Effects of various tillage depths on soil physical and chemical properties of tea plantation

ObjectiveA reasonable depth of cultivation which would not only effectively prevent the deterioration of soil structure but also could fully create a well-developed environment such as water,fertilizer and air for tea plants was studied to provide technical ways for guiding tea farmers in scientific farming.MethodIn this study,fild experiment was conducted. No tillage was as control(CK). Three tillage depths including,10 cm tillage,20 cm tillage and 30 cm till-age were set to study the effects of various tillage depths on soil bulk density,water content,porosity,three-phase ratio and nutrient.ResultCompared to CK,soil bulk density of 0-30 cm layer decreased to various extents after tillage,and that in 30 cm tillage treatment significantly reduced(P<0.05,the same below). Tillage significantly increased soil water content,and 20 cm tillage had the best effects on 0-10 and 10-20 cm soil layer,30 cm tillage had the optimal effects on 20-30 cm soil layer. In addition,tillage also increased non-capillary porosity,but reduced capillary porosity. Overall the total porosity still increased. Tillage had significant effects on soil porosity at the depth of 0-10 cm. The soil porosity was significantly affected by 20 cm tillage at the depth of 10-20 cm,while 30 cm tillage had significant effects on the noncapi-llary and total porosity at the depth of 20-30 cm. After tillage,the gas phase and liquid phase ratios at the depth of 0-10 cm increased significantly,while the solid phase ratio decreased significantly,and 20 cm tillage had the optimal effects. While 30 cm-tillage had the best coordination effects on three-phase ratio at the depth of 20-30 cm. After tillage,the con-tent of organic matter at the soil depth of 0-10 cm decreased,while the content of organic matter at 20-30 cm increased significantly under 20 cm and 30 cm tillage. The content of readily available nutrient at the soil depth of 0-30 cm increased to different degrees after tillage. An analysis of principal components showed that the total porosity and solid phase ratio were the key factors that affected the soil physical properties of the tea plantation,while the available phosphorus was the key factor in nutrient fertility index.ConclusionTo sum up,different tillage depths can reduce soil bulk density,in-crease soil water content,improve soil porosity and coordinate three-phase ratio of soil,and 20 cm tillage has the best ef-fects on comprehensive improvement of tea plantation soil.