Exploring the interactive effect of water and fertilizer on yield, soil water and nitrate dynamics of young apple tree is of great importance to improve the management of irrigation and fertilization in the apple-growing region of semiarid northwest China. A two-year pot experiment was conducted in a mobile rainproof shelter of the water-saving irrigation experimental station in Northwest A&F University, and the investigation evaluated the response of soil water and fertilizer migration, crop water productivity (CWP), irrigation water use efficiency (IWUE), partial factor productivity (PFP) of young apple tree to different water and fertilizer regimes (four levels of soil water: 75%–85%, 65%–75%, 55%–65% and 45%–55% of field capacity, designated W₁, W₂, W₃ and W₄, respectively; three levels of N-P₂O₅-K₂O fertilizer, 30-30-10, 20-20-10 and 10-10-10 g plant⁻¹, designated F₁, F₂ and F₃, respectively). Results showed that F₁W₁, F₂W₁ and F₃W₁ had the highest average soil water content at 0~90 cm compared with the other treatments. When fertilizer level was fixed, the average soil water content was gradually increased with increasing irrigation amount. For W₁, W₂, W₃ and W₄, high levels of water content were mainly distributed at 50~80 cm, 40~70 cm, 30~50 cm and 10~30 cm, respectively. There was no significant difference in soil water content at all fertilizer treatments. However, F₁ and F₂ significantly increased soil nitrate-N content by 146.3%~246.4% and 75.3%~151.5% compared with F₃. The highest yield appeared at F₁W₁ treatment, but there was little difference between F₁W₁ and F₂W₂ treatment. F₂W₂ treatment decreased yield by 7.5%, but increased IWUE by 11.2% compared with F₁W₁ treatment. Meanwhile, the highest CWP appeared at F₂W₂ treatment in the two years. Thus, F₂W₂ treatment (soil moisture was controlled in 65–75% of field capacity, N-P₂O₅-K₂O were controlled at 20-20-10 g·tree⁻¹) reached the best water and fertilizer coupling mode and it was the optimum combinations of water and fertilizer saving.

Rapid human development has altered land use types, significantly impacting carbon stock, and poor land use will lead to an increase in carbon emissions and exacerbate climate change. Understanding the relationship between land use changes and carbon storage is critical for developing sustainable land management strategies that support carbon sequestration and climate change mitigation. In this study, we analyzed and processed the land use transition changes from 1990 to 2020 and calculated the corresponding carbon storage. Based on the patterns of change and influencing factors (elevation, slope, soil type, GDP, population density, etc.), we predicted the future changes in land use and carbon storage in the Yiluo River Basin under different social development scenarios. It was found that due to the severe impact of natural factors, from 1990 to 2020, the area of cultivated land and grassland decreased by 1150.04 km² and 936.66 km², respectively, and the area of forested land and built-up area expanded by 1087.84 km² and 969.26 km², respectively. Carbon stocks in the region decreased between 1990 and 2010, followed by a modest recovery from 2010 to 2020, resulting in a total reduction of approximately 2.188 × 10⁶ t. Spatially, carbon stocks diminished in the eastern part but increased in the western part. To assess the long-term sustainability implications, the study simulated four future development scenarios for human society: natural development, urban development, ecological protection, and water conservation. The results showed that in the urban expansion scenario, the proportion of construction land increased significantly, while the ecological protection scenario led to a substantial expansion of forested areas. Notably, carbon stocks showed a significant increase only under the ecological protection scenario, whereas they exhibited a declining trend in all other scenarios.

As a major tributary of the Yellow River, the Yiluo River holds vital importance for regional water resource management and ecological sustainability. In this study, the SWAT (version 2012) and PLUS models were used in combination to simulate the hydrological responses of the basin and to analyze how land use changes have influenced runoff dynamics over time. During the calibration and validation periods, the Nash–Sutcliffe efficiency coefficient (NS) and coefficient of determination (R²) for the SWAT model both exceeded 0.8, while the Kappa coefficient for the PLUS model indicated an overall accuracy of 0.91, confirming the applicability of both models to the Yiluo River Basin. However, despite strong annual performance, potential monthly or seasonal simulation uncertainties should be acknowledged and warrant further analysis. From 2000 to 2020, the areas of forest land, water, urban land, and unused land in the Yiluo River Basin increased by 795.15 km², 29.33 km², 573.67 km², and 0.25 km², respectively, while cultivated land and grassland decreased by 814.50 km² and 583.89 km². The spatial distribution of the annual average runoff depth generally exhibited a pattern of “higher in the upstream and lower in the downstream”. An increase in the forestland and grassland areas was found to suppress runoff generation, whereas the expansion of urban land promoted runoff production. Implementing water-sensitive land use strategies—such as expanding forest cover and conserving grasslands—is crucial for reducing the negative hydrological impacts of urban land expansion. Such measures can improve runoff regulation, enhance groundwater recharge, and support the sustainable management of water resources within the basin. Assuming climate conditions remain constant, land use in the Yiluo River Basin in 2025 and 2030 is expected to remain dominated by cultivated land and forestland. Under this scenario, the annual average runoff is projected to increase by 0.42% and 0.51% compared to in 2020, respectively.

The purpose of this research was to investigate how adding dietary guar gum to high‐lipid diets affected the fish growth and gut health of common carp ( Cyprinus carpio ). A normal‐lipid diet (5% crude lipid; control) and four high‐lipid diets (10% crude lipid) with 0% (high‐fat [HF]), 0.3% (GG0.3), 1% (GG1), and 3% (GG3) of guar gum were developed and fed to fish (4.53 g) for 8 weeks. The findings showed that HF induced impairment of intestinal morphology and mucosal barrier, oxidative stress, gut dysbiosis, and gut inflammation. Compared to the HF, guar gum‐containing diets substantially improved gut villus height, upregulated the expression levels of nuclear factor erythroid 2-related factor 2 and zonula occludens-1 , and downregulated the expression levels of toll-like receptor 1 ( tlr1 ), tlr5 , myeloid differentiation factor 88 , interleukin-1β ( il-1β ), il-6 , and il-8 . Moreover, the GG0.3 and GG1 diets dramatically increased catalase (cat) and occludin expression levels. Furthermore, the GG1 and GG3 diets improved the microbiota composition by increasing Fusobacteria and Cetobacterium abundance while lowering Proteobacteria, Acidovorax , Acinetobacter , Serratia , and Comamonas abundance. Correlation analysis revealed that guar gum improved gut health by modulating gut microbiota and tight junction proteins. The findings indicated that guar gum can ameliorate HF diet‐induced intestinal damage in fish.