陕北黄土高原农牧交错带土地生产潜力及人口承载力

根据陕北黄土高原农牧交错带生态环境特点以及作物生长发育过程对光、热、水、土资源的要求和利用效率,运用逐步订正法对该地区的土地生产潜力进行了定量估算,并对其土地的人口承载力进行了计算与分析,指出了提高该地区土地生产潜力及人口承载力的途径。结果表明,该地区光温生产潜力为光合生产潜力的65.21%,气候生产潜力为光温生产潜力的37.91%,土壤生产潜力为气候生产潜力的32.19%,现实生产能力仅为土壤生产潜力的42.47%;在现实生产能力水平下,人民生活仅能维持我国低消费水平,如果要实现世界中等消费水平,必须使土地的现实生产能力达到土壤生产潜力的89.40%,气候生产潜力的27.00%。提高该地区土地生产潜力及人口承载力的途径包括提高植被覆盖度,控制土地荒漠化;发展设施农业和灌溉农业,提高作物产量;改进施肥方法,培肥地力;因地制宜,开发滩区等。

Discussion on land production potentiality and land carrying capacity in agriculture and pasturage interlaced zone in Loess Plateau of Northern Shaanxi

Based on environmental characteristics and the requirement and use efficiency of light,heat,water and soil resources by crops in their developing process,this paper estimates the potential land productivity in quantities,calculates the land carrying capacity and points out the ways to improve the potential land productivity and the land carrying capacity by using step correcting method in agriculture and pasturage interlaced zone in loess plateau of Northern Shaanxi.It is surveyed that thermal productive potential is 65.21% of light productive potential;climate productive potential is 37.91% of thermal productive potential;soil productivity potential is 32.19% of climate productive potential;and actual productivity is(42.47%) of soil productivity potential.Actual productivity just maintains the need of low consumption level of China.To attain middle consumption level in the world,the soil productive potential must get to(89.40%) and the potential climate productivity 27%.The methods we should take now include:increasing vegetation to control land desertification;developing irrigation agriculture to increase crop yields;improving means to fertilize the soil;taking tillage techniques,to exploit bottomland and according to local conditions.