Low water and fertilizer use efficiency have become important factors restricting the sustainable development of agriculture in extreme arid areas, typically like Xinjiang in China. In order to optimize the water and fertilizer management system of grape drip irrigation in the region, field experiments were carried out to study the effects of different water and fertilizer treatments on the physiological growth, yield, and quality of grapes. Meanwhile, principal component analysis, grey correlation analysis, and regression analysis were used to quantify the relative optimal amount of water and fertilizer. The results showed that the effects of water and fertilizer interaction on the photosynthetic index and fluorescence index of grape leaves, in different growth periods, ng reached extremely significant levels (p < 0.01). The physiological indicators showed regular changes with the increase and decrease of water and fertilizer use and the appropriate amount of water and fertilizer could maintain the index at a superior level. Meanwhile, there are differences in the index of different growth stages and regular changes with the growth period. The effects of water and fertilizer interaction on the yield, water use efficiency, and quality of drip irrigation reached a very significant level (p < 0.01). The yield reached the maximum in W3F2 treatment and the yield increased by 29.76% compared with the minimum yield of W1F1. The quality index reached a superior level in W3F2 treatment. The results of principal component analysis and grey correlation analysis showed that the optimal water and fertilizer dosage was W3F2 (irrigation 750 mm, fertilization 750 kg ha⁻¹), of which N (300 kg ha⁻¹)-P₂O₅ (150 kg ha⁻¹)-K₂O (300 kg ha⁻¹), and multiple regression analysis was employed to determine the optimal range of water and fertilizer use is the following: Irrigation volume 725–825 mm and fertilization amount 684–889 kg ha⁻¹, of which N (273.6–355.6 kg ha⁻¹) - P₂O₅ (136.8–177.8 kg ha⁻¹) - K₂O (273.6–355.6 kg ha⁻¹). The research results can provide a scientific basis for the water and fertilizer management and drip irrigation technology of drip irrigation in seedless white grape fields in extremely arid areas and it is of great significance for the efficient use of regional water and fertilizer resources and the realization of sustainable socio-economic development in the region.

To address the growing scarcity of freshwater resources, the use of saline water for agricultural irrigation is gaining increasing attention. This study presents findings from a two-year field experiment conducted during the 2023 and 2024 maize-growing seasons in northwestern China. The objective of the experiment was to evaluate the main and interactive effects of saline irrigation water on soil water–salt dynamics, maize growth, photosynthetic characteristics, water productivity, and carbon emissions. The experiment involved nine treatments with three irrigation amounts: 4500 m³ hm⁻² (W1), 5625 m³ hm⁻² (W2), and 6750 m³ hm⁻² (W3), combined with three water salinity levels: 0.85 g L⁻¹ (S1, freshwater), 3 g L⁻¹ (S2), and 5 g L⁻¹ (S3). Results indicated that both irrigation amount and salinity level significantly affected water–salt dynamics, with more soil accumulating in the 0–100 cm soil layer under saline irrigation water; however, this effect diminished with higher irrigation amounts. The maximum leaf area index and plant height were affected by both the irrigation amount and salinity level, as well as their interaction. Photosynthetic capacity declined with increasing salinity of the irrigation water, ultimately reducing grain yield and irrigation water use efficiency. Compared to freshwater (S1), the average maize grain yield under S2 and S3 treatments decreased by 6.28% and 15.43% in 2023 and by 7.82% and 17.48% in 2024, respectively. Additionally, for the same irrigation amount, higher salinity of the irrigation water (S2, S3) significantly reduced total soil CO₂ emissions, with reductions of 10.08% and 27.53% in 2023, and 11.97% and 28.01% in 2024, respectively. In summary, to optimize the utilization of saline water, enhance maize yield, and improve soil carbon sequestration, we recommend maintaining the salinity of irrigation water below 3 g L⁻¹, and using an irrigation amount of 6750 m³ hm⁻² (W3S2) for optimal outcomes in the study area.

To address residual plastic film in fields in which mulched drip irrigation technology is applied, a sprayable degradable film (consisting of 1–5% clay, 5–20% humic acid, 0.5–5% crosslinker, and 0.5–5% auxiliary and water) can be used as a superior alternative to the plastic film applied in drip-irrigated fields. A field experiment was conducted in Xinjiang, Northwest China, to test the impacts of five different mulching treatments (SF1, sprayable degradable film applied at 1900 kg ha⁻¹; SF2, sprayable degradable film applied at 1900 kg ha⁻¹; SF3, sprayable degradable film applied at 2500 kg ha⁻¹; PF, plastic film; and NF, no film mulching) on cotton growth and development, yield, and water use efficiency. The results showed that, compared to the NF treatment, sprayable degradable film mulching (SF1, SF2, and SF3) positively impacted the soil hydrothermal environment, promoted root growth, significantly increased plant height and leaf area, and enhanced physiological characteristics, which, in turn, increased yield and water use efficiency by 11.79–15.00% and 21.88–30.21%, respectively. The maximum yield and water use efficiency were observed in the PF treatment, amounting to 5345 kg ha⁻¹ and 1.28 kg m⁻³, respectively, and they had no significant differences from those in the SF3 treatment. In general, applying moderate amounts of sprayable degradable film at a rate of 2500 kg ha⁻¹ represents an effective agronomic strategy for managing residual film contamination while maintaining stable cotton yields.