Various kinds of human disturbances on cropland are the main reasons for soil erosion and land degradation.Farming practices in mountainous areas vary greatly among cropland plots because of the heterogeneity of bioph...Various kinds of human disturbances on cropland are the main reasons for soil erosion and land degradation.Farming practices in mountainous areas vary greatly among cropland plots because of the heterogeneity of biophysical conditions and differences in farmers'management behavior.The main purpose of this paper is to develop a composite index of cropland physical disturbance intensity(CLDI)to reflect the plot-scale discrepancy of potential soil erosion in mountainous areas.The study was based on both plot survey and household interview data,collected from six typical catchments in mountainous areas of southwestern China.Four kinds of physical disturbance practices and two kinds of conservation practices during one crop rotation period were synthesized to develop the CLDI index.The rough set theory was referenced to avoid subjectivity during weight allocation.The results show that conventional tillage,deep fertilization,and manual weeding are the main causes of cropland soil erosion,whereas manure application in combination with seasonal fallow reduces soil erosion.Different crop types as well as cropland location factors determine the spatial pattern of CLDI.Crop rotation modes with major crops of tobacco and maize resulted in a maximal CLDI,and cropland plots with a distance radius of 150 meters away from households received the most intensive physical disturbance.These results are critical to help better protect rural environments in mountainous areas.Based on the results,methods to reduce cropland soil erosion are suggested.展开更多
当不同时段的∑EI各种组合计算的R值与土壤流失量的相关系数都很接近且都达到极显著水平的情况下,应以与土壤流失量相关系数最大的时段雨强为R值的计算参数。据此,闽东南R值的最佳计算组合为∑EI_(60),其简便算式为R=sum from 1 to 12 0...当不同时段的∑EI各种组合计算的R值与土壤流失量的相关系数都很接近且都达到极显著水平的情况下,应以与土壤流失量相关系数最大的时段雨强为R值的计算参数。据此,闽东南R值的最佳计算组合为∑EI_(60),其简便算式为R=sum from 1 to 12 0.0199P_i^(1.5682)。研究点R值年际间变化很大;年內主要集中分布于5—9月份。展开更多
基金jointly funded by the National Key Basic Research Program of China (973 program) (Grant NO.2015CB452702)the National Natural Science Foundation of China (Grant NO.41371539)partially supported by the CDM Fund Grant Project in China (Grant NO. 2013030)
文摘Various kinds of human disturbances on cropland are the main reasons for soil erosion and land degradation.Farming practices in mountainous areas vary greatly among cropland plots because of the heterogeneity of biophysical conditions and differences in farmers'management behavior.The main purpose of this paper is to develop a composite index of cropland physical disturbance intensity(CLDI)to reflect the plot-scale discrepancy of potential soil erosion in mountainous areas.The study was based on both plot survey and household interview data,collected from six typical catchments in mountainous areas of southwestern China.Four kinds of physical disturbance practices and two kinds of conservation practices during one crop rotation period were synthesized to develop the CLDI index.The rough set theory was referenced to avoid subjectivity during weight allocation.The results show that conventional tillage,deep fertilization,and manual weeding are the main causes of cropland soil erosion,whereas manure application in combination with seasonal fallow reduces soil erosion.Different crop types as well as cropland location factors determine the spatial pattern of CLDI.Crop rotation modes with major crops of tobacco and maize resulted in a maximal CLDI,and cropland plots with a distance radius of 150 meters away from households received the most intensive physical disturbance.These results are critical to help better protect rural environments in mountainous areas.Based on the results,methods to reduce cropland soil erosion are suggested.
文摘当不同时段的∑EI各种组合计算的R值与土壤流失量的相关系数都很接近且都达到极显著水平的情况下,应以与土壤流失量相关系数最大的时段雨强为R值的计算参数。据此,闽东南R值的最佳计算组合为∑EI_(60),其简便算式为R=sum from 1 to 12 0.0199P_i^(1.5682)。研究点R值年际间变化很大;年內主要集中分布于5—9月份。
