Study On Production Potentiality Of Land And Population Carrying Capacity In Karst Area

Production potentiality of land is the largest production potentiality of land under the currently technical level of cultivation and corresponding measures of technology which includes the current potentiality and the potential potentiality. Forecasting analysis on the land and population carrying capacity resolves the balance relation among population,land and grain, and is also an important link of Overall Planning of Land Utilization, at the same time, is the need tapping the production potentiality and seeking the developing space.In this dissertation, according to the characters of Qianxi County and taking the AEZ as the basic way, the method of forecasting production potentiality of land at the county level in karst area.The conclusions are as follows through forecasting production potentiality of land in Qianxi County:(1) The production potentiality of paddy in seven sorts of grain plants (which are soybean, corn, wheat, pea, paddy, tobacco, red tobacco) is the largest in Qianxi County.(2) The comprenhensive potentiality of grain plants in every town of Qianxi County is higher, the photo-thermal production potentiality is more than 7488.5 kg/ hm2 and the peak amount reaches 10285.9 kg/ hm2 which appears in Zhongshan Town of the middle Qianxi County. The climatic production potentiality arrives to 8196.2 kg/ hm2, and the highest number of the production potentiality of climate-soil is 5037 kg/ hm2.(3) The degree of soil and water declining the photo-thermal production potentiality is higher in every town of Qianxi County that is between 54.04% and 61.19%.Thus, the measures regulating water and soil can be made by the agriculture controling water and improving soil fertility.(4) The rate of climatic production utilization is lower and the growing potentiality is higher in every town of Qianxi County. The growing potentiality is optimistic in every town of Qianxi County which proportions are all more than 60% .(5) The growing margin of comprenhensive production potentiality of farming land all over the county is higher, and the average growing margin is 99.47%.The land and population carrying capacity of Qianxi County is forecasted from the angle of movements and through the dialectical relation among population, resource and environment considered and the theories of planning of Land Utilization and agricultural ecology and the technology of computer used. The conclusion that the land and population carrying capacity of qianxi county will be surplus in the future of 20 years according to the quantitative analysis under the quanlitive precondition.In the end, on the ground of the characters of land in qianxi county, the channels of sustainable utilization of the land resource and the its status in the construction of New Countryside are pointed out and the ways and measures of improving the production potentiality of land are put forward.This work can lay a solide foundation for the regulation and construction of land resource and provide an important method for the Overall Planning of Land Utilization at the level of county.