Study On Ecologic Effect Of Soil Tillage Depth And Straw Recycling In Directly Sowing Rice Field

The effects of soil tillage depth and straw recycling model on growth, yield and yield components of crop, The physicochemical properties of soil, soil water content and the trait of potential weed communities were studied from 2005 to 2006 year.The results were followed as below:1 The effect on crop growth and yieldThe dry matter content increased with the increase of soil tillage depth at different stage. The effects of soil tillage depth and straw recycling on plant height and group of rice had no significant differences. The effects of tillage depth on plant height,group,yield and yield components had no significant difference, the effects of straw recycling on plant height,group,yield and yield components had no significant difference.2 the effect on dry matter of root system of direct riceThe total root dry weight of different soil tillage model had significant difference. The total dry matter of roots among non-tillage and low tillage medium tillage deep tillage had significant differences. At panicle initiation, flowering and mature stages, the differences of dry matter of roots among non-tillage, low tillage, medium tillage and deep tillage were distinct(a=0.05)At panicle initiation, flowering and mature stages, the root dry weight in 10.5-21cm soil layer increased with increase of tillage depth,and had significant differences. The changes of the root dry weight of all tillage depth is the most obvious in 7-14cm soil depth.3 The effects on the concentration of TN and TP in the surface water of rice fieldsThe content of TN and TP can be decreased by soil tillage and straw recycling can decrease . The period within a week after the fertilizer application was a critical time to control N, P loss and leaching from flooded paddy field.4 The effects on ecology characteristics of field...