This paper summarized the high yield cultivation technology for summer maize using dense planting and drip irrigation with integrated water and fertilizer management in Northern Anhui Province. Before sowing, maize varieties suitable for dense planting, such as Annong 218, are selected. Fine land preparation is carried out, and straw returning is implemented to enhance soil fertility. Precision sowing is performed before June 25 using a navigation-equipped seeder to complete direct seeding, fertilization, and drip tape laying in a single operation. Base fertilizer is applied through layered deep placement of maize-specific compound fertilizer at 40-45 kg/667 m², accompanied by the installation of a precise drip irrigation system. Field management emphasizes accurate regulation of water and fertilizer, with staged drip irrigation and topdressing according to growth stages. Chemical control to prevent lodging is applied at the 6-8 leaf stage. Pest and disease control follows a prevention-first approach, and pesticides should be applied during the seedling stage, bell mouth stage, and tasseling and flowering stage to prevent rust, maize borer. Harvesting is conducted when the grain milk line disappears and moisture content falls below 28%, using high-performance combine harvesters. Post-harvest operations include grain drying, drip tape recycling, and straw returning. This technology system integrates superior varieties, dense planting, precise water and fertilizer management, and full mechanization to achieve high yield, efficiency, and green sustainable production in summer maize cultivation.

ERF (Ethylene Responsive Factor) transcription factors are an important subfamily of the AP2/ERF family, characterized by a highly conserved AP2 domain. They specifically recognize and bind to cis-acting elements such as GCC-box and DRE/CRT in the promoters of target genes, playing a central regulatory role in plant responses to biotic and abiotic stresses. Members of the ERF family are primarily involved in regulating responses to abiotic stresses such as drought, high salt, low temperature, and hypoxia, while others mediate resistance to biotic stresses like pathogens through hormone signaling pathways involving salicylic acid and jasmonic acid. In recent years, several key ERF members involved in stress responses have been identified in maize, and their crucial roles in enhancing drought tolerance, salt tolerance, and disease resistance have been confirmed through genetic transformation. Through literature research and inductive analysis, this review summarizes the structural characteristics and functional classification of ERF transcription factors in maize, with a focus on elucidating their regulatory mechanisms and networks under biotic and abiotic stress conditions. ERF transcription factors, via their conserved AP2 domain, bind to cis-acting elements such as the GCC-box and DRE/CRT, participate in phytohormone signaling pathways including abscisic acid (ABA), jasmonic acid (JA), and ethylene (ET) to regulate downstream stress-responsive gene expression. 229 maize AP2/ERF family genes have been identified, among which 105 ERF subfamily members respond to abiotic stresses such as drought, salinity, and extreme temperatures, as well as biotic stresses such as Exserohilum turcicum and Fusarium graminearum, some genes (e.g., ZmERF21 and ZmEREB92) have broad-spectrum stress tolerance potential. ERF transcription factors are the core nodes of maize stress resistance regulatory network, enhancing resilience through multiple collaborative approaches. Future research should integrate technologies like ChIP-seq and gene editing to further elucidate ERF target genes and interaction networks, excavate superior allelic variants, provide genetic resources and theoretical support for molecular design and breeding of maize stress resistance.

In order to explore the high-quality development path of agriculture adapting to climate change in Ningxia Hui Autonomous Region, this paper analyzed the characteristics of resource endowment utilization based on methods such as literature analysis, mathematical statistics, and multi-scenario emission simulation, in Ningxia. The results showed that the air temperature presented a significant rising trend, the total precipitation presented a decreasing trend, the drought trend was obvious, and the light resources generally presented a decreasing trend from north to south, in Ningxia. Over the past 20 years, the sown area of grain crops in Ningxia had shown a highly significant decreasing trend. The sown area of maize had increased by 57.0%, with an average increase of 101000 hectares every 10 years. In the next 30 years, the number of days from sowing to ripening would gradually increase from north to south, and the interdecadal trend would be decreasing. Under the influence of climate change, agricultural production will face the declining coupling degree of arable land with climate and water resources, and the pressure of grain production will be increasing in the future, in Ningxia. On this basis, this study puts forward suggestions on how to adapt to climate change and promote high-quality development of agriculture, based on the characteristics of resource endowment. It proposed to adjust the crop planting industrial layout in Ningxia to promote the planting structure in response to climate change in a coordinated manner. And it is also proposed facilitating the establishment of an overall efficiency improvement system for agricultural scientific and technological innovation in-depth exploration of the impact laws and adaptation mechanisms of climate change, aiming to provide decision-making references for the high-quality development of agriculture in Ningxia and offer suggestions for building a strong agricultural country.

With the improvement of the ability to resist dominant disasters, unnoticeable natural hazards have gradually evolved into a key factor affecting the continuous and balanced increase of crop yield in China. Understanding the mechanisms, characteristics and countermeasures to the unnoticeable natural hazards could provide important theoretical and technological supports to the implement strategies for hazard alleviation. This paper reviews the types of the main unnoticeable natural hazards on maize production, and points out the diversity and complexity of them. The study explores the impact of unnoticeable natural hazards on maize growth and development, revealing that these hazards significantly inhibit photosynthesis, delay growth stages, and reduce pollination and seed-setting rates. Additionally, they impede plant growth and lead to poor kernel development, ultimately compromising both maize yield and quality. Specifically, drought and high temperatures exacerbate water stress, while waterlogging and prolonged overcast/rainy conditions cause root hypoxia and insufficient light energy, respectively. Furthermore, low-temperature chilling injury slows growth and increases physiological disorders. Collectively, these factors lead to yield reduction and diminish farmer income. According to the specific characteristics of different types of unnoticeable natural hazards, the technical measures for preventing or reducing the agricultural unnoticeable natural hazards were put forward, aiming at providing reference for high and stable yield of maize. Through scientific management and countermeasures, the adverse effects on maize production can be effectively mitigated, and both yield and quality can be enhanced.

The current production status of summer maize was systematically reviewed in Xiaoxian, Anhui Province, and its high yield cultivation techniques were summarized. In the study area, the planting area of summer maize has been continuously expanding with steadily increasing yields, highlighting the need to focus on key aspects such as variety selection, sowing quality, soil quality, fertilizer and water management, and mitigation of abiotic stress. Based on these considerations, an integrated green cultivation technology for enhancing yield and efficiency has been developed, which includes: selecting certified varieties tolerant to dense planting, resistant to lodging and major diseases, and suitable for mechanical grain harvesting; promoting precision sowing through uniform crushing and incorporation of previous crop straw, implementing stubble-based precision direct seeding technology centered on “optimal timing, appropriate seeding rate, suitable soil moisture, and adequate sowing depth”, complemented by trenching for waterlogging prevention; adopting a green pest control strategy with a “seal first, kill later” approach to weed management, combining scientific pesticide application based on pest monitoring, and promoting “one-spray, multiple-promotion” technology in later stages to preserve leaves and increase grain weight; implementing precision water and fertilizer management by determining fertilizer application rates according to soil fertility and target yield, emphasizing split deep application of nitrogen fertilizer, advocating integrated water-fertilizer technology to regulate fertilizer via water, and applying chemical growth regulators as needed based on seedling conditions; practicing timely late harvesting by selecting ear or grain harvesting methods based on grain moisture content after maize reaches full maturity, supported by drying technology. The demonstration and application of this technical system provide a reference for achieving high yield, high efficiency, and ecological sustainability in summer maize production.

The key measures of integrated drip irrigation and water fertilizer technology for maize planting were summarized and analyzed in Xiaoxian, Anhui Province. In terms of variety selection, certified high quality varieties suitable for dense planting, lodging resistance, and mechanized operations are chosen, with seed coating or chemical treatment applied. In terms of land preparation, land preparation quality was improved through precise straw management and deep tillage and loosening, combined with precision seeding technology, laying the foundation for dense planting. During sowing, wide-narrow row configuration and shallow-buried drip irrigation were adopted to ensure precise water and fertilizer supply and promote uniform, robust seedling emergence. For fertilization management, balanced application of nitrogen, phosphorus, potassium, and zinc, along with staged topdressing, was implemented to meet the demands of key growth stages. For disease and pest control follows an integrated “one-spray, multiple-promotion” strategy, combined with soil sealing and stem-and-leaf weed control. During harvesting, appropriate delayed harvesting is practiced to increase 1 000-grain weight, and grain direct harvesting and supporting drying technologies are promoted to achieve full mechanization. Demonstration planting in 2024 resulted in large-scale balanced yield increase, improved resource use efficiency, and synergistic development of grain production and ecological protection. This article provides a reference for the large-scale promotion and application of integrated drip irrigation and water fertilizer technologies.

To explore the effects of different nitrogen (N) and phosphorus (P) combined application rates on dry matter accumulation, grain yield, root development, and nutrient uptake and utilization of maize, a pot experiment was conducted using Denghai 605 as the test cultivar with a split-plot design. 4 nitrogen application levels were set: 0 (N0), 225 kg/hm² (N1), 300 kg/hm² (N2), and 375 kg/hm² (N3); 4 phosphorus application levels were established: 0 (P0), 60 kg/hm² (P1), 90 kg/hm² (P2), and 120 kg/hm² (P3), resulting in a total of 16 treatments. Key indicators including aboveground dry matter accumulation, grain yield, root morphological traits, and nutrient uptake and utilization efficiency were measured for each treatment. The results showed that under the same nitrogen (or phosphorus) application level, the aboveground dry matter accumulation and grain yield of summer maize showed an increasing trend with the increase in phosphorus (or nitrogen) application rate. The N3P3 treatment achieved the highest aboveground dry matter accumulation and grain yield, with the aboveground dry matter accumulation reaching 84.01 g/plant at the flowering stage and 313.31 g/plant at the full maturity stage, and the grain yield being 190.74 g/plant. The root length, root surface area, root volume, and root dry weight of summer maize also exhibited an increasing trend, with the N3P3 treatment performing optimally. At the full-ripening stage, under the same nitrogen application level, the root-shoot ratio increased slightly with the increase of phosphorus application rate：under the same phosphorus application level, the root-shoot ratio decreased slightly with the increase of nitrogen application rate. Under the same nitrogen (phosphorus) application level, the nitrogen (phosphorus) uptake efficiency and nitrogen (phosphorus) partial factor productivity of summer maize showed a gradual increasing trend with the increase of phosphorus (nitrogen) application rate. Overall, reasonable combined application of nitrogen and phosphorus can promote root development, enhance nutrient uptake and utilization efficiency, and thereby increase the dry matter accumulation and yield of summer maize. Under the experimental conditions, the N3P3 treatment yielded the best results.

[Objective] The detection of corn borer infestations is essential for improving corn yield and quality, as corn borer pests pose a significant threat to global corn production. In traditional agricultural practices, identifying corn borer infestations relies on manual field inspections or trapping tools, which are labor-intensive, time-consuming, and difficult to implement over large areas. These methods are further limited by their susceptibility to human error and inability to meet the demands of modern precision agriculture. To address these challenges, a method for detecting corn borer infestations using low-altitude, close-range imagery captured by unmanned aerial vehicles (UAVs) was investigated. By focusing on detecting boreholes rather than insect bodies, this approach overcomes the difficulties of detecting corn borers, which are nocturnal and often concealed within plant tissues, thereby enhancing the applicability of field-based detection and aligning with practical field conditions. [Methods] Based on the YOLOv11 (You Only Look Once v11) object detection algorithm, a model named YOLO-ESN was introduced, for corn borer infestation detection. The YOLO-ESN model was optimized through multiple modifications. In the Backbone, an enhanced lightweight attention (ELA) mechanism was incorporated to increase sensitivity and improve the extraction of small visual features, such as boreholes, by modeling spatial dependencies in horizontal and vertical directions using one-dimensional convolutions. In the Neck, a C3k2-Spatial and channel reconstruction convolution (C3k2-SCConv) module was introduced to reduce the number of model parameters while improving feature fusion efficiency through spatial and channel reconstruction, suppressing redundant information. In the Head, a small-object detection branch, termed the P2 detection head, was added, enabling YOLO-ESN to directly utilize shallow, high-resolution features from early network layers to enhance the detection of fine-grained targets like boreholes. Additionally, a combined loss function of normalized Wasserstein distance (NWD) and efficient intersection over union (EIoU) was employed to optimize bounding box regression accuracy, addressing gradient vanishing issues for small targets and improving target localization stability and robustness. A decision tree algorithm was applied to classify infestation severity levels based on borehole detection results, and heatmaps were generated to visualize the spatial distribution of corn borer infestations across the field. [Results and Discussions] Multiple experiments were conducted using a constructed dataset of corn borer infestation images. The results demonstrated that YOLO-ESN achieved an mAP@50 of 88.6% and an mAP@50:95 of 40.5%, representing an improvement of 7.6 and 4.9 percentage points, respectively, compared to the original YOLOv11 model. The total number of parameters in YOLO-ESN was reduced by 11.52%, contributing to a lighter model suitable for UAV deployment. Ablation studies evaluated individual contributions: incorporating the ELA mechanism alone improved mAP@50 by 0.3 percentage points, and the parameters are reduced by 10.57%; replacing the C3k2 module with C3k2-SCConv reduced parameters by 2.5% while increasing mAP@50 by 0.9 percentage points; adding the P2 detection head enhanced mAP@50 and mAP@50:95 by 4.1 and 1.2 percentage points, respectively; and introducing the NWD+EIoU loss function improved mAP@50 and mAP@50:95 by 1.9 and 1.2 percentage points, respectively. Comparative experiments demonstrate that YOLO-ESN outperforms a range of mainstream object detection models, including Faster R-CNN, SSD, YOLOv8, YOLOv11, and YOLOv12. YOLO-ESN achieves an mAP@50 and an mAP@50:95, surpassing Faster R-CNN by 14.9 and 9.7 percentage points, respectively, and SSD by 17.8 and 11.4 percentage points, respectively. With a compact parameter size of 8.37 M, YOLO-ESN delivers excellent detection accuracy and generalization, striking a strong balance between performance and efficiency. Although its inference speed (32.48 frame/s) was slightly slower than YOLOv12 (75.44 frame/s), it offered a superior trade-off between accuracy and efficiency. These results validated YOLO-ESN as a lightweight, high-performing solution for small object detection tasks, such as dense small targets in remote sensing images. The decision tree algorithm classified infestation severity with high accuracy, achieving F₁-Scores of 0.906, 0.803, and 0.842 for mild, moderate, and severe infestations, respectively. Heatmaps generated from borehole detection results enabled spatial visualization of infestation severity, providing a scientific basis for quantitative monitoring and targeted pesticide application in field infestations. [Conclusions] The proposed YOLO-ESN model has more advantages in overall detection accuracy and running speed. While improving the lightweight degree and deployment efficiency of the model, it also shows better recognition ability in small target detection, and can accurately locate the wormhole area on the corn leaf, effectively improving the bounding box regression accuracy and feature extraction efficiency. Compared with the traditional insect recognition method, the use of wormholes as detection objects is more in line with the actual field situation, effectively avoiding the problems of insect occlusion and strong concealment, and improving the availability of field image data and algorithm robustness. The heat map generated by the model detection results can also effectively display the distribution changes of insect pests in farmland, providing a scientific basis for precision pesticide spraying and farmland management. Overall, this study provides an effective solution for the intelligent detection of corn borer pests, has strong versatility and promotion prospects, and can provide strong technical support for precision agriculture and smart farmland management.

[Objective] The accurate identification of maize tassels is critical for the production of hybrid seed. Existing object detection models in complex farmland scenarios face limitations such as restricted data diversity, insufficient feature extraction, high computational load, and low detection efficiency. To address these challenges, a real-time field maize tassel detection model, LightTassel-YOLO (You Only Look Once) based on an improved YOLOv11n is proposed. The model is designed to quickly and accurately identify maize tassels, enabling efficient operation of detasseling unmanned aerial vehicles (UAVs) and reducing the impact of manual intervention. [Methods] Data was continuously collected during the tasseling stage of maize from 2023 to 2024 using UAVs, establishing a large-scale, high-quality maize tassel dataset that covered different maize tasseling stages, multiple varieties, varying altitudes, and diverse meteorological conditions. First, EfficientViT (Efficient vision transformer) was applied as the backbone network to enhance the ability to perceive information across multi-scale features. Second, the C2PSA-CPCA (Convolutional block with parallel spatial attention with channel prior convolutional attention) module was designed to dynamically assign attention weights to the channel and spatial dimensions of feature maps, effectively enhancing the network's capability to extract target features while reducing computational complexity. Finally, the C3k2-SCConv module was constructed to facilitate representative feature learning and achieve low-cost spatial feature reconstruction, thereby improving the model's detection accuracy. [Results and Discussions] The results demonstrated that LightTassel-YOLO provided a reliable method for maize tassel detection. The final model achieved an accuracy of 92.6%, a recall of 89.1%, and an AP@0.5 of 94.7%, representing improvements of 2.5, 3.8 and 4.0 percentage points over the baseline model YOLOv11n, respectively. The model had only 3.23 M parameters and a computational cost of 6.7 GFLOPs. In addition, LightTassel-YOLO was compared with mainstream object detection algorithms such as Faster R-CNN, SSD, and multiple versions of the YOLO series. The results demonstrated that the proposed method outperformed these algorithms in overall performance and exhibits excellent adaptability in typical field scenarios. [Conclusions] The proposed method provides an effective theoretical framework for precise maize tassel monitoring and holds significant potential for advancing intelligent field management practices.

Based on the practical experience of the winter wheat-summer maize multiple cropping model in Qingyang City,Gansu Province, the key high yield cultivation techniques were systematically summarized and its economic benefits were analyzed in this paper. For variety selection, early-maturing varieties with strong stress resistance and a requirement of ≤2 100℃ effective accumulated temperature, such as Kewo028, KWS7340, and KWS6333, were preferred. In terms of production management, emphasis was placed on timely land preparation and sowing with haste, with sowing should be completed by June 30 at the latest; integrated mechanical sowing combining “no-tillage, fertilization, and seeding” was adopted. Planting density was optimized, and 2-3 seeds per hole was recommended for mechanical sowing. Scientific fertilization was implemented, with a one-time application of 20 kg of pure nitrogen and 12 kg of pure phosphorus per 667 m⊃2;. Weed control was conducted via unmanned aerial vehicle (UAV) spraying of herbicides such as 6 g of 30% topramezone and 180 g of 25% mesotrione-terbuthylazine per 667 m⊃2;. Integrated pest and disease control was achieved through a combination of agricultural (selection of pest-and-disease-resistant varieties and implementation of scientific crop rotation), biological (introduction of natural enemies, etc.), and chemical (application of 7% cyantraniliprole suspension concentrate, 75% trifloxystrobin-tebuconazole water-dispersible granules, etc.) measures to manage pests and diseases including Spodoptera frugiperda and Setosphaeria turcica. A three-level prevention and control system consisting of “meteorological early warning, field monitoring, and emergency response” was established to reduce the risk of meteorological disasters, and timely harvesting was carried out during October 20-30. Economic benefit analysis shows that suitable varieties (Kewo028) can achieve a net profit of 320 yuan/667 m⊃2;. At present, the disaster resistance and mitigation capacity of this model need further improvement, and the technical systems such as agricultural machinery adaptation, agronomic integration, and variety breeding also require continuous refinement. To this end, it is necessary to strengthen the construction of agricultural infrastructure and promote the transformation of high-standard farmland; establish a technical service network to facilitate technology transfer. This study provides a reference for similar crop cultivation in relevant regions.

To understand the research hotspots and trends in the field of maize drought stress studies, this paper used 1 842 articles published between 1994 and 2023 from the Web of Science database as samples, and conducted a visual analysis of the publication output and keywords using CiteSpace software. The results showed that: (1) The development trend of this field from 1994 to 2023 can be divided into three stages: the embryonic period (1994-2007), the slow development period (2008-2015), and the explosive growth period (2016-2023), with the number of publications showing an exponential growth trend. (2) Keyword clustering analysis revealed that the keywords in this field formed 9 clusters, generating 6 research hotspots covering 3 aspects: biological phenotypes (yield characteristics, growth and development), physiological responses (oxidative stress, gene transcription, and water use efficiency), and mitigation measures (drought resistance). (3) Keyword burst analysis indicated that the research themes in the embryonic period focused on abscisic acid regulatory mechanisms, genetic traits, and yield characteristics; those in the slow development period centered on the improvement of maize drought tolerance under climate change; and the research themes in the explosive growth period were water use, gene expression, and the drought-resistant mechanism of salicylic acid. Overall, water use, gene expression, and the drought-resistant mechanism of salicylic acid in maize under drought stress may remain frontier research directions in the future. This study provides a reference for maize drought resistance research.

To reveal the spatial differentiation patterns of yield ratios (PIR, PDR, IDR) among different cultivated land types (paddy field, irrigated land, dryland) for winter wheat and summer maize in Henan, the paper analyzed their coupling mechanism with cultivated land grade and terrain conditions, so as to provide a scientific basis for improving cultivated land irrigation use efficiency and optimizing cultivated land resources management. Based on the cultivated land grade database and township-level grain yield data (2031 towns for winter wheat, 2000 towns for summer maize) of Henan, 8 grading factor indicator zones (excluding the Huainan hilly and mountainous region) were selected as the study objects. The yield ratios were calculated using the area-weighted method. The correlation between cultivated land grade and IDR was fitted using trend analysis, and the spatial differentiation characteristics of IDR were interpreted with terrain classification. The results showed that: (1) at the indicator zone level, the volatility of yield ratios for both winter wheat and summer maize followed the pattern: IDR>PIR>PDR. The IDR showed the largest difference (0.55 for winter wheat and 0.48 for summer maize), indicating that the yield difference between irrigated land and dryland was most significantly affected by regional conditions; (2) at the provincial level, the regional differences in yield ratios were reduced and the patterns were weakened due to the area-weighted average neutralizing regional heterogeneity; (3) a positive correlation was found between cultivated land grade and IDR (the better the cultivated land quality, the larger the IDR). The sensitivity of winter wheat IDR to cultivated land quality (absolute slope value 0.030) was higher than that of summer maize (0.011); (4) under the same cultivated land grade, terrain ruggedness was positively correlated with IDR (IDR in mountainous and hilly areas was higher than that in plains and basins). The yield ratios among cultivated land types of winter wheat and summer maize in Henan exhibit the significant regional differences and scale dependence. Winter wheat shows a stronger dependence on irrigation conditions. It is suggested to prioritize enhancing the irrigation guarantee capacity for winter wheat on high-quality cultivated land; while for low-quality cultivated land, it requires synergistic improvements in both soil conditions and irrigation infrastructure to improve grain yield.

In light of the low phosphorus fertilizer utilization efficiency and the potential risk of non-point source pollution in the corn production system of the Tumochuan Plain, this study investigated the effects of combined application of fulvic acid and phosphorus fertilizer. Corn yield, dry matter accumulation in various plant organs, and phosphorus uptake were measured to calculate phosphorus fertilizer utilization efficiency. The effects of fulvic acid on phosphorus absorption and corn yield were analyzed, and an appropriate application rate of fulvic acid for the region was determined. The results indicated that (1) the appropriate application of 96 kg/hm² P₂O₅ combined with 450 kg/hm² fulvic acid (P₁+FA₃) could significantly enhance corn yield by 7.49% to 27.96%. (2) The P₁+FA₃ treatment promoted the biomass accumulation of various above-ground organs of corn. Specifically, stem biomass increased by 18.85% to 35.26%, leaf biomass by 13.46% to 23.64%, and grain biomass by 9.68% to 27.41% compared to other treatments. (3) The P₁+FA₃ treatment significantly improved the absorption and utilization efficiency of phosphorus fertilizer, enhanced agronomic efficiency of phosphorus fertilizer and partial productivity of phosphorus in corn. In conclusion, within the corn production system of the Tumochuan Plain, the combined application of 450 kg/hm² fulvic acid under an appropriate phosphorus fertilizer rate could synergistically improve both corn yield and phosphorus use efficiency.

【Objective】 To optimize the soybean-maize intercropping system in the Huang-Huai-Hai region, this study aimed to evaluate the effects of different row ratio configurations on crop agronomic traits, canopy structure of the population, yield components, edge effects, and overall economic benefits. The goal was to identify suitable row ratio configurations, thereby improving land resource use efficiency and economic returns. 【Method】 Three row ratio configurations were implemented: 4 rows of soybean intercropped with 2 rows of maize (4:2), 6 rows of soybean intercropped with 4 rows of maize (6:4), and 4 rows of soybean intercropped with 4 rows of maize (4:4), using monoculture soybean (SCK) and monoculture maize (MCK) as controls. Crop dry matter accumulation, leaf area index (LAI), relative chlorophyll content (SPAD), canopy light transmittance, and yield components were measured. The inner and outer row sampling approach was adopted to evaluate edge effects and overall economic benefits. 【Result】 Compared with monoculture, intercropping significantly decreased per-plant dry matter accumulation in maize during the filling, milking, and maturity stages, and in soybean during the full flowering, full pod, grain filling, and full maturity stages. Among the row ratio configurations, maize exhibited maximum per-plant dry matter accumulation under the 4:4 pattern, whereas soybean achieved its highest accumulation under the 6:4 pattern. Row ratio configurations significantly influenced inter-row variations in dry matter accumulation and yield for both crops. Maize yield followed the order 4:4 pattern>4:2 pattern>6:4 pattern, representing reductions of 15.22%, 18.02%, and 12.62% relative to MCK, respectively; soybean yield followed the order 6:4 pattern>4:4 pattern>4:2 pattern, corresponding to reductions of 55.99%, 50.43%, and 56.00% compared with SCK, respectively. Intercropped maize exhibited pronounced edge advantage, with border row maize yields significantly exceeding those of inner rows. Within the intercropping system, both maize and soybean demonstrated lower canopy light transmittance, LAI, and SPAD values compared with their monoculture counterparts. Maize canopy light transmittance, LAI, and SPAD values followed the consistent ranking: 4:4 pattern>4:2 pattern>6:4 pattern; soybean canopy light transmittance followed 4:4 pattern>6:4 pattern>4:2 pattern, while its LAI and SPAD values mirrored the ranking pattern observed in maize. Maize LAI was significantly influenced by row ratio configuration, whereas no significant inter-row variations were detected for maize SPAD values or for soybean LAI and SPAD values. In evaluations of economic returns and intercropping advantages, the 4:4 pattern configuration demonstrated superior performance, achieving the highest values for land equivalent ratio (LER), relative crowding coefficient (K), and economic benefits. Maize in intercropping exhibited higher LER and K values relative to soybean, with the maize competition ratio (CR_m) being significantly greater than that of soybean (CR_s) (CR_m>1, CR_s<1), demonstrating maize's competitive dominance in interspecific competition. 【Conclusion】 Although intercropping reduced per-plant dry matter accumulation, LAI, and SPAD values for both crops compared with monoculture, it significantly increased the land equivalent ratio (LER) and overall economic benefits. Under the experimental conditions, the 4:4 pattern exhibited more optimal canopy architecture, with maize demonstrating pronounced edge advantage. This system maintained maize yield while generating additional soybean income, thereby achieving the synergistic enhancement of total productivity and economic returns.

【Objective】 This study aimed to investigate the effects of different row ratio configurations on canopy light distribution, layer-specific photosynthesis, and crop yield formation in a maize-soybean strip intercropping system, thereby providing a theoretical basis for high-yield and high-light-efficiency cultivation. 【Method】 A field experiment was conducted under field conditions during the 2023-2024 growing seasons, with monoculture maize (SM) and monoculture soybean (SS) serving as controls. Four maize-soybean strip intercropping configurations were established: four rows of maize with six rows of soybean (4M6S), four rows of maize with four rows of soybean (4M4S), three rows of maize with four rows of soybean (3M4S), and two rows of maize with four rows of soybean (2M4S). The planting density of maize was consistently maintained at 67 500 plants/hm² across all intercropping treatments. The soybean planting densities under SS, 4M6S, 4M4S, 3M4S, and 2M4S treatments were 160 000, 153 144, 128 351, 151 068, and 183 556 plants/hm², respectively, and the effects of different row ratios on the light distribution, photosynthetic performance and yield in the canopy of the composite population were analyzed. 【Result】 The 4M4S treatment resulted in a higher leaf area index (LAI) and greater light transmittance in the middle canopy layer in maize. The LAI under 4M4S was 4.07%, 4.41%, 4.71%, and 5.46% higher than that under 4M6S, 3M4S, 2M4S, and SM, respectively. At the R1 stage, the light transmittance at the ear leaf of maize under 4M4S was 9.76%, 21.11%, 46.83%, and 48.16% higher than that under SM, 2M4S, 4M6S, and 3M4S, respectively. Concurrently, the 4M4S treatment enhanced the net photosynthetic rate of the lower leaves in maize, which was 10.45% and 8.58% higher than that under 3M4S and 4M6S, respectively. The overall radiation use efficiency (RUE) under 4M4S was 1.38%, 6.69%, and 8.01% higher than that under 4M6S, 3M4S, and 2M4S, respectively, demonstrating a stronger photosynthetic capacity under this treatment. The 4M4S treatment achieved the highest yields for both maize and soybean. The two-year average maize yields for 4M6S, 4M4S, 3M4S, and 2M4S were 8.88, 9.22, 8.44, and 8.86 t·hm^-2, respectively, while the corresponding soybean yields were 1.44, 1.44, 1.37, and 1.29 t·hm^-2, respectively. The land equivalent ratio (LER) for all intercropping patterns exceeded 1.27. Row ratio configuration significantly influenced interspecific relationships between maize and soybean. The aggressivity of maize relative to soybean under 3M4S, 4M6S, and 2M4S treatment was 3.91, 4.41, and 11.32 times that under 4M4S treatment, respectively. In 2023, the relative crowding coefficient was the smallest under 3M4S, followed by 4M4S; in 2024, the value for 4M4S was 3.19%, 10.58%, and 21.82% lower than that under 3M4S, 4M6S, and 2M4S, respectively. Thus, the 4M4S treatment effectively ensured maize yield while simultaneously increasing soybean production. 【Conclusion】 The 4M4S treatment enhanced maize light interception, thereby improving light transmittance within the middle and lower canopy layers of the maize population. This configuration enabled leaves across different canopy positions—both inner and outer rows—to maintain high photosynthetic capacity, while also preserving the photosynthetic performance of soybean plants. Consequently, the system's radiation use efficiency was significantly improved, and both crop yield and land equivalent ratio were markedly increased. Furthermore, this treatment resulted in the smallest values for interspecific competitiveness, relative crowding coefficient, and net effect among all configurations. Therefore, the 4M4S treatment was identified as the most suitable row ratio configuration under the experimental conditions.

【Objective】 The 4:6 maize-soybean intercropping model, widely promoted in the Huang-Huai-Hai region, has issues such as poor ventilation and light penetration, and poor grain setting in the middle rows of intercropping maize. Therefore, this study explored optimizing row spacing configurations to improve the canopy structure of intercropping maize populations and enhance the yield of intercropping systems, for providing a theoretical basis for the promotion and application of maize-soybean strip intercropping in the Huang-Huai-Hai region. 【Method】 From 2023 to 2024, soybean variety HeDou 22 and maize variety Liyuan 296 were used as test materials. Under the maize-soybean 4:6 planting pattern, five row spacing configurations were set: equal row spacing of 60 cm (ER) and narrow-wide row spacing of 40 cm+70 cm+40 cm (WNR1), 40 cm+80 cm+40 cm (WNR2), 40 cm+90 cm+40 cm (WNR3), and 40 cm+100 cm+40 cm (WNR4) to study the impacts of row spacing configurations on the yield, accumulation of dry matter, plant traits, and canopy characteristics of intercropping maize. 【Result】 Under the maize-soybean 4:6 intercropping pattern, the wide-narrow row planting of intercropping maize significantly increased its yield. The WNR3 treatment showed an average yield increase of 6.68% compared with ER over two years, with a 10.49% increase in post-anthesis dry matter accumulation. The yield improvement primarily stemmed from increased kernel number per ear (8.24%-9.95%) and 1 000-grain weight (2.66%-3.04%) in the middle rows. Compared with ER treatment, the wide-narrow row planting alleviated the "shade avoidance response" in the middle rows. Under the WNR3 treatment, the height difference between middle-row and border-row maize plants narrowed by 2.3%, stem diameter increased by 5.7%, leaf senescence was delayed, and the SPAD value of ear-leaf at the silking stage improved by 1.95%-14.95%. As the row spacing of middle rows increased, canopy light transmittance and single-plant leaf area exhibited an upward trend. The WNR3 treatment improved bottom-layer light transmittance by 29.11% and ear-layer light transmittance by 25.44% in the middle rows. However, no significant difference was observed between WNR3 and WNR4 treatments. Although the WNR4 treatment further enhanced canopy ventilation and light conditions, the light interception rate of the intercropping maize population significantly decreased, leading to reduced post-anthesis photosynthetic product accumulation and grain yield. 【Conclusion】 Under the intercropping mode of maize and soybean 4:6, the configuration of 40 cm+90 cm+40 cm wide and narrow rows could significantly improve the crown structure of maize, enhance photosynthetic performance, increase post-flower dry matter accumulation and grain yield, which was an effective way to optimize the yield of intercropping system in Huanghuaihai region.

【Objective】 This study aimed to explore the regulatory effects of different plant height combinations of maize varieties on the light distribution and light resource utilization of the population canopy under the soybean and maize strip intercropping pattern. 【Method】 From 2023 to 2024, four maize varieties with different plant heights were used as experimental materials, including the short-stemmed varieties of MY73 and Denghai 605 (DH605), and the tall varieties of Jingke 968 (JK968) and Xianyu 1466 (XY1466), as well as the soybean variety Qihuang 34. The row configuration of maize and soybean was both 4:4. Different intercropping patterns were set, including intercropping of the same maize variety in all four rows as the control (S-MY, S-DH, S-JK, and S-XY), with 6.75×10⁴ plants/hm² for each of the four rows and intercropping of tall and short varieties (middle row tall variety JK968, edge row short variety MY73: MY-JK-1, MY-JK-2; middle row tall variety XY1466, edge row short variety DH605: DH-XY-1, DH-XY-2), and two types of planting densities were set, with 6.75×10⁴ plants/hm² for each of the four rows (MY-JK-1, DH-XY-1), 6.75×10⁴ plants/hm² for the middle rows, and 8.25×10⁴ plants/hm² for the edge rows (MY-JK-2, DH-XY-2). The plant spacing of soybean in each treatment was the same. The focus was on analyzing the effects of different intercropping patterns on the canopy structure of the population, light distribution, photosynthetic characteristics of maize and crop yield. 【Result】 The combined planting of maize varieties with different plant height optimized the canopy structure, significantly improved the light transmittance of the spike layer in the maize population, increased the leaf area index and photosynthetic characteristics, and ultimately promoted the increase in total system yield. During the silk production stage, the light transmittance of the spike layer in MY-JK-1 and MY-JK-2 increased by 18.55%-88.22% compared with S-MY and S-JK, and that in DH-XY-1 and DH-XY-2 increased by 39.26%-55.77% compared with S-DH and S-XY. The net photosynthetic rate (P_n) of the four varieties (except MY73) in the tall and short plant combination pattern was all increased. Among them, the P_n of DH605 in the DH-XY-2 pattern is 6.88% higher than that of S-DH, and the P_n of XY1466 in the DH-XY-2 pattern is 10.31% higher than that of S-XY. At the same time, the maximum photochemical efficiency (F_v/F_m) and potential activity (F_v/F_o) of the spike leaf also increased. The yield of maize under the MY-JK-2 pattern increased by an average of 19.44%, 9.58% and 1.66% over two years compared with the S-MY, S-JK and MY-JK-1 patterns, respectively. The average increase of DH-XY-2 over two years was 30.20%, 14.94% and 9.21% compared with the S-DH, S-XY and DH-XY-1 patterns, respectively. The maize yield (12 536.58 kg·hm^-2) and total system yield (14 001.29 kg·hm^-2) under the DH-XY-2 pattern were the highest in both years. 【Conclusion】 Compared with the intercropping pattern of single maize varieties, the combined planting of maize varieties with different plant heights could optimize the canopy structure of the population, improve the light distribution of the population canopy, and increase the light transmittance of the maize ear position layer and the photosynthetically active radiation at the top of soybean. At the same time, it improved the leaf area index and photosynthetic characteristics of maize, promoted the accumulation of photosynthetic products, and ultimately increased the total system yield. With the increase of edge row density, the maize yield was further enhanced. Under the conditions of this experiment, in the eastern part of the Huang-Huai-Hai region, it was recommended to use the combined planting of short-stemmed DH605 and tall XY1466, with a middle row density of 6.75×10⁴ plants/hm² and an edge row density of 8.25×10⁴ plants/hm².

【Objective】 Based on of “High-Yield and High-Efficiency Maize-Soybean Intercropping Technology R&D and Integrated Demonstration” project of National Key Research and Development Program in the 14th Five-Year Plan seven demonstration sites were established across Shandong, Henan, Anhui, and Jiangsu Provinces. Key technology research and integrated demonstrations were conducted. To comprehensively evaluate the yield performance, economic benefits, and ecological effects of the project demonstration sites, this study conducted a systematic assessment using neighboring farmers as a control, so as to provide a scientific basis for optimizing maize-soybean intercropping in the region. 【Method】 A comprehensive evaluation index system was established, covering three dimensions: yield, economy, and ecology. Through field surveys in seven demonstration sites and their neighboring farms, the differences in overall benefits of maize-soybean intercropping between the demonstration fields and local farmers were assessed. 【Result】 For yield, the intercropping in the demonstration fields was about 10% to 19% higher compared with neighboring farmers. In terms of economic benefits, the net output value per unit area in the demonstration sites was 5% to 21% higher on average. However, input costs increased by 7% to 15%, resulting in a net benefit per unit area only 2% to 18% higher. From an ecological perspective, the carbon footprint of the demonstration areas was approximately 9% to 34% higher than that of surrounding farmers, and the nitrogen footprint was 5% to 45% higher. This was mainly due to the increased use of fertilizers and diesel to ensure high yields. Based on the differences in yield, economic, and ecological dimensions between surrounding farmers and the demonstration areas, the CVI (comprehensive variation index) levels of all seven demonstration areas were at a moderate difference level (corresponding value of level 3). Among them, the ECI (economic convergence index) performed well (levels 3 to 4), especially with the smallest land output rate differences (the North Shandong, North Anhui, and North Jiangsu regions reaching the optimal level 5). This further proved that although surrounding farmers had lower yields and land output, the high inputs in the demonstration areas reduced the unit output efficiency, objectively narrowing the net profit gap with surrounding farmers and supporting the higher ECI value. The main limitation for the improvement of the comprehensive index in all regions was the relatively low yield, as the YCI (yield convergence index) of all regions concentrated at the poor level of 1 to 2. 【Conclusion】 The technological innovation and application of the project had a positive effect on promoting the yield and economic benefits of maize and soybean intercropping in the Huang-Huai region. But its sustainable promotion still faces challenges, such as rising costs and increasing ecological pressure. Finding ways to reduce costs and improve efficiency was therefore a key focus for the next stage of technological innovation.

【Objective】 This study aimed to explore the effects of different organic amendments combined with chemical fertilizers on maize yield and soil fertility in medium and low yield fields, so as to provide a scientific basis for selecting the best organic fertilization measure. 【Method】 The study focused on medium and low yield fields in Loess Plateau, conducting maize field trials in 2022 and 2023 for two consecutive years. Four organic amendment agent treatments were set up: straw return combined with chemical fertilizer (SF), biochar combined with chemical fertilizer (B), organic fertilizer combined with chemical fertilizer (M), and biological organic fertilizer combined with chemical fertilizer (EM), with chemical fertilizer alone (F) as the control. By measuring maize grain yield and various soil physical, chemical and biological indicators under different treatments, correlation analysis and principal component analysis were used to establish the minimum dataset for evaluation indicators. Fuzzy mathematics was then applied to assess soil fertility. 【Result】 Compared with F treatment, the percentage of soil water-stable macroaggregates (R_>0.25) significantly increased by 19.8% and 17.8% under SF and B treatment, respectively, while the percentage of soil aggregates <0.053 mm (R_<0.053) significantly decreased by 17.2% and 14.0%; soil moisture content significantly increased by 7.6% and 13.0%, respectively. The M and EM treatments similarly improved the percentage of soil water-stable macroaggregates and surface soil moisture, but the differences were not significant. The application of organic amendments combined with fertilizers improved the geometric mean diameter (GMD) and mean weight diameter (MWD) of soil aggregates, with SF treatment showing a significant increase compared with F treatment, but no significant differences were observed under B and M treatments. Compared with the F treatment, different organic amendment treatments significantly increased soil organic matter content by 16.1%-28.5% and available phosphorus content by 23.1%-195.4%. The DOC under SF treatment and the DON under M treatment showed the most significant increases. The MBC and MBP under EM treatment and the MBN under M treatment were the highest, significantly increasing by 36.9%, 216.4% and 63.3% than that under F treatment, respectively. Compared with the F treatment, the activities of β-glucosidase, N-acetyl-glucosaminidase and leucine aminopeptidase under SF, M and EM treatment increased by 13.3%-57.0%, 21.4%-22.0% and 24.3%-35.1%, respectively. While B treatment showed a significant increase in β-glucosidase activity, but not in N-acetyl-glucosidase and leucine aminopeptidase activity. The soil total enzyme activity index (TEI) ranked as EM>M>SF>B>F treatment, with the EM treatment significantly higher than SF, B and F treatment. The application of organic amendments enhanced soil aggregate structure, increased soil organic matter and nutrient content, and boosted soil enzyme activity, thereby improving soil IFI, with increases ranging from 0.6% to 36.9%, where EM, M and B treatments showed significant increases. Over the two-year trials period, the maize yield was increased significantly by 13.4%-18.5% with the application of organic and biological organic fertilizers compared with F treatment, and the maize yields under these treatments were significantly higher than that under SF treatment. 【Conclusion】 The application of organic amendments combined with chemical fertilizers improved the quality of soil fertility and increased the yield of maize, with M and EM treatment being the most effective.

Green manuring is essential for improving soil quality and nutrient uptake. With the gradual depletion of phosphorus (P) resources, more attention is being paid to the role of green manures in cultivation systems, such as maize-green manure intercropping, to find possible pathways for enhancing soil P utilization. A maize-green manure intercropping experiment was started in 2009 to investigate the effects and mechanisms for enhancing P uptake and yield in maize. Three species of green manures (HV: hairy vetch; NP: needle leaf pea; SP: sweet pea) and a sole maize treatment (CK) were used, resulting in four treatments (CK, HVT, NPT, and SPT) in the experiment. During 2020-2023, the intercropping treatments enhanced maize yields in 2020 and 2021, particularly in the HVT treatment with increases of 13.7% (1.96 t ha^-1) and 13.0% (2.13 t ha^-1) compared with CK, respectively. Grain P accumulation of maize was significantly higher in the intercropping treatments than CK in 2020, 2021, and 2023, and with an average increase of 10.6% over the four years (5.2% for NPT, 10.8% for SPT and 15.9% for HVT) compared with CK. Intercropping promoted maize growth with a greater root length density and a higher organic acid release rate. HVT changed the soil properties more dramatically than the other treatments, with increases in the acid phosphatase and alkaline phosphatase activities of 29.8 and 38.5%, respectively, in the topsoil (0-15 cm), while the soil pH was reduced by 0.37 units compared to CK (pH=8.44). Intercropping treatments facilitated the conversion of non-labile P to mod-labile P and stimulated the growth of soil bacteria in the topsoil. Compared with CK, the relative abundance of Gemmatimonadota, known for accumulating polyphosphate, and Actinobacteriota, a prominent source of bioactive compounds, increased significantly in the intercropping treatments, especially in HVT and SPT. A PLS-PM analysis showed that intercropping promoted soil P mobilization and the enrichment of beneficial bacteria by regulating maize root morphology and physiology. Our results highlight that maize-green manure intercropping optimizes root traits, soil properties and bacterial composition, which contribute to greater maize P uptake and yield, providing an effective strategy for sustainable crop production.  

Persistent overcast rain was an essential limiting factor for summer maize production, of which immediate impact was the dual pressure of waterlogging and shading.  However, the mechanisms underlying independent and combined effects of waterlogging and shading on maize yield losses remain understudied, particularly across different growth stages.  Denghai 605 (DH605) was selected to be subjected shading, waterlogging, and their combined stress at the 3rd leaf stage (V3), the 6th leaf stage (V6), and tasseling stage (VT).  Results showed that shading, waterlogging and their combination significantly restricted leaf area expansion, reduced leaf net photosynthetic rate (P_n) and net assimilation rate (NAR), thereby decreasing the crop growth rate (CGR) and biomass accumulation.  Additionally, compared to control, the process of lignin synthesis was inhibited under stressed treatment, resulting in diminished stem mechanical strength and impaired vascular system development, which substantially reduced assimilate remobilization efficiency to the ear and ultimate grain yield.  Waterlogging and combined stresses exhibited maximum impact at the V3 stage, followed by V6 and VT stages, while shading effects were most pronounced at the VT stage, followed by V6 and V3 stages.  Moreover, the compound stress exacerbated the damage brought about by a single stress.  As climate change is projected to increase the frequency of multiple abiotic stress occurrences, these findings provide valuable insights for future summer maize breeding research under persistent rainfall conditions.

Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.  However, in maize (Zea mays L.), the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.  This study demonstrates that mutation of maize callose synthase12 (ZmCals12) results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues, leading to plant dwarfing and male sterility.  Histochemical β-glucuronidase (GUS) activity assay and mRNA in situ hybridization (ISH) revealed that ZmCals12 expression mainly occurs in the vascular transport system.  ZmCals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas (PDs) and surrounding phloem cells (PCs) of the vascular bundle.  The drop-and-see (DANS) assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants, resulting in decreased symplastic transport.  Paraffin section analysis revealed that less-developed vascular cells (VCs) in Zmcals12 mutants likely disrupted sugar transport, contributing to the pleiotropic phenotype.  Furthermore, impaired sugar transport inhibited internode development by suppressing auxin (IAA) biosynthesis and signaling in Zmcals12 mutant.  These findings elucidate the mechanism by which ZmCals12-mediated callose deposition and symplastic transport regulate maize growth and development

This study aims to breed high-yielding and high-quality silage maize hybrids suitable for the Silk Road cold and arid region in Gansu, in order to solve the demand for silage maize varieties due to the shortage of silage feed. Experimental materials were derived from a cross between female parent G2281 and male parent 17RT. Five trial sites were established to carry out field trait observation, seed testing, yield measurements, various identification and testing. The results showed that the average dry matter yield from the 2-year multi-point regional trials was 35162.3 kg/hm², which was 4.3% higher than that of the control group. The rate of average yield increase was more than 70%. The 1-year multi-point production test yielded an average dry matter output of 36048.0 kg/hm², an increase of 8.7% compared to the control, and yield increase reached 100%. In the whole plant quality analysis, the neutral detergent fiber (NDF) content was 39.3%, acid detergent fiber (ADF) content was 20.2%, crude protein (CP) content was 7.6%, and starch (ST) content was 30.4%. It is resistant to Pythium stem rot and head smut, with strong lodging resistance, good green retention and excellent comprehensive properties. Based on the above research results, a new silage maize cultivar ‘Jinhui 658’ with strong adaptability is selected and bred, which is suitable for planting in cold and dry spring maize area of Silk Road in Gansu Province, and plays a role in promoting the quality and efficiency of silage maize industry.

The aim is to clarify the synergistic effect of kitchen waste composting and intercropping systems. In this experiment, the kitchen waste from the public canteen of Inner Mongolia Minzu University was used as the test material. EM bacteria (EM), saline-alkali soil (TR), and the cellulose-decomposing bacterial strain (JX) selected from the microbiology laboratory of Inner Mongolia Minzu University were inoculated for composting respectively, and then were buried in the saline-alkali soil. Corn and peanut intercropping pot experiments were conducted with saline-alkali soil (CK) as the control. The results showed that under monoculture conditions, EM and JX increased the activities of alkaline phosphatase and cellulase in monoculture corn soil, respectively, and both increased the activity of catalase in corn soil; JX increased the root activity of corn. TR and JX increased the activity of cellulase in monoculture peanut soil, increased the activity of SOD in peanut roots, and reduced the MDA content in peanut leaves. Under intercropping conditions, EM increased the soil sucrase and urease activities, while JX increased the soil urease activity. JX also increased the POD activity and MDA content in corn leaves. Both EM and JX increased the SOD activity in peanut roots under intercropping. Compared with monoculture, intercropping with EM increased the soil sucrase activity in corn, and intercropping with JX increased the POD activity in corn leaves and roots, as well as the SOD and POD activities in peanut roots. Intercropping of corn and peanut increased the SOD activity in peanut roots and the POD activity in corn roots. Overall analysis showed that intercropping of corn and peanut increased the antioxidant enzyme activities in crop roots. EM kitchen waste compost can activate soil enzyme activity, improve crop physiological characteristics, and synergistically improve the productivity of intercropping system in saline-alkali land, providing technical support for saline-alkali land improvement and organic waste resource utilization. Whether in monoculture or intercropping conditions, inoculation with cellulose-decomposing bacteria from kitchen waste compost had a positive effect on soil enzyme activities and the physiological activities of corn and peanut.

To optimize the N and P dosing scheme for corn-soybean composite planting, a pot experiment with four N levels (0, 270, 300, 330 kg/hm², labelled N0, N1, N2, N3) and four phosphorus levels (0, 60, 90, 120 kg/hm², labelled P0, P1, P2, P3), was conducted in a mixed planting of corn and soybean, which was cultivated indoors for 60 d. Soil nutrients, soil enzyme activities, and physiological activities of corn and soybean leaves and roots were measured. The results showed that P2 and P3 increased soil alkaline dissolved nitrogen (7.81%-48.99%) and effective phosphorus content (21.33-fold increase) and soil enzyme activities at different N application levels; N2 and N3 increased soil alkaline dissolved nitrogen (19.57%-48.99%) and effective phosphorus content (9.81-fold increase) at different phosphorus application levels; and N3P2 increased soil sucrase (32.36%) and alkaline phosphatase (29.89%) activities, N3P2 increased soybean root POD activity, decreased root MDA content, and increased leaf SOD activity; and N1P1 and N2P1 increased maize root POD activity, decreased leaf and root MDA content, and increased leaf and root SOD activity. The high nitrogen and high phosphorus pairing increased soil alkaline dissolved nitrogen and effective phosphorus content, and high nitrogen or phosphorus increased soil sucrase and alkaline phosphatase activities, while the low nitrogen and high phosphorus pairing increased soil cellulase activity; N₃P₂ enhanced the quality of corn-soybean mixed planting soils, and strengthened the physiological activity of crop seedlings.

Maize is the crop with the largest planting area in China, playing a crucial role in safeguarding national food security. Dwarfing breeding is a core approach to break the bottleneck of maize yield per unit area by optimizing plant architecture and increasing planting density. This paper systematically reviews the research progress on maize dwarf genes, with a focus on clarifying the biological significance of maize plant height traits, the practices of dwarf genetic breeding, and the regulatory mechanisms of plant hormones on plant height, while proposing future research directions. The results show that: (1) maize plant height is co-regulated by the number of internodes and internode length. Dwarf plants can reduce lodging risk by shortening internode length, optimize canopy structure, and improve light energy use efficiency and adaptability to dense planting, but it is necessary to coordinate the relationship between dwarfing and yield traits. (2) Maize dwarf genetics is divided into two major systems: single-gene and multi-gene. In the single-gene system, the br2 gene has the clearest molecular mechanism—it inhibits the elongation of stem cells, reducing stem length by 40% to 50% compared with the wild type, with a more significant effect on internodes below the ear position—and it is the most widely used major gene at present. The multi-gene system can avoid the defect of pleiotropy by accumulating minor-effect genes, and varieties such as 'Aidan 268' that balance dwarfing and high yield have been bred. (3) Gibberellin (GA), brassinosteroid (BR), and auxin (IAA) are the core hormones regulating plant height: mutations in GA synthesis-related genes (d1, an1) or signal genes (d8, d9) lead to dwarfing, loss of function of BR synthesis genes (brd1, na2) or signal genes (ZmBRI1a) causes stunted plants, and abnormal function of the IAA polar transport gene (br2) results in dwarfing of lower stem nodes. Currently, maize dwarf breeding has problems such as a relatively small number of applicable genes (more than 60 dwarf genes have been discovered, and about 40 have been cloned), genetic linkage drag restricting the coordination of traits, and insufficient functional verification of novel dwarf genes (such as the mapped genes K718d and d8227). In the future, it is necessary to explore medium dwarf genes suitable for dense planting, use genome-wide selection technology to aggregate multiple genes, and integrate phenomics with artificial intelligence to screen for ideal plant architecture, so as to breed maize varieties with the characters of dwarf stalks for lodging resistance, dense planting for high yield, wide adaptability and easy mechanical harvesting, and provide support for the sustainable development of the maize industry.

To investigate the effects of adjusting sowing dates on maize yield and meteorological adaptability in Hohhot, and to identify the optimal sowing period for optimizing cultivation practices and enhancing productivity, a field trial was conducted in Saihan District, Hohhot, in 2024 using the waxy maize variety ‘Hetiannuo 1’ with three sowing dates (April 21, May 9, and May 22). Growth stages, yield components, and meteorological factors were analyzed through field experiments and weather observations. A randomized block design was adopted to record data on growth phases and yield parameters for each sowing treatment. Delayed sowing shortened the total growth period, and accumulated temperature (≥10°C) and sunshine duration showed positive correlations with growth duration. The highest yield was observed in the May 9 sowing treatment, which exhibited superior grain number per ear and 100-grain weight compared to other sowing dates. Correlation analysis revealed that accumulated temperature and sunshine during the tasseling-to-milking stage significantly enhanced yield, while excessive rainfall during the milking-to-maturity stage reduced grain number and yield. The optimal sowing date for maize in Hohhot is May 9, and it ensures balanced utilization of light, thermal and water resources, mitigates risks of heat stress and prolonged rain, improves ear development, and maximizes yield. These findings provide scientific basis for the optimization of local maize planting system and the improvement of yield and climate adaptability.

To further screen and enrich the types of excellent fresh waxy maize varieties, this study conducted a demonstration trial with 18 fresh waxy maize varieties including Heijin 699, Ruihezaonuo, and Shenketiannuo 99 as test materials, comparing and analyzing their growth period, main agronomic traits, ear traits, occurrence of diseases and insect pests, quality, and yield. The results showed that Ruihebainuo 80 germinated 7 days after sowing; it had a plant height of 213.7 cm, with no lodging or stem breaking; the ear length was 20.1 cm, tip barrenness was 0.3 cm, and the fresh 100-grain weight was 35.8 g; the total quality score was 88.8 points, and the yield reached 16 716.7 kg/hm⊃2;. Shenketiannuo 99 germinated 6 days after sowing; its plant height was 207.5 cm, with a lodging rate of 0.4% and no stem breaking; the ear length was 19.6 cm, tip barrenness was 0.9 cm, and the fresh 100-grain weight was 37.2 g; the total quality score was 88.1 points, and the yield was 14 441.7 kg/hm⊃2;. Huanaicaitiannuo 102 germinated 6 days after sowing; it had a plant height of 234.1 cm, with a lodging rate of 0.4% and no stem breaking; the ear length was 21.7 cm, tip barrenness was 1.0 cm, and the fresh 100-grain weight was 42.5 g; the total quality score was 87.8 points, and the yield amounted to 16 039.6 kg/hm⊃2;. Shenbaitiannuo No. 3 germinated 7 days after sowing; its plant height was 196.3 cm, with no lodging or stem breaking; the ear length was 19.3 cm, tip barrenness was 1.1 cm, and the fresh 100-grain weight was 41.0 g; the total quality score was 88.2 points, and the yield was 13 981.3 kg/hm⊃2;. Huhongnuo No. 1 germinated 6 days after sowing; it had a plant height of 227.3 cm, with no lodging or stem breaking; the ear length was 19.1 cm, no tip barrenness, and the fresh 100-grain weight was 40.5 g; the total quality score was 90.4 points, and the yield reached 14 731.3 kg/hm⊃2;. Heijin 699 germinated 7 days after sowing; its plant height was 188.1 cm, with no lodging but a stem breaking rate of 1.7%; the ear length was 18.0 cm, tip barrenness was 0.4 cm, the fresh 100-grain weight was 34.7 g, and it had purple kernels; the total quality score was 88.5 points, and the yield was 12 708.3 kg/hm⊃2;. For all the above varieties, the incidence grade of sheath blight, stem rot and Asian corn borer was grade 1. Comprehensively, Ruihebainuo 80 had an outstanding yield advantage and excellent quality performance; three varieties, namely Huanaicaitiannuo 102, Shenketiannuo 99 and Shenbaitiannuo No. 3, showed good yield and quality, with good comprehensive traits; Huhongnuo No. 1 had relatively high yield, excellent quality and good marketability; although Heijin 699 had no prominent yield advantage, it had a sweet, tender and glutinous taste, good quality and purple kernels, with good commercial appearance. All the 6 above-mentioned varieties had good comprehensive performance and could be promoted for cultivation in the study area.

The breeding process, cultivation characteristics, and key cultivation techniques of the maize variety Fukeyu No.1 were summarized. This variety was developed by crossing the inbred line FS0744 (female parent) with FS0770 (male parent) and was approved by the Anhui Provincial Variety Approval Committee in 2024 (Wanshenyu 2024T009). The plant type was semi-compact, with a total growth period of approximately 100 days. In regional trials, the average plant height was 262.5 cm, and the 1 000-grain weight was 310.0 g. Stable resistance to small spot disease and stalk rot disease, with excellent comprehensive resistance performance. Quality analysis revealed a test weight of 732-742 g/L and a crude protein content of 10.34%-10.59%. Multi-year, multi-location trials indicated that the variety was high yielding and stable, with yield increase of 7.62%-18.6% compared to the control variety Zhengdan 958. This variety is suitable for planting in summer-sown maize production areas north of the Huai River. Key cultivation techniques include the following steps: apply sufficient base fertilizer during land preparation and use granular insecticides to control soil pests; conduct summer sowing from mid-May to early June at a planting density of 63 000-67 500 plants/hm²; sun dry seeds before sowing and apply seed coating or chemical dressing to control pests and diseases and promote robust seedlings; during field management, thin and finalize seedlings in a timely manner, strengthen intertillage and weeding, and manage fertilizer and water appropriately. At the tasseling stage, combine topdressing with soil hilling; supplement water and fertilizer during the grain-filling stage to prevent premature senescence. Delay harvesting appropriately at maturity; mechanically harvest when the kernel milk line disappears and a black layer forms, and dry the grains promptly to a moisture content below 14% for safe storage. This study provides a reference for the promotion and application of this variety in similar ecological regions.

Unbalanced fertilizers supply with highly intensity and excessive nitrogen (N) and less potassium (K), lead to the decrease of soil fertility year by year.  Balanced fertilization is one of the most effective measures to reduce fertilizer use while improving maize yield and efficiency.  Two N levels (180 and 225 kg N ha⁻¹, abbreviated N12 and N15) and four K treatments (0, 75, 150, and 75+75 kg K₂O ha⁻¹, abbreviated K0, K5, K10, and K5+5) were set to study the effects of combined application of N and K on the biomass and nutrient accumulation and remobilization characteristics in waxy maize.  The results demonstrated that grain yield increased when higher amounts of K were applied at constant N levels, showing an average increase of 1,254.8 kg ha⁻¹ (2020) and 727.3 kg ha⁻¹ (2021) compared with K0.  Under same N and K application, K5+5 increased grain yield by increasing kernel weight.  Under K5+5 treatment, the biomass and nutrient accumulation had no significant difference between N12 and N15.  Compared with K10, K5+5 not only enhanced the average remobilization amount (RBA) of biomass, but also increased RBA of N, phosphorus (P) and K.  In addition, the average remobilization efficiency (RBE) of biomass, N, P and K in K5+5 were increased 3.3, 4.6, 10.6 and 4.2%, respectively.  Furthermore, topdressing K improved the apparent contribution to grain (AC) of biomass, N, P and K, which promoted more nutrient to grains, and significantly increased nutrient harvest index.  Considering yield and fertilizer use efficiency, we recommend optimized K application (basal and topdressing 75 kg ha⁻¹) and moderately reduced N application (from 225 to 180 kg ha⁻¹) in the production of spring-sown waxy maize in southern China.

Optimizing sowing dates (SDs) is a potential strategy for adjusting maize production to climate change and increasing yield.  However, there is still a lack of research on the combined effects of lodging and yield in relation to climatic variables across various SDs.  This study aims to investigate the changing patterns and distribution of important climatic variables during the maize growth season, their impact on yield and lodging, and the critical factors affecting lodging at crucial growth stages under different SD scenarios.  In this study, we assessed the impact of climate change on yield and lodging by conducting field experiments over 5 years (2015, 2016, 2019–2021) encompassing 25 SDs in the Sichuan basin, China.  Results demonstrated that the lodging rate had a significant effect on the coefficient of variation (CV, 3.31–10.50%) of maize yield.  A 1% increase in lodging rate, led to a decrease of 58.05 kg ha^-1 in yield.  Changes in SDs notably affected solar radiation (Sr) from emergence to silking (E-R1).  Additionally, the study found that Sr explained 34.7% of the lodging rate variation in E-R1.  Analysis of historical meteorological data showed notable inter-annual variations in Sr trends, with a decline of -8.7763 MJ m^-2 yr^-1 from 1990 to 2021, especially noticeable from late May to early July.  Variation Partitioning Analysis (VPA) revealed that climatic variables during the period from emergence to physiological maturity (E-R6) and E-R1 explained 43.9 and 53.2% of yield, respectively, across different SDs.  These variables also contributed 56.0 and 45.4% to lodging.  Using Random Forest (RF) determined that changes in SDs significantly impacted lodging rates mainly through modifications in basal internode morphology, which explained 69.79% of the variation.  The study identified optimal sowing dates for achieving high and consistent yields, primarily occurring between late March and mid-April, attributed to increased Sr during E-R1.  Overall, this research provides valuable insights into the effects of climate change on stalk lodging and offers guidance on adjusting sowing dates to mitigate maize lodging rates.

Waterlogging stress has been found to have adverse impacts on plant growth, subsequently reducing crop yields.  Spermidine (Spd), a second messenger, positively affects the growth of plants under waterlogging stress.  However, the molecular mechanisms of exogenous Spd application alleviating waterlogging stress remained unclear.  In this study, we performed physiological analysis and multi-omics to underlying the effect of Spd application on waterlogging stress.  Spd application increased genes expression level of light-harvesting complex (LHC) and photosynthesis-related and starch-related pathway, inhibited chlorophyll degradation and maintained higher photosynthetic rate, thus increased biomass accumulation under waterlogging stress.  The activation of genes related trehalose and Spd biosynthesis would result in high accumulation of trehalose and endogenous Spd.  Inhibiting 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO,) expression contributed to reduced ethylene emission.  All those changes increased maize resistance to waterlogging.  After Spd sparying, auxin-related genes up-regulated and IAA content was increased, those favor cell elongation in maize and thus keep normal growth after Spd application under waterlogging stress.  Most of genes involved in lipids were up-regulated and thus increased lipids content and protected cell membranes in maize after Spd application under waterlogging conditions.  All those changes contributed to increasing the resistance to waterlogging stress.  These findings broaden our understanding of the regulatory roles of Spd in alleviating waterlogging damage and will provide evidence for breeding waterlogging-tolerant maize varieties.

Starch plays a crucial role as a storage component, greatly affecting the grain yield and quality of maize (Zea mays L.).  To meet future demands, it is essential to understand the genetic basis of the natural variation in kernel starch content (SC) for maize breeding.  Through a genome-wide association study (GWAS), we identified 84 and 96 loci associated with kernel SC within two years that overlapped with 185 candidate genes.  The candidate gene ZmMYB71, which encodes a myeloblastosis (MYB)-related transcription factor, exhibited the highest co-expression frequency with starch synthesis genes.  We demonstrated that ZmMYB71 functions as a nuclear located transcription repressor, and the kernel SC of mutants increased by over 2.32%, with a minor effect on amylose content or 100-grain weight.  Sh1, Sh2, and GBSSI showed up-regulation in mutants by 1.56-, 1.45- and 1.32-fold, respectively, consistently with the RNA sequencing result; their promoter activities may be directly repressed by ZmMYB71 through the GATATC and TTAGGG motifs.  Furthermore, the ZmMYB71 elite haplotype Hap1 was present in over 55% of the high-starch maize sub-populations BSSS and PB but only in 7.14% of the low-starch sub-population PA.  Comparing the Hap1 haplotype frequencies in different breeding stages found that its frequency in the inbred group released after 2010 is significantly higher at 40.28%, in contrast to 28.57% and 27.94% in the years 1980 and 1990, and 2000, respectively.  The finding provides valuable information on the natural variation in SC of the maize kernel and suggests that ZmMYB71 serves as a negative regulator with the potential to be used to improve SC in the kernels.

Soil salinization is a global ecological problem restricting agricultural production, and its bioremediation technology has attracted much attention. In this study, salt-tolerant strains were isolated from saline-alkaline soil in Tianjin, and the salt-promoting ability of the strains on maize seedlings was assessed by NaCl medium screening, 16S rRNA gene identification, and sand culture test. Three salt-promoting strains (WQ-08, WQ-26, and BH-39) were isolated and identified as Bacillus subtilis, Priestia megaterium, and B. pumilus, respectively. Under 100 mmol/L NaCl salt stress, when strains WQ-08, WQ-26 and BH-39 were respectively added for co-cultivation with maize seedlings, the growth inhibition of maize seedling MC812 was significantly alleviated: the plant height, stem-leaf dry weight and root dry weight in the WQ-08 treatment group increased significantly by 33.32%, 37.04% and 36.84% respectively compared with other treatments, while the root length, stem-leaf fresh weight and root fresh weight in the BH-39 treatment group increased significantly by 27.33%, 29.35% and 30.55% respectively compared with other treatments. Physiological indexes showed that the antioxidant enzyme activity of maize seedlings in each treatment group decreased significantly. In the strains WQ-08, WQ-26, and BH-39 treatment groups, the SOD activity of maize seedlings decreased by 9.77%, 5.60% and 7.71%, the POD activity by 20.44%, 22.24% and 25.27%, and the CAT activity by 34.46%, 31.27% and 23.28% (P<0.05). The study demonstrated that the three strains possessed both salt tolerance and growth-promoting abilities, which effectively alleviated the salt stress damage to maize seedlings and provided potential microbial resources for crop improvement in saline and alkaline areas.

The ground temperature in spring in the low-lying areas of Northeast China is low, which easily leads to poor seedling quality and slow growth of maize. Under the conservation tillage mode, this phenomenon is more obvious. The development of root-promoting and seedling-strengthening technology may be an important way to increase maize yield. Plant growth-promoting bacteria and trace elements can promote root growth and reduce low temperature stress. This study aimed to explore the role of the technologies in promoting the growth and yield of maize in low-lying land. The study was conducted in Changjiadian Village, Liujiaguanzi Town, Lishu County, Jilin Province in 2023 and 2024. Five treatments were set up, which were (1) farmers’ routine; (2) rhizosphere application of microbial phosphate fertilizer; (3) rhizosphere application of growth-promoting bacterial agent A28; (4) rhizosphere application of growth-promoting bacteria agent P24; (5) spraying humic acid trace element foliar fertilizer on plant shoot. Plant samples were collected during the whole growth period of maize, and root and aboveground biomass, leaf area index, yield and its components were measured. The results showed that the root-promoting and seedling-strengthening techniques could improve the growth of maize seedlings. At the seedling stage (the sixth leaf expansion stage), the leaf area index increased by 25.9%-141.2%, the root biomass increased by 15.7%-82.4%, and the aboveground biomass increased by 10.7%-84.6%. At the same time, it also significantly delayed the senescence of leaves and roots in the later stage, increased the 100-grain weight and grain number per ear of maize, and finally significantly increased the yield of maize by 4.9%-18.7%. The effect of increasing yield was shown as growth-promoting bacterial agent > microbial phosphate fertilizer > trace element foliar fertilizer. Among them, the growth-promoting bacterial agent A28 had the best yield-increasing effect and stability, with an average yield increase of 16.2%. This paper believed that the rhizosphere microbial regulation technology could effectively reduce the stress of soil low temperature on the growth of maize seedlings, and ultimately increase the yield of maize, which had a wide application value in the low-lying areas of Northeast China.

Wheat-maize rotation is a widely used planting pattern in oasis irrigated areas in northwest China.  Although this planting pattern has the advantage of breaking the barrier of continuous cropping to some extent, it also has some problems such as large evaporation and prominent soil degradation during fallow period, which seriously restricts the improvement of crop yield.  Planting green manure (GM) after wheat and returning it to field can effectively improve soil physicochemical properties, regulate photosynthetic characteristics of subsequent crops and promote crop yield.  However, the photosynthetic physiological mechanism of crop yield improvement under different green manure return methods (GMRM) is still unclear.  Therefore, by exploring the relationships among soil moisture and temperature environment, maize root structure, photosynthetic characteristics, fluorescence characteristics and yield under different GMRM, this study aims to provide theoretical basis for clarifying the photosynthetic physiological mechanism of GMRM to improve maize yield.  A three-year field experiment was conducted at a research station in the Shiyang River Basin (Gansu, China).  Five treatments were involved in this study: (i) conventional tillage without GM (CT), (ii) no-tillage with total GM mulching (NTG), (iii) no-tillage with removal of aboveground GM (NT), (iv) tillage with total GM incorporation (TG), and (v) tillage with only root incorporation (T).  Results showed that the NTG and TG significantly increased soil water content (SWC) in 0-110 cm soil layer, soil temperature (ST) of maize seedling (V3) to jointing stage (V6), canopy cover (CC), leaf stay-greenness (SG), root length (RL), net photosynthetic rate (P_n), transpiration rate (T_r), actual photochemical efficiency of PSII (ՓPSII), maize biomass and grain yield (GY) compared with CT.  In addition, NTG and TG significantly decreased ST of maize big trumpet stage (V12) to blister stage (R2), and dissipation of excess energy (NPQ) compared with CT.  The GM return to field could improve root structure and canopy coverage of maize mainly by improving soil water content.  The optimization of maize root structure and canopy coverage increased maize chlorophyll content (SPAD) value and promoted P_n.  The increase of P_n inhibits the increase of NPQ, thus promoting ՓPSII.  The increase of ՓPSII promoted the increase of maize biomass, and finally realized the increase of maize GY. 

Glycosylphosphatidylinositol (GPI) anchoring is one of the common post-translational modifications in eukaryotic cells. In fungi, it exerts a wide range of biological functions by targeting proteins to the cell wall, but only few studies focus on the roles of GPI anchoring in plant pathogenic fungi. Here, we reveal a role of GPI anchoring in the maize fungal pathogen Cochlibolus heterostrophus. We found that GPI-anchored proteins were widely accumulated in hyphae, appressorium and infection hyphae of C. heterostrophus. Deletion of ChGPI7, which encodes a key enzyme involved in the biosynthesis of GPI anchors, resulted in significant reduction of vegetative growth and conidiation, as well as virulence due to impairment of appressorium formation and invasive growth. The ∆Chgpi7 mutants also showed severe defects in cell wall integrity, resulting in a significant reduction of stress resistance. Deletion of ChGPI7 and hydrofluoric acid (HF) pyridine treatment both led to removal of cell wall GPI-anchored proteins and exposure of chitin, the results suggested that GPI anchored proteins could protect chitin from host immune recognition. A total of 124 proteins were predicted to be GPI anchored proteins in C. heterostrophus, including a putative cell wall glycoprotein ChFEM1. Deletion of ChFEM1 also resulted in significant reduction in virulence and defects in infection structures, as well as cell wall integrity. We further found that cell wall localization and protein abundance of ChFEM1 were affected by ChGPI7. Our results showed that GPI anchoring regulates cell wall integrity and immune evasion for infection of C. heterostrophus.

Long-term excessive nitrogen (N) application does not increase or even decreases grain yield and N use efficiency (NUE) of maize, in which the roles of root morphological and physiological characteristics are not clear.  The goal of this study was to explain the mechanism underlying no increment in grain yield under excessive N application from the perspective of root morpho-physiological characteristics.  A 10-year long-term N fertilizer trial was conducted in Jilin Province, Northeast China, growing maize at three N fertilizer levels (zero N, N0; recommended N, N2; and high N level, N4) in 2019, 2020 and 2021.  Two widely planted maize genotypes: ‘Xianyu 335’ (XY335) and ‘Zhengdan 958’ (ZD958) were used.  Grain yield, N content, root morphology and other physiological characteristics were analyzed to further evaluate the relationships between N uptake, N utilization, plant growth, and root systems under different N treatments.  Compared with N0, root biomass, post-silking N uptake and grain yield were significantly improved with increased N input, whereas no significant differences were observed between recommended N and high N.  High N application increased root length and root surface area, but decreased root activity (measured by TTC (2,3,5-triphenyltetrazolium chloride) method), nitrate reductase activity and root activity absorbing area regardless of genotypes.  Root length and root to shoot ratio negatively contributed to N uptake (by -1.2% and -24.6%), while root surface area, root activity, nitrate reductase activity and root activity absorbing area were positively contributed to N uptake.  The interaction effect between cultivar and N application was significant on NUE.  XY335 obtained the highest NUE (11.6%) and N recovery efficiency (18.4%) through higher root surface area (23.6%), root activity (12.5%), nitrate reductase activity (8.3%) and root activity absorbing area (6.9%) compared with other treatments.  Overall, recommended N application promoted Post N uptake, NUE and grain yield by root surface area and root activity, nitrate reductase activity and root activity absorbing area, while high N application did not increase or even decreased NUE by reducing root surface area, root activity, nitrate reductase activity and root activity absorbing area.  Our case study successfully revealed that root surface area, root activity, nitrate reductase activity and root activity absorbing area were the limiting factors of NUE increase under high N application.

To select shade-tolerant maize cultivars adapted to low-light conditions in the Huang-Huai-Hai region and thereby improve maize yield in this area, twelve widely cultivated maize cultivars in the region were selected as experimental materials. These cultivars were subjected to a 6-day shading treatment starting at the tasseling stage, and indicators, including silk number, dry matter accumulation, and yield, were measured. The results showed that shading significantly reduced the silk number, silk length, dry matter accumulation, and yield, with the extent of reduction varying among different cultivars. On average, yield decreased by 91.64%, corresponding to a reduction of 11.79 t/hm². Further analysis revealed that ear diameter, ear length, number of kernels per ear, 1000-kernel weight, silk number, and silk length were all significantly positively correlated with yield, indicating that these indicators could serve as effective criteria for evaluating shade tolerance in maize. Based on a comprehensive evaluation of shade tolerance traits and cluster analysis, ‘Jingke 968’, ‘Denghai 605’, and ‘Xundan 20’ were ultimately identified as shade-tolerant cultivars.