Evaluation of Mathematical Models in Nitrogen Transfer to Overland Flow Subjected to Simulated Rainfall

Abstract

The chemical transfer from soil to runoff leading to nutrient loss of sloping farmland has been recognized as a major threat to soil fertility and receiving water bodies [1-3]. There is most concern regarding nitrogen (N) transfer, as it is increasingly applied to boost crop yields producing eutrophication in surface waters [4, 5]. Accordingly, many field, laboratory and modeling works have been undertaken in an attempt to investigate N loss and transfer via overland flow and propose mitigation methods [5, 6].

Effects of Hydrological Processes on Surface and Subsurface Nitrogen Losses from Purple Soil Slopes

“…Additionally, purple soil slopes account for 70% of the total farmlands in the Three Gorges Reservoir Area along the Yangtze River (Ma et al, 2016). There is evidence that NH4-N, NO3-N and TN from sloping farmlands of purple soils can be exported in large numbers subjected to various slope gradients and rainfall intensities (Ding and Zhang, 2009;Jia et al, 2007;Xie et al, 2020;Xu et al, 2011;Zhao et al, 2015). Xu et al (2011) reported that N losses due to sediment transport accounted for 53%～62% of total N losses from field observations.…”