| 摘要: |
| 利用室内模拟降雨试验,研究了在坡面施入硝酸铵对土壤矿质氮素随地表径流流失和入渗的影响,初步探讨了降雨-地表径流-土壤矿质氮素的有效作用深度(Effective Depth of Interaction,EDI),分别用反推法和拐点法确定了不施肥试验和施肥试验时的土壤矿质氮素EDI。结果表明:①与不施肥相比,施肥增加了土壤矿质氮素的地表流失量,施25,50和100 g NH4NO3处理矿质氮分别多流失了55.22,73.32和85.50 mg/m2;②施肥使土壤肥料的入渗量增加,但对肥料的入渗深度和土壤矿质氮素EDI影响很小;③同一坡面不同坡位NO-3-N的EDI值不同,表现为坡中下部较大,坡顶部和坡底部均较小。避免在雨季大量表施速效氮肥,是减少矿质氮流失的关键。 |
| 关键词: 模拟降雨 黄土坡面 氮素迁移 有效作用深度 |
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| 基金项目:国家自然科学基金项目（90610030）；陕西省教育厅省级重点实验室重点科研计划项目(05JS35)；黄土高原土壤侵蚀与旱地农业国家重点实验室基金项目(10501-142)；西安理工大学优秀博士论文基金项目(106-210623) |
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| Soil nitrogen transport affected by applying NH4NO3 on the loess slope |
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| Abstract: |
| According to the results of simulated runoff experiments,the soil nitrogen transport affected by applying NH4NO3 on the loess slope are studied.Meanwhile,the effective depth of interaction (EDI) of runoff with soil mineral nitrogen is analyzed,and the methods to confirm EDI of both NH4NO3-applied experiments and no-NH4NO3-applied ones are recommended.The results are as follows.①There is no evident influence of the same type of fertilization on soil erosion.But it has a great impact on the amount of soil mineral nitrogen loss in runoff and leaching.Compared with that of no-NH4NO3-applied,the loss amount of mineral nitrogen by surface runoff and sediment in the NH4NO3-applied experiments with 25,50 and 100 g NH4NO3 increases by 55.22,73.32 and 85.50 mg/m2,respectively.Meanwhile,the infiltration of nitrate is augmented by NH4NO3-applied.②The same type of fertilization can rarely influence the depth of leaching and the EDI of soil NO-3-N.③The EDI of soil NO-3-N is deeper than that of soil NH+4.There are different spatial distributions of the EDI along the slope land,deeper in the middle and lower parts,while shallower in the upper and lower parts.To reduce the loss amount of soil mineral nitrogen by runoff and sediment，largely applying NH4NO3 in rainy season should be avoided. |
| Key words: artificial rainfall,loess slope land,soil nitrogen release and transport,effective interaction depth |
