Effects Of No Tillage And Straw Returning On Rice Growth And Soil Properties

Rice is one of the main grain crops in our country.The safety,high quality,high yield and high efficiency of rice production are of great significance to food security.Straw resources can be the most effective and convenient use in rice production through straw returning.Straw nutrients can improve the soil physical,chemical and biological properties,enhance soil fertility,and reduce the environmental pollution caused by straw burning and waste,which can realize the sustainable development of rice production.Our works have been carried out since 2008,we used super rice Y two and 087 as the test material,the five treatments of no tillage,no tillage + straw returning,face of conventional tillage and tillage+ straw surface application,tillage + straw returning straw deep application were researched three times,respectively.The effects of the no tillage and straw mulching on the growth of rice,rice yield,soil physical,chemical and biological characters,and the correlation between rice yield and soil properties were investigated.The main test results are as follows:1 After years of no tillage treatment,the yield of early and late rice decreased by 0.49%and 4.08%respectively,and the yield of late rice decreased significantly,and the yield of rice decreased significantly.The direct cause was that the soil available P,available K and organic matter content,sucrase,urease and catalase activities decreased significantly in the late season,and the rate of panicle formation and the number of effective panicles decreased significantly.2 After years of no tillage + returning to the field,rice straw treatment showed better yield increasing effect.The yield of early and late rice increased by 4.06%and 0.17%,respectively,and the yield increase of early rice was remarkable.The direct reason for early rice season production is long-term no tillage + straw returning treatment face is decreased soil bulk density,total porosity,capillary porosity,available K and organic matter content,catalase activity increased significantly,so as to promote the increase of per panicle.The direct cause of the late rice season production is long-term no tillage straw returning treatment makes the surface application decreased soil bulk density,total porosity,capillary porosity,available P,available K and organic matter content,invertase,catalase activity increased significantly,so as the total grain number per panicle was increased significantly.3 Consecutive years of conventional tillage was under the condition of continuous straw incorporation could significantly increase rice yield,tillage + straw returning treatment face of early and late rice yield was increased by 2.30%,4.26%,conventional tillage +straw deep application of treatment of early and late rice yield was increased by 7.99%,7.55%,and deep application of straw returning treatment to compare the effect of straw yield surface application better yield increasing effect of returning treatment.As long as the face of the direct cause of initiation of somatic embryogenesis in Pinus banksiana +straw returning treatment of straw returning is the face of yield of early season decreased soil bulk density,total porosity,capillary porosity,available P and organic matter content,catalase activity increased significantly,so as to promote the total grain number per panicle was increased;the direct cause of late season tillage + straw surface application returning treatment increased is decreased soil bulk density,total porosity,organic matter content,catalase activity increased significantly,so as to promote the effective panicle number was significantly increased.The direct cause of the early season + straw returning treatment initiation of somatic embryogenesis in Pinus banksiana deep application of straw deep application to field production yield of early season is decreased soil bulk density,total porosity,capillary porosity,available P,available K and organic matter content,urease,invertase,catalase activity increased significantly,so as to promote the total grain number per panicle was increased;late season + straw deep application of the direct cause of initiation of somatic embryogenesis in Pinus banksiana incorporation yield is decreased soil bulk density,total porosity,capillary porosity,available K and organic matter content,invertase activity improved significantly,so as the effective panicle number and total grain number per panicle increased significantly.