袋控缓释条件下硝态氮、铵态氮对桃尿素吸收、分配的影响

采用15N示踪技术,在袋控缓释条件下,研究不同形态氮素对当年生毛桃尿素态氮吸收分配的影响。结果表明:单独尿素处理、尿素与硝态氮混施、尿素与铵态氮混施,尿素与硝态氮、铵态氮按1∶1∶1混施4个处理15N利用率分别为13.81%、10.92%1、5.53%和15.78%,尿素与铵态氮混施、尿素与硝态氮、铵态氮1∶1∶1混施显著高于其它处理,均能提高植株对尿素态氮的吸收利用;而尿素与硝态氮混施,15N利用率显著低于其它处理,降低了植株对尿素态氮的吸收利用。从15N在植株不同器官的分配来看,各处理植株叶片的15N分配率最高,均占植株总吸收量的60%以上,其它依次为根主干枝梢。植株总吸氮量以尿素与铵态氮混施处理最高,但该处理表观生长量低于尿素与硝态氮混施处理。

Effect of NO3- -N and NH4+ -N on Urea Absorption and Distribution in Peach under Coated Controlled Release Conditions

The effects of different nitrogen forms on absorption and distribution of urea in peach were studied under bag-coated controlled release condition using the 15N trace technique.The results showed that the utilization rate of 15N was 13.81%,10.92%,15.53% and 15.78% respectively in four different treatments which were urea alone(T1),urea mixed with nitrate(T2),urea mixed with ammonia nitrogen(T3) and the mixed fertilizer of urea,nitrate and ammonia nitrogen at the ratio of 1∶1∶1(T4).The utilization rate of urea nitrogen could be increased significantly by T3 and T4 treatments,but decreased by T2 treatment.The distribution of 15N was higher in leaves than the other organs,accounting for over 60% of the total absorption.The rank of others was roots>trunks>branches.The total nitrogen absorption was the highest when urea mixed with ammonium nitrogen,but its apparent growth amount was lower than that of urea mixed with nitrate.