不同叶龄期氮磷钾缺失对棉花生长及养分积累的影响

目的]利用不同叶龄期棉花营养供应的中断,探寻不同时期棉花缺素症状及其养分的吸收积累状况.方法]设计缺N、缺P、缺K和对照处理的水培试验,分析测定棉花株高、叶面积、营养元素含量和干物质积累量等指标,研究了N、P、K素缺失对棉株生长性状及N、P、K养分吸收的影响.结果]缺素对棉株的生长发育有明显的抑制作用,缺氮、缺磷、缺钾处理的棉株株高和倒四叶叶面积平均较正常棉株分别降低了37.4;、20.8;、27.6;和33.3;、32.5;、20.3;.同时,缺素严重影响了棉株对N、P、K养分的吸收积累,缺氮处理的棉株在四叶期、八叶期和十二叶期的N吸收积累量分别比正常棉株的降低了53.3;、37.8;和27.5;；缺磷处理的棉株在四叶期、八叶期和十二叶期的P吸收积累量分别比正常棉株的降低了75.2;、73.1;和74.1;；缺钾处理的棉株在四叶期、八叶期和十二叶期的K吸收积累量分别比正常棉株降低了44.9;、38.3;和37.4;.氮磷钾的缺失均会显著降低棉花整株干物质的积累量,分别比正常棉株下降了24.1;、13.4;和24.0;.结论]大量元素的缺失显著影响棉花生长发育和光合产物的积累,在生育前期(八叶期以前)氮磷钾缺失显著延缓棉花生长和减少养分吸收,后期(十二叶期以后)氮磷钾缺失显著降低棉花干物质积累.因此,依叶龄合理施肥能及时供给棉花养分需求,提高养分利用效率,为棉花高效生产提供理论依据.

Effect of N, P and K Elements Deficiency on Growth and Nutrition Accumulation of Cotton during Different Leaf Ages

【Objective】This study aims to explore nutrient deficiency symptom,nutrient absorption and accumulation of cotton during the different periods by using nutrition supply disruption in different leaf ages of cotton.【Method】Effect of N,P and K elements deficiency on the growth and the nutrition accumulation of cotton in different leaf ages was studied by applying N,P and K deficiencies and CK treatments under water condition to measure the height,the leaf area,the contents of nutrition and the dry matter accumulation of cotton.【Result】The results suggested that the growth of cotton was significantly restrained by lacking N,P and K.Compared with the normal cotton,the height of cotton and the average leaf area of the last leaf but four under the condition of elements deficiency declined 37.4%,20.8%,27.6%and 33.3%,32.5%,20.3% respectively.The elements absorption of cotton significantly dropped under the condition of elements deficiency.Compared with the normal cotton,the N accumulation rate of N deficiency during the fourth leaf age,the eighth leaf age and the twelfth leaf age decreased 53.3%,37.8%and 27.5%respectively,the P accumulation rate of P deficiency during the fourth leaf age,the eighth leaf age,the twelfth leaf age decreased 75.2%,73.1%and 74.1%respectively,the K accumulation rate of K deficiency during the fourth leaf age, the eighth leaf age,the twelfth leaf age decreased 44.9%,38.3%and 37.4%respectively.Compared with the normal cotton,the dry matter accumulation of cotton under the condition of N,P and K elements deficiency declined 24.1%,13.4%and 24.0%respectively.【Conclusion】In this experiment condition, lacking N,P and K in prophase(before the eight leaf age) significandy delayed cotton growth and reduced the nutrient absorption,but lacking N,P and K in anaphase(after the twelve leaf age) greatly decreased the dry matter accumulation.Therefore,rational application of fertilizer according to the leaf age could timely supply nutrients to cotton,enhance nutrients' utilization efficiency and provide theoretical basis for cotton efficient production.