水肥耦合对棉花产量和氮累积利用的影响

研究膜下滴灌施肥条件下,不同滴灌水量和滴灌施肥用量对棉花产量、氮素动态累积和氮素利用效率的影响。通过设置5个滴灌施肥水平和3个水分水平的完全组合处理以及一个不施肥对照处理,研究了水肥耦合对棉花干物质动态累积量、籽棉产量、氮动态累积量和氮素利用效率的影响。在收获后棉花地上部分器官质量从高到低依次为棉铃,茎秆和叶,而氮素主要集中在棉铃内部,其次是叶片,茎秆最少。灌溉水量显著增加了棉花叶片,茎秆和棉铃质量,从而增加了干物质量和籽棉产量,同时灌溉水量显著增加氮累积量和氮肥利用率。水肥对氮肥偏生产力,氮肥农学效率和氮肥生理利用率影响显著。灌溉水量降低至60%ETc会抑制棉花对氮素的吸收,使干物质量和籽棉产量下降,但可以显著提高氮肥利用率,氮肥偏生产力,氮肥农学效率。在本试验条件下,灌水量在380 mm,施肥量(N-P2O5-K2O)为(250-100-50)kg/hm2时,可以获得低于最高产量6%的籽棉产量,并节省15%的灌水量和16.7%施肥量。

Coupling Water and Fertilizer Effects on Cotton Yield,Nitrogen Accumulation and Nitrogen Use Efficiency

A field experiment was conducted to evaluate the effect of different drip irrigation water quality and fertilization amount on the in-fluence of cotton yield, the dynamic accumulation of nitrogen and nitrogen use efficiency under mulch and fertigation. The complete combina-tion treatments with five drip irrigation fertilization levels and three water levels and a no fertilizer control are set to study the coupling effect on the amount of dry matter dynamic accumulation, seed cotton yield, dynamic accumulation and nitrogen use efficiency of nitrogen. The re-sults show that on the ground after harvest, the part organ weight of cotton from high to low in order is the bolls, stem, leaf;nitrogen mainly concentrates in the bolls, followed by leaf, and in the stem is the least;irrigation water significantly increases the cotton leaf, stem and bolls quality, the quality of dry matter and seed cotton yield, and significantly enhances the N accumulation amount and nitrogen use efficiency at the same time. The coupling effect on productivity, fertilization of nitrogen, nitrogen agronomic efficiency and utilization rate of nitrogen phys-iological effect is remarkable;irrigation water reducing 40% will suppress the absorption of nitrogen, the quality and seed cotton dry matter production, but can significantly improve the utilization rate of nitrogen fertilizer, nitrogen partial productivity, nitrogen efficiency of agricul-ture. It is concluded that under this experimental condition of 380 mm irrigation water and 250-100-50 kg/hm2 fertilizer (N-P2O5-K2O), 6% below the maximum yield of seed cotton yield can be obtained, and save 15% of irrigation water can be saved by 15% and fertilizer rate can be saved by 16.7%.