Ability of green cover from sainfoin (Onobrychis viciifolia Scop.) and dog rose (Rosa canina L.) to control erosion and improve soil organic carbon and nitrogen stocks in terraces of Northwest Turkey

Abstract

The main aim of this study was to evaluate the impact of green cover and afforestation on soil properties, erosion susceptibility, as well as soil organic carbon (SOC) and soil total nitrogen (STN) contents and stock capacities. Mineral soil samples from two soil depths (0-10 cm and 10-20 cm) were obtained from a bare soil plot (BSP), a young forest plot (7-year-old juvenile cover; YFP), a mature forest plot (MFP) used as a reference control, a young forest plot with sainfoin green cover (YFP + S), and a young forest plot with dog rose green cover (YFP + R). The soil samples were analyzed for pH, water holding capacity (WHC), soil texture, dispersion ratio, bulk density, SOC, STN, and soil extractable P and K. Soil bulk density, soil volume, and the SOC and STN were used to calculate the mean SOC and STN stocks. Results showed that afforestation and green cover significantly influenced the chemical and physical properties of the soil, reduced its dispersion ratio, and increased its SOC and STN stock capacities (P < 0.05). The mean SOC stock was highest for MFP (39.7 t C ha(-1)), followed by YFP + R (37.1 t C ha(-1)), YFP + S (35.7 t C ha(-1)), YFP (22.1 t C ha(-1)), and BSP (10.9 t C ha(-1)). However, the mean STN stock was highest for YFP + S (2.40 t N ha(-1)), followed by MFP (2.25 t N ha(-1)), YFP + R (2.08 t N ha(-1)), YFP (1.88 t N ha(-1)), and BSP (0.55 t N ha(-1)). These results indicate that with proper care and management, natural or artificial leguminous and shrub species can provide year-round soil protection and minimize soil erosion in black pine plantation terraces. Growing these species could enhance soil productivity by increasing soil organic matter, improving the soil structure, and increasing the water holding capacity and nutrient retention of the soil.