Study On Soil Acidification Characteristics And Regulation Mechanism Of Tea Gardens In Southern Anhui Province

Tea garden soil was generally acidic,but when the pH of tea garden soil was lower than 4.0,the physiological process of tea plants is significantly inhibited,and the nutrient supply capacity of tea garden soil is significantly reduced,which affects the synthesis and metabolism of free amino acids and tea polyphenols.Based on the location monitoring of typical tea garden soils in Anhui Province,the acidification status and trend of tea garden soils in southern Anhui Province were analyzed,and the relationship between the distribution of active aluminum forms in tea garden soils in southern Anhui Province and pH value and tea planting years was studied.Through the soil column simulation study on the migration behavior of calcium in acidified tea garden soil,the improvement measures based on the application of dolomite powder were proposed to provide the premise basis for the adjustment of soil acidification and the formation of quality tea raw materials in southern Anhui tea garden.This paper draws the following conclusions:1.Soil acidification was serious in tea plantations in southern Anhui Province.The supply of nutrients was unbalanced.Tea soil was rich in nitrogen and phosphorus,but the content of potassium was relatively insufficient.The soil data of tea plantations in the main tea producing areas of Anhui Province showed that the surface soil values of all the surveyed tea plantations were lower than the lower limit of the suitable range for tea plant growth,and the Soil acidification rate tends to decrease with the increase of soil depth,and the acidification rate was 0.06 pH unit/year.2.With the increase of tea planting years,the exchangeable aluminum in tea garden soil showed an upward trend,while the pH showed a downward trend.pH was negatively correlated with tea planting years and exchangeable Al3+ with correlation coefficients of-0.952 and-0.819 respectively(p<0.01).The regression analysis of pAl-pH shows that the slope of linear regression equation is between 0.208 and 0.659.3.Calcium migrates faster with water,about 1.11 cm/d.In 20-40 days,the calcium ions added to the soil column will leach to less than 30 cm.The relationship between pH and pCa and pAl was pCa=2.11 pH-4.66(R=0.9146 p<0.01),pAl=2.92 pH-6.91(R=0.9138 p<0.01).The results showed that calcium ion could decrease the content of latent acid in the soil tillage layer(0-30 cm),and thus increase the pH of the soil tillage layer.4.The effect of applying dolomite powder on increasing soil pH was greater in the vertical than in the horizontal.If dolomite was used as soil amendment in acidified tea garden,high temperature and humidity season should be selected,furrow covering should be adopted in the application mode,and the depth should be 10-15 cm.At the same time,relatively loose physical properties of the soil should be maintained to facilitate the dissolution,diffusion and migration of calcium ions.