用土壤信息系统评价土地种植机动性的数学模型及应用

A MATHEMATIC MODEL FOR EVALUATION LAND FLEXIBILITY BY MEANS OF SOIL INFORMATION SYSTEM AND ITS APPLICATION

土地种植机动性(Land Fleibility)意指土地交换种植不同作物的机动能力。它是土地生产能力和土地潜力的一个重要指标。这方面研究还处在起步阶段。木文借助于加拿大土壤信息系统,研究和提出了评价土地种植机动性的一个数学模型,并用这个模型计算和分析了加拿大不同气候及其它成土因素条件下代表性土地单位的土地种植机动性指数,认为此模型可用。进而又用此模型计算和分析了加拿大全国,特别是加拿大大草原三省的土地种植机动性指数。所得结果与加拿大全国和大草原地区的实际情况相吻合。研究表明,此模型可作为省或国家规模的寻找和评价农地的一个快速方法,并可用来宏观地掌握全省或全国的土地潜力,土地开垦不足或过垦的情况,从而作为农地使用调整和国土整治的一个管理工具。同时本研究也说明了建立土壤信息系统和充分发挥其功能的重要性和迫切性。

Land flexibility means how many types of crop can be selectively and productively grown in a land. It is an important index of the land productivity and land capabitity. Research in this field is still in its starting stage. This article introduced and proposed a mathematic model for calculating the land flexibility index. The model was used to calculate and analyse the land flexibility indices of some representative land units under different conditions of climate and other soil-forming factors in Canada. The results indicated that the model was rea sonable and applicable. Furthermore, it was also used to calculate and analyse, the land fixibility indices for whole Canada (755 map units in all), especially for the three prairie provinces in Canada. The results accorded with the actual situations of both whole Canada and the prairies. This research also showed that this model could be taken as a quick way to search and evaluate agricultural lands in a province or in a nation, and could be used to macroscopically master the potentials, over-reclamation or under-reclamation of lands in a province or in a nation. So it is an administering tool for readjusting and realigning lands in a country-wide scope. Moreover, this research also revealed that establishing a soil information system and bringing it into full play would be very important and urgent.