Assessing the Impact of Cultivated Land Change on Grain Productive Capacity:A Case Study in the Central and Western Regions of Jilin Province

The current situation of grain supply and demand in our country is still tense,and the trend of cultivated land converting to non-agricultural use will get more obvious.The conflicts between the goal of local government's grain safety and farmers' interests have not been thoroughly solved.Furthermore,internationalization of domestic grain-production is progressing and opportunity and challenge of market for agricultural products coexist recently.Under the above-mentioned background,analysis of the changing patterns of cultivated land in main grain production areas and assessment of the impact of this change imposed on grain productivity is of great significance.This paper aims to explore the systematic approach to assess the impact of regional cultivated land change on grain productive capacity,by analyzing the spatial distribution of change of cultivated land quality caused by change of cultivated land quantity through GIS technology.Central and west regions of Jilin Province were selected as study area,this paper analyzed the impact of cultivated land change on its grain production capacity within this region.The result shows: 1)The quantity of cultivated land has increased by 8 200 hectares;2)Through dividing cultivated land quality into fifth grades and analyzing the spatial distribution of change amount of each graded cultivated land,detailed information about the cultivated land quality has been obtained.the third-grade cultivated land reduced plentifully among these decreased cultivated land,while the first-grade cultivated land reduced little at the same time;On the other hand,the fifth-grade cultivated land increased plentifully among the increased cultivated land and the first-grade cultivated land increased little simultaneously;3)By analyzing the change pattern of grain yield in study area in combination data of change amount with data of grain yield per hectare within each graded cultivated land;it has been found that the grain production has only increased 0.52×10~4t.Decreased amount of grain production caused by reduction of cultivated land was 39.09×10~4t.And decreased amount of second-grade and third-grade cultivated land accounts for 28.36% and 44.82% respectively of the total decreased amount of grain production.At the same time,the increased amount of the second-grade cultivated land played quite an important role in grain production,accounting for 44.53% of the total increased amount of grain production;4)To obtain a dynamic equilibrium of cultivated land general quantity in this area,the dual balances of the quantity and quality of cultivated land should be guaranteed simultaneously.