滴灌条件下不同产量水平棉花各生育期需肥规律的研究

对不同产量水平的滴灌棉花各生育期定期定点采集有代表性的植株样品,分析其干物质N、P、K含量,研究不同产量水平滴灌棉花各生育期吸收N、P、K的量与比例及其区别。结果表明:滴灌棉花在苗蕾期对氮素的吸收是占主要的,占棉花这时期吸收养分总量的38.21%~50.75%。蕾期到花铃期对养分的需求量最大,吸收N占棉花整个生育期吸收总N的83.55%~66.27%、吸收P2O5占总P2O5的74.02%~52.39%、吸收K2O占总K2O的80.14%~76.52%。滴灌棉花对N、P、K的需求也具特色即对氮的需求较早,且量也较大;磷的需求稍晚,但要求持续时间最长;钾素的需求时间和强度则居于氮、磷之间。高产棉株单位面积上吸收N、P2O5、K2O的量高于一般产量和中高产棉株的吸收量,并且对K2O吸收的绝对量最大。不同产量棉株对N、P2O5、K2O养分吸收比值总体上是相近的,但在各生育期养分吸收比值有差异。

A Study of Pattern of Requirement of Fertilizer in Different Cotton Developmental Stage under Drip Irrigation Condition

The representative samples of plants with different levels of cotton production under the drip irrigation condition were collected,the content of N,P,K in the dry matter were analyzed,the status of the N,P,K proportion and absorption in different cotton yield under the drip irrigation condition were studied. The results showed that:nitrogen absorption is a major demand at seedling stage and bud stage under the drip irrigation condition,accounts for 38.21%-50.75% in this period of the cotton.The demand for nutrient from bud stage to boll stage is the greatest,the absorption of N accounts for 83.55%-66.27% in all the cotton yield,the absorption P2O5 accounts for 74.02%-52.39% in all of the absorption P2O5,the absorption K2O accounts for 80.14%-76.52% in all of the absorption K2O.The demand of N,P,K is special in the cotton yield under the drip irrigation,the demand for N is earlier and higher,the demand for P2O5 is later and the longest.In high yield cotton field the absorption of N,P2O5,K2O is higher than that in medium high yield and its yield in per unit area.And the absorption of K2O is the largest.The nutrient absorption ratio is similar on the whole,but in the different growth period the nutrient absorption ratio has differences.