Effect Of Green Manure Application On The Improvement Of Tobacco-growing Soil Fertility And Yield & Quality Of Tobacco

In this paper, the effects of the different incorporation quantities of the Chinesemilk vetch and wheat and the milk vetch incorporation in different ways (coverageand incorporation) on field nutrition, rhizosphere microbial, agronomical character oftobacco plant, tobacco plant dry matter accumulation, the dynamic uptake andaccumulation of nitrogen, phosphorus and potassium, the chemical composition oftobacco and the yield & quality of tobacco were studied systematically. The mainresearch results are as follows:1. The amount of available nutrient (N, P, K and organic matter) in soil increasedwith the increasement of green manure incorporation quantity. Green manureincorporation could also adjust the pH level of soil. The pH value increased in theearly period of tobacco growth, while it decreased in the late time. The more thequantity of green manure incorporated, the greater the pH value changed.The amount of available nitrogen, potassium and pH value of the treatment of1500kg/667m~2 deducted its nutrient content (N, P, K) were lower than CK in the earlygrowth period of the tobacco plant, but its amount were higher in the late period.Compared with other treatments of the same green manure incorporation quantity, theavailable nutrient (N, P, K and organic matter) in this treatment were lower.The effects of the different green manure incorporations on the amount ofavailable nitrogen and potassium in the dry tobacco-growing soil were greater thanthat in the paddy soil. On the active organic matter, the result was opposite. On theavailable phosphorus and the pH level, the differences were not significant.The amounts of available N, P and K, active organic matter and the pH levelunder incorporated treatment with the Chinese milk vetch were higher than that underthe covered treatment in the early growth period of tobacco, but it reversed in the laterperiod. The differences between the incorporated treatment and the covered treatmentwere not significant on the amount of available nitrogen, phosphorus, potassium andthe pH level, but the difference was great in the content of active organic matter. 2. The increasement of green manure incorporation also improved the amount ofthree kinds of rhizospheric microbial biomass including fungi, bacteria, actinomyces.The amount of rhizospheric bacteria reached the maximum on the vigorous growthstage, but the amount of rhizospheric actinomyces and rhizospheric fungi reached theminimum. The order of the amount of these three rhizospheric microbial was2000kg/667m~2＞1500kg/667m~2＞1000kg/667m~2＞CK in each growth period of tobaccoplant. In the experiments of Chinese milk vetch in different ways, the amounts of thethree kinds ofrhizospheric microbial biomass among the treatments were different.3. On the dry matter (including root, stem, leaf) accumulation of tobacco plant ineach growth period of tobacco, the relationship of the different green manureincorporation quantity was 2000kg/667m~2＞1500kg/667m~2＞1000kg/667m~2＞1500kg/667m~2 (the treatment deducted the nutrients)＞CK. In the whole growth period,the increasement of green manure incorporation enhanced the accumulation of N andK, but the effect was not significant on the accumulation of P.In the experiments of Chinese milk vetch in different ways, the amount of thedry matter accumulation in root, stem and leaf were the most and its accumulationrate was the fastest under the covered treatment. The covered treatment improved theabsorption of N and K, but it didn't for the absorption of P.4. The contents of chemical composition were enhanced including total sugar,reducing sugar. The correlation between the chemical composition and the greenmanure incorporation quantity was positive. The content of total sugar was significantpositive correlative with the green manure incorporation quantity. The reducing sugarwas very significant positive correlative with the green manure incorporation quantity.The nicotine content was negative correlative with the green manure incorporationquantity, and the correlation coefficient was significant. By the analysis of the ratio ofvarious chemical compositon, the yield of the 2000kg/667m~2 treatment was the largest.The quality of the 1000kg/667m~2 treatment in dry field and 1500kg/667m~2 treatmentin paddy field were the best. In the experiment of green manure incorporation indifferent ways, the green manure covered treatment was the best.