不同施氮量对夏玉米产量、氮肥利用率及氮平衡的影响

Effect of different N rates on yield of summer maize,fertilizer N recovery and N balance

通过田间小区试验研究了不同施氮量对夏玉米产量、氮肥利用率、硝酸盐淋溶及氮平衡的影响。结果表明，施氮对夏玉米子粒有显著的增产作用，但随施氮量的增加产量变化不大。氮肥利用率在9．2％-22．6％之间，随施氮量的增加而降低。施氮可明显提高0-160cm剖面土壤NO3^--N含量，而且随深度的增加NO3^--N含量呈降低趋势，累积峰主要在20—60cm之间。玉米收获后，随着施氮量的增加氮素的损失量增加，各施氮处理的硝态氮残留量在121～221kg／hm^2之间，以N250处理的残留量最高，残留率近65％。

A field experiment was carried out to study the effects of different N rates on the yield, fertilizer N recovery, nitrate leaching and N balance in summer maize. The results indicated that N application could increase the grain yield of summer maize significantly, but which didn＇t change too much with N rate increasing. Fertilizer N recovery of different N treatments was ranged from 9.2 % to 22.6 %, which decreased with the N rate increasing. N application also increased NO3^- - N content in soil profde of 0 to 160 cm depth, and which decreased with the soil depth, the peak point was between 20 cm and 60 cm. After summer maize was harvest, apparent N losses increased with N rate increasing. Soil residual Nzi. was ranged from 121 to 221 kg/hm^2 in 0 - 200 cm, the highest NO3^- - N residual of 220.6 kg/hm^2 was in the treatment of N250, apparent N residual rate was nearly 65 %.