The Effects Of No Tillage And Straw Returning On Soil Ecological Environment And Wheat Growth

With Yangmai15and16as material, the research of No-tillage and straw mulching was conducted. There were four tillage treatments:NTS (No-tillage and straw mulching), RNT(Rotation tillage, no-tillage in wheat and convention tillage in rice), RCT(Rotation tillage, convention tillage in wheat and no-tillage in rice), CT(Convention tillage, CK1); There were four straw mulching treatments:NTH(No-tillage and high subble remaining), CTS1(Convention tillage and full straw returning), CTS2(Convention tillage and half straw returning), CTB (Convention tillage and straw burning,CK2). The research aimed to study the influence of different tillages and straw mulching on soil ecological environment and wheat yield. Soil Fertilizer features, wheat suction fertilizer characteristics, growth rhythm of wheat were discussed. Through the research, some scientific suggestions for effectively carrying out no-tillage, rational rotation and straw mulching could be provided. The main results are as following.1. Because of different tillages, SMBN differed between different treatments. Treatments of no-tillage, rotation tillage and straw mulching treatments favored for improving SMBN. Before seeding, soil respiratory rate significantly differed between treatments, SMBN of CT and CTS2treatments were the highest. After wheat harvesting, compared with CT, soil organic matter and total nitrogen in the plough layer of0-21cm of NTS, NTH, RNT, CTS1and CTS2treatments were increased by9%-28%、5%-25%, CTS1and CTS2were the highest, CTB was also higher than CT, while the increased range was lower than direct straw mulching. At the wheat maturity stage, alkali-hydrolyzable N, available K of no-tillage, RNT and convention tillage and straw returning treatments were higher than CT, while available P was not significantly increased.2. Straw returning was good for maintaining water in soil. It was also good for wheat growing during earlier growing stage, but the wheat was thin and long. Straw returning during later growing stage had little effect on the height of wheat plant, the height of NTS treatment was very low during maturation stage, which could increase wheat lodging-resistance ability. The upper-three leaf areas of RNT and straw returning treatment were high, which were good for wheat yield. After regreening stage, dry matter of NTS and NTH treatments were affected, the amount of dry matter were relatively lower; dry matter of CTS1was lower than CT and CTB, the amount of straw returning was large, which might affect dry matter accumulation, dry matter of NTS was also lower than CT and CTB during the whole growing stage, the years of no-tillage might affect wheat growing, dry matter of RNT treatment was relatively higher, which created foundation for high yield.3. Nitrogen rate, phosphorus rate and potassium rate of wheat were relatively higher during seedling stage, tillering stage and regreening stage, with the pushing forward of growing period, Nitrogen rate, phosphorus rate and potassium rate of wheat were gradually dropping. Rotation tillage especially RNT was in favor of N, P, K accumulation. N absorption of NTS was rapidly declining after flowering period, which somewhat affected absorption nitrogen accumulation. The amount of absorption P accumulation was affected in the treatments of convention tillage and straw returning. No tillage treatments were not in favor of absorption K accumulation increasing, rotation tillage and straw returning treatments were in favor of absorption K accumulation increasing.4. Wheat yield of NTS was declined by3.5%compared with CT, the reason was, with the extending of the no tillage time, the soil was compact, which affected wheat emergence rate, root growth and then affected wheat yield. CTS2>CT>CTS1, that showed straw returning treatments were in favor of wheat yield increasing, while the excessive amount of straw returning affected wheat yield. RNT was increased by9.23%compared with CT, which showed rotation tillage, especially RNT treatment was in favor of wheat yield increasing. Convention tillage and straw returning treatments were in favor of wheat crude protein and wet gluten increasing, which improved the quality of strong and middle gluten of wheat. Peak viscosity and breakdown value of no tillage, rotation tillage and CTS treatments were higher than CT, which would not reduce wheat edible quality.