Scientists have discovered a peculiar phenomenon in the study of soil nutrients: rainfall on rainy days also affects changes in soil nutrients. So the scientists measured soil nutrients before and after rainfall using a soil nutrient fastness tester, and then analyzed and compared the changes of rainwater to soil nutrients.
Under rain erosion, the soil nutrients change from the solid phase adsorption state to the liquid phase dissolution state. On the one hand, the soil nutrients are lost due to the horizontal migration caused by the formation of sediment particles. On the other hand, the preferential flow channels penetrate into the deep soil. , And the formation of underground runoff and loss. For the former, scholars at home and abroad have conducted a lot of research on the loss of soil nutrients affected by rainfall (P) and rain intensity through natural rain or simulated rainwater processes. Some scholars have considered the value of rain erosion (R). It was found that the loss of particulate nitrogen and phosphorus increased with the increase of rainwater erosivity, while the loss of dissolved nitrogen and phosphorus had no significant correlation with rainwater erosivity. For the latter, the simulation of the process of seepage through different layers of soil was very complicated. Therefore, the relevant research data is very limited.
The riparian zone is the interface between land and water ecosystems and has important hydrological and ecological functions such as corridors, buffer zones, and bank protection. In recent years, due to the effects of the Yellow River Xiaolangdi Water Control Project and agricultural development, the natural wetland ecosystem in the downstream riverbank area has rapidly shrunk. In the absence of riparian buffer protection, water and soil erosion and soil nutrient loss caused by rainwater in the riparian area directly enter the river water body, which in turn has an important impact on river water quality. In this study, a standard runoff observation field was established to monitor several times of strong rainwater processes in the Mengjin-Tianjin Yellow River beach area, and then a preliminary study was conducted on the loss of soil nutrients in the cultivated land of riverbanks due to the difference in rainwater erosivity under natural rainfall conditions. The results of the study have practical significance for the protection of agricultural ecology in the river bank area.
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