黄河三角洲盐渍棉花施用氮、磷、钾肥的效应研究

为探讨盐渍土抗虫棉施用NPK肥的效应及其营养生理机制，指导滨海盐渍土抗虫棉合理施肥，在黄河三角洲盐渍土低、中、高盐棉田种植转Bt基因抗虫棉鲁棉研28，研究N、P、K肥配合施用对其养分吸收利用、Na⁺吸收积累、光合速率、干物质积累和产量的影响。结果表明，N、P肥配合，尤其是N、P、K肥配合施用显著增加了低、中、高盐田棉花的N、P、K养分吸收量，减少了Na⁺吸收积累量。低、中、高盐田棉花的N、P、K养分农学利用效率均以NPK配施的处理较高，氮养分农学利用效率分别为0.20、1.95和2.07 kg皮棉 kg^–1 N，磷养分农学利用效率分别为0.87、8.35和8.71 kg皮棉 kg^–1 P，钾养分农学利用效率分别为0.26、2.89和3.77 kg皮棉 kg^–1 K。N、P、K肥配合施用还维持了较高的棉株叶面积、叶绿素含量和净光合速率。低、中、高盐田棉花的生物产量和皮棉产量也均以NPK配施的处理较高，皮棉产量分别增产2.53%、28.67%和30.47%。中、高盐棉田的施肥效应明显好于低盐棉田。表明根据盐碱程度分类合理施肥是减轻盐渍土营养障碍、改善棉花营养、提高养分农学利用效率和棉花产量的有效途径。

Effects of N,P, and K Fertilizer Application On Cotton Grown in Saline Soil in Yellow River Delta

It is urgent and necessary to provide the technology of economic application on fertilizers for nutrition improvement of Bt cotton and cotton production in coastal saline soil in the Yellow River Delta. The experiments were conducted with Bt cotton cultivar SCRC28 in coastal saline soil in the Yellow River Delta, Shandong province. The effects of different amounts and ratios of N, P and K, and N and P fertilizers on nutrient (N, P and K) assimilation, Na⁺ assimilation, net photosynthetic rate (P_n), dry matter accumulation and lint yield of Bt cotton were investigated in three types (low, middle and high levels of salinity) of coastal saline field. The results showed that nutrient uptake of Bt cotton in the treatments of NP, NPK especially, in low, middle and high levels of salinity field was significantly higher than that in corresponding controls. And the Na⁺ uptake of cotton in the same treatments was significantly lower than that in corresponding controls. Nutrient use efficiency in agronomy(NUEa) of cotton in the NPK treatment in low, middle and high levels of salinity field was the highest among the three treatments. NUEa of Bt cotton in the NPK treatment in low, middle and high levels of salinity field was 0.20, 1.95, and 2.07 kg lint kg^–1 N, 0.87, 8.35, and 8.71 kg lint kg^–1 P, and 0.26, 2.89, and 3.77 kg lint kg^–1 K, respectively. The coordination of N, P and K fertilizers could maintain the highest leaf area, chlorophyll content and P_n among the three treatments in low, middle and high levels of salinity field, respectively. The biomass yield and lint yield of Bt cotton in the NPK treatment in low, middle and high levels of salinity field were also the highest among the three treatments, respectively. The lint yield in the NPK treatments in low, middle and high levels of salinity field was 2.53%, 28.67% and 30.47% higher, respectively, than that in corresponding controls. And the fertilization effects in middle and high levels of salinity field were obviously better than those in low level of salinity field. Further analysis indicated, rational fertilizer application, according to the classification of soil salinity, was an effective way to alleviate nutrition obstacles of saline soil, improve cotton nutrition, and enhance the NUEa and cotton yield in coastal saline fields.