自然降雨条件下红壤坡地磷素随径流垂向分层输出特征

发布时间：2018-12-09 19:55

【摘要】：为研究自然降雨条件下红壤坡地磷素径流输出特征,采用野外大型土壤水分渗漏装置对活地被物覆盖、死地被物敷盖和裸露对照这3种处理的地表径流、壤中流和地下径流的磷素输出开展了为期一年的试验观测.结果表明:(1)3种处理下径流总磷和可溶性磷浓度变化趋势总体表现为地表径流略高于壤中流,并随着土层深度的增加有降低趋势;总磷累积输出量大小排序为裸露(1.61 kg·hm~(-2))敷盖(1.33 kg·hm~(-2))覆盖(0.82 kg·hm~(-2));(2)裸露对照坡地磷素输出以地表径流为主要途径,占总磷径流输出总量的57%,壤中流和地下径流输出量分别占6%和37%;有覆盖和敷盖措施的坡地磷素输出以地下径流为主,占总磷径流输出总量的71%以上,而地表径流输出量则不足14%;(3)各处理中地表径流、壤中流和地下径流磷素输出均以颗粒态为主,占磷输出总量的64%~97%.地下径流是红壤坡地磷素流失不可忽视的重要通道,覆盖和敷盖措施可控制磷素径流流失总量,但未能显著降低磷素径流流失浓度.
[Abstract]:In order to study the characteristics of phosphorus runoff output in red soil sloping land under natural rainfall, the surface runoff of three treatments, I. e., live land cover, dead land cover and naked control, was covered by large soil water leakage device in the field. Phosphorus output from soil and underground runoff has been observed for a year. The results showed that: (1) the change trend of total phosphorus and soluble phosphorus concentration in runoff under three treatments was that surface runoff was slightly higher than that in soil and decreased with the increase of soil depth; The order of total phosphorus cumulative output is bare (1. 61 kg hm~ (-2) cover (1. 33 kg hm~ (-2) covering (0. 82 kg hm~ (-2);). (2) the surface runoff was the main way of phosphorus output in bare control slope land, accounting for 57% of total phosphorus runoff output, and 6% and 37% of total phosphorus runoff output in soil and underground runoff, respectively; The phosphorus output of slope land with mulching and covering measures is mainly underground runoff, accounting for more than 71% of total phosphorus runoff output, but the surface runoff output is less than 14%. (3) Phosphate output from surface runoff, soil flow and underground runoff was mainly granular, accounting for 640.97% of total phosphorus output. The underground runoff is an important channel for phosphorus loss in red soil sloping land. The total amount of phosphorus runoff loss can be controlled by mulching and covering measures, but the concentration of phosphorus runoff loss can not be significantly reduced.
【作者单位】：江西省水土保持科学研究院;江西省土壤侵蚀与防治重点实验室;
【基金】：国家自然科学基金项目(41401311,41601297)
【分类号】：X144;X52

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