Correlation Analysis between Regional Cultivated Land Change and Grain Production Capacity—A Case Study in Northeast China

To research the changing patterns of current regional cultivated land and explore its impact on grain productivity is of great significance.Taking Northeast China as a study area,this paper analyzed the impact of the cultivated land change on grain sown area,per unit grain yield and total grain yield,and also the impact of the change of main crop planting structure on grain yield.The result shows: ⑴The cultivated land increased 188.8×104ha with a general trend of increase in the northern part and decrease in the southern part in view of the spatial distribution.⑵The grain sown area has increased 162.67×104ha.Per unit grain yield in most high-yield cultivated land presented an increase trend;per unit grain yield in mid-yield cultivated land presented a steady-going trend and furthermore with little increase in a few places;the changing trend of per unit grain yield in most low-yield cultivated land presented an increase trend.⑶The area of high-yield cultivated land,mid-yield cultivated land and low-yield cultivated land increased by 34.44×104ha,12.57×104ha and 141.83×104ha respectively,but their increase amount of grain yield was 305.04×104t,14.25×104t and 122.88×104t respectively.This shows the increase of both per unit grain yield in high-yield cultivated land and area of low-yield cultivated land promoted the increase of total grain yield in Northeast China.⑷The grain yield of four major crops in Northeast China presented different changing trends: the corn presented an increase-decrease-increase trend,the rice and wheat presented an increase-decrease trend and the bean yield increased continuously.The grain sown area of the four major crops presented a fluctuated changing trend: the corn presented an increase-decrease-increase trend,the bean sown area increased continuously,the rice sown area presented little increase and wheat presented an increase-decrease trend.In view of the regional difference,the corn production in Northeast China was further concentrated in Jilin province while that of bean,rice and wheat production further concentrated in Heilongjiang province.In a word,the grain production in Northeast China presented an obvious specialization and regionalization trend.