Soil Moisture Regulation under Mulched Drip Irrigation Influences the Soil Salt Distribution and Growth of Cotton in Southern Xinjiang, China

Abstract

Water deficiency, together with soil salinization, has been seriously restricting sustainable agriculture around the globe for a long time. Optimal soil moisture regulation contributes to the amelioration of soil water and salinity for crops, which is favorable for plant production. A field experiment with five soil water lower limit levels (T1: 85% FC, T2: 75% FC, T3: 65% FC, T4: 55% FC, and T5: 45% FC, where FC is the field capacity) was conducted in southern Xinjiang in 2018 to investigate the responses of soil water–salt dynamics and cotton performance to soil moisture regulation strategies. The results indicated that in the horizontal direction, the farther away the drip irrigation belt, the lower the soil moisture content and the greater the soil salinity. In the vertical direction, the soil moisture and soil salinity increased first and then decreased with an increase in soil depth after irrigation, and the distribution was similar to an ellipse. Moreover, the humid perimeter of soil water and the leaching range of soil salt increased with a decrease in the soil moisture lower limit. Though more soil salt was leached out for the T5 treatment at the flowering stage due to the higher single irrigation amount, soil salinity increased again at the boll setting stage owing to the long irrigation interval. After the cotton was harvested, soil salt accumulated in the 0–100 cm layer and the accumulation amount followed T3 > T5 > T1 > T2 > T4. Moreover, with a decline of soil moisture lower limit, both plant height and nitrogen uptake decreased significantly while the shoot–root ratio increased. Compared with the yield (7233.2 kg·hm−2) and water use efficiency (WUE, 1.27 kg·m−3) of the T1 treatment, the yield for the T2 treatment only decreased by 1.21%, while the WUE increased by 10.24%. Synthetically, considering the cotton yield, water–nitrogen use efficiency, and soil salt accumulation, the soil moisture lower limit of 75% FC is recommended for cotton cultivation in southern Xinjiang, China.

Identification of novel candidate loci and genes for seed vigor-related traits in upland cotton (Gossypium hirsutum L.) via GWAS

“…In recent years, mechanical DS of cotton has been widely used due to its cost-saving and labor-saving advantages, leading to rapid and uniform seed germination becoming necessary conditions for high yield and mechanization in the cotton industry. However, seeds with low SV make it difficult for mechanical DS to achieve full seeding, which leads to problems such as subsequent filling of the gaps with seedlings and final singling of seedlings (Xie et al, 2014)-for example, Xinjiang Province is the major cottongrowing area in China and experiences serious saline-alkali stress (He et al, 2023). A high SV of cotton varieties will improve seed germination in the field and thus increase the yield.…”

The Impact of Long-Term Mulched Drip Irrigation on Soil Particle Composition and Salinity in Arid Northwest China

“…Soil particle composition, serving as a pivotal gauge of soil texture [13] and hydraulic properties [14][15][16], significantly influences soil water-salt transport, erosion, degradation, and microbial community composition. Currently, a plethora of studies have scrutinized the impacts of MDI on diverse crop varieties [17,18], film mulching materials [19,20], soil water-salt distribution [21,22], and optimal irrigation schedules tailored to specific regions and crops [23]. Given the severe water scarcity in arid regions, local farmers prioritize partial soil physical and chemical properties, such as texture and salinity, directly impacting crop yields, over hydraulic conditions.…”

Regulatory effects of silicon nanoparticles on the growth and photosynthesis of cotton seedlings under salt and low-temperature dual stress

“…Cotton is an important strategic reserve material in China, and Xinjiang is the main producing area [ 17 , 18 ], but the growth and yield formation of cotton in this region is seriously threatened by soil salinization [ 19 ]. Meanwhile, the area frequently suffers from unpredictable climates such as cold and low-temperature stress during the cotton seedling stage, especially in the southern region of Xinjiang.…”