摘要: |
【目的】探讨不同降雨强度下秸秆覆盖对降雨入渗的影响,为提高坡耕地雨水资源利用效率及土壤侵蚀的防治提供理论依据。【方法】以烤烟为供试材料,采用人工模拟降雨法,分析了不同降雨强度(40、80和120 mm/h)、秸秆覆盖量(0、3 750、7 500、15 000 kg/hm2)和叶面积指数条件下降雨入渗率的变化特征。【结果】随着降雨时间延长,降雨入渗率呈下降趋势,并逐渐趋于稳定,且秸秆量越高,入渗率趋于稳定的时间越短。平均入渗率随降雨强度和秸秆量的增加而上升,且不同降雨强度间存在显著性差异。当无秸秆覆盖时,烤烟冠层可以显著增加降雨入渗率;而当秸秆覆盖量达到7 500 kg/hm2和15 000 kg/hm2时,烤烟冠层覆盖会不利于降雨入渗。平均入渗率分别与降雨强度和秸秆量呈极显著正相关关系,而与叶面积指数相关性不显著。基于降雨强度、秸秆量和叶面积指数建立了降雨入渗率的最优回归方程,决定系数R2为0.834,方程拟合度达到极显著水平。【结论】降雨强度、秸秆覆盖和烤烟冠层覆盖均是影响坡耕地降雨入渗的关键因素。在相同降雨强度下,虽然秸秆覆盖或烤烟冠层均可有效提升降雨入渗率,但当两者共同作用时,秸秆覆盖为主要影响因素。 |
关键词: 秸秆覆盖;烤烟;叶面积指数;入渗率;坡耕地 |
DOI:10.13522/j.cnki.ggps.2019201 |
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Effect of Rainfall Intensity and Straw Mulching on Infiltration of Rainfall into Slope Planted with Flue-cured Tobacco |
LYU Kai, DUAN Yingdan, WU Bozhi
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Faculty of Agronomy and Biotechnology, Yunnan Agriculture University, Kunming 650201, China
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Abstract: |
【Objective】Water infiltration is an important hydrological process impacting and being impacted by many biotic and abiotic factors and processes. In this paper we experimentally studied how rainfall intensity and straw mulching in separation or coupling impact rainfall infiltration into a slope planted with flue-cured tobacco.【Method】The experiment was conducted in a slope using a rainfall simulator. We compared three rainfall intensities (40, 80 and 120 mm/h) and four straw mulches (0, 3 750, 7 500 and 15 000 kg/hm2). The infiltration rate and leaf area index (LAI) of the tobacco were measured during different growth stages of the tobacco.【Result】Infiltration rate decreased asymptotically with time in a rainfall event before reaching a constant, and increasing straw mulching reduced the time required for the infiltration to reach steady state. Average infiltration rate was positively related to both rainfall intensity and straw mulching at significant level, but varied between different rainfall intensities at significant level. Canopy could significantly increase average infiltration rate in soil without straw mulching, but it could made water difficult to infiltrate when the soil was mulched with straw at 7 500 kg/hm2 and 15 000 kg/hm2. A stepwise regression model was derived to link average infiltration rate to rainfall intensity, straw mulching rate and LAI, with a coefficient of determination (R2) of 0.834.【Conclusion】Rainfall intensity, straw mulching and canopy are key factors modulating rainfall infiltration into slope planted with flue-cured tobacco. Rainfall infiltration can be enhanced by straw mulching and canopy in separation, while under their coupling, the impact of straw mulching was more significant. |
Key words: straw mulching; flue-cured tobacco; leaf area index; rain infiltration; slope farmland |