渭北旱地冬小麦监控施氮技术的优化  

Optimization of Nitrogen Fertilizer Recommendation Technology Based on Soil Test for Winter Wheat on Weibei Dryland

作　　者：曹寒冰[1] 王朝辉[1] 师渊超 杜明叶 雷小青 张文忠 张璐 蒲岳建 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]陕西省永寿农业技术推广中心,陕西永寿713400 [3]陕西省合阳农业技术推广中心,陕西合阳715300 [4]陕西省凤翔农业技术推广中心,陕西凤翔721400 [5]陕西省彬县农业技术推广中心,陕西彬县713500 [6]陕西省蒲城农业技术推广中心,陕西蒲城715500 [7]陕西省耀州农业技术推广中心,陕西耀州727100

出　　处：《中国农业科学》2014年第19期3826-3838,共13页Scientia Agricultura Sinica

基　　金：财政部;农业部现代农业产业技术体系建设专项(CARS-3-1-31);国家公益性行业(农业)科研专项(201303104;201103003);农业科研杰出人才培养计划

摘　　要：【目的】氮素是限制旱地小麦增产的主要养分因子,不合理施氮不仅难以增加小麦产量,还会造成土壤剖面硝态氮累积、氮素损失增大和氮素利用效率降低。优化氮肥用量推荐方法、解决旱地小麦不合理施氮问题,对旱地小麦可持续生产有重要意义。【方法】基于平衡土壤氮素携出,以稳定作物产量、培肥土壤和调控硝态氮残留为目标,对现有的土壤硝态氮监控施氮方案(施氮量=作物目标产量需氮量+肥料氮素损失量+收获/播前土壤硝态氮安全阈值(55.0/110.0 kg·hm-2)-环境氮素投入量-秸秆还田带入氮素量-种子带入氮素量-生长季土壤氮素矿化量-收获/播前1 m土壤硝态氮)进一步优化,得出公式:施氮量=作物目标产量需氮量+收获/播前土壤硝态氮安全阈值(55.0/110.0 kg·hm-2)-收获/播前1 m土壤硝态氮。应用这一方法在西北典型旱地冬小麦种植区渭北旱塬两年6县30个地块布置田间试验。【结果】在该区域由于不合理施氮或没有规范的氮肥推荐方法,不同试验地播种前1 m土壤累积硝态氮积累量变化较大,介于34.2—708.4 kg·hm-2,平均为165.2 kg·hm-2,其中有17块在小麦播种前超过110 kg·hm-2。优化后的监控施氮技术确定的小麦氮肥用量介于30.0—247.3 kg·hm-2,平均为128.4kg·hm-2,较农户习惯氮肥用量(171.6 kg·hm-2)减少25.2%。监控施肥和农户习惯施肥的小麦籽粒产量平均分别为5 658和5 489 kg·hm-2,籽粒氮含量为20.8和20.3 g·kg-1,两者均无显著性差异。监控施肥能够显著提高氮素利用率和氮肥偏生产力,较农户习惯施肥分别提高24.0%(由46.3%提高到57.3%)和130.1%(由34.9 kg·kg-1提高到80.3 kg·kg-1)。收获时,农户习惯施肥0—100 cm土层的硝态氮残留量介于17.4—203.4 kg·hm-2,地块间变幅大,平均为70.6 kg·hm-2;而监控施肥介于15.6—113.9 kg·hm-2,平均为51.4 kg·hm-2,稍低于预期的55 kg·hm-2的目标。在降水较多的夏闲期,�【Objective】Nitrogen（N） is the main nutrient factor limiting wheat yield increase on dryland. Unreasonable application of N fertilizer not only makes it difficult to increase wheat yield, but also leads to increased nitrate N（NO3--N） residual in soil, enhanced N losses, and reduced N use efficiency. Therefore, it is of great significance to optimize the method of N fertilizer recommendation and solve the problem of unreasonable N fertilizer application for the sustainable production of wheat on dryland.【Method】 Based on balancing N output from soil by crop production and aimed at stabilizing crop yield, improving soil fertility and regulating NO3--N residual, the present method for Recommendation of N fertilizer Based on Monitoring NO3--N in 1.0 m Soil（RNBM, N application rate = N required for the target crop yield ＋ Fertilizer N losses ＋ Safety threshold of NO3--N in 1 m soil at harvest or before sowing（55.0/110.0 kg·hm-2）- N input from environment- N input with straw retention- N input with seed- Soil N mineralization during winter wheat growing season- NO3--N in 1m soil at harvest or sowing） was optimized to be as： N application rate = N required for the target crop yield ＋ Safety threshold of NO3--N in 1 m soil at harvest or before sowing（55.0/110.0 kg·hm-2）-NO3--N in 1 m soil at harvest or before sowing. Using the optimized RNBM, two-year field experiments on 30 plots were carried out in six counties on Weibei Arid Tableland in Shaanxi Province. 【Result】 As the result of chronically unreasonable application of N fertilizer due to the lack of normative N fertilizer recommendation methods, it was found that in this region, the NO3--N residual in 1.0 m soil at sowing varied largely among different sites from 34.2 kg·hm-2 to 708.4 kg·hm-2, with the average to be 165.2 kg·hm-2and 17 of 30 sites higher than 110.0 kg·hm-2. Nitrogen application rates determined by the optimized RNBM ranged from 30.0 kg·hm-2 to 247.3 kg·hm-2, with the average of 128.4 kg·hm-2, which was

关 键 词：旱地 冬小麦 硝态氮 氮肥 优化 

分 类 号：S512.11[农业科学—作物学]