秸秆和生物炭对紫色土坡耕地产流产沙与 氮素流失的影响.

[Objective] The aims of this study are to investigate the specific improvement effects of different additions of straw and biochar on the sloping arable land of purple soil, so as to provide theoretical references for the reasonable prevention and control of soil erosion in the Three Gorges Reservoir area. [Methods] The effects of rice straw (4, 7, 10 t/hm²) and biochar (13,39,65 t/hm²) on sediment yield and nitrogen loss in purple soil slope were studied by artificial rainfall simulation method, with bare slope as the control. [Results] (1) Under the condition of high intensity rainfall, the mixture of biochar with purple soil accelerated the process of runoff production on slope, and the application of mixed straw could prolong the initial time of runoff production and reduce the rate of runoff production. (2) The cumulative sediment yield of purple soil increased by 0.64%~66.29% compared with the control group after adding biochar, but decreased by 42.58%~70.27% after adding mixed straw. The inhibitory effect of mixed straw on sediment yield on slope was much stronger than that on runoff yield on slope. (3) The nitrogen loss process in surface runoff was dominated by NO-3-N, and the overall loss moduli of TN, NO3-N and NH+4-N were the largest under biochar treatment, and the smallest under mixed straw treatment. [Conclusion] The application of crushed straw can promote seepage and inhibit flow, effectively control soil, water and nutrient loss in purple slope farmland, while the short-term application of biochar may have negative effects. [ABSTRACT FROM AUTHOR]