黄淮海平原县域粮食单产的增长趋势及其稳定性比较

Increasing Tendency and Stability of Grain Yield per Unit Area of Counties in Huang-huai-hai - Plain

建国以来黄淮海平原粮食单产持续增长，近年来仍然高于全国同期单产增速。尽管个别高 产区单产年均增长率下降，但广大中低产区粮食单产的年均增长率仍然维持着较高的水平，全区 粮食单产的增长潜力在于对广大中低产区的投入改造，而生产条件的改善可明显增强粮食单产年 际间增长的稳定性。表２，参３。

Grain yield per unit area increased continually during the past near 50 years in HuangHuai -hai plain,and its increasing speed in recent years still kept higher than the average of all the country. The potential of grain production of all the plain lied in the widely middle-low yield regions,so it is very important to increase the agricultural input of the regions to improve the pro- duction condition. But with the improving of the production condition,the stability of grain yield per unit area enhanced obviously.