Changes in Cultivated Land Area and Associated Soil and SOC Losses in Northeastern China: The Role of Land Use Policies

Abstract

Land use policy is the driving factor influencing land use; however, little research has been conducted to identify the role of agricultural policy in influencing land cultivation and associated soil and soil organic carbon (SOC) losses. The aims of this study were to explore temporal changes in cultivated land, soil erosion, and SOC loss and to identify the role of land use policy. The present study was conducted using the revised universal soil loss equation by integrating remote sensing images from 1980, 1990, 2000, and 2017. The study found that cultivated land areas increased from 275.11 thousand km2 in 1980, to 300.03 thousand km2 in 2000, and to 344.16 thousand km2 in 2010, and then decreased by 326.94 thousand km2. The mean soil loss rates changed from 590.66 t·km−2·yr−1 in 1980 to 634.25 t·km−2·yr−1 in 2010, and then decreased to 495.66 t·km−2·yr−1 in 2017. Soil loss rate increased with increasing slope gradient. The changes in SOC loss rates demonstrated the same pattern as that of soil loss, with the largest loss rate of 728.27 kg·km−2·yr−1. These changes can be explained by changed land use policy and population growth. In future land use management, reasonable implementation of soil conservation measures should be undertaken to reduce soil and SOC losses in the black soil region of northeastern China.

Blackland Conservation and Utilization, Carbon Storage and Ecological Risk in Green Space: A Case Study from Heilongjiang Province in China

“…HLJP has a large number of black soil resources, and is a major region for land use policy and comprehensive landscape renovation, and is influenced by numerous policies and plans [ 77 , 78 ]. In the framework of territorial spatial planning, for instance, the scope of green space system planning has increased from focusing primarily on urban built-up regions, to the entire area scale of “mountains, water, forests, farms, lakes, and grasses” [ 79 ].…”

Spatiotemporal Pattern Differentiation and Influencing Factors of Cultivated Land Use Efficiency in Hubei Province under Carbon Emission Constraints

“…In view of the destruction of the ecological environment of cultivated land caused by the massive use of chemical substances in cultivated land utilization, including chemical fertilizers and pesticides, we should actively use science and technology to realize the transformation of the cultivated land utilization mode [109]. Specifically, we should move away from the traditional cultivated land utilization mode relying on the input of chemical fertilizers and pesticides and towards the modern cultivated land utilization mode, which reduces fertilizer and pesticides in favor of harmless livestock and poultry manure and a cleaning ecosystem [110][111][112].…”

Response of Soil Detachment Rate to Sediment Load and Model Examination: A Key Process Simulation of Rill Erosion on Steep Loessial Hillslopes

“…Soil erosion is a serious environmental problem worldwide, and results in the area of cultivated land decreasing, the soil quality declining, sediment deposition on riverbeds, and serious flooding disasters [1][2][3][4][5][6][7]. All the environmentally harmful consequences of soil erosion greatly threaten the sustainable development of human beings.…”

“…where D r is the net detachment rate of soil particles by flow (m 3 s −1 m −1 ), β is a flow detachment efficiency coefficient correlated with soil cohesion, w is flow width (m), v s is setting velocity of soil particles (m/s), T c is the transport capacity (m 3 m −3 ), and qs is the actual sediment load (m 3 m −3 ). Equation (1) shows that the detachment rate increases negatively with the sediment load. A linear equation between two extreme cases of clear water (q s /T c = 0) and the maximum sediment load (q s /T c = 1) was assumed [18].…”