Effects of Water - Nitrogen Coupling on Soil Water Distribution and Yield in Cotton Field

【Objective】 Research Effects of Water - Nitrogen Coupling on Soil Water Distribution and Yield in Cotton Field. 【Methods】 The split zone test design was adopted, with irrigation amount as the main area, with 2,250.0 m³/hm²( low irrigation),3,450.0 m³/hm²( traditional irrigation) and 4,650.0 m³/hm²( high irrigation), with three irrigation amounts (expressed as W₁,W₂ and W₃). kg/hm²(0 blank), 300.0 kg/hm² (traditional fertilizer application) and 600.0 kg/hm² (high nitrogen application), three pure nitrogen inputs (expressed in N₁, N₂ and N₃) were used to carry out field experiments in dry inland cotton areas of northwest China. The effects of different water and nitrogen treatments on the growth and final yield of cotton plants were evaluated by measuring soil moisture, salt content, dry matter accumulation of cotton plants in different periods and final yield under different treatments. 【Results】 The results showed that the salt and water consumption in soil under W₃N₂ treatment was 64.2% higher and 92.4% higher than those in W₁N₁ treatment. Under the combination of W₃N₃ water and nitrogen application, the boll number, boll quality and seed cotton yield of cotton plants reached the highest, which was 30.0% higher than that of W₁N₁ treatment. 【Conclusion】 It is not that the higher the application of water and fertilizer, the better the growth trend and the higher the yield. On the contrary, the relatively low combination of water and fertilizer application provides more favorable conditions for the growth and development of cotton, which not only provides theoretical basis for field water and fertilizer management, but also effectively controls the amount of water and fertilizer application, which is of great significance in increasing production and income and environmental protection.