Effect Of Rotation Pattern On Soil Ecosystem And Yield And Quality Of Tobacco

By means of field culture and laboratory analysis, based on actual instance, This paper investigated and analyzed the nutrition of soil in different stubble in soil of the tobacco zone of northeast; studied the effect on edaphon, enzyme and fertility in soil ecosystem in tobacco following tobacco and following next crops with being selected different number of year; appraised the effect of different stubble number of year on partial character of soil ecosystem; provided the science theoretic foundation for the study of obstruction of tobacco in succession. This paper studied the effect on yield and quality of tobacco in different stubble of different treatment; found out fitting stubble and treatment and analyzed the correlation between nitrogen of soil and nitrogen of tobacco leaves. Through the above study, to supply the theoretic foundation and means by taking the fitting rotate manner and fertilize treatment for the tobacco zone of northeast in China. The results were as follows: 1 By Hierarchical Cluster Analysis of the nutrient of thirty samples, the result could be drawn that the second and forth sample of soil suited to plant tobacco. In whole nurient of soil of different stubble in different zone in the Northeast District, 56.67 percent of the whole samples, the content of effective phosphoric was lower, under 20.00mg/kg, phosphor should be supplied. 2 Comparing with tobacco tobacco following tobacco and following next crops, the average of bacteria in the soil of just stubble was obviously bigger than following tobacco six years, about 48.97 percent, while the average of actinomycetes and fungus was less than tobacco following tobacco and following next crops, following tobacco six years increased respective 33.82% and 32.51%, following tobacco two years increased respective 28.92% and 23.69%. The average of ammonia-oxidizing bacteria and nitrobacteria in the soil of just stubble was higher than those of tobacco following tobacco and following next crops, while the number of denitro-bacteria was less than tobacco following tobacco and following next crops. The number of biomass carbon of microorganisms of soil in just stubble was greater than that of tobacco following tobacco and following next crops. 3 Comparing with just stubble, catalase, peroxidase, urease, invertase and pH of soil in tobacco following tobacco and following next crops decline. Following tobacco six year declined respectively 5.68%,19.35%,3.11%,12.79% and 2.44%, following tobacco two years declined respectively 19.32%,19.35%,3.89%,20.93% and 1.44%, following next crops declined respectively 22.73%,16.13%,3.11%,8.91% and 1.58%. The correlation between organic 4 matter and peroxidase of soil was positive, rjust stubble= 0.984**, correlation was significant at the 0.01 lever. The correlation between organic matter and invertase of soil was positive, rjust stubble= 0.881*, correlation was significant at the 0.05 lever. 5 We could draw the conclusion that increasing the input of P, K and B fertilizers could make the tobacco grow higher and have a wider base stem, more effective leaves per plant, the biggest leaf area per plant and heavier dry weight per plant through analyzing the agricultural characters of tobacco. The ratio of N:P2O5:K2O=1:1:3 treatment is avail for the agricultural characters of tobacco. 6 Through the analysis of chemic content, the conclusion was drawn that in the average of whole treatment, the kalium and total sugar of tobacco leaves in wheat stubble was significant higher than soybean stubble, increased respectively 15.69% and 20.52%, while the chlorine, total nicotine, nitrogen and crude albumen of tobacco leaves was lower than soybean stubble, declined respectively 25.00%, 17.51%, 19.02% and 20.54%. The ratio of N:P2O5:K2O =1:1:3 treatment was in favor of the form of tobacco leaf. 7 Through the analysis of economic properties of the initial baked tobacco,the conclusion was drawn that the average quality and production of tobacco leaf of two stubble, the proportion of good, good and middling, average price and production value per 667m2 were higher than soybean stubble, increased respectively 2.14, 1.87, 1.56 and 1.79 times. So considering the economic element the wheat stubble was avail to soybean stubble.