冬小麦土壤氮素表观平衡率估算和氮肥决策

Estimation of Apparent Soil-Nitrogen-Balance Rate and Nitrogen Management for Winter Wheat

本文以土壤氮素表观平衡值和剖面无机氮动态为依据,通过两年田间试验的验证,提出在北京地区冬小麦亩施氮素12～15 kg 时可以获得较高产量,而且土壤氮素基本平衡。半数以上的氮素化肥基施或拔节后追施可能引起 NO_3^--N 向浅层地下水移动。试验结果表明少施基肥,起身初期一次施用尿素追肥并结合灌水,不仅可以提高产量,而且可以减少氮肥损失和对环境污染的可能。

Based on apparent nitrogen-balance-index and fluctuation of Nmin in soil profile,the two- year field study demonstrated that winter wheat got a yield of 4950～6900kg·hm^(-2)and soil nitrogen kept a balance with application of 180～225kg·hm^(-2)in Beijing area.More than half of that amount of chemical fertilizer-N used as base dressing or top dressing after booting stage would cause NO_3-N leaching to the underground water.It was suggested that with the reduced amount of basic fertilizer and top dressing of urea in single-dose before elongation,not only relatively high yield of winter wheat,but also the reduction of environmental pollution could be obtained.