Effects of different natural vegetation management measures on red soil erosion in hilly orchards

The effect of managing the natural vegetation with different mechanical and chemical methods to minimize runoff and soil erosion in the red soil hilly orchards was investigated. The traditional tillage without herbicide practiced by farmers resulted in 33.2 m³/hm² runoff and 167.8 t·km^-2 soil loss per year. The management of natural vegetation with sequential herbicide treatments such as paraquat, glyphosate, G-G-P(glyphosate-glyphosate-paraquat), P-P-G (paraquat-paraquat-glyphosate) and sod culture reduced the surface runoff by 47.7%, 20.8%, 31.4% and 41.3%, 45.5%, respectively. The five treatments also reduced the soil loss by 52.4%, 39.0%, 48.1%, 50.7%, and 55.2%, respectively, and the nutrient loss through runoff by 50.2%, 37.0%, 41.8%, 45.8%, and 60.3%, respectively. Average soil covers by natural vegetation 30 days after application with paraquat, glyphosate, G-G-P, P-P-G and tillage without herbicide were 67.2%, 30.3%, 36.8%, 51.2% and 55.1%, respectively, as compared with the sod culture method. It showed that paraquat applications allow to maintain a higher vegetation cover resulting in lower soil erosion, which is a promising measure for soil-water and soil fertility preservation.