Impacts of tillage practices on ephemeral gully erosion in a dry-hot valley region in southwestern China

Abstract

Ephemeral gully (EG) erosion can cause soil loss and result in soil degradation. Appropriate tillage practices are beneficial to soil conservation and avail against soil erosion. Currently, how tillage contributes to soil erosion of EG at the catchment scale is still unclear. To quantify EG erosion and analyze the effects of tillage practice on EG erosion in a typical farmed dry-hot valley catchment, EGs under five tillage practices including conventional tillage (CT), contour ridge tillage in sugarcane land (CRT-40S), vegetable land (CRT-40 V) and in orange land (CRT-25), and without tillage in abandoned land (CK) were investigated. Five field surveys were conducted during two growing seasons from April 2013 to February 2015. The results showed that EG erosion was most serious after crops being harvested, followed by that before crops being planted, after crops being planted subsequently. The average EG erosion modulus of two growing seasons was 231.85 t km−2 a−1. Considering the effect of tillage practices, EG erosion modulus was the largest under CK, followed by CT, CRT-25, CRT-40 V and CRT-40S subsequently, indicating that contour ridge tillage practice would benefit for controlling EG erosion. We found that farmlands with conventional tillage practice had to be abandoned when EGs were developed intensively. But EG erosion did not terminate after being abandoned. The redundancy analysis further confirmed that tillage practice was the dominant control on EG erosion in the dry-hot valley. Our results suggested that appropriate tillage practice such as contour ridge tillage can efficiently restrain EG erosion in the dry-hot valley.