Effects of soil erosion–deposition on corn yields in the Chinese Mollisol region

Abstract

Soil erosion is a major challenge for crop production maintenance and improvement in agricultural regions worldwide. However, quantifying the impacts of soil erosion rate on crop yield has not been carried out often, and there are few reports on impacts of soil deposition crop yields, especially in the Chinese Mollisol Region. Thus, this study quantified soil erosion–deposition rates (SEDRs) at three agricultural catchments in the Chinese Mollisol region using the 137Cs technique and assessed soil erosion–deposition impacts on corn (Zea mays L.) yield. The results showed that SEDRs varied from −5471.7 (deposition) to 9956.0 (erosion) t km−2 yr−1. The distributions of both soil erosion and deposition in the three catchments were in coexistence, but soil erosion was dominant. In addition, above 2500 t km−2 yr−1 of soil erosion rates (larger than slight erosion rates) in the three catchments accounted for 41.0 %, indicating that soil erosion was severe. Moreover, corn yields in the three catchments ranged from 1.9 to 14.6 t ha−1. Compared with deposited sites, corn yields in eroded sites were 19.2 %–40.6 % lower. Furthermore, when soil erosion rates were moderate (2500–5000 t km−2 yr−1), corn yields were 32.4 % lower than those in non-eroded sites. The spatial distribution of corn yield was opposite to that of soil erosion rate at catchment and slope scales. The relationship between corn yields and soil erosion rates had a negative linear relationship (p < 0.01), which was validated with acceptable accuracy. There was a positive linear relationship between corn yields and soil deposition rates without statistical significance (p > 0.05). These findings are valuable for assessing how soil erosion–deposition affects crop yields to implement countermeasures for controlling soil erosion and maintaining sustainable agricultural development.