膜下滴灌棉花水氮耦合对其干物质和水分利用效率的影响

Impact of Coupling of Water and Nitrogen on Dry Matter and Water Use Efficiency of Cotton under Plastic Mulching by Drip Irrigation

在膜下滴灌条件下,设置不同水、氮用量,测定不同生育期各处理的植物干物质积累和土壤水分含量,结合试验区详细的气象资料,计算棉田各处理水分利用效率。结果表明,随着氮肥用量的增加,棉花干物质积累的快速增长期推迟,最大积累速率增加,棉花干物质的快速增长期在初花-盛铃期,持续45 d左右,棉花总干物质随氮肥用量的增加而增加,灌水量对干物质积累也表现出同样的趋势。干物质水分利用率(WUE)随着灌溉水量、施氮量的增加呈现先增加而后降低的趋势。试验中最优水氮组合为灌水4 800 m3/hm2、施氮肥300 kg/hm2。在这个组合下,棉花干物质积累、水分利用效率和产量均达到最大。

A field experiment with water and nitrogen at different levels was carried out to evaluate effects on dry matter accumulation and water use efficiency（WUE） in cotton.Different treatments of water and nitrogen were set,and cotton dry matter accumulation and soil moisture were measure at different growth stages,detailed meteorological data of experimental district were applied to calculate WUE of different treatments.The total dry matter weight was increased with the increment of nitrogen（N） fertilizer amount,fast rising periods was delayed,but the maximum rates of accumulation was increased,the fast rising period of dry matter was from early flowering stage to boll full stage and sustained about 45 days.The irrigation water showed the same trends.The research also indicated that WUE of dry matter was increased at first and then decreased with water and N added.Based on the results obtained in this experiment,the optimum combination of water and N was the irrigation 4 800 kg/hm2 and N 300 kg/hm2.Under these conditions,the dry matter accumulation and yield of cotton was expected the maximum.