87 kg/ha), which was 46.8% higher than CK. CN2 maintained comparable yields while delivering higher enzyme activities and microbial abundance, positioning this strategy as suitable for soil remediation. Co-application enriched two beneficial phyla, Proteobacteria and Planctomycetota (19% in CN2), with Proteobacteria positively correlating with urease activity and alkali-hydrolyzable N (p < 0.05), while Verrucomicrobiota negatively correlated with urease activity. In conclusion, 25–50% N reduction with an organic fertilizer (3000 kg/ha) synergistically enhances yield, soil enzymes, and beneficial microbiota, supporting sustainable high-yield agriculture with improved soil fertility. Full article

Red soil regions commonly experience land degradation and low nutrient availability. Excessive fertilizer use in recent years has intensified these challenges, necessitating scientifically informed fertilization strategies to ensure agricultural sustainability. To identify optimal fertilization strategies for maize cultivation in Yunnan’s red soil regions, this study conducted field experiments involving partial substitution of nitrogen fertilizer with organic manure to determine whether this approach improves soil health and boosts maize yield. Four treatments were compared in a randomized complete block design over one growing season: no fertilization (NF), soil testing and formula fertilization (STF), 15% organic fertilizer (swine manure) replacing nitrogen fertilizer (OF15), and 30% organic fertilizer replacing nitrogen fertilizer (OF30). The results indicated that substituting organic fertilizer for nitrogen fertilizer reduced soil acidification while increasing total phosphorus (TP) and available phosphorus (AP), thereby enhancing soil physicochemical properties. Maize grown under OF30 exhibited improved agronomic traits including plant height, stem diameter, ear height, and ear length. Additionally, the partial replacement of synthetic fertilizer with organic fertilizer notably increased maize yield and the weight of 100 grains, but there was no significant difference (p < 0.05) between OF15 and OF30. Moreover, the OF30 treatment generated the highest economic return of 25,981.73 CNY·ha⁻¹. Correlation and principal component analyses revealed that substituting organic fertilizer for nitrogen fertilizer notably influenced total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), and yield, with maize yield positively correlated with TP and AP content. This study presents evidence that replacing 30% of nitrogen fertilizer with organic fertilizer is a viable strategy to enhance soil health, maize productivity, and profitability in Yunnan’s red soil regions, providing a crucial scientific foundation to support sustainable agricultural development in the region. Full article

Organic amendments provide a sustainable strategy to enhance soil quality in degraded environments while also helping to reduce greenhouse gas emissions, for example, by improving soil structure, minimizing the use of synthetic fertilizers, and promoting a green economy. This study assessed the comparative effects of two organic amendments—vermicompost leachate and biochar—on the performance of popcorn maize (Zea mays L. var. everta) cultivated in saline soil conditions. Four treatments were evaluated: T0 (Control), T1 (Vermicompost leachate), T2 (Biochar), and T3 (Vermicompost leachate + Biochar), each with 10 replicates arranged in a Completely Randomized Design (CRD). Although various soil physicochemical, microbiological, and agronomic parameters displayed no significant differences compared to the control, the application of biochar resulted in considerable improvements in soil total organic carbon, the microbial community (mesophilic aerobic bacteria, molds, and yeasts), and increased seed length and diameter. In contrast, vermicompost leachate alone negatively impacted plant growth, leading to decreases in leaf area, stem thickness, and grain yield. Specifically, grain yield declined by 46% with leachate alone and by 31% when combined with biochar, compared to the control. These findings emphasize the superior effectiveness of biochar over vermicompost leachate as a soil amendment under saline conditions and highlight the potential risks of widely applying compost teas in stressed soils. It is recommended to conduct site-specific assessments and screenings for phytotoxins and phytopathogens prior to use. Additionally, the combined application of leachate and biochar may not be advisable given the tested soil characteristics. Full article

Plastid division regulatory genes play a crucial role in the morphogenesis of chloroplasts and amyloplasts. Chloroplasts are the main sites for photosynthesis and metabolic reactions, while amyloplasts are the organelles responsible for forming and storing starch granules. The proper division of chloroplasts and amyloplasts is essential for plant growth and yield maintenance. Therefore, this study aimed to examine the J175 (FtsZ2-2) gene, cloned from an ethyl methanesulphonate (EMS) mutant involved in chloroplast and amyloplast division in maize, through map-based cloning. We found that J175 encodes a cell division protein, FtsZ (filamentous temperature-sensitive Z). The FtsZ family of proteins is widely distributed in plants and may be related to the division of chloroplasts and amyloplasts. The J175 protein is localized in plastids, and its gene is expressed across various tissues. From the seedling stage, the leaves of the j175 mutant exhibited white stripes, while the division of chloroplasts was inhibited, leading to a significant increase in volume and a reduction in their number. Measurement of the photosynthetic rate showed a significant decrease in the photosynthetic efficiency of j175. Additionally, the division of amyloplasts in j175 grains at different stages was impeded, resulting in irregular polygonal starch granules. RNA-seq analyses of leaves and kernels also showed that multiple genes affecting plastid division, such as FtsZ1, ARC3, ARC6, PDV1-1, PDV2, and MinE1, were significantly downregulated. This study demonstrates that the maize gene j175 is essential for maintaining the division of chloroplasts and amyloplasts and ensuring normal plant growth, and provides an important gene resource for the molecular breeding of maize. Full article

This study examined the regulatory mechanism of calcium (Ca) amendment on the dynamics of soil organic carbon (SOC) fractions and extracellular enzyme activities, elucidating the role of Ca in soil carbon cycling processes. A field experiment with maize was conducted, comparing treatments of low calcium (T1), high calcium (T2), and a calcium-free control (CK). Measurements included inter-root SOC fractions—soluble organic carbon (DOC), microbial biomass carbon (MBC), and readily oxidizable organic carbon (ROC)—and the activities of the following extracellular enzymes: β-xylanase, β-glucosidase (β-glu), phenol oxidase (Phox), peroxidase (Pero), phosphatase (Phos), acetylaminoglucosidase (NAG), and urease. The main findings indicated the following: (1) Calcium addition significantly increased SOC content (115.04% and 99.22% higher in T1 and T2, respectively, than CK during the entire reproductive period) and enhanced microbial activity (elevated DOC and MBC). However, SOC decreased by 8.44% (T1) and 16.38% (T2) relative to CK in the late reproductive stage (irrigation–ripening), potentially reflecting microbial utilization (supported by the inverse correlation between SOC and MBC/DOC), and maize carbon reallocation during grain filling. (2) Calcium activated β-glu, Phox, Phos, NAG, and urease (p < 0.05), with pronounced increases in Phox (241.13 IU·L⁻¹) and Phos (1126.65 U·L⁻¹), indicating enhanced organic matter mineralization and phosphorus availability. (3) Calcium-driven MBC and ROC accumulation was associated with the positive regulation of Phox (path coefficient > 0.8) and the negative regulation of Phos. SOC was co-regulated by β-glu and Phos (R² = 0.753). (4) Calcium dynamically optimized the short-term carbon distribution through enzyme activity while promoting long-term sequestration. Our study provides new evidence supporting multi-pathway interactions through which calcium mediates enzyme networks to influence the soil carbon cycle. The findings provide a theoretical foundation for calcium fertilizer management and soil carbon sequestration strategies in agriculture, advancing academic and practical goals for sustainable development and carbon neutrality. Full article

The adsorption performance of maize seeds in air-suction seed metering devices directly affects the operational quality of maize seeders. The suction holes on the seed metering disc play a crucial role in determining the device’s ability to adsorb maize seeds and serve as a key design parameter for air-suction seed metering systems. Existing research has primarily focused on seed posture control and suction force models for standard particles, while experimental studies on the actual adsorption performance of maize seeds remain scarce. To further investigate the adsorption characteristics of maize seeds under different suction hole geometries, this study employed a self-developed adsorption force measurement platform to conduct experiments on maize seeds in various adsorption postures. The resulting force–displacement curves reveal the variation of adsorption force as seeds detach from the suction holes. To assess the applicability of conventional suction force calculation models, computational fluid dynamics (CFD) simulations were performed to analyze the adsorption mechanism of standard particles. The simulation results indicate significant limitations in commonly used suction force estimation methods. For instance, in experiments evaluating the effect of equivalent adsorption area, the relative error between the suction force estimated by the traditional pressure-based method for triangular holes and the actual measured force reached 40.82%. Similarly, the relative error between the force estimated by the airflow drag method for square suction holes and the actual measured force under the same conditions was 17.14%. Therefore, when evaluating actual seed adsorption, it is essential to comprehensively consider factors such as suction hole geometry, blocked suction area, seed shape, vacuum pressure, and the overlap depth between the seed boundary and the suction hole, all of which significantly influence the adsorption effect. Full article

This study used integrated in vitro and in vivo approaches to investigate how the starch source (glutinous rice, indica rice, maize, or high-amylose rice) influences starch digestion kinetics and, consequently, the apparent nutrient utilization and amino acid metabolism in goslings. Four diets were formulated using glutinous rice, indica rice, maize, and high-amylose rice, and in vitro digestion and animal experiments were carried out. The data showed the particle sizes of the four starches: glutinous rice ≈ indica rice < corn < amylose. The glutinous rice starch grain is a porous polyhedron with an angular surface, the corn starch grain is an ellipsoid with a smooth surface, the indica rice starch grain is a polyhedron with a smooth and compact surface, and the high-amylose starch grain is an irregular polyhedron with a smooth surface. Starch digestibility was relatively stable for the indica and corn-based diets, and starch digestibility was higher for the indica rice diet compared to the corn- and high-amylose starch-based diets. The utilization of Asp, Ser, Glu, Gly, and Phe was higher for the glutinous rice diet compared to the maize and high-amylose diets. Furthermore, with this diet, the availability of Thr and Ala was observed to be higher than with the indica rice and high-amylose diets. In conclusion, the particle size and structure of starch from different sources (glutinous rice, indica rice, corn, and high-amylose rice) were different, significantly affecting the starch digestion rate. The glutinous rice diet enables a fast digestion rate for starch, which is rapidly digested in the proximal intestine. The inadequate supply of glucose in the distal intestine enhances the oxidative energy supply from dietary amino acids in that region, thereby improving the apparent digestibility of both starch and crude protein. Full article

Grain moisture influences grain number formation during the critical period as well as determining the final grain weight during the grain-filling period in maize (Zea mays L.). To clarify the relationships between grain number, grain weight, and grain moisture dynamics, a 2–year field experiment in a split-plot design was conducted with two irrigation treatments, well irrigation (WI) and no irrigation (NI), and with four husk removal treatments, including no husk removal as control (H₀) and removal of 1/4 (H_1/4), 2/4 (H_2/4), 3/4 (H_3/4), and 4/4 (H_4/4) of the husk layers, respectively. Husk removal reduced the maize grain number, grain dry weight, and yield, and the reductions were larger under no irrigation (33.4–33.5%) than under well irrigation conditions (27.7–33.2%). By contrast, irrigation increased grain water content by 11.1–13.4% and grain dry weight by 6.5–10.4%, regardless of husk removal. Meanwhile, the interactive effects between irrigation and husk removal were significant in grain water content but not in grain yield, reflecting the larger negative effects of husk removal on maize grain yield. In conclusion, husk plays a crucial role in grain number formation during the critical period and grain weight during the grain-filling period, especially in drought conditions, in relation to the trade-offs between yield enhancement and grain desiccation in maize production. Full article

Nitrogen (N) plays a decisive role in the growth and yield of crops. Hence, a high maize grain yield depends upon substantial N inputs. In the present study, morphological traits and yield components, grain yield, rain use efficiency (RUE), and N partial factor productivity (NPFP) were analyzed in two maize hybrids (ZP666 and NS6030) for 2 yr using four N rates (0 (N0), 60 (N60), 120 (N120), and 180 (N180) kg N ha⁻¹). In a climatically more favorable year (2022), the studied traits and NPFP were higher, while RUE was lower. Hybrid ZP666 had higher values of morphological traits and yield component traits, except 1000-grain weight, grain yield, RUE, and NPFP, than hybrid NS6030. The highest values for morphological traits, yield components, grain yield (9383 and 9456 kg ha⁻¹), and RUE (27.1 and 27.2 kg ha⁻¹ mm⁻¹) were obtained at 120 and 180 kg N ha⁻¹. The NPFP decreased significantly with increasing N input, from 137.6 (control) to 52.5 kg grain per kg fertilizer N (180 kg N ha⁻¹). A suitable hybrid selection and the application of a moderate N fertilizer rate of 120 kg N ha⁻¹ could contribute to high yields and lower nitrogen losses to the environment and promote sustainable agriculture. Full article

Background/Objectives: A critical part of the maize life cycle takes place during the summer, and due to climate change, its growth and development are increasingly exposed to the irregular and unpredictable effects of drought stress. Developing and using new cultivars with increased drought tolerance for farmers is the easiest and cheapest solution. One of the concepts to screen for drought tolerance is to expose germplasm to various growth scenarios (environments), expecting that random drought will occur in some of them. Methods: In the present study, thirty-two maize hybrids belonging to four FAO maturity groups were tested for grain yield at six locations over two consecutive years. In parallel, data of the basic meteorological elements such as air temperature, relative humidity and precipitation were collected and used to compute two indices, scPDSI (Self-calibrating Palmer Drought Severity Index) and VPD (Vapor Pressure Deficit), that were assessed as indicators of drought (water deficit) severity during the vegetation period. Practical implementation of these indices was carried out indirectly by first analyzing yield data using a factor analytic model to detect latent environmental variables affecting yield and then correlating those latent variables with drought indices. Results: The first latent variable, which explained 47.97% of the total variability, was correlated with VPD (r = −0.58); the second latent variable explained 9.57% of the total variability and was correlated with scPDSI (r = −0.74). Furthermore, latent regression coefficients (i.e., genotypic sensitivities to latent environmental variables) were correlated with genotypic drought tolerance. Conclusions: This could be considered an indication that there were two different acting mechanisms in which drought affected yield. Full article