The Research Over The Sudden Change Of Cultivated Land Quality By Rapid Variational Factors

Using Daxing District of Beijing as an example, on the basis of the results of theagricultural land classification, from cultivated land consolidation,cultivated landreclamation, exploitation of cultivated land,new construction land appropriation offarmland,cultivated land disaster,arable land adjustment, suitability evaluation ofsloping cultivated land and other trigger pointswhich caused the rapid variationsofgradational quality of cultivated land,this paper analyses the change of cultivatedlandgrading,the change of capacity and the space distribution ofgradational quality ofcultivated land in the research area.This paper also proposedevaluation methods ofgradational quality of cultivated land’s changing which caused byrapid variationalfactors.All above this can providetechnology and decision-making basis for achievingsustainable, efficient and intensive use of cultivated land resources and realizing astrategic change in management of land resources from quantity-based one to onebased on both quality and quantity.The study results showed that: the natural grade,use grade and economic grade ofnew cultivated land in Daxing District are distribute in8and9two levels.The naturalgrade and use grade of those cultivated land which decline in number distribute ingrade8and grade9,and economic grade is distribute between grade8-10.Thesituation of capacity loss due to reduction in the amount of cultivated land is:Theoretical production capacity reduced90,100tons, realizableproduction capacityreduced79,600tons,realistic production capacity reduced72,900tons.The averagenatural grade in quality construction area of cultivated land in Daxing District is8.038,the average use grade is8.012and the average economic grade is8.704.Itfollows that the gradational quality of cultivated land has improved significantly afterthe construction. The average natural grade increased0.282, the average use gradeincreased0.160and the average economic grade increased0.080.Studies suggest that：Many factors caused the rapid variationsof gradationalquality of cultivated land.Based on classifing and merging these factors,the evaluationof gradational quality could react the similar or differential between these factors.Atthe same time, adopt different techniques to evaluate the gradational quality ofcultivated landwere more scientific.Obtained through empirical analysis,to carry outprime cropland consolidation and land consolidation project, the quality of cultivatedland have been significantly improved. This explains, to carry out the construction ofthe quality of cultivated land has a significant role to improve the quality of cultivatedland.It also provides empirical case for China to continue to implement high standardsof construction of prime cropland and land remediation projects.