Effect of topographic variations and tillage methods on gully erosion in the black soil region: A case‐study from Northeast China

Abstract

Gully erosion is considered to be a severe land degradation process around the world. The combined effects of tillage methods and topographic variation on gully erosion are poorly understood. This study investigated permanent gullies in three farmland, geomorphic areas in the black soil region of Northeastern China: low mountains and hills, tableland, and rolling hill areas. Cross-sectional measurements were used to obtain estimates of volumetric soil loss from the gullies. Digital contour maps and remote sensing images were used to obtain the topography and row direction data. The results showed that tableland area had the greatest volumetric soil loss and was the most prone to develop gully erosion, followed by the low mountains and hills, and finally the rolling hill areas. Topography was the dominant control on gully erosion and volumetric soil loss and length density increased first and then decreased as a function of increase of slope gradient. Farmland with slope gradient between 15 and 20 had the most serious gully erosion. Hillslope gullies were classified into three types by morphological indicators. Compared to other geomorphic areas, low mountains and hills had the most gully types and the greatest variability of morphology. Surface areas and volumes were related to gully type. Different tillage methods have affected the frequency of gully occurrence. Cross-slope tillage areas were more prone to develop gully erosion than contoured tillage and up and down slope tillage areas, especially for farmlands with slope of 5 to 10 . The results suggest that gully erosion could be reduced if up and down slope tillage was used for slope gradients less than 15 and contoured tillage was used for slope gradient greater than 15 . This study demonstrates the combined effect of topographic variations and tillage methods on gully erosion, and highlights the importance of considering different tillage methods under different geographical conditions to control gully erosion.

Short‐term conservation tillage degrades soil infiltration properties in the black soil region of Northeast China

“…Therefore, in the initial stages of the implementation of conservation tillage management, it is necessary to implement appropriate drainage measures to mitigate the intensification of soil erosion, especially the development of gully erosion. In the same region, the result of Tang et al (2020Tang et al ( , 2022 indicated that tillage management significantly affects the development of ephemeral gully and CT is prone to the development of gully erosion on long, gentle hillslopes.…”