灌溉水平对冬小麦氮素吸收及氮素平衡的影响

应用15N示踪技术对不同灌溉条件下冬小麦的氮素吸收及氮素平衡进行了研究 ,结果表明 ,冬小麦的氮素积累及对肥料氮的利用率均以高灌处理较高 ,而肥料氮的损失量则以低灌处理较多。在冬小麦的氮素积累过程中 ,低灌的影响主要表现为冬小麦对肥料氮的吸收持续时间较短 ,尤其是对追肥氮的吸收主要集中在施肥后 2 0d内。在肥料氮素损失过程中 ,低灌导致肥料氮在施肥初期损失量过大 ,这是造成低灌条件下的肥料氮素损失总量较大的主要原因

EFFECT OF DIFFERENT IRRIGATION ON NITROGEN UPTAKE OF WHEAT AND N BALANCE

The effect of different irrigation on nitrogen uptake of wheat and N balance were investgated with 15 N tracer technique.The results showed that the amount of nitrogen uptake of wheat and recovery of fertilizer N under high irrigation was higher,and the loss of fertilizer N was lower than that under low irrigation.Under high irrigation,the absorptio of 15 N fertilizer of wheat lasted longer,while 15 N fertilizer at jointing stage was absorbed mainly within 20 days after fertilizer application under low irrigation. 15 N fertilizer was lost largely soon after fertilizer application and the amount of 15 N fertilizer lost was higher under low irrigation.