The Hetao Irrigation District in Inner Mongolia faces serious challenges from soil salinization and water scarcity. This paper aims to investigate the differences in soil water-salt conditions before autumn irrigation under different preceding crops and to determine suitable autumn irrigation schedules for various "preceding crop-planned subsequent crop" combinations. Soil water and salt data from the 0~100 cm depth were collected from 94 field monitoring sites during 2023-2025. SPSS 27 was used to statistically analyze the differences under different preceding crops (maize, sunflower, wheat). The SHAW model was then applied to simulate water and salt transport during the freeze–thaw period, and the model was calibrated and validated. Based on this, 147 simulation scenarios were established to systematically evaluate the effects of salinization level (light, moderate, severe), preceding crop, irrigation timing (early, mid, late), and irrigation quota (0~300 mm) on soil water-salt status in the 0~40 cm layer before spring sowing. Preceding crops significantly influenced the soil water-salt profile before autumn irrigation. Preceding maize fields showed the highest soil water content, preceding sunflower fields exhibited the strongest salt accumulation at the surface, and preceding wheat fields had relatively lower and more uniformly distributed water and salt. Preceding sunflower generally required higher irrigation quotas, averaging 15~50 mm and 15~40 mm more than preceding maize and wheat, respectively, to achieve the same soil moisture target. The "preceding-subsequent crop" matching strategy directly affected water use efficiency. Under all salinization levels, preceding wheat required lower irrigation quotas to achieve target water-salt conditions for the three subsequent crops, saving 15%~35% water compared to preceding sunflower. The preceding crop significantly influences the appropriate autumn irrigation quota. Developing tailored irrigation schedules according to preceding crop conditions is essential for water-efficient and sustainable agricultural practices in the Hetao Irrigation District.

In order to explore the effects of different irrigation methods and varieties on rice yield and water use efficiency (WUE) in Northeast China and East China, based on CNKI and Web of Science databases, this study retrieved relevant literature published from January 2000 to December 2024, and finally included 103 studies (54 in Northeast China and 49 in East China). The Meta-analysis method was used to evaluate the comprehensive effects of different irrigation methods and varieties using standardized mean difference (SMD) as the effect size index. The results showed that: ① Compared with flooding irrigation, controlled irrigation, and alternate wetting and drying irrigation, the comprehensive effect of intermittent irrigation was the best in Northeast and East China, and the SMD of rice yield was 0.47 and 0.57, respectively, corresponding to the yield increase of about 7.9% and 10.9%. The SMD of WUE was 2.17 and 1.44, respectively, with the corresponding increase of 64.0% and 49.2%. ② The variety type had regional regulation effect on irrigation effect. In Northeast China, drought resistant and water-saving varieties such as "Longjing 26" and "Longdao 22" had good adaptability to intermittent irrigation, which could synergistically improve rice yield and WUE; In East China, the yield advantages of high-yield and water-demanding varieties such as "II-you 725" and stable-yield and adaptive varieties such as "Liangyoupeijiu" were obvious, while some drought resistant and water-saving varieties had more potential in WUE. ③ The optimal irrigation variety adaptation model was jointly shaped by the regional "climate-soil-water resources" system. In conclusion, irrigation mode was the dominant factor affecting rice yield and WUE, and variety selection was the key control link. Irrigation and variety configuration should be optimized according to local conditions to achieve high yield, high efficiency and water-saving production of rice.

Autumn irrigation is a non-growing season irrigation practice. Its main aims are salt leaching and moisture retention. It accounts for about one-third of the annual water use in the Hetao Irrigation District. This presents significant water-saving potential. To advance water conservation in the irrigation district, this study employed field experiments and the HYDRUS-1D dual-porosity model. The goal was to investigate differences in soil moisture retention and salt leaching effects between intermittent and traditional autumn irrigation. The study also quantified the water-saving potential of intermittent autumn irrigation. Results indicate the following: ① Intermittent autumn irrigation slightly underperforms traditional autumn irrigation in moisture retention. The pre-spring-planting surface soil moisture content was at 93%~103% of the traditional methods, basically meeting the moisture retention requirements.. However, its salt leaching efficacy surpasses traditional approaches, achieving 4%~60% higher surface soil desalination rates. When irrigation intervals exceed 2 days, salt return rates decrease by 57%~82%. ② Reducing the number of intermittent autumn irrigation cycles from 4 to 2 increased topsoil desalination by 140%. It also decreased the moisture content by 5%. When the irrigation interval increased from 2 to 6 days, the desalination effect of the topsoil increased by 92%. The moisture content of the topsoil decreased by 4%. This indicates that as the number of irrigations decreases and the irrigation interval increases, the salt leaching effect of intermittent autumn irrigation improves significantly. However, this may have some adverse effects on moisture retention. ③ For slightly saline-alkali soils, both intermittent and traditional autumn irrigation at 1 200 m3/hm2 showed negligible water-saving effects. For moderately saline-alkali soils, intermittent autumn irrigation applied at 1 800 m3/hm2 and traditional autumn irrigation at 2 100 m3/hm2 achieved water savings of 300 m3/hm2 (14.3%). For severely saline-alkali soils, the intermittent autumn irrigation quota is 2 700 m3/hm2, while the traditional autumn irrigation quota is 3 600 m3/hm2. This yields water savings of 900 m3/hm2 (25%). In future production practices, intermittent autumn irrigation should be prioritized for moderately and severely saline-affected farmland.

This study aimed to determine the optimal irrigation regime for sea buckthorn, assess the applicability of the WOFOST model for simulating its growth and yield in the semi-arid Loess Plateau, and thereby enhance both yield and water use efficiency (WUE). The research was conducted in Shenmu City, Shaanxi Province. Utilizing data from six controlled experiments and twelve simulation scenarios in 2024, the WOFOST model was calibrated and validated for simulating sea buckthorn growth. We systematically analyzed the effects of different irrigation levels (low, medium, high) across four growth stages (sprouting, leaf expansion, fruit expansion, and maturation) on growth, yield, and WUE. The results indicated that the fruit expansion stage is the most water-sensitive period for sea buckthorn. A low to medium irrigation levels (FASW=0.5–0.7) during the fruit expansion and maturation stages was found to be optimal, whereas excessive irrigation decreased WUE. The WOFOST model demonstrated high accuracy in simulating aboveground biomass, leaf area index, soil water content, and fruit biomass (with R2 0.85 and NRMSE mostly below 20%), confirming its suitability for the region. Based on controlled experiments and model simulations, an optimized irrigation regime for sea buckthorn in the semi-arid Loess Plateau was proposed. This regime focuses on the fruit expansion stage as the key period for water regulation, maintaining root-zone soil moisture by performing four irrigation events at a suitable threshold (FASW≈0.5) while coordinating irrigation management across other growth stages. Under a total irrigation amount of 196.98 mm, this approach achieved simultaneous improvement in yield and water use efficiency.

in order to explore the response mechanism of rice seedlings to light supplementation under gibberellin soaking, 150 mg/L gibberellin and distilled water were used to soak rice seeds, and the far-red light, blue light, far-red light and blue light were set within 22∶00-24∶00, and the photosynthetic parameters of rice seedling leaves were determined by li-6400 photosynthetic instrument. four photoresponse models, including the rectangular hyperbolic model, non-rectangular hyperbolic model, modified rectangular hyperbolic model, and exponential model, were used to fit the photosynthetic rate of rice seedlings, and the photosynthetic parameters of rice were analyzed according to the model with the highest degree of fitting. the results show that among the four light response models, the rectangular hyperbolic correction model has the best fitting effect and accurate characteristic parameters. the maximum net photosynthetic rate, apparent quantum efficiency and water use efficiency of rice seedlings were greatly increased by 150 mg/L gibberellin soaking and far-red light and blue light co-irradiation, and the improvement in water use efficiency ranged from 1.10% to 3.77%. while the light compensation point and dark respiration rate were reduced, indicating that the rice seedlings treated with gibberellin soaking and far-red light and blue light had stronger photosynthetic ability, lower respiratory consumption and higher weak light utilization rate.

To address the limitations of traditional open-channel flow measurement devices-such as structural complexity, significant head loss, and weak resistance to hydraulic disturbances-this study proposes and designs a novel weighing-based open-channel flow measurement device. A theoretical functional model relating flow rate to measured weight is established through dimensional analysis, and calibration experiments are conducted in a D50 open channel under various channel slopes (0.000 2~0.005 0). The results indicate that the power-law flow–weight relationship exhibits high fitting accuracy across all operating conditions, with coefficients of determination R ² exceeding 0.95, thereby verifying the stability and applicability of the proposed model. Owing to its simple structure, high sensitivity, and low susceptibility to hydraulic disturbances, the device enables rapid and reliable measurement of instantaneous open-channel flow without altering existing hydraulic conditions. This work provides a feasible new technical approach for water measurement and scientific water-resource management in irrigation districts.

To enhance the monitoring accuracy of soil-moisture sensors, five typical soil-moisture automatic monitoring sites in Hangzhou were selected. Two calibration methods-the stratificational calibration method (independent calibration for each soil layer) and the integrated calibration method (combining calibration results from multiple soil layers)—were applied to calibrate the parameters of the FDR type soil-moisture sensors. The calibration results, along with the factory calibration parameters, were compared and analyzed against the measured values obtained by the drying method. The results indicate that the stratificational calibration method achieved the highest accuracy, with an MAE ranging from 0.05% to 0.89%, and cross-sensor validation errors were within ±2%. The integrated calibration method yielded an MAE between 0.36% and 2.04%, which reduces calibration and deployment efforts while meeting conventional monitoring requirements. In contrast, the factory calibration parameters resulted in an MAE of 1.91% to 5.92%, indicating that the monitoring accuracy is relatively low. Therefore, in practical application, it is necessary to carry out targeted calibration work for soil-moisture sensors based on the data usage scenarios.

Identifying integrated management strategies for saline-alkali land that can simultaneously reduce salinity and alkalinity, improve soil fertility, and enhance ecological functions is of great significance for improving cultivated land quality, increasing agricultural production stability, and promoting the efficient and sustainable utilization of saline-alkali land resources. This study investigated the effects of different amendment measures on soil water and salt status, organic carbon, nutrient improvement at the maize jointing stage, as well as maize growth and development at the jointing, tasseling, and harvest stages, in order to provide a scientific basis for the amelioration of saline-alkali soils in the Qingtongxia Irrigation Area of Ningxia. A total of eight treatments were established, mainly including the application of organic and inorganic amendments and different tillage practices, such as film mulching, deep tillage, and varying distances between maize roots and drip irrigation belts. The results showed that, at the jointing stage, all treatments except T8 (maize roots 70 cm away from the drip irrigation belt) significantly increased soil moisture in the 0~40 cm layer. Among them, T4 (film mulching) increased soil moisture by 44.51%~57.31% compared with the control T1 (no amendment, no mulching, and no deep tillage). All treatments showed certain effects in reducing soil alkalinity and salinity within the 0~40 cm layer. Among them, T3 (phosphogypsum + natural humus + nitro humic acid) and T4 performed particularly well, with soil pH decreasing by 0.11~0.32 units and total salt content decreasing by 48.86%~63.65% relative to the control. The soil fertility improvement effect in the plow layer was mainly observed in T2 (organic fertilizer) and T3: the former was more favorable for soil organic carbon accumulation, whereas the latter showed greater advantages in increasing nitrogen, phosphorus, and potassium contents, as well as microbial biomass carbon and microbial biomass nitrogen, which increased by 70.68% and 55.64%, respectively, compared with the control. In terms of crop growth, maize emergence rates were relatively low under T2 and T3. At harvest, plant height, stem diameter, and relative chlorophyll content under T3 were 25.62%, 4.19%, and 3.75% higher than those of the control, respectively, and grain yield increased by 1.73 times compared with the control. Under T4, maize emergence reached 100%, and at harvest, plant height, stem diameter, and relative chlorophyll content were 29.47%, 2.22% and 8.81% higher than those of the control, respectively, while grain yield increased by 2.85 times. T8 showed the poorest performance. In summary, film mulching was the optimal measure for ameliorating saline-alkali soil in the Qingtongxia Irrigation Area. Compared with the control, it reduced total salt content in the 0~40 cm soil layer by 49.77%~54.82%, decreased soil pH by 0.13~0.20 units, and increased soil moisture by 44.51%~57.31%. Meanwhile, it improved soil organic carbon and nutrient contents in the 0~20 cm layer. In terms of crop performance, the film mulching treatment achieved a maize emergence rate of 100%, and grain yield was 2.85 times higher than that of the control.

To investigate the effects of different subsurface drainage configurations and tillage depths on soil water-salt transport and desalinization efficiency in severely saline-alkali farmlands of the Yanqi Basin in Xinjiang, three leaching irrigation experiments were conducted over two years with varying pipe spacing (20, 30, 40 m), burial depth (1.2, 1.5 m), and tillage depth (0, 0.3, 0.7 m). A three-way analysis of variance (ANOVA) was employed to identify the main effects and interactions of drainage layout parameters and tillage practices on the desalinization rate. The results showed that: ① the subsurface drainage discharge exhibited a unimodal pattern with increasing drainage time; the cumulative drainage volume per unit area and the drainage-to-irrigation ratio were inversely proportional to drain spacing, and positively proportional to drain burial depth and tillage depth; ② after irrigation–leaching, the mean soil moisture content in the plough layer (0~60 cm) increased by 35.88% in the treatment plots, which was 10.33% lower than that in the open-ditch drainage control (CK); soil salinity decreased by 33.34% in the treatments, representing a 22.80% greater reduction than CK. Soil water and salinity in the profile decreased with decreasing drain spacing and increasing drain burial depth and tillage depth; ③ both drainage layout parameters and tillage depth had highly significant effects on the desalinization rate (p 0.01). The desalinization rate increased with smaller pipe spacing and greater burial and tillage depth, and a significant interaction existed between drainage parameters and tillage depth (p 0.01); ④ based on the entropy weight–TOPSIS comprehensive evaluation, the 2024WI-T4 treatment performed best across the three experiments. It is recommended that the study area adopt a pipe spacing of 20 m, a burial depth of 1.5 m, and a tillage depth of 0.7 m to efficiently enhance both drainage performance and soil desalinization effectiveness.

Hebei Province is one of the first national pilot regions for fallow programs and also a key national grain-producing area. Therefore, the fallow policy places greater emphasis on balancing food security with sustainable water use. The first pilot cycle has now concluded. Under the overarching goal of food security, has the fallow policy achieved a reduction in irrigation water use. In light of this, this paper treats the fallow pilot program in Hebei Province as a quasi-natural experiment based on an external policy shock, studying 85 counties and cities from 2011 to 2019 to empirically evaluate the effects of the fallow pilot policy and analyze its impact mechanisms. The results show that the fallow policy reduced irrigation water use in pilot counties by 15.3%, while grain output increased by 0.9%, achieving the dual goals of "water saving without reducing production." The mechanism analysis indicates that the water-saving effect primarily stems from adjustments in planting structure and technological progress. The planting structure contributed to a 7.43% reduction in total water use and 52.74% reduction in irrigation intensity, while technological progress accounted for 28.98% of the total water use reduction and 2.1% of the intensity reduction. Heterogeneity analysis reveals that labor input exerted a negative moderating effect on water saving. Regional heterogeneity analysis shows significant water-saving effects in Hengshui (coefficient -0.238 3), Langfang (coefficient -0.204 1), and Xingtai (coefficient -0.252 6), with Langfang performing particularly well in both total water savings and intensity reduction (intensity coefficient -4.235 3).

Water conservation is a key ecological service for maintaining watershed ecological security and sustainable water resource utilization. To reveal the evolution patterns and driving mechanisms of water conservation in a typical plain-lake type watershed, this study takes the Baiyangdian Basin as the study area. Based on InVEST model, this study quantitatively assesses the spatiotemporal distribution characteristics of water conservation function from 1990 to 2020, and employs Geo-Detector model to identify the primary driving factors and interaction effects. The results show that: ① The average water yield of Baiyangdian Basin decreased from 109.31 mm to 69.12 mm from 1990 to 2020, showing an overall fluctuating trend of first decreasing and then increasing, and spatially exhibiting a pattern of "high in the southeast and low in the northwest". ② The average water conservation depth of Baiyangdian Basin decreased from 4.94 mm to 2.17 mm, showing an overall trend of "first decreasing and then increasing", with the high-value area gradually expanding and the low-value area shrinking. ③ Land useis the dominant factor affecting the spatial differentiation of water conservation, followed by evapotranspiration and topographic elements, while precipitation and vegetation cover have a relatively weak effect. The interaction of multiple factors shows a significant "nonlinear enhancement" characteristic. These findings aim to provide scientific basis for ecological restoration and water resource management in plain lake-type watersheds.

To investigate the effects of different irrigation managements on the stability of paddy soil carbon pools under conditions of elevated CO₂ concentration and temperature (CT), this study simulated future climate scenarios using open-top chambers (OTCs). ¹³CO₂ pulse labeling was conducted at the rice vegetative and reproductive growth stages by measuring the content of POC and MAOC as well as the ¹³C incorporation into these pools, aimed at analyzing the allocation characteristics of photosynthetic carbon. The results showed that although no significant differences in MAOC content were observed among treatments, CT increased POC content, providing a fundamental carbon source for the continuous formation of MAOC. Regarding the flow of ¹³C-labeled photosynthetic carbon, its proportion in MAOC increased over time, ranging from 32.1% to 48.4% in the short term and reaching 36.4% to 60.2% at the yellow maturity stage. At the yellow maturity stage, CT treatment significantly increased the retention of ¹³C-POC and ¹³C-MAOC. Compared with FI, the FI-CT treatment increased ¹³C-POC and ¹³C-MAOC by 42.6% to 111.1% and 94.0% to 103.7%, respectively; compared with CI, the CI-CT treatment increased them by 36.5% to 69.2% and 71.3% to 76.6%, respectively. More importantly, water-saving irrigation promoted greater allocation of photosynthetic carbon to the stable MAOC pool, and the retention of photosynthetically assimilated carbon from the vegetative stage was higher than that from the reproductive stage. These findings suggest that under elevated CO₂ concentration and temperature, water-saving irrigation may enhance the carbon sequestration potential of paddy ecosystems by promoting the transformation of photosynthetic carbon into MAOC.

Greenhouse gas emissions from agricultural fields are a significant factor contributing to the greenhouse effect and global warming. To explore the impact of nitrogen fertilizer application rates on greenhouse gas emissions from maize fields in the cold region of Northeast China and to validate the applicability of the WHCNS model in this area, this study established three fertilization treatments in a maize field at Heilongjiang Green Grassland Ranch: conventional fertilization, increased nitrogen by 20%, and decreased nitrogen by 20%. The static chamber-gas chromatography method was employed to monitor the CO? and N?O emission fluxes throughout the entire maize growth period. Based on the measured data, the WHCNS model was calibrated and validated, and was subsequently used to simulate the patterns of greenhouse gas emissions under different fertilization treatments. The results indicate that: ① Compared to the conventional treatment, the increased nitrogen by 20% treatment raised the cumulative emissions of CO? and N?O by 33.89% and 40.75%, respectively; whereas the decreased nitrogen by 20% treatment reduced the cumulative emissions of CO? and N?O by 21.20% and 27.22%, respectively. ② The simulation results of the WHCNS model demonstrate its effectiveness in simulating greenhouse gas emissions from the maize field. The coefficient of determination (R2) and root mean square error (RMSE) for CO? simulations ranged from 0.87 to 0.95 and 2.91 to 5.32 kg/(hm²·d), respectively. For N?O simulations, the R2 and RMSE ranged from 0.72 to 0.83 and 1.14 to 1.59 g/(hm²·d), respectively. The simulation accuracy and stability for CO? were superior to those for N?O. In conclusion, a 20% reduction of nitrogen fertilizer application can effectively suppress greenhouse gas emissions from maize fields. The WHCNS model can be applied to simulate greenhouse gas emissions from maize fields in Heilongjiang Province, providing a reliable tool for assessing the environmental effects of regional agricultural management practices.

To explore the effects of different mulching materials on evaporation inhibition and water quality parameters of plain reservoirs in arid regions, a field experiment was conducted in this study. Three types of mulching materials were selected, namely EPS rectangular floating panels (FP), black PE floating balls (FB), and black floating covers (TFC), with two coverage rates (100% and 75%) set, and non-mulching treatment (CK) served as the control. The effects of various mulching materials on evaporation characteristics, near-water surface temperature, and water quality parameters of evaporation tanks were analyzed. The results showed that the water surface coverage rate was significantly linearly negatively correlated with evaporation and water quality parameters (R ²0.9, R ²0.8), while it was non-linearly positively correlated with evaporation inhibition rate (R ²＞0.8), indicating that the coverage rate was the core factor regulating evaporation inhibition effect and water quality parameters. At the coverage rates of 100% and 75%, the average evaporation inhibition rates of the three mulching materials were 80.75% and 59.75% for FP, 69.25% and 46.5% for TFC, and 62% and 40.5% for FB, respectively. Mulching materials could alter the temperature distribution near the water surface by absorbing solar radiation. Increasing the coverage rate reduced the temperature difference between 5 cm above the water surface and 0 cm at the water surface (T ₀ decreased by 0.20~0.44 ℃), while it increased the temperature difference between 0 cm at the water surface and 5 cm below the water surface (T ₁ increased by 0.20~0.31 ℃), thereby weakening the evaporation driving force. Analysis of water quality indices of evaporation tanks revealed that all mulching materials significantly slowed down the rising rates of water electrical conductivity, pH value, and total bacterial count, and delayed water quality deterioration. During the mulching period, the dissolved oxygen (DO) content and its saturation in water were maintained above 15 mg/L and 100%, respectively, which met the requirements of aquatic organism survival and farmland irrigation water quality. This study can provide a scientific reference for evaporation control and efficient utilization of water resources in plain reservoirs in arid regions.

To quantify the effects of local wind field gradients on water surface evaporation processes and the water-saving efficiency of floating-ball covers, and to compare the fitting performance of the FAO-56 Penman–Monteith (ET?) and Penman (1948) models under different wind conditions, this study established an in-situ experimental site in the Turpan region of Xinjiang. The experiment covered three wind speed gradients: "open," "calm," and "strong wind" (Groups A, B and C). By conducting synchronous comparative observations of evaporation, water temperature, and micrometeorological elements for both blank (open) and floating-ball-covered water surfaces, combined with a systematic analysis based on energy balance principles, the intrinsic regulatory mechanisms of wind fields on the water surface evaporation process were explored. The results showed that: ① Observation data indicated that the peak daily evaporation of the blank water surface in the strong wind zone exceeded 16 mm/d, which was significantly higher than that in the calm wind zone. Moreover, the measured values significantly exceeded theoretical values calculated from net radiation, confirming that strong winds can markedly enhance evaporation intensity by accelerating water vapor transport. ② The evaporation suppression efficiency of floating-ball covers exhibited a significant non-linear decrease with increasing wind speed (dropping from 65% to 57%). Analysis revealed that dynamic disturbances induced by strong winds disrupted the saturated water vapor boundary layer beneath the cover, intensified heat exchange at the water-air interface, and enhanced the vertical mixing of the water body, thereby leading to a significant weakening of water-saving efficiency. ③ Model comparison results indicated that after accounting for water heat flux (G), the Penman (1948) model provided a better fit than the FAO-56 PM (ET?) model for the open and calm wind zones. However, both models still significantly underestimated measured evaporation in the strong wind zone. This reflects that the evaporation process under strong wind (wind gap) conditions is highly sensitive to turbulent exchange and external heat supply (advection), suggesting that the applicability of these classical models in strong wind environments requires further verification and modification. This study clarifies the key controlling factors contributing to evaporation prediction deviations in local wind environments and the spatial heterogeneity of the water-saving effect of physical covers, providing theoretical references for the accurate simulation of evaporation processes on heterogeneous underlying surfaces and the application of evaporation suppression technologies.

To investigate the response mechanisms of rice to drought stress at different growth stages in the Jianghuai Hilly Region, identify the critical sensitive stages, and provide a scientific basis for regional water-saving and drought-resistant production. Single and combined drought treatments were applied at the tillering, jointing-booting, and grain-filling stages. Yield, water productivity, dry matter accumulation, and water consumption characteristics were measured for all treatments in 2023-2024. A partial least squares structural equation model (PLS-SEM) was used to analyze the intrinsic pathways through which drought affects yield and water use. Mantel tests were employed to validate the overall correlation between drought treatment patterns and multidimensional crop response patterns. Results show that drought stress significantly suppressed rice water consumption, exhibiting a "feed-forward effect" where early-stage drought persistently inhibited water demand in later stages. Yield responses showed significant stage specificity: tillering-stage drought primarily affected panicle number but triggered a compensatory increase in spikelets per panicle; jointing-booting stage drought was the most critical phase, severely reducing spikelets per panicle and seed-setting rate; grain-filling stage drought directly caused a sharp decline in seed-setting rate and 1 000-grain weight. PLS-SEM path analysis (GoF=0.630) indicated that shoot dry matter was the core hub through which drought affected yield, while water productivity was jointly determined by the positive driving force of yield and the negative constraint of water consumption. Mantel tests further confirmed a highly significant correlation between the drought treatment gradient and the integrated response pattern of crop yield, dry matter, and water use traits (Mantel's r=0.509, p0.001), supporting drought as a global dominant factor. This study reveals the stage heterogeneity in rice's response to drought and identifies the jointing and filling stages as core regulatory windows. Conclusions derived from multiple analytical methods corroborate each other, providing a reliable theoretical basis for drought-resistant cultivation and efficient water management for rice in the Jianghuai Hilly Region.