中文摘要：

设置高水（260mm）、中水（200mm）、低水（140mm）3水平的灌水量和高氮（270kg·hm-2）、中氮（180kg·hm-2）、低氮（90kg·hm-2）3水平的施氮量,进行完全组合设计,研究膜下分区交替滴灌和施氮对棉花干物质累积与氮肥利用的影响.结果表明：膜下分区交替滴灌棉花干物质量在中氮高水和高氮高水处理最高;与高氮高水处理相比,中氮高水处理干物质累积的施氮利用效率提高了34.0%～44.6%（平均提高34.7%）,灌水利用效率降低了6.4%～10.7%（平均降低10.2%）.对于棉花氮素累积,中氮高水处理的的施氮利用效率最高,高氮中水处理的灌水利用效率最高;与高氮中水处理相比,中氮高水处理的施氮利用效率提高了29.0%～41.7%,灌水利用效率下降了5.5%～14.0%.在棉花产量较高的水氮耦合处理中,中氮高水处理的棉花氮回收率、氮肥农学利用效率和表观利用效率均高于高氮中水和高氮高水处理,而氮肥吸收比例和氮肥生理利用效率无显著差异.表明中氮高水处理最有利于膜下分区交替滴灌水氮耦合效应的发挥.

英文摘要：

A field experiment with complete combination design was conducted to study the effects of partitioning alternative drip irrigation with plastic mulch and nitrogen fertilization on the dry matter accumulation and nitrogen use efficiency of cotton plant.Three levels of irrigation（260,200,and 140 mm） and of nitrogen fertilizer（270,180,and 90 kg·hm-2） were installed.The cotton dry mass was the highest in treatments medium nitrogen/high water and high nitrogen/high water.As compared with that in high nitrogen/high water treatment,the nitrogen use efficiency for dry matter accumulation in medium nitrogen/high water treatment was increased by 34.0%-44.6%,with an average of 34.7%,while the water use efficiency was decreased by 6.4%-10.7%,averagely 10.2%.As for the nitrogen accumulation in cotton plant,the nitrogen use efficiency was the highest in medium nitrogen/high water treatment,and the water use efficiency was the highest in high nitrogen/medium water treatment.Compared with high nitrogen/high water treatment,medium nitrogen/high water treatment increased the nitrogen use efficiency for cotton nitrogen accumulation by 29.0%-41.7%,but decreased the water use efficiency for cotton nitrogen accumulation by 5.5%-14.0%.Among the treatments of coupling water and nitrogen of higher cotton yield,treatment medium nitrogen/high water had the higher cotton nitrogen recovery rate,nitrogen agronomic efficiency,and apparent use efficiency than the treatments high nitrogen/medium water and high nitrogen/high water,but no significant differences were observed in the nitrogen absorption ratio and nitrogen physiological efficiency.Treatment medium nitrogen/high water was most beneficial to the coupling effects of water and nitrogen under partitioning alternate drip irrigation with plastic mulch and nitrogen fertilization.