Changes Of Cultivated Land Resources And Its Impact On Grain Production In Typical Back Soil Areas Of Northeast China

Cultivated land is an important natural resource for food security.Through studying the impact of the quantity and quality of cultivated land on total grain yield,the cultivated land resources should be reasonably protected and the sustainable development of grain production should be maintained.Typical black soil area in Northeast China has a fertile soil and appropriate natural conditions.As an important grain production base for China,this area has made tremendous contributions for food security.This paper was based on the relative theory of mechanism which cultivated land resources play a role in grain production.The relationships between cultivated land resources and grain production,the current situation and quantity changes and the impact of changes on food production were mainly discussed in this paper.The main results were as following.1.The changes of cultivated land resources in typical black soil area of Northeast China have been discussed.From the current situation of cultivated land quality and land use dynamics from 1984 to 2014,the results showed that their quantities were increased in the past three decades.The quality of cultivated land was higher,but the soil quality was declining due to soil erosion and top layer thinning.2.The changes of grain production in typical black soil area have been analyzed in past 30 years.In 2014,the total grain output in the study area was 29,588,600 tons,which was 2.46 times of that in 1984.The grain yield per hectare was 8057.41kg/hm2 in 2014,which was 1.75 times of that in 1984.The sowing area of grain crops accounted for 93.82%of all farm crops.In the 30 years,maize has become the main grain crop in this study area since it was easy harvested with high yielding.3.The impacts of cultivated land resources on grain production have been carefully considered.Based on the analysis of the factorization model of grain production,the contribution rate of cultivated land area and grain yield per hectare was calculated relatively large.Based on the correlation between cultivated land area and grain yield per hectare,it further showed that the relationship between them was positively correlated.The effect of additional quality of cultivated land on grain yield based on C-D function showed that the total power of agricultural machinery and the effective irrigation area have great contribution to grain yield per hectare.