Agricultural land use and management weaken the soil erosion induced by extreme rainstorms

Abstract

Elucidation of the soil erosion processes induced by extreme rainstorms provides better understanding and responding of agricultural system to global climate change. However, less attention has been given to the field investigation of soil erosion in the actual event of heavy rainfall. The purpose of this study was to assess the response capacity of agricultural land use and management to the heavy rainfall on northern rocky mountain area of China. (1) Compared with abandoned land and forest-grass land, the agricultural land experienced strong erosion. The erosion modulus (Em) of terrace land dominated by embankment failure (9490 t km−2) was less than that of sloped cropland dominated by rill/gully erosion (11,252 t km−2). (2) Concentrated flow was the main factor causing soil erosion, and almost all erosion occurred in the flow path. (3) Appropriate agricultural land use and management, such as terraced land, drainage channels, bio-embankments and plant pit cofferdam, could weaken soil erosion during extreme rainstorms. However, plastic film mulching aggravated soil erosion by rapidly forming concentrated flow. (4) To reduce the soil erosion on agricultural land under heavy rain event, we suggest managers should protect the bare soil with vegetation, conduct drainage measures, build high standard terraces in appropriate locations, and strengthen farmer training on agronomic measures. Our results could be applied to the response strategies of agricultural systems to global climate change.