夏棉干物质积累和氮磷钾吸收分配规律的研究

Studies on Rules of Dry Matter Accumulation and Absorption and Distribution of Nitrogen,Phosphorus and Potassium for Summer Cotton

夏棉在亩产皮棉60～65kg产量水平下,每生产50kg 皮棉约需氮素6.6kg,P_2O_52.2kg,KO_27.3kg。干物质积累特点是,现蕾以前积累率为4%,现蕾至开花期急剧增加,占37%左右。开花至吐絮期仍有大量积累,约占60%。植株养分含量是生育前期高于后期.不同生育期养分吸收情况是,现蕾以前吸收量少,现蕾至开花期养分吸收增多,约有62%的氮素,61%的氧化钾和44%的磷酸是这一阶段吸收的。开花至吐絮仍大量吸收养分,约有1/3的氮素和氧化钾,50%的磷酸是开花以后吸收的。

The yield of summer cotton has close relation with the status of growth &development and nutrient absorption in each growing stage.The experiment s-hows that 6.6kg of N,2.2kg of P_O_5 and 7.3kg of K_2O are needed to produce50kg of lint cotton under theper-mu yield level of 60～65kg.The accumulativerates of dry matter are 40% before square stage,37% from squaring to floweringstage and 60% from flowering to boll-opening stage.The content of N,P andK in plant at the earlier stage is higher than that of the laterstage.Theabsor-ptive rates of nutrient in different stages are:before squaring stage,summercotton absorbs less nutrient;from squaring to flowering stage,64% of N,61%of K and 43% of P are absorbed;from flowering to boll-opening stage,onethird of N & K and one half of P are absorbed.