Abstract:In order to investigate the effect of straw returning and plastic film mulching on soil improvement and rice yield increase in northeast rice area, Jijing 88 was selected as the test material, and two kinds of cultivation were carried out in film transplanting(F) and non-filming(F0) transplanting. In the model, there are 5 groups of straw returning soil gradients of 0%, 20%, 40%, 60%, 100%(S0, S1, S2, S3, S4) to explore the physical and chemical properties of straw returning and plastic film mulching on rice soil and impact of rice yield. The results showed that under the same straw returning amount, the soil bulk density and pH value of F were lower than F0, and the soil was treated with nitrogen, organic matter(except S0), alkali nitrogen and quick-acting. The content of phosphorus and available potassium was higher than F0. Regardless of the film or the amount of straw, the soil bulk density and pH value decreased first and then increased. Soil total nitrogen and organic matter(In addition to S0), the contents of alkaline nitrogen, available phosphorus and available potassium all increased first and then decreased. Compared with F0 and F treatments, grain yield was increased under the same amount of straw returning. Above all, 60% of the straw returning amount combined with the mulching film can effectively fertilize the soil and increase rice yield.