Effect Of Straw Returning Soil On Soil Fertility, Yield And Quality Of Tobacco Leaves

In order to find suitable crop straw types and fertilizer application for the production of tobacco in Qujing, this paper shows a method by composting crop residues and inorganic fertilizer in the field to study the influence of agronomic traits, economic character, quality tobacco and tobacco soil fertility by straw of different crops and different amount of rape straw to tobacco. It showed that:1. Different Straw crops returning soil significantly increased tobacco plant height and tobacco yield, added the tobacco stem, promoted the improvement of agronomic traits, significantly increased the value of tobacco production, tobacco average price level and upper the proportion of superior tobacco to deferent degrees, rape straw is the optimal effect, its production reach to 28619.8kg/hm2, average price is 13.93 yuan/kg, grade index is 69.67, the proportion of superior tobacco is 43.71%. Straw returning soil significantly increased the potassium content, reduced the quantity of total sugar and reducing sugar content, improved the coordination chemistry of tobacco leaves; poly-phenols and non-volatile organic acid content of leaves have also been significantly enhanced. Within the different crop straw treatment on the quality of tobacco,rape straw> wheat straw> corn straw> without straw return soil.2. by increasing the amount of rape straw, tobacco height, maximum leaf length and width, leaf number and stem of tobacco plants and other agronomic characters are increased gradually; nicotine, potassium content are increased to different degree, total sugar and reducing sugar content are decreased; poly-phenols, carotenoids, non-volatile organic acid content increased through a change process from rising to dropping.6000kg/hm2 rape straw is optimum to improve the economic traits and the physical and chemical properties, its poly-phenols, carotenoids, non-volatile organic acids reached the highest values which are 25.29mg/g,262.02μg/g,101.50mg/g.3. Straw returning soil can regulate the soil pH, increase soil nutrient content, the amount of soil organic matter, available Nitrogen, available phosphorus, available potassium, exchangeable calcium and magnesium content are increased progressively by the straw. After the rape straw decomposition, soil organic matter, available N, available P and available K content increased rapidly, about 50 days after transplanted, the number reach to the highest, but its decreased since the vigorous growth. But for the late demand for nutrients reduced, soil organic matter, available P and available K content are slowly improved, but available nitrogen in the soil after transplanted from 90 to 130 days are increased and then decreased.