Responses Of Soil Water-Salt Variation And Cotton Growth To Drip Irrigation With Saline Water In The Low Plain Near The Bohai Sea

To test the feasibility and sustainability of drip irrigation with saline water in the Low Plain near the Bohai Sea (BHLP) in North China, the effects of drip irrigation using saline water on soil water salt, cotton growth, seed cotton yield and fibre quality were conducted during 2017-2018. Five salinity levels of irrigation water were set up: 1.3, 5.4, 8.8, 12.4 and 15.9 dS m?(1). Cotton evapotranspiration increased first and then decreased with increasing salinity of irrigation water. Soil EC(e)within the cotton root zone at each stage increased with greater salinity of irrigation water. After a 2-year experiment soil desalination occurred in the main root layer (top 0-60 cm soil layer) when water salinity was less than 8.8 dS m?(1). The significant (p < 0.05) decline of seedling establishment rate and seed cotton yield only occurred in 15.9 dS m?(1) treatment in 2017 when saline water was drip irrigated right after sowing. Leaf area index and plant height were inhibited when irrigation water salinity was more than 12.4 dS m?(1) in both years. Additionally, saline water irrigation had little effect on fibre quality. To avoid a secondary salinization risk in this region, water with the salinity level of <= 8.8 dS m?(1) was recommended under drip irrigation. (c) 2020 John Wiley & Sons, Ltd.