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采用人工模拟降雨装置,以华南地区典型雨强65、120 mm/h及坡度5°为实验条件,对华南红壤横向径流和纵向淋失的氮素流失规律进行了研究。结果表明:横向地表径流和其它形式均为2种雨强下雨水的主要分配途径,雨水在横向地表径流中的分配比例均超过39%,大于纵向淋失和横向壤中流的分配比例之和。2种雨强下横向地表径流总氮、硝态氮和氨氮流失比例均超过90%,远大于相应雨强下的壤中流与入渗流失比例,横向地表径流是各形态氮素流失的主要途径;雨强由65 mm/h增大至120 mm/h时,地表径流造成的氨氮、硝态氮和总氮流失量增加到2.42~2.67倍,淋溶损失造成的氨氮、硝态氮和总氮流失量则增加到1.42~2.33倍,雨强对地表径流各形态氮素流失的影响比淋失的要大。
The artificial rainfall simulator was used to study the law of nitrogen loss in horizontal runoff and longitudinal leaching of red soils in southern China with the typical rainfall intensity of 65,120 mm / h and the gradient of 5 ° in southern China. The results show that both horizontal surface runoff and other forms are the main distribution ways of rainwater under two kinds of rainfall intensity. The distribution proportion of rainwater in horizontal surface runoff is over 39%, which is greater than the sum of distribution proportion of vertical leaching and lateral flow. The ratio of total nitrogen, nitrate nitrogen and ammonia nitrogen loss in the transverse surface runoff exceeded 90% under the two kinds of rainfall intensity, which was much larger than the ratio of infiltration and infiltration under the corresponding rainfall intensity. The lateral surface runoff was the main way of nitrogen loss ; When the rainfall intensity increased from 65 mm / h to 120 mm / h, the ammonia nitrogen, nitrate nitrogen and total nitrogen loss caused by surface runoff increased to 2.42-2.67 times. The ammonia nitrogen, nitrate nitrogen and total nitrogen The amount of nitrogen loss increased to 1.42-2.33 times. The effect of rainfall intensity on the loss of nitrogen from the surface runoff was greater than that from leaching.