不同灌溉方式下土壤中氮素分布和对棉花氮素吸收的影响

目的]研究滴灌和漫灌下不同施肥量对棉花氮素吸收的影响.滴灌和漫灌不同灌溉方式在不同施肥处理(N 240、360和480 kg/hm2)下0～100 cm土层土壤NO3--N分布及棉花氮素吸收.方法]通过网室土柱模拟实验,研究滴灌和漫灌在不同施肥处理(N 240、360和480 kg/hm2)下,0～100 cm土层土壤NO3-N分布及棉花的氮素吸收.结果]滴灌各施肥处理硝酸盐主要积聚在40～60 cm土层,漫灌各施肥处理主要积聚在60～80 cm土层.棉花氮肥利用率相对较低为16.47;～28.37;;不同施肥量下土壤0～100 cm土层硝态氮残留量较高为60;～81;,且N240和N480施肥处理漫灌残留量均高于滴灌;氮肥总回收率比较高,各处理均达到87;以上.结论]滴灌、漫灌下作物氮素吸收量差异不显著.

Soil Nitrate-N Distribution and Effect on Cotton Plant N Absorption under Different Irrigation method

【Objective】This paper studied the distribution of nitrate-N in soil profile of 0-100 cm and N absorption under drip irrigation and flooding irrigation in cotton field.【Method】Using soil column method in a mesh house,N was applied at the rates of 240,340 and 480 kg/hm2 respectively.【Result】The result showed that the content and moving depth of nitrate-N increased with the increase of nitrogen fertilizer rate,both in flooding irrigation and drip irrigation.The highest N-residuals appeared at 40-60 cm depth in soil profile under drip irrigation,while in flooding irrigation,nitrate-N concentrated at 60-80 cm depth in soil profile.N use efficiency of cotton was relatively low,from 16.47% to 28.37%;The residue of nitrate-N at 0-100 cm was between 60%-81%,and NUE under drip irrigation in N240 and N480 treatment was higher than in flooding irrigation.The rates of total N recovery was higher than 87% at all the treatments.【Conclusion】No significant differences were observed in cotton N absorption amount between drip irrigation and flooding irrigation.