Effects Of Rice Straw Returning On Resistance Physiology,Seeding Emergence And Yield Of Wheat

The waste and incineration of straw caused worsening ecological and social problems. Straw returning is an efficient way to deal with a large number of the remaining straw. Jiang su is riched in straw resources, straw returning is the preferred way to solve the excess straw. Jiang huai region mainly adopts wheat-rice double cropping system. So potted experiment and plot experiment were conducted to investigate the effects of different amount, depth and tillage patterns of rice straw returning on resistance physiology, seeding emergence and yield of wheat. The main results were as follows:(1) Effects of the amount of rice straw returning on anti-senescence, seeding emergence and yield of wheatThe amount of rice straw returning had little impact on seeding emergence of wheat, the more the straw returned, the lower the seeding height. The proper amount of returned rice straw could promote the growth of roots, advance the activity of roots, and delay the senescence of roots of wheat in the late growth stage. The proper amount of returned rice straw could delay the degradation of chlorophyll and photosynthetic, could advance the activity of SOD and CAT of flag leaves in the late growth stage, thereby delayed the senescence of flag leaves of wheat, thus increased the yield of wheat. The effect was most significant when returned at9000kg/hm2.(2) Effects of the depth of rice straw returning on anti-senescence, seeding emergence and yield of wheatThe depth of rice straw returning had little impact on seeding emergence of wheat, the deeper the straw returned, the lower the seeding height. When the depth of rice straw returning reached at15cm, the number of root vessels in jointing period was the lagest, the number of roots was the lagest, the activity of roots reached the highest level, the ability of anti-senescence of roots was the best, the degradation rate of chlorophyll and photosynthetic was the lowest, the activity of SOD and CAT of flag leaves reached the highest level, the ability of anti-senescence of flag leaves was the strongest in the late growth stage, the yield of wheat was the highest.(3) Effects of rice straw returning in different tillage patterns on seeding emergence and yield of wheatThe seedling emergence rate and emergence evenness of wheat were decreased when the rice straw was returned to the field, which was minimal impacted in the low plowing pattern. The seedling emergence uniformity of wheat was improved when the rice straw was returned to the field, which was better in the low and deep plowing pattern. Deficiency or unevenness of soil water and straw hindering were the main factors affecting seedling emergence of wheat. The number of wintering tillers and summit seedlings of wheat were increased under the rice straw returning in the no-tillage and deep plowing pattern. The number of ears and the rate of ears of wheat were decreased under the rice straw returning, which were minimal impacted in the low plowing pattern. The yield components of wheat were affected, and the yield of wheat was decreased when the rice straw was returned to the field, which was the highest in the low plowing pattern. The decreased seedling emergence rate and emergence evenness under the rice straw returning affected the yield by effecting the1000-grain weight and the number of productive ears of wheat.(4) Effects of rice straw returning in different tillage patterns on lodging resistance of wheatIn the whole growth stage, the lodging index of the base of the first three sections of wheat under the rice straw returning in different tillage patterns were lower than the contrast under no-straw returning. The lodging resistance of wheat was significantly affected in the low and deep plowing pattern. The lodging resistance of wheat was mainly affected by the bending moment of culm in anthesis, and was mainly affected by the breaking resistance in milking and dough stage. The fresh weight, plant height, height of gravity center and length of intemode of wheat were affected under the rice straw returning, which were greater affected in the low and deep plowing pattern in the late stage. The thickness of culm wall, dry weight of unit internode and the plumpness of internode of wheat were increased under the rice straw returning, the thickness of culm wall of wheat was greater affected in the low plowing pattern, and the dry weight of internode was greater affected in the deep plowing pattern in the late stage. Rice straw returning improved the lodging resistance by decreasing the fresh weight, wheat height and internode length, and by increasing the plumpness of intemode of wheat.