| 封志明,方玉东.甘肃省县域农田氮素投入产出平衡研究[J].干旱地区农业研究,2006,(2):152~158 |
| 甘肃省县域农田氮素投入产出平衡研究 |
| Analysis on nitrogen input／output balance in croplands on county level in Gansu province |
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| DOI：10.7606/j.issn.1000-7601.2006.02.34 |
| 中文关键词: 氮素平衡 平衡模型 县域 甘肃 |
| 英文关键词:Gansu province county level nitrogen balance balance model |
| 基金项目:中国科学院知识创新工程重要方向项目(KZCX3-sw-333) |
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| 中文摘要: |
| 盆栽或田块尺度上土壤养分的试验研究,难以阐明区域尺度上农田养分的平衡问题。本研究通过分析影响农田氮素平衡的投入与产出因素,确立了6个投入项、5个产出项,建立了县域农田氮素平衡模型,根据模型研究了甘肃省2000年县域农田氮素平衡特征及其空间规律性。结果表明,甘肃省2000年农田氮素共投入48.52×104 t,产出59.87×104 t,亏缺11×104 t,亏缺率为23.4%,农业生产以过度消耗地力为特征;在县域水平上,甘肃省西部河西走廊及其以北地带、祁连山地等地区农田氮素存在盈余,盈余量大体在0.002 t/(hm2.a)0.4 t/(hm2.a)变化;甘肃东中部地区农田氮素普遍亏缺,亏缺量大体在0.006 t/(hm2.a)0.4 t/(hm2.a)变化。2000年甘肃省农田氮素投入化肥比重最大,其次是有机肥,化肥、有机肥与其它来源的氮素比例大体为65∶30∶5。在农田氮素的产出结构中,土壤侵蚀对农田氮素的输出影响最大,农田氮素的生物产出次之,农田氮素的生物有效产出率为34.15%。 |
| 英文摘要: |
| It is difficult to illustrate the nitrogen-balanced mechanism of farmlands on regional level through pot-cultivation and field trials.Based on the analysis of output and input factors,6 inflows and 5 outflows were chosen to establish the nitrogen-balanced model of farmlands on county level.The surplus and deficit of nitrogen in Gansu province in 2000 were calculated and the attributes of its spatial distribution were explored.The results indicated:(1) The nitrogen input and output of farmlands in Gansu province in 2000 were 48.52×104 t and 59.87×104 t respectively,so the deficit of nitrogen in farmlands was 11×104 t and the deficit ratio was 23.4%,showing that the excessive depletion of nitrogen was evident.N surplus was widespread in Qilian mountain,Hexi corridor and its northern regions,and N deficit was prevalent in the east and middle regions of Gansu.(2) In the structure of N input in Gansu province in 2000,chemical fertilizer took the highest proportion, and next was organic fertilizer.The ratio of chemical fertilizer,organic fertilizer and other nitrogen sources was 65∶30∶5.(3) In the structure of N output,the proportion of soil erosion was the largest,and the biomass output took the second place.The effective output rate of biomass N in farmlands was 34.15%. |
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