Effects Of Tillage And Straw Returning On Field Ecological Environment And Wheat Growth

In the process of wheat production,soil tillage and straw returning are important agronomic measures.Different tillage measures and straw returning will affect soil physical and chemical properties,heavy metal content and nutrient uptake and yield formation of wheat to some extent.The conservation tillage system with straw returning,less tillage and no-tillage as specific measures can solve the problems of soil erosion,water shortage and drought in China,and has unique economic,social and ecological effects.In order to investigate the soil physical and chemical properties and the growth and development of wheat in response to different tillage methods and straw returning,this study used Yangzhou University's rice-wheat rotation conservation tillage located test platform.In the two years of 2017 and 2018,Yangmai 22 was selected as Test materials,set up no-tillage and straw returning(NTS),no-tillage in wheat and convention tillage in rice(RT2),convention tillage in wheat and no-tillage in rice(RT1),convention tillage and full straw returming(CTS),minimum tillage and half straw returning(MTS),and convention tillage(CT)six treatments,studied straw returning and different tillage methods.The effects of straw returning and different tillage methods on farmland ecological environment and wheat growth and development were studied,soil and wheat fertilizer characteristics growth patterns were revealed,in order to effectively develop no-tillage,ration tillage and straw returning techniques.The results are as follows:1.The bulk density of soil layers was affected by different tillage methods.Among them,the soil under no-tillage treatment was tight,and the bulk density of different tillage layers was larger.The bulk density of 0-20cm soil layer reached 1.38g/cm3.Tillage and straw returning improved soil compaction.The treatments of rotation tillage,minimum tillage and returning straw to the field were conducive to the improvement of soil organic matter,while the content of no-till organic matter was mainly concentrated in the upper layer of soil and the average of two years after rice and wheat is increased by 28.12%and 11.77%.Tillage and straw returning increased the total nitrogen content of the soil cultivation layer,and the total amount of straw in the soil after wheat was 8.76%higher than that of straw.Under tillage conditions where no-tillage promoted the accumulation of alkali and nitrogen in the middle and lower layers,the appropriate amount of straw returning to the field can increase the content of alkali nitrogen.Returning the appropriate straw to the field was beneficial to increase the effective phosphorus and available potassium content of the wheat,and the total amount of straw returned to the field was 27.60%more than the total amount of straw after 2 years and 23.69%more.The available phosphorus and potassium in two rotation tillage was not much different.The heavy metal content under no tillage showed no obvious concentration,except Cd,which can reduce the accumulation of heavy metals in the soil by returning the straw to the field2.At the early stage of wheat growth,the full plant height of straw returning was higher than that of no straw returning;the plant height of no-tillage treatment after joining was lower.The area of the top three leaves of no tillage in the wheat season was slightly lower than that of wheat,and the area of the upper three leaves of straw was the largest.20 days after flowering,no-tillage,rotation tillage,minimum tillage and straw returning could increase the chlorophyll content of wheat and slow down the chlorophyll content.The reduction in wheat season's no-tillage was less than that of wheat season.No-tillage increased dry matter accumulation in the late growing periods of wheat.No-tillage and straw returning to the field can promote the absorption of nitrogen in the later stage,and it was beneficial to promote the cumulative potassium uptake of wheat plants,but the effect of phosphorus absorption in the no-tillage treatment was not obvious,no-tillage and straw returning to promote the absorption of nitrogen in the later stage,which was beneficial to increase the amount of potassium uptake by wheat plants,but in the late stage,the effect of phosphorus absorption of no-tillage was not significant.In the wheat growth the potassium content of full straw returning was higher than that of no straw returning,which increased the amount of potassium uptake by wheat plants.3.In 2017,the 1000 grain weight of cultivated straw and half straw returning was significantly lower than that of wheat cultivation treatment.The actual yield of wheat with full straw returning was 8.60%higher than that of no straw returning.In 2018,the number of ears per acre in tillage treatment was higher and the increase in the number of no-tillage treatment increased the yield,the real yield of no-tillage wheat increased by 7.90%compared to the no straw returning treatment.Wheat production was higher than no-tillage treatment.The actual yields in the two years were the highest in the field of full straw returning and no-tillage in the wheat season,which was 8.60%and 8.57%higher than that of no straw returning.