Effects Of Soil Amendment With Lime And Organic Materials On Renovated Tobacco Field

Incubation experiments and field trials were used to study soil structure improvement, adverse acidification regulation and inorganic nitrogen management. The experiment sites were located in Leshan and Puchang and Shiping in Guizhou Provence based on degree of disturbance in renovated tobacco field. The main conclusions were as follows:The growth and agronomic and economic traits of tobacco were promoted with liming amendment in renovated tobacco field. The incubation experiments showed that the release of latent acid in acid yellow soil was stimulated after adding lime. Hence, a reasonable application rate of lime was a key regulator of acidity in renovated tobacco field. When the application rate of lime reached 1.50 t/hm2 at soil p H5.0, the effects of soil acidity correction and tobacco economic traits were optimal. The favorable effects of application liming were also obtained at different planting years of renovated tobacco field. Closed relationships were also found between lime dosage and rate of p H change, stable p H status and settling time of p H in the incubation experiment.The soil nutrient contents were coordinated and the quality of water stable aggregates were improved after adding four kinds of organic material, including corn stalks, carbonized corn stalks, humic acid potassium and vermicompost organic fertilizer, then the formation of high fertility soil planted tobacco was promoted. Among the renovated tobacco fields with poor soil structure, the optimal effects were achieved in a two-year renovated tobacco field with corn stalks treatment and four-year renovated field with humic acid potassium treatment. All of organic materials could coordinate the status of nitrogen, potassium nutrient accumulation and distribution in tobacco. In addition, soil p H values were significantly reduced with applying corn stalks, and carbonized corn stalks and vermicompost organic fertilizer during the incubation experiment and field trials.Interestingly, parts of soil nutrient contents were increased with amendment of corn stalks, carbonized corn stalks, humic acid potassium and vermicompost organic fertilizer plus lime. What’s more, these treatments eliminated the acidification effects and improved the integrated soil fertility. Among the renovated tobacco field with poor and acidic soil, liming with corn stalks was suitable for renovated field and lime plus humic acid potassium was fitted for the four-year renovated tobacco field. The effects of humic acid potassium or vermicompost organic fertilizer co-application with lime was better than corn stalks or carbonized corn stalks co-application with lime as respects to promoting nutrient accumulation in tobacco.The fastest growth of tobacco, the largest amount of nitrogen accumulation and production were all reached the maximum value with the nitrogen application rate of 90 kg/hm2. Hence, the best of inorganic nitrogen fertilizer application rate was 90 kg/hm2 in renovated tobacco field. Based on the relationship between transplanting period and SPAD value of leaves, the normal range of 3rd position leaves were 28.8±3.5 and 26.4±4.7 after transplanting 21 days and 51 days respectively. The normal range of 9th and 15 th position leaves were 35.3±3.6 and 40.8±3.7 after transplanting 81 days respectively. Using portable instruments guiding nitrogen management of renovated tobacco field could be achieved by measuring tobacco SPAD value.Therefore, application liming or plus organic materials would guide the nitrogen management in renovated tobacco field with the help of chlorophyll meter on the conditions of the acidic and soil structure problems. This could help to improve the integrated soil fertility and the production of tobacco in different planting years in renovated tobacco fields.