Geographical change law of effects of corn plastic mulching on increasing temperature and production in Northeast China

In order to make corn plastic mulching project planning well, the geographical change law of increasing production and income effect of corn plastic mulching was analyzed by developing model between increment and accumulated temperature in Northeast China. The result shows that the corn yield increases by about 35%～55% by plastic mulching in the northern and eastern parts of northeast China where accumulated temperature is deficient, around 20% in the most areas of middle, below 10% in the south; if considering single cropping, it has no effect on yield in most areas of Liaoning Province. In mesothermal area where accumulated temperature is 2400～2850℃, the range of increasing production is the biggest, income increase is approximately 1700～2000y/hm², which is the major region to popularize the technique. The range of increasing production is bigger in north of Heilongjiang Province where accumulated temperature is under 2200℃, it is comparatively suitable for popularizing the technique. Most areas of Liaoning Province where accumulated temperature is over 3000℃, the effect of production increase is not noticeable, and the technique is unsuitable. Geographical distribution of production and income increment varies wildly in Changbai mountain of Northeast China, and the difference is small in the plain.