Impact erosion‐induced land degradation on rainfall infiltration in different types of soils under field simulation.

Land degradation induced by water erosion is a worldwide problem for sustainable agriculture. Erosion results in the alteration of soil properties to a varying extent that depends on soil type. However, limited attempts have been made to assess the impact of erosion‐induced land degradation on soil infiltration on a wide range of soil types. Herein, field rainfall simulation experiments were performed on prewetted bare heavy‐textured soils at three erosion degrees (no, moderate, and very severe) for five types of soils (Calcic Luvisol, Ferric Luvisol, Plinthic Alisol, Plinthic Acrisol, and Acric Ferralsol). Soil infiltration rate was determined at two rainfall intensities (45 and 90 mm hr−1) and 3‐min intervals for 60‐min runoff duration on microplots (3 m long × 0.8 m wide, 10° slope). At the low rainfall intensity, the impact of erosion‐induced land degradation on rainfall infiltration increased from Calcic Luvisol to Plinthic Acrisol, and the steady state infiltration rate (fc) was well characterized by bulk density and 1.4‐nm intergrade minerals (Adj‐R2 = 0.79, p < 0.001). At the high rainfall intensity, fc was negatively related with illite solely (Adj‐R2 = 0.25, p < .05) and generally increased with an increase of erosion severity; the impact of erosion‐induced land degradation on fc was magnified for Calcic Luvisol and Acric Ferralsol but lessened for other soil types. Collectively, the impact of erosion‐induced land degradation generally increased with increased soil structural stability at the low rainfall intensity and was determined by the interaction between soil structure and rainfall at the high rainfall intensity. [ABSTRACT FROM AUTHOR]