To explore the regulatory effect of coal gangue on soil water under different salinity conditions, this study conducted a one-dimensional vertical infiltration experiment. Using Sandy soil in southern Hubei as the substrate, three salinity levels were established by adding NaCl (A1: 0; A2: 2 g/kg; A3: 4 g/kg), and four coal gangue mass addition ratios (0%, 15%, 30%, and 50%) were tested. This study systematically analyzed the regulatory effect of coal gangue as a soil amendment on the soil water infiltration process. The results showed that: ① The addition of coal gangue significantly affected the wetting front migration rate and cumulative infiltration. In the A1 group (non-saline), the 15%, 30%, and 50% coal gangue treatments inhibited wetting front migration (P0.05), whereas in the A3 group (high-saline), all coal gangue treatments accelerated migration by up to 5.96%. ② The relationship between cumulative infiltration and time was consistent with the Kostiakov model (R20.9), and the wetting front migration distance followed a power function of infiltration time (Z=E t^F ). ③ Coal gangue reduced the water content of each saline-alkali soil profile, but the effect on electrical conductivity (EC) varied according to the degree of salinization: the EC of the A1 and A2 groups increased, while that of the A3 group decreased. This study indicates that the addition of coal gangue is beneficial for the reclamation of saline-alkali soil.

To investigate the effect of water-saving irrigation on soil active organic carbon in paddy ecosystems, a field experiment was conducted with two irrigation methods: flooded irrigation and alternate wetting and drying (AWD) irrigation. The results showed that: Compared with flooded irrigation, the AWD treatment improved the soil aeration of the paddy field, promoted the growth of rice roots and soil microorganisms, accumulated more carbon from rice rhizodeposition, and promoted the fixation of new carbon by microorganisms. AWD irrigation increased soil organic carbon and dissolved organic carbon (DOC), while microbial biomass carbon increased slightly. The water use efficiency increased by 42.70%. The total CH? and CO? emissions during the whole rice growth stage were reduced by 79.47% and 6.33%, respectively. The global warming potential decreased by 7.63%, and the greenhouse gas intensity was reduced by 10.06%. Therefore, AWD irrigation is more conducive to carbon sequestration and emission reduction in paddy fields.

To investigate the effect of organic fertilizer application on soil fertility and wheat yield under brackish water irrigation, a field experiment was conducted with four treatments: freshwater irrigation, single application of compound fertilizer (T1); freshwater irrigation, combined application of compound fertilizer and organic fertilizer (T2); brackish water irrigation, single application of compound fertilizer (T3); brackish water irrigation, combined application of compound fertilizer and organic fertilizer (T4).The mineralization of brackish water was 3 g/L, and the irrigation rate was set at 80 mm. The application rates were 1.125 t/hm² for compound fertilizer and 22.5 t/hm² for organic fertilizer. The results show that: organic fertilizer application under brackish water irrigation increases the soil water content of 0~40 cm soil layer in the early stage of wheat fertility by 14.03%~87.31%, and reduces the total salt content of 0~60 cm soil layer in the late stage of wheat fertility by 6.56%~10.71%, which can effectively alleviate the problem of soil water content decline and salt accumulation caused by brackish water irrigation; The improvement effects of organic fertilizer on NO₃ ^--N, available phosphorus and available potassium in brackish water irrigated soils mainly appeared in the early reproductive stage, while the enhancement effects on NH₄ ⁺-N, alkali-hydrolyzable nitrogen and organic matter were more significant in the latter stage of the reproductive stage, resulting in the increase of the overall fertility of 4.43%~20.34%; The application of organic fertilizers increased the length of wheat spikes by 4.42%, the number of effective spikes by 8.84%, the number of grains per spike by 3.47%, and the final yield by 7.26% under brackish water irrigation, compensating for the reduction in the number of effective spikes and the yield reduction caused by brackish water irrigation. This study indicates that under brackish water irrigation, the application of organic fertilizer can help maintain soil fertility and ensure stable crop yields.

The autumn irrigation water volume in the Hetao Irrigation District accounts for approximately one-third of the annual water diversion volume. Autumn irrigation can improve soil moisture and leach salts to suppress soil alkalinity. Hetao Irrigation District is a key area for in-depth water conservation and control in agriculture，and appropriate autumn irrigation water volume is of great significance for improving water resource utilization efficiency in the irrigation district. This study conducts autumn irrigation experiments on lightly saline-alkali land and explores suitable autumn irrigation water volumes by analyzing the dynamics of soil water, heat, and salt during the freeze-thaw period. This experiment was carried out in 2021-2022. Six gradient levels of autumn irrigation amounts were set in the experiment, named W1(1 425 m3/hm²), W2(1 500 m3/hm²), W3(1 575 m3/hm²), W4(1 650 m3/hm²), W5(1 725 m3/hm²) and W6(1 800 m3/hm²). The results showed that after autumn irrigation, each experimental site formed a water-bearing zone with a water content greater than 25% in the soil layer at a depth of 40 cm. During the stable freezing period, a frozen-dried layer with a water content of less than 10% appeared in each experimental site from the ground downward. Except for the W1, other experimental sites formed a salt accumulation layer of about 3.5 g/kg at a depth of 35~80 cm in the soil layer; W5(1 725 m3/hm2) is the optimal treatment, which is more suitable for corn sowing; W4(1 650 m3/hm2) is the sub-optimal treatment, which is more suitable for wheat sowing. This study found that favorable soil conditions for spring sowing could be predicted. Specifically, conditions were more favorable when the following criteria were met after autumn irrigation: soil salinity in the 0–10 cm layer was leached to below 2 g/kg, the salt accumulation layer was leached below a 30 cm depth, and the maximum thickness of the frozen-dried layer remained at 40~45 cm during the stable freezing period. These results can provide a scientific basis for autumn irrigation management in the Hetao Irrigation District.

Farmland ecosystems play a crucial role in achieving carbon neutrality, where accurate carbon source/sink accounting forms the fundamental basis for optimizing agricultural management practices. Current carbon accounting systems predominantly focus either on single greenhouse gas emissions or dryland farming systems, failing to systematically quantify the coupled effects of water management, soil carbon pools and crop carbon uptake in irrigated paddy fields, leading to significant biases in assessing emission reduction and carbon sequestration potential. Targeting the paddy fields in Jintan District, Changzhou, this study developed a comprehensive life-cycle carbon accounting methodology for irrigated rice systems, systematically evaluating the impacts of different irrigation regimes (continuous flooding, intermittent irrigation and controlled irrigation) on greenhouse gas emissions and carbon sequestration potential. By integrating static chamber-gas chromatography monitoring, soil carbon pool dynamics analysis and crop carbon stock estimation, we established a hybrid accounting methodology incorporating water management adjustment coefficients ( K_{\mathrm{C}{\mathrm{H}}_{\mathrm{4}}}、 K_{{\mathrm{N}}_{\mathrm{2}}\mathrm{O}}) and soil carbon correction factors (CSF). The results demonstrated that controlled irrigation significantly reduced CH₄ emissions (p0.01) and overall global warming potential, while increasing soil organic carbon storage (CSF=1.001), increasing the root-to-shoot ratio to 0.25 and enhanced belowground carbon input. Compared with traditional continuous flooding, controlled irrigation reduced carbon emissions by 1 546.48 kg CO₂e per hectare. This methodology innovatively combines field measurements with emission factor approaches, filling the methodological gap for carbon accounting in China's subtropical rice-growing regions and providing a replicable technical framework for CCER agricultural carbon sequestration projects.

Irrigation districts face the challenges such as the uneven spatiotemporal distribution of water resources, and supply-demand conflicts. These issues are particularly acute during dry seasons, when water security is critical, and wet seasons, when water is often wasted. Scientific scheduling is urgently needed to improve water use efficiency and coordinate agricultural, domestic, and industrial water demands. This study selected the Ganfu Plain Irrigation District as a case study, developing a joint water distribution scheduling model by coupling a one-dimensional hydrodynamic model with the Non-dominated Sorting Genetic Algorithm (NSGA-II). By simulating the dynamic processes of water levels and flows in the canal system, and considering diverse water demands, intelligent optimal scheduling schemes were designed for both dry and wet seasons. The model used the dual objectives of maximizing the overall water supply satisfaction rate and the priority-weighted water supply. The optimization scheme for the wet season reduced wasted water by 14%. For the dry season, priority-weighted regulation reduced ineffective water supply by 3.26 million m3. The joint scheduling method integrating hydrodynamic model with intelligent algorithm can accurately quantify the water supply and demand in the irrigation district, providing a technical approach for dynamic regulation under complex water use scenarios. Differentiated seasonal scheduling strategies (prioritizing critical needs during dry seasons and reducing spillage during wet seasons) significantly enhance water resource utilization efficiency, offering valuable insights for similar irrigation districts facing seasonal hydrological fluctuations. The dual-objective optimization framework balances water supply equity and efficiency, supporting effective quantification of water use priorities and providing a new paradigm for refined water resource management in irrigation districts. This study demonstrates alignment between canal system flow processes and water demand through intelligent algorithms, providing actionable technical solutions for water conservation, efficiency enhancement, and sustainable water resources utilization in irrigation districts.

Soil moisture is a dominant factor affecting vegetation recovery in arid and semi-arid areas. In order to reveal the characteristics of soil moisture deficit and compensation degree of twisted-strip forest land in alpine sandy areas, this study took the Republican Basin as the study area and adult twisted-strip forests as the research objects, and carried out a quantitative study based on the field positioning monitoring of soil moisture (ZL6 Soil Moisture Detection System) combined with indoor measurements and mathematical calculations. The results showed that: ① The soil water storage capacity of the forest land in the study area shows seasonal variations, being significantly higher at the beginning of the growing season than at the end. For instance, the overall profile (0~160 cm) water storage capacity was the highest in June, reaching 131.04 mm, and dropped to 96.61 mm in August, with a difference of 34.43 mm. ② The soil water storage capacity increases first and then decreases with depth. Based on this variation, the soil layers are divided into shallow (0~40 cm), middle (40~120 cm), and deep (120~160 cm) layers, with average water storage capacities of 10.78、14.17 and 10.10 mm, respectively. ③ The soil water deficit varies significantly with the seasons. The overall deficit in the profile (0~160 cm) is the greatest in August, reaching 552.89%, and the smallest in June, at 362.88%. The soil water deficit decreases with increasing depth. The shallow layer has the most severe deficit, with an average deficit of 50.73%, followed by the deep layer with an average deficit of 47.42%. ④ Rainfall compensation for the soil layers was characterized by a positive value for the shallow soil layer (0~10 cm) (with a peak of 7.53%), while the rest of the soil layers are generally negative (with a minimum value of -8.92%). Throughout the entire growing season, the soil moisture deficit in mature twisted stem forests is severe. Therefore, to promote their sustainable development, measures such as reducing planting density or coppicing for rejuvenation are recommended.

Investigating the effects of different coupled water and fertilizer management practices on weed community diversity in rice fields is crucial for promoting the ecological sustainability of paddy ecosystems. In this study, two irrigation modes (flooded irrigation W0, alternate wetting and drying irrigation W1) and three fertilization methods (no fertilization F1, inorganic fertilizer F2, organic fungal fertilizer +inorganic fertilizer F3) were set up in a typical double-season rice field in the Poyang Lake Plain to analyze the indexes of weed species, density, and diversity of paddy rice fields under different water-fertilizer coupling measures. The results showed that for late rice, the mean weed density under the W1 treatment was 28.26% lower than that under W0, with aquatic and hygrophilous weed densities being 28.61% and 27.16% lower, respectively. However, the effect of irrigation on weed density was less pronounced in the early rice season. This may be attributed to frequent rainfall during the early rice period, which masked the impact of irrigation methods on field water conditions. Among the fertilizer treatments, F3 resulted in the lowest weed density. Compared to F1, the density in F3 was lower by 41.00% in the early season and 28.30% in the late season. Compared to F2, it was lower by 11.81% and 15.11%, respectively. In addition, the W1 and F3 treatments both reduced the importance values of the dominant species Monochoria vaginalis, Cyperus difformis, and Rotala rotundifolia. Under the W1F3 treatment, indices of species richness (Margalef), diversity (Shannon-Wiener), and dominance (Simpson) were generally higher than in other treatments. In contrast, the Pielou evenness index showed little variation among treatments. This indicates that the W1F3 treatment can enhance weed diversity, which is beneficial for maintaining biodiversity in paddy fields. This study can provide a scientific basis for weed regulation and diversity conservation in paddy ecosystems.

To investigate the impact of drought-to-flood alternation, as well as single drought and single flood stresses, on the yield of winter wheat, this study utilized "Huaimai 55" as the experimental material. A pot experiment was conducted to simulate drought-to-flood alternation during the jointing and heading stages of winter wheat. The experiment included nine drought-to-flood alternation treatments with initial soil moisture at 65% field capacity, varying drought durations of 4、8 and 12 days, and flood depths of 10 cm for 4、8 and 12 days. Additionally, three single drought treatments, three single flood treatments, and one control group were established, totaling 16 treatments. The study analyzed the yield reduction patterns under different drought and flood scenarios and explored the interactive effects of drought and flood on yield components. Results indicated that the yield of winter wheat under drought-to-flood alternation treatments was significantly lower than the control group. Specifically, the most severe yield reduction (98.10%) occurred when drought lasted for 12 days followed by 12 days of flooding, highlighting the detrimental effects of prolonged drought and flood conditions. Single drought for 12 days and drought for 12 days followed by flooding had the strongest impact on reducing the total grain number, with reductions exceeding 90%. Compared to single drought treatments, the most significant negative interaction effect was observed in the 4-day drought followed by 12-day flood treatment, resulting in an 80.73% yield loss. Compared to single flood treatments, the most severe combined reduction effect was observed in the severe drought followed by flood treatment group, with reductions exceeding 88%. The results showed that if wheat experiences an early-stage drought, subsequent waterlogging should be avoided to minimize yield loss.

In response to the problem of shallow average water depth and high evaporation commonly found in plain reservoirs in arid zones, water saving by preventing evaporation at the source has become an important strategy for water resource management. In order to investigate the effect of physical cover on water surface evaporation inhibition, three kinds of circular structural covers with different geometrical shapes were selected in this study to analyze the inhibition effect on water surface evaporation through tests under hydrostatic conditions. At a 91% coverage rate, white EPS foam discs, hemispheres and whole balls with a diameter of 150 mm were used to cover the water surface of a cylindrical evaporator with a surface area of 1.13 m², and outdoor evaporation prevention tests were carried out under static water conditions in Turpan, Xinjiang, to analyze the effects of different geometrical shapes of the physical structure on the evaporation inhibition rate. The study shows that under the same conditions, the three geometrical shapes of coverings have different effects on the evaporation inhibition rate of the water surface, in descending order: the whole sphere, hemisphere, and disc, with the evaporation inhibition rate of 87.98%, 85.39%, and 83.37%, respectively; the whole sphere covering the water surface can also reduce the temperature of the water body, which is attributed to the fact that the structure of the sphere can block the solar radiation more efficiently and limit the direct contact between the water surface and the atmosphere, thus reducing the potential of the water surface and the atmosphere. This is attributed to the spherical structure’s ability to more effectively block solar radiation and limit the direct contact between the water surface and the atmosphere, thereby reducing latent heat flux and heat exchange. Considering factors such as water saving efficiency, cost-effectiveness, durability, and adaptability, the sphere coverage method shows greater promise for practical engineering applications.

Nighttime evapotranspiration is a vital component of evapotranspiration, playing an important role in maintaining the physiological activity and nighttime growth of winter wheat. This study investigates the relationship between nighttime and daytime evapotranspiration in winter wheat across three different regions and constructs an XGBoost model, which was interpreted using SHAP. The results indicate that the nighttime-to-daytime evapotranspiration ratio changes with the growth stage, showing significant regional differences. The nighttime-to-daytime ratios at the CH-Oe2 and FR-Gri sites exhibit a declining trend as the growth period progresses, while the US-ARM site shows relatively minor variations. Evapotranspiration (ET), vapor pressure deficit (VPD), and air temperature (TA) exhibit a significant negative correlation with the nighttime-to-daytime ratio. The extremes of daytime and nighttime VPD generally demonstrate a parabolic relationship with ET, with varying inflection points across regions. ET peaked at a VPD of around 15 kPa for the CH-Oe2 and FR-Gri sites, while the US-ARM site has a peak inflection point of approximately 23 kPa. Additionally, the nighttime ET peak inflection points are lower than those during the day, occurring around 7~8 kPa at the CH-Oe2 and FR-Gri sites. The R2 values for both daytime and nighttime evapotranspiration models are highly significant. VPD, soil water content (SWC), wind speed (WS), and longwave radiation are the main factors affecting nighttime evapotranspiration in winter wheat, with considerable regional variability, influencing the combined effects of local water availability and meteorological conditions.

This study aims to investigate the differences in water use efficiency (WUE) among distinct vegetation types on the Loess Plateau and explore their underlying influencing mechanisms. Focusing on four representative vegetation types—Pinus tabuliformis, Populus simonii, Robinia pseudoacacia, and Hippophae rhamnoides—this research systematically measured their photosynthetic characteristics, leaf functional traits, and soil physicochemical properties. Statistical analyses, including one-way analysis of variance (ANOVA), Pearson correlation analysis, and stepwise regression modeling, were employed to quantify relationships and identify key drivers. The results indicate that: ① Significant differences in WUE exist among the four vegetation types (P0.05). Hippophae rhamnoides exhibits the highest intrinsic WUE, followed by Pinus tabuliformis, with Populus simonii performing the worst. ② Photosynthetic rates of Hippophae rhamnoides and Populus simonii are significantly higher than those of Pinus tabuliformis and Robinia pseudoacacia. Hippophae rhamnoides has the highest intercellular CO? concentration, indicating strong water utilization and gas exchange capabilities. Populus simonii has the largest leaf area, while Robinia pseudoacacia has a higher specific leaf area. Hippophae rhamnoides has smaller leaf areas but higher leaf quality, demonstrating drought adaptation features. The soil water content and porosity are highest in Hippophae rhamnoides forests, providing optimal soil water retention, whereas Robinia pseudoacacia has the highest soil bulk density and lowest porosity. ③ The WUE of Pinus tabuliformis is mainly influenced by intercellular CO? concentration and soil porosity. For Populus simonii, key factors include photosynthetic rate and specific leaf area. Robinia pseudoacacia relies on leaf area, while the WUE of Hippophae rhamnoides is closely related to intercellular CO? concentration and leaf area. ④ Different vegetation types exhibit varying adaptation strategies for WUE. Hippophae rhamnoides demonstrates strong drought adaptability, Pinus tabuliformis enhances WUE by inhibiting photosynthesis and transpiration, while Populus simonii and Robinia pseudoacacia improve WUE through optimized leaf morphology and photosynthetic capacity. During vegetation restoration on the Loess Plateau, Hippophae rhamnoides is prioritized for extreme arid zones, while Robinia pseudoacacia and Populus simonii are suitable for moderately low arid zones. For Pinus tabuliformis planting, attention must be paid to soil structure improvement.

To explore the effect of gibberellin soaking on the water use efficiency of rice seedlings, the soaking experiment was carried out with "Jingzhan No.1" rice seeds as the experimental material, and 12 treatments with gibberellin soaking time of 12, 18 and 24 h and soaking concentrations of 0、50、100、150 and 200 mg/L, and 3 control groups were set up to analyze the effects of gibberellin soaking on the fresh and dry weights of roots and shoots, photosynthetic rate, transpiration rate, relative water content and water use efficiency of rice seedlings. The results showed that the relative water content, photosynthetic rate and water use efficiency of rice seedlings in T7 (150 mg/L gibberellin soaking for 18 h) were the largest, and the indexes increased by 11.30%, 179.46% and 140.43%, respectively, compared with the control group. The comprehensive value of agronomic traits, calculated using the entropy weight method, was highest in the T7 treatment group (0.855 5). In conclusion, soaking "Jingzhan No.1" rice seeds in a 150 mg/L gibberellin solution for 18 h effectively promoted seedling growth and dry matter accumulation, and significantly improved the water use efficiency. This study provides a theoretical basis for enhancing rice water use efficiency.

To identify an optimal ‘dry sowing and wet emergence’ (a practice of sowing into dry soil followed by drip irrigation for germination) water management strategy for cotton in the arid regions of Northwest China, this study evaluated its effects on photosynthetic characteristics, canopy-level physiological indices, yield, and fiber quality. A field experiment was conducted in Aksu, Xinjiang, from 2021 to 2022. The experiment involved various treatment combinations of different emergence water amounts and drip irrigation frequencies. The results indicated that high-frequency irrigation significantly enhanced cotton's physiological activity. Compared to low-frequency treatments, it increased the two-year average intercellular CO? concentration(Ci), stomatal conductance(Gs), net photosynthetic rate(Pn), and transpiration rate(Tr) by 9.99%、6.73%、12.57% and 7.55%, respectively. Similarly, higher emergence water amounts promoted canopy development; compared to low water amount treatments, they increased the two-year averages of Leaf Area Duration (LAD) and Net Assimilation Rate(NAR) by 83.37% and 69.35%, respectively. When compared against the traditional winter irrigation control (CK), an optimized combination of high frequency and high-water amount showed no significant differences in yield (lint and seed cotton yields decreased by only 1.95% and 3.01%, respectively) or fiber quality (FQI decreased by 11.01%). Crucially, however, the irrigation water applied during the growing season was substantially reduced by 38.46%. Furthermore, correlation analysis revealed that NAR was strongly associated with yield (r=0.65), while Dry Matter Accumulation (DMA) was strongly associated with fiber quality indices (r=0.66). In conclusion, an optimized ‘dry sowing and wet emergence’ strategy using high-frequency irrigation with a large emergence water amount can achieve substantial water savings without significantly compromising cotton yield or quality. This study provides a robust theoretical basis for developing water-saving and high-efficiency cotton production systems in arid regions.

The river, lake and reservoir systems in Jiangsu Province are facing ecological protection pressure under urbanisation and industrial upgrading, and the existing water quality assessment focuses on physical and chemical indicators but neglects the public perception dimension. Jiangsu Province is densely populated with rivers and lakes and is rich in water resources, but rapid urbanisation and industrial upgrading have intensified the pressure on environmental protection of water bodies. In order to analyse people's satisfaction with the water bodies of major rivers, lakes and reservoirs in Jiangsu Province, based on the Specification for the Evaluation of the Condition of Watersheds (DB32/T 4463-2023), this study distributed 13 075 questionnaires through a combination of on-site and online surveys to 114 water bodies in Jiangsu Province, and conducted a public satisfaction evaluation of the water bodies surveyed in terms of water quality and aquatic ecology, development and management of watersheds, and the landscape and the surrounding environment. Public satisfaction was investigated and evaluated. This study combined the hierarchical analysis method (AHP) and the fuzzy comprehensive evaluation method (FCE) to construct a multidimensional evaluation system containing three system layers and 13 perception indicators, and rated the comprehensive satisfaction of all water bodies. The results show that the public is satisfied with the water quality condition as a whole. The public's overall satisfaction with rivers in Jiangsu Province in this survey reached 81.01 points, lakes reached 80.15 points, and reservoirs reached 84.37 points. Among them, 69.7% of the rivers, 56.25% of the lakes and 91.84% of the reservoirs scored 80 points or more in overall satisfaction. In terms of geographical differences, the province's water body satisfaction is generally ‘high in southern Jiangsu, northern Jiangsu, followed by central Jiangsu lower’ distribution pattern. Among them, agricultural surface pollution, illegal fishing, over-farming and other problems in water bodies such as Guangyang Lake, Laizidang, and Taidong River are the main reasons for the low satisfaction of the public in the two evaluation system layers of water quality and sensory conditions (B1) and water ecology and water landscape conditions (B2). This paper suggests that the relevant authorities should strengthen the daily supervision of waters, enhance the management system of privately contracted and transboundary water bodies, and increase social participation through public education, so as to provide a scientific basis for the practice of the ‘people-centred’ ecological governance concept and the promotion of harmonious and sustainable development of water and human beings.

Investigating the spatial correlation network and driving factors of agricultural water conservancy investment efficiency in the Yangtze River Economic Belt holds significant practical implications for promoting high-quality development. This study employs a game cross-efficiency model to measure agricultural water conservancy investment efficiency across the Yangtze River Economic Belt from 2011 to 2022. A modified gravity model and social network analysis are utilized to identify spatial correlations, while Quadratic Assignment Procedure (QAP) regression is applied to pinpoint driving factors. The results show that: ① Temporally, agricultural water conservancy investment efficiency exhibits a fluctuating upward trend followed by a fluctuating decline, with spatial gradients showing "upper middle lower reaches." ② A pronounced spatial spillover effect manifests as a core-periphery network structure. The network features loose connectivity, high efficiency with limited pathway diversity, and strong hierarchical segmentation, indicating incomplete spatial accessibility among provincial nodes. ③ In the spatial network, downstream provinces function as core hubs generating resource siphon effects (net beneficiaries), midstream provinces act as transitional "channels," and upstream provinces serve as net spillover sectors. The network demonstrates asymmetric interactions without reciprocal synergies. ④ Disparities in policy support intensity, fiscal capacity, and farmer income levels exhibit significant positive correlations with network development, whereas disparities in economic development levels and rural education attainment show negative correlations. Based on these findings, policy recommendations include establishing cross-regional coordination mechanisms for resource allocation, optimizing fiscal systems to empower underdeveloped regions, and implementing dual-enhancement initiatives targeting farmer competency and income.

The performance of agricultural irrigation metering valves directly affects the measurement accuracy and operational efficiency of farmland pipe irrigation systems. Typically, these valves use a rectifier with a multi-circular-hole structure for internal flow straightening. However, these porous rectifiers can lead to increased metering errors and higher energy consumption. This study developed a computational fluid dynamics (CFD) model using ANSYS Workbench software to analyze parameters such as flow velocity distribution, pressure gradient, and turbulence intensity inside the rectifier. Based on the analysis, an improved rectifier structure was proposed, and its hydraulic performance was compared with the original design to verify its effectiveness. The results showed that the velocity difference across the original porous rectifier was 1.93 m/s, the pressure drop was 2990 Pa, the peak turbulence intensity reached 0.252 m2/s2, and the pressure loss was highly dependent on flow velocity. In contrast, the improved rectifier, which incorporated a quadratic surface guide structure and a modified grid-like flow channel, reduced the velocity difference to 0.793 m/s, the pressure drop to 742 Pa, and the maximum turbulence intensity to 0.145 m2/s2. Moreover, the influence of flow velocity on pressure loss was significantly reduced. In summary, the improved rectifier effectively suppressed turbulence, made the velocity distribution more uniform across different regions, and reduced the overall pressure drop. The design is therefore suitable for optimizing the internal structure of agricultural irrigation metering valves.