文章基本信息

标题：SUBSURFACE NITROGEN TRANSFER OF SLOPING FARMLAND IN PURPLE SOIL UNDER DIFFERENT PRECIPITATION INTENSITIES
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作者：Meixiang Xie ; Zhanyu Zhang ; Pingcang Zhang 等
期刊名称：Fresenius Environmental Bulletin
印刷版ISSN：1018-4619
出版年度：2017
卷号：26
期号：11
页码：6479-6491
语种：English
出版社：PSP Publishing
摘要：The nitrogen transfer of sloping farmland affects the water environment and crop yields in Three Gorges Reservoir area. Laboratory experiments were conducted to study subsurface nitrogen transfer in purple soil subjected to different precipitation intensities. Simulated precipitation events of three intensities (low [1 mm/min], moderate [1.5 mm/ min] and high [2 mm/min]) were performed to observe soil water content and nitrogen transfer in two soil layers. The upper soil layer was at depths of 15 cm and the lower soil layer was at depths of 35 cm in the soil tank. Four observation spots (upper layer [spots 1, 2, 3 and 4]and lower layer [spots 1#, 2#, 3# and 4#]) were set along the slope equidistantly in each layer. The results showed that a prolonged low intensity precipitation is more likely to cause rapid regression of soil water content than a short high precipitation. The progress of N03-N and TN transfer coincided positively with the soil water content but N03-N displayed contrasting trends between the upper and the lower soil layer. The NH4-N and TN concentrations revealed no remarkable spatiotemporal difference but distinguishing distributions between two soil layers. Additionally, the TN concentrations displayed the least growth at spots 4 and 4#. This study showed prominent accumulation of NO3-N and TN concentrations down the slope. The increase in precipitation intensity promoted the velocities of nitrogen transfer, and mean concentrations of nitrogen had significant differences subjected to three precipitation intensities. Study results provide new insights into the spatiotemporal response of subsurface nitrogen transfer to precipitation.
关键词：Eight spots;precipitation intensity;soil layers;soil water content;spatiotemporal features