Sugar beet is one of the main sugar crops and an important cash crop in the three northern regions of China (Northeast China, North China, and Northwest China). As an arid region, Xinjiang lacks water resources. The establishment of a reasonable drip-irrigation system for sugar beet in Xinjiang can not only achieve the goal of high quality and high yield, but is also crucial for the efficient utilization of water and fertilizer. This research was implemented in the experimental field of the Xinjiang Academy of Agricultural Sciences’ Sugar Beet Improvement Center in Manas County, Xinjiang, from the year 2019. Taking ST 15140 sugar beet as the experimental variety, a field study was conducted to investigate the effects of different irrigation and fertilization methods on the yield and sugar content of sugar beets. Ten treatments of two irrigation levels (W1: 4500 m³ ha⁻¹, W2: 5400 m³ ha⁻¹) and five fertilization methods (F1, F2, F3, F4, and F5) were carried out in a randomized block design with three replications. The yield and sugar content; growth indicators such as leaf photosynthetic rate, stomatal conductance, chlorophyll content and intercellular CO₂ concentration; and fertilizer-use efficiency (nitrogen-use efficiency (NUE), phosphorus-use efficiency (PUE), and potassium-use efficiency (KUE)) during the sugar beet growing seasons were determined. The results indicated that the W1F3 (4500 m³ ha⁻¹, N 229.5 kg ha⁻¹ + P₂O₅ 180 kg ha⁻¹ + K₂O 202.5 kg ha⁻¹ + hydroquinone 229.5 g ha⁻¹) treatment had the highest yield and sugar content of 132.20 Mg ha−1 and 15.61%, respectively. For crop growth indicators, the photosynthetic rate (33.27 μmol m⁻² s⁻¹) and the stomatal conductance (252.67 mmol m⁻² s⁻¹) under W1F3 were both the highest among all of the treatments. The fertilizer-use efficiency in W1F3 was in the following order: KUE > NUE > PUE. The highest KUE (128.10%) and NUE (65.49%) occurred under W1F3 at the sugar accumulation stage of the crop growing season. In addition, K determined the yield and sugar content of sugar beet by influencing growth factors such as the photosynthetic rate, chlorophyll content, intercellular CO₂ concentration, along with the KUE, which explained 30.2%, 5.1%, 10%, and 14.7% of the variation in yield and sugar content, respectively. The results of this study indicated that the application of an inhibitor with optimized-minus-N fertilization under lower irrigation (W1F3) was the optimal treatment. Above all, K determined the yield and sugar contents of sugar beets, emphasizing the pivotal role of K in the growth, physiological processes, and output of sugar beets.

Rational fertilization is a win-win strategy for rural incomes and environmental restoration in ecologically fragile regions. However, the long-term cumulative grape productivity response to soil fertility has rarely been quantified. Here, long-term fertilization experiments (over 15 years) in the desert–oasis transitional zone of Sinkiang, China, were used to evaluate the interactions among grape yield, quality, fertilization, soil nutrients, and microbial communities. There were five treatments, as follows: CK₀ (no planting and no fertilizing); NP (synthetic nitrogen and phosphorus); M (manure only); NPM₁ (0.25 times NP and 0.33 times M); and NPM₂ (NP and 0.5 times M). The grape yield increased with the application of total nitrogen. The soluble solids and reducing sugar contents had significant positive linear correlations with grape yield, but the opposite trend was found between grape yield and titratable acidity and tannin contents. The redundancy analysis showed that fertilization, soil nutrients (soil organic carbon, available nitrogen, and dissolved organic nitrogen), and microbial communities (ratio of fungi to bacteria, ratio of Gram-negative bacteria to Gram-positive bacteria, and total phospholipid fatty acids) accounted for 31.9%, 19.7%, and 26.8% of the grape yield and nutritional ingredients, respectively. The path analysis identified that fertilization, soil nutrients, and the microbial communities were significantly positively associated with the grape yield, soluble solids, and reducing sugars, while their associations with titratable acidity, tannins, and phenols were significantly negative. These results suggested that fertilization is a viable strategy for regulating grape yields and grape quality because it alters soil fertility in ecologically fragile regions.

To improve cotton yield in salinized arid fields, excess salt is removed and phosphorus content is increased. Adjusting phosphate fertilizer timing with water and fertilizer reduces phosphorus binding with calcium ions. Salt removal precedes phosphate application, enhancing soil phosphorus availability and promoting better growth. However, the optimal time for delaying phosphate fertilizer drip irrigation remains unclear. Therefore, this study evaluated the total salt, soil available phosphorus, and cotton yield under the condition of delayed phosphate fertilizer application. We conducted a field experiment using a completely randomized design to adjust the timing of phosphatic fertilizer application and apply the same amount of pure phosphorus. Specifically, “t” was defined as the total duration of one irrigation cycle, and the starting points for phosphorus application were as follows: T1, 1 h; T2, 1 h + 1/3 t h; T3, 1 h + 2/3 t h; CK, 1/3 t h. These values represent the duration of salt leaching through irrigation in each treatment. Phosphate fertilizer was applied to the soil after salt washing was complete. The results revealed that the T2 treatment exhibited the highest SPAD value (64.53), which was 11.46% and 15.48% higher than that of the T1 and T3 treatments. The 0–20 and 20–40 cm soil layers under the T2 treatment had the highest pH values of 9.12 and 9.37, representing increases of 1.93%, 1.21%, 4.50%, and 1.38% compared with T1 and T3 treatments, respectively (p < 0.05). At the bud stage, the Olsen-P in the T2 treatment was 82.86% and 26.53% higher than that in the T1 and T3 treatments, respectively (p < 0.05). The T2 treatment achieved the highest yield of 6492.09 kg/hm², which was 31.47%, 31.53%, and 2.77% higher than that of T1, T3, and CK. Overall, the T2 treatment increased cotton yield and reduced the adsorption of calcium ions to available phosphorus in salinized soil. This study provides an effective technical approach for the sustainable development of salinized cotton fields in Xinjiang.

Introduction: As biodegradable plastic (BP) film gradually replaces traditional polyethylene (PE) film as an environmentally friendly alternative in agriculture, its impact on the soil microbial environment has attracted considerable attention. Methods: This study examined the effects of different film coverings on the quantity, activity, and diversity of soil microorganisms by comparing fully biodegradable films with thicknesses of 0.01 mm and 0.012 mm to conventional PE films in typical cotton fields of Xinjiang. Results: Results showed that the overall trends in microbial population dynamics were generally consistent across treatments. The abundance of bacteria and actinomycetes was highest under PE film, while fungi abundance peaked under the 0.012 mm BP film. With longer cultivation time, soil microorganisms exhibited a significant increase in total carbon source metabolism. Across the entire cotton growth period, different mulching treatments had only minor effects on microbial diversity. Both film cracking rates and the local environmental conditions emerged as key factors influencing the soil microbial community. Conclusions: Considering the need for a low cracking rate during the seedling stage as well as soil environmental sustainability, BP film with a thickness of 0.01mm appeared to be the most suitable degradable option for practical use in cotton fields. Nevertheless, comprehensive evaluation of its long-term environmental benefits will require further research and sustained monitoring in conjunction with cotton growth.

Background: Cotton straw returning (CSR) is widely implemented in Xinjiang to achieve in situ residue utilization and ameliorate saline–alkali soils. However, its long-term efficacy in improving soil fertility without inducing secondary salinization remains poorly understood. Methods: This study evaluated the effects of different CSR durations on soil physicochemical properties and cotton yield across four major cotton-growing regions of Xinjiang, China (Shawan, Wusu, Manas, and Shihezi). Cotton fields with different CSR durations were classified into four treatments: CK (0 years), T1 (5 years), T2 (10 years), and T3 (20 years). Soil bulk density (BD), exchangeable sodium percentage (ESP), and key soil fertility indicators were measured to assess comprehensive soil fertility and soil secondary salinization risk. Results: CSR generally enhanced soil physicochemical properties, but responses exhibited spatial heterogeneity. Soil BD decreased in Wusu and Shihezi but showed temporary increases in Manas and Shawan. SFI increased continuously with CSR duration in Shawan and Wusu, whereas it peaked at around 10 years in Shihezi and Manas. Cotton yield was highest under the 20-year treatment in Manas but peaked under the 10-year treatment in the other regions. Notably, prolonged CSR (>10 years) elevated ESP in some areas, suggesting an increased risk of secondary salinization. Conclusions: A CSR duration of roughly 10 years appears optimal for balancing soil amelioration and salinity control in saline–alkali cotton fields of Xinjiang.