Cheng Hou-Liang, Zhang Fu-Cang, Li Meng, Zheng Wen-Hui, Xiao Chao, Li Yue-Peng
Ministry of Education Key Laboratory of Agricultural Soil and Water Engineering in Arid Areas,Northwest A＆F University, Yangling 712100, Shaanxi, China.
Institute of Water-saving Agriculture in Arid Areas of China, Northwest A＆F University, Yangling 712100, Shaanxi, China.
Ying Yong Sheng Tai Xue Bao. 2021 Jan;32(1):211-221. doi: 10.13287/j.1001-9332.202101.029.
Water shortage and soil salinization are two main limiting factors for cotton production in southern Xinjiang. We examined the effects of soil matrix potential (SMP) regulation at various growth stages on cotton growth, soil water and salt distribution, to provide theoretical basis for water saving, salts control, and efficient production in cotton fields. The mulched drip irrigation experiments were conducted to monitor cotton growth, aboveground biomass, cotton yield, soil water and salt distribution and other indicators. Three SMP thresholds, .,W(-20 kPa), W(-30 kPa) and W(-40 kPa) were set at the seedling stage (A), seedling stage + budding stage (B), and seedling stage + budding stage + flowering stage (C), with SMP of -50 kPa at 20 cm soil depth below the emitter as the CK. The results showed that plant height, leaf area index (LAI) and aboveground biomass followed the order of WC>WB>WA>CK, when SMP were changed at various growth stages. Plant height, LAI and aboveground biomass increased with increasing SMP thresholds, with the values under WC and WC being significantly higher than the other treatments. The effective bolls per plant, single boll weight and lint percentage all increased with the increases of SMP thresholds. The yields of WC and WC were similar, which were significantly higher than those of other treatments. However, the water use efficiency of WC was significantly higher than that of WC. Controlling the SMP threshold at -20 or -30 kPa at different growth stages could improve soil moisture status of the primary cotton root zone. All treatments presented shallow salt accumulation (0-40 cm) at the harvest stage, with the bare land having greater salt accumulation than the inner film. The higher the SMP threshold was, the less salt was accumulated in the primary root zone (0-40 cm) under film. The salt accumulation (0-40 cm) under WC and WC were reduced by 24% compared with other treatments. Considering the efficient production of cotton, water saving and salt control, it was recommended to maintain the SMP threshold of -30 kPa during irrigation at various growth stages in cotton fields without leaching salts during the local off-crop period.
水资源短缺和土壤盐渍化是南疆棉花生产的两个主要限制因素。我们研究了不同生长阶段土壤基质势（SMP）调控对棉花生长、土壤水分和盐分分布的影响，为棉田节水、控盐和高效生产提供理论依据。通过膜下滴灌试验监测棉花生长、地上生物量、棉花产量、土壤水分和盐分分布等指标。在苗期（A）、苗期+蕾期（B）、苗期+蕾期+花期（C）分别设置了3个SMP阈值，即W（-20 kPa）、W（-30 kPa）和W（-40 kPa），以滴头下方20 cm土壤深度处SMP为-50 kPa作为对照（CK）。结果表明，在不同生长阶段改变SMP时，株高、叶面积指数（LAI）和地上生物量均表现为WC>WB>WA>CK。株高、LAI和地上生物量随SMP阈值的增加而增加，WC和WC处理的值显著高于其他处理。单株有效铃数、单铃重和衣分均随SMP阈值的增加而增加。WC和WC处理的产量相近，均显著高于其他处理。然而，WC处理的水分利用效率显著高于WC处理。在不同生长阶段将SMP阈值控制在-20或-30 kPa可以改善棉花主要根区的土壤水分状况。收获期各处理均表现为土壤盐分浅层积累（0-40 cm），裸地盐分积累大于膜内。SMP阈值越高，膜下主要根区（0-40 cm）盐分积累越少。WC和WC处理0-40 cm土层盐分积累较其他处理减少24%。综合考虑棉花高效生产、节水和控盐，建议在当地非作物期不进行盐分淋洗的棉田，各生长阶段灌溉时将SMP阈值维持在-30 kPa。
