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Promoting irrigation efficiency is a central pillar of global water sustainability strategies but empirical evidence shows a counterintuitive outcome named the irrigation efficiency paradox or rebound effect. This occurs when on-farm water savings do not translate into basin-scale conservation and may even intensify water scarcity. This paper critically re-examines the rebound effect, moving beyond conventional hydrological and economic explanations toward an integrated socio-hydrological perspective. We argue that the paradox is not merely a technical accounting issue or a form of the Jevons Paradox, but a systemic problem arising from interactions among behavior, institutions, and political economy. The review traces the concept’s evolution and synthesizes global evidence on its main drivers and controversies. It critically evaluates dominant research paradigms, emphasizing the need for greater methodological pluralism. Significant gaps remain, particularly regarding behavioral economics, political economy, and social and environmental externalities. We conclude that overcoming the efficiency paradox requires a policy shift from technological fixes to transformative governance. Full article

Under global climate change, analyzing carbon storage dynamics and their drivers is essential for understanding regional carbon sink capacity. Human activities and land-use change have substantially affected regional carbon storage. However, in China, most existing studies emphasize specific driving pathways, and integrated analyses of the combined effects of climate, natural, human, and landscape factors remain limited. This study aims at clarifying the integrated mechanisms by which multiple driving factors influence regional carbon storage. The InVEST model was used to analyze the carbon storage spatiotemporal changes. OPGD was then applied to evaluate the explanatory power of driving factors and their interactions, quantifying their contributions to carbon storage spatial patterns. Based on PLS-SEM, the direct and indirect effects of LULC, climate, natural, human, and landscape factors were quantified to elucidate the driving pathways of carbon storage. This study focuses on Shaanxi Province, which is a key ecological restoration region in the core area of the Loess Plateau. The main results are as follows: (1) From 2000 to 2020, carbon storage in Shaanxi Province showed a continuous increasing trend, rising from 2.97 × 10¹⁰ Mg C to 3.03 × 10¹⁰ Mg C. (2) LULC was identified as the most important direct and predominantly negative driving factor of carbon storage. (3) Natural factors had a strong positive influence on carbon storage, among which slope and NDVI exhibited the highest explanatory power; in contrast, climate factors showed weaker but still positive effects. (4) Human activities affected carbon storage through both direct and indirect pathways associated with LULC, with positive effects driven by landscape factors and negative effects driven by natural factors, while climate factors exhibited mixed but weak effects. Overall, carbon storage dynamics in Shaanxi Province reflect a hierarchical and path-dependent process shaped by the combined effects of natural constraints, human activities, and policy guidance through LULC pathways, providing important evidence for systematically understanding the driving structure and pathways of regional carbon storage. These findings highlight the importance of aligning land-use policies with regional biophysical constraints to enhance carbon sequestration efficiency. Full article

Clarifying the relationship between landscape patterns and runoff coefficient, along with identifying key influencing pathways, is crucial for formulating sustainable water resource management strategies. Since the launch of the Grain-for-Green (GfG) project in 1999, the landscape pattern of the Loess Plateau has been profoundly reshaped, altering regional rainfall-runoff processes. Assessment across 27 catchments selected in the central Loess Plateau demonstrated forest and grassland areas expanded by 738.8 km² and 480.4 km², respectively, paralleled by a 20.1% enhancement in vegetation coverage. Correspondingly, surface runoff decreased by 28.1–90.6% in the 2000s and 12.8–95.5% in the 2010s compared to the 1960s, with a similar decline in runoff coefficient. This study further developed a novel landscape unit mapping method, integrating vegetation coverage, land use, slope, and soil type to compute landscape metrics. Partial least squares regression (PLSR) and piecewise structural equation modeling (piecewiseSEM) were constructed to systematically analyze the linkage between landscape patterns and surface runoff. The constructed landscape metrics explained 64.6% of the variance in the runoff coefficient, with perimeter area fractal dimension (PAFRAC), mean perimeter-area ratio (PARA_MN), and aggregation index (AI) exerting significant influence. The findings provide a scientific basis for water resource management in regions with similar environmental characteristics. Full article

Plastic film mulching (PFM) is widely used in arid, semiarid, and seasonally arid regions, where it plays a key role in regulating agricultural productivity and CO₂ emissions. Our study aims to clarify the effects of PFM on crop yield, CO₂ emissions, and the associated tradeoffs, providing a theoretical basis for the sustainable use of PFM in agriculture. We conducted a meta-analysis to compare differences in crop yield, CO₂ emissions, and yield-scaled CO₂ emissions (YSC) between mulching and no mulching treatments while identifying factors influencing these outcomes. Our findings demonstrated that PFM enhanced crop yields of maize, wheat, and cotton by 33.2% (p < 0.001), 21.8% (p < 0.05), and 26.3% (p < 0.05), respectively. PFM stimulated CO₂ emissions in maize fields by 36.8% (p < 0.001), while decreasing them in wheat and cotton fields by 11.8% (p < 0.05) and 8.1% (p > 0.05), respectively. Consequently, PFM significantly lowered YSC for maize by 39.3% (p < 0.05) and reduced it for cotton by 27.4% (p > 0.05), but led to a 38.3% increase in YSC for wheat (p > 0.05). For maize and cotton, when crop yields exceeded 6 t/ha, the YSC under plastic film mulching was higher than that under non-mulching. In contrast, for wheat, within the conventional yield range (below 10 t/ha), the YSC under plastic film mulching was lower than that under non-mulching. For cotton, the lowest YSC under PFM was achieved under the combined conditions of water inputs > 500 mm, air temperature > 8 °C, soil pH > 8, and N inputs < 200 kg N ha⁻¹. For wheat, the lowest YSC under PFM was obtained under water inputs < 350 mm, air temperature < 8 °C, light-texture soils, and N inputs < 200 kg N ha⁻¹. For maize, the lowest YSC under PFM was achieved under water inputs < 350 mm, air temperature < 8 °C, heavy-texture soils, soil pH < 8, and N inputs < 200 kg N ha⁻¹. These insights offer guidance for the optimal use of PFM to enhance carbon efficiency and crop yield in agricultural systems. Full article

Soil organic carbon (SOC) and total nitrogen (TN) are key indicators of soil fertility; however, the dynamics of carbon (C) and nitrogen (N) fractions during winter wheat growth under different tillage systems remain poorly understood. This study examined the effects of three tillage practices: no tillage (NT), subsoiling tillage (SS), and deep tillage (DT) on four soil organic carbon fractions (SOC, soil organic carbon; EOC, easily oxidized organic carbon; DOC, dissolved organic carbon; POC, particulate organic carbon) and four nitrogen fractions (TN, total nitrogen; NO₃⁻-N, nitrate nitrogen; NH₄⁺-N, ammonium nitrogen; DON, dissolved organic nitrogen) across five winter wheat growth stages (sowing, overwintering, jointing, filling and harvest) in the 0–50 cm soil profile. The results showed that SOC, its labile fractions, and TN all decreased with increasing soil depth, with tillage effects mainly confined to the 0–20 cm layer. SS achieved the highest SOC and TN contents in the topsoil, while NT and SS significantly enhanced the surface enrichment of C and N. In contrast, DT promoted more uniform nutrient distribution into the 30–50 cm subsoil. DON continuously accumulated throughout the growing season with faster accumulation rates under SS and NT; DOC peaked at the jointing stage, while EOC and NH₄⁺-N followed a consistent “decline–recovery–decline” seasonal pattern. SS yielded the highest total SOC stock (166.20 t ha⁻¹) in the 0–50 cm profile, particularly in the 0–30 cm layer. Correlation analysis showed that the coupling relationships among C and N indicators varied with soil depth, with the strongest positive correlation between SOC and EOC in the topsoil. Both SS and DT maintained higher soil water content (SWC) than NT in the 20–50 cm layers throughout the experimental period. In conclusion, SS emerges as the optimal balanced tillage strategy for dryland wheat fields on the Loess Plateau, simultaneously improving topsoil fertility, water retention, and C sequestration; meanwhile, DT is more effective for enhancing subsoil water and nutrient conditions. These findings provide a scientific basis for targeted tillage management to sustain soil fertility and productivity in rainfed dryland farming systems. Full article

Land use change profoundly impacts the trade-offs and synergies among ecosystem services in ecologically fragile watersheds. Optimizing land use patterns based on ecological function zoning is an important approach to coordinate multiple ecosystem services and promote sustainable watershed management. This study focuses on the Wuding River Basin within the Chinese Loess Plateau, using Self-Organizing Map, multi-objective genetic algorithms, and the Future Land-Use Simulation model to explore land use optimization schemes. The results show that the windbreak and sand fixation service in the Wuding River Basin presents a spatial pattern of higher values in the northwest and lower values in the southeast, while the other six services exhibit a pattern of higher values in the east and lower values in the west. Based on the ecosystem service cluster characteristics, the basin can be divided into soil and water conservation zones, habitat conservation zones, and ecologically fragile zones. The trade-offs and synergies between ecosystem services within different zones differ significantly, with the trade-off between food supply, soil conservation, and habitat quality being particularly prominent. After optimization, the food supply and soil conservation in the soil and water conservation zones increased by an average of 0.63 × 10⁴ t and 1.94 × 10⁵ t, respectively. The food supply in the habitat conservation zones increased by 0.11 × 10⁴ t, while habitat quality remained stable. In the ecologically fragile area, water production and carbon sequestration services increased by an average of 0.26 × 10⁴ t and 0.58 × 10⁵ t, respectively. During the optimization process, the reasonable allocation of grassland and unused land played a key role in balancing service conflicts. This study provides a scientific basis for coordinating trade-offs in watershed ecosystem services and achieving land use optimization management through the framework of service clusters, functional zones, and multi-objective optimization. Full article

In the fragile Loess Plateau ecosystem, straw return is a key measure to improve its low soil organic matter. However, the short-term carbon retention efficacy of straw return, which depends on the initial balance between carbon mineralization and sequestration, remains unclear across different soil textures. This study investigated the short-term impacts of straw return on organic carbon fractions in three soils with varying textures via laboratory incubation. Results showed that while straw return universally increased active organic carbon pools, its accumulation in the mineral-associated organic carbon (MAOC) pool was texture-dependent. Straw incorporation, especially maize straw, effectively promoted MAOC formation in clayey soils (Phaeozems and Anthrosols) with large specific surface areas. Conversely, in Arenosols, carbon was retained in active pools, limiting long-term retention potential. The mechanism involves a combined regulation by soil physicochemical properties, where clay content and specific surface area are fundamental physical drivers for MAOC accumulation, synergistically influenced by chemical factors like pH and electrical conductivity through processes such as cation bridging. These findings provide critical scientific evidence for developing texture-specific straw return management strategies for the Loess Plateau. Full article

Soil nitrogen availability is a major constraint to crop productivity in rainfed arid and semi-arid regions. The influence of straw strip mulching on nitrogen availability and transformation across soil layers remains unclear. This study investigates the effect of straw strip mulching on soil nitrogen dynamics and crop-specific variation in wheat- and potato-cultivated soils under rainfed semi-arid conditions. This study consisted of five mulching treatments, including without mulching (Tck), black plastic film mulching (Tp), straw strip mulching (Tss), plant strip without mulch (Tps), and composite strip of straw strip mulching and plant strip without mulch (Tcs) applied in wheat and potato cultivation during 2019 and 2020, and soil nitrogen fractions were determined across different soil depths. Tss mulching showed the highest increase in urease activity (48%), nitrite reductase activity (48%), microbial biomass nitrogen (52%), NH₄ (11%), acid-hydrolyzed total nitrogen (10%), acid-soluble NH₄ (6%), acid-hydrolyzed amino sugar (16%) and acid-hydrolyzable unknown nitrogen (59%) relative to Tck without mulching. While total nitrogen (11%) and acid-hydrolyzed amino acid (9%) were highest in the Tps treatment compared to Tck treatment, the mulching treatment had no significant effect on soil organic nitrogen-derived functional traits. Across all treatments, the 0–20 cm soil layer consistently showed the highest concentrations of observed soil traits, which declined with increasing soil depth. Furthermore, potato-cultivated soils showed consistently higher concentrations of these traits than wheat-cultivated soils, and the concentrations of these traits in 2020 exceeded those observed in 2019. This study highlights that maize straw mulching in strips significantly promotes soil organic nitrogen fractions, particularly in the upper soil layers, and promotes higher nitrogen availability in potato than in wheat-cultivated soils, and is recommended as an effective soil management practice to improve soil nitrogen availability in rainfed semi-arid Loess Plateau conditions. Full article

The Loess Plateau has experienced persistent vegetation greening over the past two decades, yet this recovery has occurred under a concurrent intensification of atmospheric evaporative demand and drying. This raises a key land–atmosphere question: which hydroclimatic processes most strongly constrain greening, and where do vegetation responses shift across environmental regimes? To address this issue, we integrated spatiotemporal trend analysis, Geographical Convergent Cross Mapping (GCCM)-based directional attribution, and an interpretable machine-learning framework combining Extreme Gradient Boosting (XGBoost) and SHapley Additive exPlanations (SHAP) to diagnose the dominant controls and threshold-like response patterns of vegetation activity. Using 1 km kernel Normalized Difference Vegetation Index (kNDVI) and eight hydroclimatic variables during 2000–2019, we found that regionally averaged kNDVI increased from 0.099 in 2000 to 0.164 in 2019, with a significant trend of 0.003 year⁻¹, and greening trends covered 65.503% of the Loess Plateau. Over the same period, Vapor Pressure Deficit (VPD) increased from 0.142 to 0.275 kPa (+0.133 kPa), indicating that vegetation recovery did not occur under a more humid atmospheric background. GCCM results consistently showed stronger directional influence from hydroclimatic drivers to kNDVI than the reverse, with evaporation and thermal conditions, especially Tmin, emerging as the dominant constraints, followed by Tmax, VPD, and wind speed, whereas precipitation showed comparatively weaker recoverable influence. The tuned XGBoost model achieved strong out-of-sample performance (R² = 0.9611, RMSE = 0.0188, MAE = 0.0131), and SHAP revealed clear nonlinear thresholds: evaporation and Tmin shifted into persistently positive contribution regimes beyond 302 mm and −17.6 °C, respectively; Tmax became predominantly inhibitory beyond −1.9 °C, and Palmer Drought Severity Index (PDSI) exhibited a multi-stage non-monotonic transition around −0.7. These results provide a coherent evidence chain linking directional influence, relative contribution, and threshold boundaries, offering quantitative support for identifying climate-sensitive zones and restoration risk regimes under continued warming and rising atmospheric dryness. Full article

This study used bibliometric methods to systematically analyze the development trend, knowledge structure and evolution path of the field of “quantitative research on agricultural soil respiration based on machine learning” from 2021 to 2025, and further explored its implications for agricultural soil carbon sinks. Based on 966 articles included in the core collection of Web of Science, this paper comprehensively uses tools such as Biblioshiny, CiteSpace and VOSviewer to carry out multi-dimensional analysis from the aspects of annual publication trends, international and institutional cooperation networks, keyword clustering and emergent evolution. It is found that this field has shown phased evolution characteristics of “technology-driven mechanism deepening–application expansion” in the past five years. At the beginning of the 5-year period of research, the introduction of machine learning methods and model verification were the core, then gradually expanding to multi-algorithm comparison, environmental factor coupling mechanisms and multi-source data fusion. Recently, the field has focused on regional-scale simulation, uncertainty quantification and model interpretability research. Keyword clustering identifies three thematic clusters—machine learning algorithm and model optimization, environmental driving factors and process mechanism, and remote sensing fusion and regional application—which form a knowledge system of “method–mechanism–application” collaborative evolution. The national cooperation network presents a pattern of “Asia-led, China–US dual-core, and European connectivity”. China dominates in scientific research output, and the United States plays a key role in international cooperation. This study further points out that the development of this field provides important methodological support and a scientific basis for accurate assessment, intelligent management and carbon neutralization decision-making for agricultural soil carbon sinks. Based on the above findings, future research should focus on the development of intelligent models of mechanisms and data fusion, the construction of multi-source data assimilation and uncertainty assessment frameworks, the expansion of global diversified agricultural system cases, and the promotion of an open and shared international scientific research cooperation ecology. This study provides empirical evidence and a direction reference for academic development, scientific research layout, carbon sink management and international collaboration in this field. Full article

Wheat Fusarium crown rot (FCR), predominantly caused by Fusarium species, is a devastating fungal disease that severely threatens global wheat production. In this study, we combined phytopathological assays, molecular techniques, and bioinformatic analyses to systematically identify the causal agents of FCR in Xinjiang and to screen for potential biocontrol bacteria. A total of 296 fungal isolates were obtained from 195 FCR samples, collected from Yumin County and Xinhe County. Morphological and phylogenetic analyses revealed that Fusarium culmorum was the predominant pathogen, accounting for 73.6% of the total isolates. To evaluate the resistance of local wheat cultivars, F. culmorum XN22-1, a highly virulent strain from Xinhe County, was inoculated to 30 wheat varieties. The results demonstrated that most cultivars lacked resistance to FCR, with the exception of three varieties—Xinchun 19, Xinchun 50, and Youpi 23, which showed a mid-resistance. Given the scarcity of resistant cultivars, we focused on biological control. To control FCR, Pseudomonas aeruginosa J-7, exhibiting broad-spectrum antagonistic activity, was successfully isolated from rhizosphere soil based on the analysis of healthy rhizosphere soil microbial diversity. Subsequently, pot experiments showed that P. aeruginosa J-7 could significantly reduce the disease incidence and lower the disease index of wheat FCR. Furthermore, whole-genome sequencing, in-plate metabolite analysis, and observation on inhibition of spores and mycelium revealed that P. aeruginosa J-7 mediates its biocontrol activity primarily through the production of phenazine and siderophores, which collectively inhibit conidial germination and cause structural damage to the mycelium. This study not only clarifies the composition of FCR pathogens in Xinjiang but also provides a promising biocontrol agent and new strategic insights for the management of wheat crown rot. Full article

In the complex flow fields of channels affected by sluice gates and bridge piers, winter ice transport, accumulation characteristics upstream of the gate, and the determination of entrainment thresholds are crucial for the safe operation of hydraulic projects. In this study, ice transport experiments were conducted with and without bridge piers upstream of the gate to analyze the key factors governing the transport process and accumulation morphology of floating ice. Four machine learning models were evaluated and compared to identify the optimal model for predicting the motion state of floating ice. Based on this optimal model, the discriminant conditions for ice entrainment under both pier configurations were proposed. The results indicate that, driven by incoming hydraulic parameters, gate boundary conditions, and ice discharge, the upstream floating ice undergoes a progressive evolution: “flat accumulation $\to$ “$\nabla$”-shaped accumulation $\to$ wedge-shaped accumulation $\to$ passing through the gate (entrainment)”. Compared to the GBDT, RF, and SVM models, the LR model achieves higher and more stable accuracy, precision, recall, and F1 scores under configurations without and with bridge piers. With AUC values reaching 0.993 and 0.997, respectively, this model demonstrates optimal comprehensive performance in classifying whether floating ice passes through the gate. Furthermore, based on the LR model, explicit algebraic formulas for the critical entrainment thresholds were constructed. Under the experimental conditions, the critical threshold intervals for the relative gate opening (e/H) are [0.170, 0.182] without piers and [0.142, 0.155] with piers. This study provides a solid theoretical foundation and technical support for ice-prevention operations and gate dispatching in cold-region hydraulic engineering under submerged outflow conditions. Full article

Soil erosion is a critical issue on the Loess Plateau due to weak soil and intense summer rainfall. Plant roots provide essential soil stabilization. A split-plot field experiment was conducted in Liulin County, Shanxi Province, to evaluate the effects of biodegradable mulch and organic amendments on maize root development and soil stabilization. The main plots included no mulch (N) and biodegradable mulch (M). The subplots comprised five treatments: control (CK, no amendment), peat (PT), biochar (BC), fermented pig manure (PM), and corn stover (CS). Correlation and principal component analyses were used to elucidate the underlying mechanisms. The results showed that organic amendments were the primary factor influencing the root and soil properties. Peat and biochar significantly raised the root surface area density (RSAD, p < 0.05) and root–soil composite cohesion (with increases of 122.56% and 109.06% for NPT and NBC compared to NCK, respectively). Biodegradable mulch, and its interaction with the organic amendments, had no statistically significant effect on either the root–soil composite cohesion or root system parameters. The strong positive correlations of cohesion with the root length density (RLD, r = 0.80) and root volume density (RVD, r = 0.81) highlight that root occupancy is the key mechanism for enhanced shear resistance. Therefore, biochar is recommended for its effectiveness in enhancing soil retention and its potential co-benefits for carbon sequestration. This study provides a technical reference for sustainable agriculture on the Loess Plateau, while also acknowledging the need for further research on long-term carbon dynamics. Full article

Water scarcity, poor soil, and low water and fertilizer utilization are major challenges on agricultural production in the tableland region of China’s Loess Plateau. Optimizing tillage patterns and improving soil nutrient status can improve crop yield and water and fertilizer utilization efficiency. A field trial was initiated in 2005 to assess the impacts of various tillage and fertilization practices on dryland agricultural production. A split-plot design was used, with tillage practices (traditional tillage and no tillage) as the main plot treatment and fertilization management (no fertilization (CK), mineral nitrogen (N), mineral phosphorus (P), composted cow manure (M), a combination of mineral nitrogen and phosphorus (NP), and a combination of mineral nitrogen, phosphorus, and composted cow manure (NMP)) as the split-plot treatment. An experiment was conducted from 2022 to 2024. The NMP treatment resulted in lower bulk density, a lower three-soil-phase index, and higher mean weight diameter, geometric mean diameter, soil water storage, total nitrogen, and soil organic matter than the CK. In the no-tillage treatment, the crop roots were less effective at extracting water from the deep subsoil, leading to greater residual moisture at depth (especially in the 120–200 cm soil layer) and lower yield and water use efficiency than in traditional tillage. The grain yield and water use efficiency were 9.2% and 8.4% lower, respectively, under no tillage than under traditional tillage. The NMP under traditional tillage exhibited lower surface soil bulk density and a higher three-soil-phase index, mean weight diameter, geometric mean diameter, soil organic matter, total nitrogen, and water use efficiency than the unfertilized control, resulting in higher grain yields. The NMP under traditional tillage is recommended to increase grain yield and water use efficiency in wheat–maize rotation systems in the tableland region of China’s Loess Plateau. Future studies should analyze the deep root architecture and the effect of weed competition on soil water depletion. Full article

Flood events are major drivers of soil erosion and sediment yield on the Loess Plateau, where extensive ecological restoration has been implemented. This study investigates runoff–sediment dynamics by analyzing 215 flood events recorded in the Chabagou watershed (1959–2022), with a focus on changes under intensifying restoration efforts. Using long-term hydrological and rainfall data, we applied cluster and discriminant analyses to classify flood events based on sediment hysteresis loops and evaluated variations across three management periods (1959–1979, 1980–1999, and 2000–2022), characterized by progressive increases in check dam construction and vegetation recovery. The results show that the floods characterized by short duration, low peak flow, and low sediment concentration were predominant, accounting for 77.7% of the recorded 215 events. A clear decreasing trend was observed, with average sediment yield and peak discharge declining by approximately 68% and 52%, respectively. Anticlockwise hysteresis loops were most common (45.6%), followed by complex (27.9%) and figure-of-eight loops (23.7%). The proportion of figure-of-eight loops increased notably from 17% to 39%, indicating reduced sediment connectivity due to large-scale ecological restoration. Extreme rainfall events consistently produced complex hysteresis patterns, influenced mainly by rainfall intensity but increasingly modulated by human interventions. These results highlight adaptive watershed management strategies that target figure-of-eight and complex flood events to mitigate erosion and flood risks. Full article