基于养分平衡和土壤测试的冬小麦氮素优化管理方法研究

以养分平衡和土壤测试为基础,把氮素供应与作物氮肥特性结合起来,通过田间试验研究冬小麦分期优化供氮量。结果表明:冬小麦播种前0～30cm土壤Nmin大于30kg/hm2时,不施基肥(氮),足以满足冬小麦从播种到返青期对氮素的需求;返青期保证供氮量90kg／hm2(0～60cm土壤Nmin 肥料氮),可以满足冬小麦从返青期到拔节期对氮素的需求;拔节期保证供氮量100kg／hm2(0～90cm土壤Nmin 肥料氮),可以满足冬小麦从拔节期到收获期对氮素的需求,最终达到目标产量。上述返青期90kg/hm2,拔节期100kg／hm2的优化供氮量下,氮肥利用率可达44％,收获后0～90cm土壤残留Nmin低于50kg/hm2,从而使氮素资源高效利用,并降低对环境污染的风险。在此基础上提出了一个基于养分平衡和土壤测试的冬小麦氮素资源分期优化管理方法。

Study on Nitrogen Optimized Management at Different Growing Stage of Winter Wheat Based on Nutrient Balance and Soil Test

Based on nutrient balance and soil testing, the field experiment was conducted to study optimized nitrogen supply at different growing stage of winter wheat. The main results were as follows: When soil Nmin of 0-30 cm was higher than 30 kg/hm2 before sowing of winter wheat, it can meet the demand of winter wheat for nitrogen from sowing to regreening stage, even though no basal N fertilizer was applied. When nitrogen supply by soil Nmin in 0-60 cm and fertilizer was 90 kg/hm2 at regreening stage, it can meet the demand of winter wheat for nitrogen from regreening to shooting stage. When nitrogen supply by soil Nmin in 0-90 cm and fertilizer was 100 kg/hm2 at shooting stage, it can meet the demand of winter wheat for N from shooting to harvesting stage. Under the condition of nitrogen supply 90 kg/hm2 at regreening stage and 100 kg/hm2 at shooting stage, N fertilizer recovery reached 44% and soil residual Nmin in 0-90 cm was lower than 50 kg/hm2 after winter wheat harvest. Optimized management method of N resource at different growing stage of winter wheat based on nutrient balance and soil testing was established according to these experiment''s results.