Sediment Discharge from a Ridged Field with an Andisol

摘要

Soil erosion in ridged field plots with Kuroboku soil, an Andisol, was observed between May and October for 3 years at a cropland site in northwest Kanto, Japan. The amount of sediment yield from the plot planted with cabbage was much less than that from the bare plot. The observed results suggest that the rates of ridge erosion, detachment, and transport of soil particles due to surface runoff in the furrow channels of the planted plot were less than those of the bare plot. Soil erosion on the bare plot during most events was a transport-limited process. The Yang sediment transport equation effectively estimated the sediment yield from the bare ridged plot with Kuroboku soil when a transport-limited process was considered to be dominant. The equation is likely to be suitable to estimate the sediment transport capacity of furrow channel flow for the study soil. The equation overestimated the sediment yield for the planted plot. To estimate sediment yield for the planted ridged field in the study site, soil erosion prediction models including a routine taking into account the soil detachment rate and sediment transport capacity of furrow channel flow are needed.