Effect Of Organic Manure On Yield And Quality Of Flue-cured Tobacco

Tobacco is an important economic crop in China. As one of the main tobacco-planted regions, there is an area of 47,000hm2 planting tobacco in Chongqing. Tobacco industry is not only the leading industry of breaking away from poverty but also the primary resource of finance and revenue in tobacco-planted regions in Chongqing. Currently, the lower quality tobacco and being short of competition in international market, is the most important problem of tobacco production all over the country. As a crop which should be paid equal attention to yield and quality, the quality of tobacco is subjected to soil, breed, planting technique, climate and cool technology, and etc, especially the soil is the dominant factor. The reason is that the fitting soil fertilizer is the base of gaining high quality tobacco. Improving efficiency of fertilizer utilization, reducing the amount of application of chemical fertilizer, improving the growth environment of the flue-cured tobacco, and realizing the high-quality production of the flue-cured tobacco has already become an urgent problem. Through scientific applying fertilizer set up a good circulation of farmland of nutrient, it is the key point of solving this problem in order to offer the good ecological environment for the flue-cured tobacco.In the main planting-tobacco soil (yellow soil) of Chongqing, the field experiment was conducted to study the effect on flue-cured tobacco quality and yield by offering different kinds and different content organic manure. The conclutions were as follows:Among the available seven kinds of organic manures (compound organic manure, straw, pig dung, cow dung, rapeseed cake, peat, barnyard manure), compound organic manure, combining 20% organic-nitrogen and chemical fertilizer, was most outstanding on increasing yield, 15% compaired to CK (NPK fertilizer); the barnyard manure was most worst, and decrease 77.5kg/hm² in yield and 52.4Yuan/hm in economic benefit. The yield and benefit of other organic manure treatments were all higher than that treatment with the same NPK fertilizer, respectively higher 49.7～353.5kg/hm² and 379.2～2846.1Yuan /hm². Combination of organic manure could significatively enhanced the yield-rate of better tobacco, and the proportion of superior smoke treated with cole cake increased 7% than CK. Comprehensive analysis by the yield, the benefit and the leaf quality, compound organic manure, rapeseed cake and straw were better and the barnyard manure was worst. The effect was best for straw and rapeseed cake with 20% organic-nitrogen and for compound organic manure with 40% organic-nitrogen.Cooperate applying organic manure increased the number of leaves, and the same effect to leaf area, the stem encircles and the plant height. When smoke growth 80 days after transplanting, cole cake and straw treatment had the higest plant height and leaf area, then the compound organic manure treatment, and the control was worst. Cooperate applying organic manure improved plant uptake of nitrogen, phosphorus and potassium, and met plant high nutrient need for a longtime. Among the different treatments, the compound organic manure, straw and rapeseed cake were better than manure soil and the peat. The effect was best when organic-nitrogen content was 20%, 20%, 40% account to total nitrogen for compound organic manure, Straw and cole cake repectively.Upside leaf had higher nicotine and the total nitrogen content obviously than the middle leaf's and downside leaves irrespective of all different fertilizer treatment. The leaf tobacco nicotine content of different treatments amplitude ranged from 16.00 g/kg to 30.09 g/kg, and the total nitrogen content ranged form 13.56 g/kg to 22.65g/kg. The content was reasonable for all the treatments besides the control and pig dung treatment. Compound organic manure, Straw and rapeseed cake treatment when organic-nitrogen was 20% significantly increased the sugar content with 10.3% compare the control in the middle leaves and downside leaves, while in the downside leaves the increament was 43.0%, but it was not significant in the upside leaves. The other organic manure treatments decreased sugar content in upside leaves with 16% compared to the control treatment. The cooperate applying 20% other organic manure treatments decreased protein content of upside the leaf tobacco and increased total sugar content with 5.6% in downside tobacco leaves compare with the control besides the barnyard manure and the peat treatment.As measured by different chemical composition ratio in tobacco leaf, appropriate amount of organic manure increased Shi-muke as well as the total sugar/total nitrogen ratio while decreased the total nitrogen/nicotine ratio of middle leaf in middle leaves which caused an appropriate ratio among these composition. Among all the organic fertilization treatment, rapeseed cake, Straw and compound organic manure had the best performance in improving quality of tobacco leaves and the right amount ranged from 20% to 40%(measured by the organic nitrogen content to total nitrogen content).All organic manure treatments increased mineral nitrogen supply (NH₄⁺-N and NO₃^- -N content) significantly compare to chemical fertilizer only and the increasement was ranged from 30% to 113.7% when tobacco growth 80 days which showed that organic manure and organic matter of soil were mineralized in mass in the flue-cured tobacco exuberant vegetal period and then met the high nitrogen need, but when mature period, the difference was not significant. All these indicated that the appreciate organic manure application content (no more than 40%) was good for exuberant vegetal period and mature period and more appreciate organic ssmanure may caused the higher (28%-66%) mineral nitrogen content compare to the chemical fertilizer during the mature period as the result showed which may impede the mature of the flue-cured tobacco. All organic feritilization treatments had higher soil available N, P and K. content than the chemical fertilizer control and rapeseed cake, the straw and the compound organi manure had the highest content.As the results showed, among the seven organic-manure reatment, the compound organic manure, the straw and rapeseed cake had the best performance in increasing tobacco yield, soil P, K content and improving quality of leaves which the appreciate content was 20%～40%, 20% and 20% respectively. Above all, all experiment was carried only one year, then it is necessary to carry out longer-term experiments to further investigate the potential effects of organic manure.