Effect Of Cultivation And Fertilization On The Yield, Quality And Soil Of Flue-cured Tobacco In Zunyi

Continual cropping and excessive fertilization are ubiquitous in cultivation of flue-cured tobacco in Zunyi, Guizhou, which produced serious soil and environment problems such as poor yield and quality, disappearance of tobacco style and characteristics, low soil organic matter, degraded physical properties of soil, change of soil microbe groups and communities, and decreased fertilizer use efficiency and environment pollution. Therefore, mono-season and long-term field experiments were established to study effects of cropping modals and fertilization on yield, quality, nutrient uptake by flue-curried tobacco and nutrients and enzymatic activities in soils. The experimental treatments in the long-term experiment included tobacco-maize rotation with chemical fertilizer plus manure (1:1), tobacco-maize rotation with chemical fertilizer only, continual tobacco cropping with chemical fertilizer plus manure (1:1), and continual tobacco cropping with chemical fertilizer only. There were five treatments in mono-season field experiments:no fertilizer (control), chemical fertilizer, 75% of chemical fertilizer plus 25% of manure,50% of chemical fertilizer plus 50% of manure, and 25% of chemical fertilizer plus 75% of manure. Following are the main results:There were lowest disease incidence but highest yield and quality of tobacco. Compared tobacco continual cropping with chemical fertilizer only, the disease incidence was decreased by 13.35% and the tobacco leaf yield was increased by 41.86%. Nutrient uptake, including nitrogen, phosphorus and potassium, by tobacco plant in rotation cropping was also increased due to high plant biomas. Mono-peack curve could be used to describe the change of available nutrients in soil for growing tobacco, indicating that soil nutrient supplies were compatible with plant requirement. This could be the reason for the local soil suitable for tobacco cultivation. Over 98% of nitrogen was nitrate and no phosphorus was detected in underground runoff. Nitrogen lose by underground runoff accounted for 22.02%～30.39% of those supplied by fertilizers and potassium for 15.85～20.44%, which suggested a large lose of nitrogen and potassium, fertilizer waste, water pollution, and necessity of fertilization improvement in tobacco cultivation. It is necessary to advocate tobacco rotation and mixture fertilization of inorganic and organic fertilizers.Organic-inorganic fertilizer can not only increase nitrogen, phosphorus and potassium available nutrient content of soil, but also improve catalase, invertase, acid phosphatase, urease activity in soil. While, While, improving the agronomic traits of tobacco, promote tobacco root, stem and leaf dry matter accumulation, increase tobacco production, and the output medium leaves rates. From leaf chemical composition, the reducing sugar content increased, lower nicotine content, total sugar, protein, shmuck value, potassium chlorine than are in the appropriate range.Which,75% of chemical fertilizer plus 25% of manure overall optimum. In summary, the cultivation process of flue-cured tobacco, it is necessary advocating cropping and Organic-inorganic fertilizer.