施氮量对枣棉间作系统棉花干物质和氮素积累的影响

以南疆主栽品种中棉所49为材料，通过4个尿素水平［纯N 0（N0）、 207（N1）、 310（N2）、 414（N3） kg/hm2］，研究了不同施氮量对枣棉间作体系中棉花的干物质动态增长以及氮素积累的影响。结果表明，各处理棉花干物质及氮素积累均符合Logistic方程，棉株生物量和氮素积累量在N0、 N1处理中表现出近冠区大于远冠区，N2、 N3则相反。近冠区过多或过少施氮推迟了棉株干物质快速积累起始时间和最大积累速率出现的时间，减少了干物质在生殖器官中的积累量，较高氮素处理引起的棉株代谢产物积累的减少量小于低氮或不施氮处理。适宜的施氮量利于棉花前期的生物量和氮素的快速积累，棉株有较大的光合产物吸收和积累速率以及较早的最大速率出现日，有利于产量的形成。氮肥施用量过多或过少均不利于棉花光合产物特征参数的协调。

Effects of different nitrogen fertilizer levels on dry matter and N accumulation of cotton under jujube and cotton intercropping

Dry matter and N accumulation of cotton cultivar, CCRI49, were studied under the jujube and cotton intercropping system at 4 nitrogen  levels, pure N 0 (N0), 207 (N1), 310 (N2) and 414 (N3) kg/ha. The results show that the cotton dry matter weights and nitrogen accumulations in different treatments are in the Logistic equations, and the biomass and N accumulation in the close crown areas of jujube are higher than those in the far crown areas under the N0 and N1 treatments, while they are opposite under the N2 and N3 treatments. The beginning times and maximum accumulated rates of rapid accumulation of dry matter are delayed when excess or insufficient N fertilizers are applied in the close crown areas, and the accumulations of dry matters in reproductive organs are reduced. The decreased values of metabolin caused by the higher N fertilizer are less than those of the low N treatmnet or non N treatment. It is shown that the optimal nitrogen rate could accelerate the accumulation of biomass and N at the earlt growth stages, improve excellent photosynthate absorption, accumulation rate and earlier present time of maximum N uptake rate, and benefit to the formation of high cotton yield. Excess and deficiency nitrogen applications are disadvantages for establishment of rational colony.