Effects of Dry Matter Accumulation and Yield Components under Different Irrigation and Fertilization Treatments

【Objective】 Effects of Dry Matter Accumulation and Yield Components under Different Irrigation and Fertilization Treatments. 【Method】 The field test was designed with split zone test, and two regulating factors of irrigation and fertilization were set up. Among them, irrigation was the main area, fertilization is the secondary area, all of which had three gradients: the irrigation amount 2,250 m³/hm²(non-sufficientirrigation amount), 3,450 m³/hm²(medium irrigation amount, traditional experience irrigation amount CK), 4,650 m³/hm², (saturatedirrigation amount) denoted by W₁,W₂ and W₃, respectively. The deputy area of nitrogen (pure N), 0(N₁, no fertilizer), 300(N₂, conventional fertilization, CK), 600(N₃, excess fertilization, 200% CK). 【Result】 Irrigation amount and fertilizer application amount could promote plant growth and yield composition to some extent, and the increase of irrigation amount and fertilizer application amount could significantly increase plant height, leaf number and boll setting rate. In terms of dry matter accumulation, increasing the amount of irrigation could significantly increase the total amount of dry matter accumulation, and increasing the amount of fertilization mainly promoted the earlier accumulation of dry matter into economic organs. The yield increased by 23.2% - 31.4% by increasing irrigation and 12.5% - 17.6% by increasing nitrogen fertilizer. 【Conclusion】 It was found that the coupling effect of water and nitrogen had significant effects on the single boll weight, seed cotton yield and lint yield of cotton. That water and nitrogen optimization strategies can improve resource utilization efficiency, reduce water and fertilizer input, and maintain the stability of yield.