The loss of
soil and water from
Slope Land', 1, 1597714)"; href="/tags/slope-land/">slope land is the major causes of regional soil
degradation and decline of land productivity. By the method of natural rainfall-runoff plot experiments in field, a preliminary study on the characteristics of loessial soil degradation on a slope scale was conducted on a fallow slope land in the Loess Plateau before and after a light erosion
rainfall event with erosion quantity 410~435 t/km~2. Experimental results showed that the soil properties similarly fluctuated along slope surface (0~5 cm) both before and after rainfall. Sand(>50 μm) content and 50~20 μm
micro-aggregate content (MA) tended to decline down from the top to the bottom of the slope, while soil clay(<2 μm) content (Cl), specific surface area (SSA), 20~2 μm MA, soil available
phosphorus (AP) and total phosphorus (TP) contents, as well as soil moisture tended to increase. This suggested that soil material and nutrients gradually transported from the top to the bottom of the slope due to situating in an erosion environment for a long term, and, consequently, soil varied to the direction of desertification in texture and degradation in fertility. Statistical analysis showed that soil AP and TP contents were positively correlated with Cl and SSA in the surface soil (0~5 cm) and that TP content was positively correlated with 20~2 μm MA. Therefore the major causes of soil degradation on slope surface were the loss of clay and fine MA (20~2 μm). The change of soil properties before and after rainfall was less significant than their spatial change along the surface, however, the analytical results of slope soil and sediment still showed that rainfall induced the transport and loss of soil available nutrients (e.g. AP), fine particles (<20 μm) as well as 20~2 μm MA, and this is just the major causes of soil quality degradation.
More abstracts about the Study on Transport of Phosphorus and Soil Degradation of Loessial Soil on Slope Land