咸水滴灌条件下棉花生长和氮素吸收对水氮的响应

[目的]研究咸水滴灌条件下棉花生长和氮素吸收对水氮的响应.[方法]试验设置了3种灌溉水盐度0.35(S1)、4.61(S2)和8.04(S3)dS/m,2个灌水量405(L1)和540(L2)mm以及2个施氮量240(N1)和360(N2) kg/hm2.[结果]棉花的株高在生长前期主要受灌溉水盐度、灌水量及二者的交互作用和盐度、灌水量和施氮量三者的交互作用影响显著,生长后期主要受灌水量的影响显著.高灌水量L2(540 mm)各处理株高为S2＞S1＞S3,施氮量对株高的生长差异影响不显著.棉花茎和叶的干物质积累量受灌溉水盐度、灌水量和施氮量其中二者的交互作用影响显著,而棉铃和总的干物质积累量受交互作用不显著.[结论]棉花的氮素吸收量受灌溉水盐度、灌水量和施氮量三因素及其两者或三者的影响显著;随着灌溉水盐度的增加,棉花的氮素吸收量呈下降的趋势;而氮素吸收量随着灌水量的增大显著增加,表明增加灌水量可促进氮素吸收.

Cotton Growth and Nitrogen Uptake in Response to Rates of Water and Nitrogen Under Drip Irrigation with Saline Water

A field experiment was conducted to study cotton growth and nitrogen uptake in response to different water and nitrogen application rates under drip irrigation with saline water.Three irrigation water salinity levels were set as 0.35(S1),4.61(S2) and 8.04(S3) dS/m;two water and nitrogen application rates were set as 405(L1),540(L2) mm and 240(N1),360(N2) kg/hm2,respectively.The results showed that plant height of cotton were influenced significantly by water salinity,application rates of water and interaction between them,and the interaction among water salinity,water application rate and nitrogen application rate at earlier growth stage,but mainly affected by water application rate at the later stage.The order of plant height were S2 > S1 > S3 with water application 540 mm(L2),while no significant difference were found on the growth of plant height between two nitrogen rates.The dry matter accumulation of the cotton stem and leaves are influenced significantly by the intreaction among water salinity,application rates of water and nitrogen application,but cotton bolls and total dry matter accumulation are not significantly influenced by the interaction.Nitrogen uptake of cotton was influenced significantly by water salinity,application rates of water and nitrogen,and interactions between two of them or among the three factors.Total nitrogen content of cotton reduced with water salinity increasing,but increased evidently when water application rate was increased.Those results suggest that higher water application rate can enhance nitrogen uptake of cotton under drip irrigation with saline water.