| 赵琳,李世清,李生秀,张兴昌,吕丽红,邵明安.半干旱区生态过程变化中土壤硝态氮累积及其在植物氮素营养中的作用[J].干旱地区农业研究,2004,(4):14~20 |
| 半干旱区生态过程变化中土壤硝态氮累积及其在植物氮素营养中的作用 |
| Accumulation of soil nitrate nitrogen in the process of ecological and its effcts in plant nitrogen nutrition in semiarid areas |
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| DOI：10.7606/j.issn.1000-7601.2004.04.02 |
| 中文关键词: 半干旱地区 石灰性土壤 残留硝态氮 生物有效性 |
| 英文关键词:semiarid area calcareous soil residual NO-3-N bioavailability |
| 基金项目:国家自然科学基金项目(30230230;40371076;40171063)； 2002年度教育部全国优秀青年教师资助项目(20022096)； 国家重点基础研究发展规划项目(G2000018605)； 黄土高原土壤侵蚀与旱地农业国家重点实验室基金项目(10501-104) |
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| 中文摘要: |
| 半干旱区农田生态系统石灰性土壤施入的氮肥和有机氮矿化产物,除植物吸收、微生物固定、粘土矿物固定、挥发损失和反硝化损失外,有相当一部分最终以NO-3-N形态残存在土壤中。土壤剖面中的残留NO-3-N通过对流和扩散等途径,逐渐向深层移动,脱离根区。影响土壤剖面NO-3-N残留累积和淋溶的主要因素包括施氮量、植物吸氮量、前作收获后的植物残留物、氮肥种类、施氮方式和降雨量等。残留NO-3-N本身具有很高的生物有效性,但能否被植物吸收利用,关键在于残留NO-3-N所在深度及其是否能够到达根区。在半干旱区降雨量较高的雨季,NO-3-N向深层移动,而在较干旱条件下即使土壤剖面深层NO-3-N,也可随水分上移供根系利用,因此土壤剖面中累积的残留NO-3-N显著影响氮肥肥效果,许多地方用一定深度土层中累积的NO-3-N作为土壤供氮指标,以减少NO-3-N的淋溶损失和提高氮肥肥效。过去对半干旱地区土壤剖面中NO-3-N的研究主要涉及3方面,一是土壤剖面中NO-3-N的残留累积及其影响因素,二是与根系分布深度相适应土层中残留NO-3-N对氮肥肥效的影响,三是根据土壤剖面中的残留NO-3-N确定农田作物施氮量。在分析过去研究结果的基础上,提出了今后需进一步深入研究的科学问题。 |
| 英文摘要: |
| Of applied N fertilizer and mineralized organic N in calcareous soil in the agro-ecosystem of semi-arid areas, apart from plant uptake, microbial-fixed, clay mineral-fixed, volatilization loss and denitrification loss, significant amount of these N remains in the soil as NO-3-N. Residual NO-3-N in soil profile moves to depth by convection and diffusion, leaving the root zone step by step. The main factors that affect the accumulation and leaching of NO-3includes: N input, plant take up, plant residual after pro-harvest, N fertilizer kinds, N fertilizer applying manner and rainfall et al. Residual NO-3-N itself has high bioavailability. Whether it can be taken up or not depends on the depth of NO-3-N and the distance to the root zone. During the heavy rainfall season in semiarid areas, NO-3-N moves to depth easily; but in dry condition, even NO-3-N in deep soil can move up with water to the root zone and be taken up. As a result, residual NO-3-N accumulated in soil profile impacts N fertilizer use efficiency remarkably. In many regions, residual NO-3-N at certain depth is used as the index of N supplied N to soil to reduce the NO-3-N leaching and improve N fertilizer use efficiency. According to past researches of NO-3-N in soil profile in semiarid areas, three aspects are concerned: first, accumulation of residual NO-3-N in soil profile and the factors that affects it; second, residual NO-3-N that coincides with root depth contributes to N fertilizer use efficiency; third, the determination of rational N input according to residual NO-3-N in soil profile. On the basis of the analysis above, a few scientific problems that should be solved in future research are emphasized. |
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