Elevation Factors of Input Output on Cultivated Land in Mountainous Area
山区耕地资源投入产出的高程因子分析

A micro-level input-output analysis of farming fields is important in understanding the human-land relationship in rural area,particularly in the mountain area.This paper makes a survey of the attributions and the input-output characters of 482 plots of farmland from 81 households in Wugou village.The data includes 50 properties for each plot.Then the paper points out that the elevation is an important factor which influences the inputs,outputs and the ratios of output to input on the cultivated land in mountain area.Along with the elevation of the farmland plot being added,its average area is tending to be gradually shortened.For example,the average number of farmland plots per household increases from 1.35 to 3.65.In the varied curve,the number of energy input of farmland system is descending with the increase of the altitude of the farmland plot,whose influence factors include the distance between the peasant habitation and the farmland plot,the natural environment around,the domestic policies of reforestation,the behaviors of households and so on.The factor of the elevation is more important in the course of output energy in farmland system.In the?drought?flat?cultivated plot,the elevation of the plot is ascending from 568 m to 673 m;the average production of wheat is descending from 246 kg to 193 kg,that is to say,its average production is descending 5 kg when its elevation raises 10 meters.And the elevation of the plot of the corn is also ascending as same as the plot of the wheat,its average production is descending from 310 kg to 210 kg,that is to say,its average production is descending 9 kg when its elevation raises 10 meters.The ratios of output to input of the drought plat farmland are higher than the sloping one,but its form of their situations is different from the angles of varied crops.After the precise calculation,the former is 1.4 times than the later when the cultivated plot is planted the wheat,and 1.6 times when it is planted the corn,and 1.1 times when it is planted the bean.It is an important approach to improve the ratio of output to input of cultivated land in the mountain area by changing the irrigation works of farmland.