Characteristics and factors influencing soil organic carbon composition by vegetation type in spoil heaps.

Introduction: The variation of organic carbon content in spoil heaps is closely related to improving soil structure, maintaining soil fertility, and regulating soil carbon cycling balance. Analyzing the soil organic carbon content and related driving factors during the natural vegetation restoration process of spoil heaps is of great significance for promoting the accumulation of soil organic carbon in the spoil heaps.

Methods: we selected spoil heaps with the same number of years of restoration to research the variations in soil organic carbon components under different vegetation types (grassland: GL, shrubland: SL, secondary forest: SF) and compared the results with those on bare land (BL).

Effects of rainfall intensity on runoff and nutrient loss of gently sloping farmland in a karst area of SW China.

Nutrient losses from sloping farmland in karst areas lead to the decline in land productivity and nonpoint source pollution. A specially tailored steel channel with an adjustable slope and underground hole fissures was used to simulate the microenvironment of the "dual structure" of the surface and underground of sloping farmland in a karst area. The artificial rainfall simulation method was used to explore the surface and underground runoff characteristics and nutrient losses from sloping farmland under different rainfall intensities.

The production processes and characteristics of nitrogen pollution in bare sloping farmland in a karst region.

Nitrogen loss in karst sloping farmland will lead to declining land productivity and environmental pollution, in which the nitrogen loss through underground pore fissures will directly lead to groundwater pollution. The characteristics of total nitrogen (TN) production were studied by simulating the "dual structure" microenvironment of sloping farmland in a karst region using an artificial rainfall simulation method. The results show that rainfall was the main driving factor of TN loss in karst sloping farmland.