Field experiments were conducted to analyze the effectiveness of the crop stress index (CWSI) obtained by infrared thermal imaging to indicate crop water status, and to determine the appropriate CWSI threshold range for wheat at different growth stages. The results showed that the sensitivity of plant physiological parameters to soil water was different at different growth stages. The sensitivity of stomatal conductance (Gs) and transpiration rate (Tr) to soil water was higher than that of leaf relative water content (LRWC) and photosynthetic rate (Pn). The characteristics of plant physiology and biomass (yield) at each growth stage showed that the plant production would not suffer from drought stress as long as the soil water content (SWC) was maintained above 57.0% of the field water capacity (FWC) during the jointing stage, 63.0% of the FWC during the flowering stage and 60.0% of the FWC during the filling stage. Correlation analysis showed that the correlation of CWSI with Gs, Tr and Pn was lower than that with LRWC and SWC at the jointing stage. CWSI was extremely significantly negatively correlated with SWC and LRWC (p < 0.01), but significantly negatively correlated with Gs, Tr and Pn (p < 0.05). At the flowering stage, CWSI was extremely significantly negatively correlated with all physiological and soil parameters (p < 0.01). The regression analysis showed that the CWSI of winter wheat was correlated with biomass (grain yield) in a curvilinear relationship at each growth stage. When the CWSI increased to a certain extent, the biomass and yield showed a decreasing trend with the increase in CWSI. Comprehensive analysis of all indexes showed that CWSI can be used as a decision-making index to guide the water-saving irrigation of winter wheat, as long as the CWSI threshold of plants was maintained at 0.26–0.38 during the jointing stage, 0.27–0.32 during the flowering stage and 0.30–0.36 during the filling stage, which could not only avoid the adverse effects of water stress on crop production, but also achieve the purpose of water saving.

To address the bottlenecks of low water and fertilizer utilization efficiency and limited yield potential inherent in Henan Province’s traditional winter wheat cultivation model of “furrow irrigation + conventional row seeding”, this study delved into the synergistic regulatory mechanisms of drip irrigation combined with wide-row precision seeding. It focused on their effects on the physiological ecology and yield-quality traits of winter wheat. A two-factor experiment, encompassing “sowing method × irrigation method” will be carried out during the 2024–2025 wheat growing season, featuring four treatments: furrow irrigation + conventional row seeding (QT), drip irrigation + conventional row seeding (DT), furrow irrigation + wide-row precision seeding (QK), and drip irrigation + wide-row precision seeding (DK). Results reveal that wide-row precision seeding optimized the canopy structure, raising the leaf area index (LAI) at the heading stage by 20.19% compared to QT, thereby enhancing ventilation and light penetration and reducing plant competition. Drip irrigation, with its precise water delivery, boosted the net photosynthetic rate of the flag leaf 35 days after flowering by 62.99% relative to QT, stabilizing root water uptake and significantly delaying leaf senescence. The combined effect of the two treatments (DK treatment) synergistically improved the canopy structure and photosynthetic performance of winter wheat, prolonging the functional period of green leaves by 29.41%. It established a highly efficient photosynthetic cycle, marked by “high stomatal conductance-low intercellular CO₂ concentration-high net photosynthetic rate”. The peak net photosynthetic rate (P_n) 13 days post-flowering rose by 23.9% compared to QT. Moreover, while reducing total water consumption by 21.4%, it substantially increased water use efficiency (WUE) and irrigation water use efficiency (IWUE) by 43.2% and 14.2%, respectively, compared to the QT control. Ultimately, the DK treatment achieved a synergistic enhancement in both yield and quality: grain yield increased by 14.7% compared to QT, wet gluten content reached 35.5%, and total protein yield per unit area rose by 13.1%. This study demonstrates that coupling drip irrigation with wide-row precision seeding is an effective strategy for achieving water-saving, high-yield, and high-quality winter wheat cultivation in the Huang-Huai-Hai region. This is achieved through the synergistic optimization of canopy structure, enhanced photosynthetic efficiency, and improved WUE. These findings provide a mechanistic basis and a scalable agronomic solution for sustainable intensification of winter wheat production under water-limited conditions in major cereal-producing regions.

Micro-sprinkling irrigation is a small-flow irrigation technology that uses the grouped outlets on the micro-sprinkling hoses to spray the pressure water evenly in the field. Plants’ barriers during the middle to late growth period of winter wheat significantly reduce the irrigation quality of the micro-spray system. It is still unclear whether soil border width in wheat fields can alleviate the negative effect. In this study, a popularly-used variety (c.v. ZM 369) was adopted to test the mitigation effect of soil borders on irrigation quality, as well as soil moisture distribution, in wheat fields. Two irrigation quotas (i.e., 75 mm and 45 mm per time) and three border widths (i.e., 2.3 m, 3.3 m, and 5.3 m) were arranged in a randomized block design in the experimental years of 2020–2022. Soil moisture distribution and irrigation quality during the middle to late growth period of winter wheat (i.e., jointing to heading stage and grain filling stage) were investigated, as well as the effects on grain yield and water use efficiency (WUE). The results showed that irrigation water distribution in the direction perpendicular to micro-spray tapes generally decreased with the distance from tapes increasing. The maximum difference between the irrigation amount and water collected under the canopy was 134 mm. The uniformity coefficient of soil moisture distribution was increased by 25.8% with a 5.3 m border width compared to a 2.3 m width. Although an irrigation quota of 75 mm was beneficial for ensuring better irrigation uniformity and more stable grain yield, grain yield and WUE were produced with an irrigation quota of 45 mm. In conclusion, it is appropriate to increase border width and adopt a small quota for the micro-spray system in the North China Plain for wheat crops.

With the advancement of urbanization, there has been a significant reduction in cultivated land, accompanied by soil erosion. Concurrently, the regularity of rainfall in recent years has been erratic, adversely impacting the grain economy and agricultural development in certain regions. Henan Province, spanning the basins of the Yangtze River, the Yellow River, the Huaihe River, and the Haihe River, possesses complex hydrological conditions and serves as a pivotal agricultural zone in China. Therefore, this paper utilizes daily rainfall data collected over 54 years (1969–2022) from 112 rain measuring stations in Henan Province to calculate the rainfall erosivity using the Zhang model and the erosivity model from the first national water survey. Meanwhile, spatial analysis was performed using the Kriging interpolation method in the ArcGIS Geostatistical Wizard, resulting in detailed spatial distribution maps of rainfall and rainfall erosivity. The study also employed Wavelet and Mann–Kendall tests to analyze the abrupt changes, trends and periodicity of rainfall and rainfall erosivity within the target region. The findings indicate that the average rainfall (1969–2022) in Henan province was 718.26 mm, while the average rainfall erosivity (R) was 3213.46 MJ mm/(hm² h). R values are positively correlated with rainfall intensity and volume, displaying an annual upward trend. Spatially, R values increase gradually from northwest to southeast, closely aligning with topographical variations. Additionally, the analysis revealed a predominant periodic cycle of 54 years in the precipitation patterns. These results offer valuable insights for environmental and agricultural management in other regions of central China.

An increase in atmospheric pollution markedly affects the climatic environment. Aerosol is the main component of atmospheric pollutants and has a significant influence on the changes of reference crop evapotranspiration (ET₀), while the effects of aerosol on ET₀ are still unclear. In this study, the influence of aerosol on the changes in meteorological elements and ET₀ in Henan Province was evaluated using online two-way coupling of WRF (Weather Research Forecast)–Chem. The results of the 30-day Online Two-way Coupling indicated that the WRF–Chem model accurately simulated the temporal and spatial variation of each meteorological element in Henan Province. Aerosol decreased the overall temperature in Henan Province by 0.036 °C, wind speed by 0.176 m s⁻¹, and barometric pressure by 20 Pa, while the relative humidity increased by 1.39%. The effect of aerosol on meteorological elements led to the change in ET₀. The extent of the effect of aerosol on ET₀ was closely related to the aerosol concentration. The variation of ET₀ ranged from −0.545 to 0.676 mm d⁻¹ for a pollution condition and −0.309 to 0.380 mm d⁻¹ for an excellent condition. The extent of the effect of aerosol on ET₀ varied among regions, and the variation of ET₀ showed distinct spatial patterns under different pollution levels. The varying degree of ET₀ in the daytime (ET_0-d) was greater than ET_0-n (ET₀ in the nighttime) regardless of the circumstances. Shortwave aerosol radiative forcing was the main cause of this phenomenon. For an excellent condition, aerosol showed positive regulation of ET_0-d in 63% of the regions and of ET_0-n in 88% of the regions. ET_0-A (aerodynamic term of ET₀) plays a dominant role in ET₀ changes in most of Henan Province. However, as the pollution level increased, more urban ET_0-R (radiation term of ET₀) also began to dominate the ET₀ changes. These results contribute to an in-depth understanding of the response of regional evapotranspiration to atmospheric pollutants and climate change.

As a prominent agricultural country, China has widely implemented returning straw to the field in agricultural production. However, as the decomposition of straw progresses, the physical properties of the soil change, inevitably leading to alterations in the soil surface evaporation model. This study investigated the variations in soil evaporation rate, soil moisture content over 60 days after returning straw to the field, and bare soil through two leaching pond experiments. Through soil moisture retention curves at different degrees of decomposition, this study analyzed the impact of straw decomposition on soil’s water retention capacity. Based on measured data, this study formulated models for the soil surface evaporation resistance of bare soil and varying degrees of straw decomposition. With the comparison and contrast between the models, this study clarified the impact of straw decomposition on soil surface evaporation resistance. The main conclusions are the following: The moisture content of the surface soil decreases exponentially over time and, after 40 days of straw decomposition, the water content of the soil under decomposition is higher than that of bare soil. As the moisture content decreases, the cumulative evaporation from the soil increases linearly. The cumulative evaporation of the decomposed straw soil is lower than that of bare soil, with a relative reduction ranging from 3.08% to 32.2%. The straw decomposition significantly enhances the water retention capacity of the soil in the medium-to-high suction range. The straw decomposition enhances the evaporation resistance of the soil surface, and the greater the degree of decomposition, the more significant the enhancement effect. The research findings not only provide a scientific basis for agricultural water management, but also possess practical implications for guiding farmers to adopt more effective moisture retention measures.