The Effects Of Slow-release Fertilizer On The Nitrogen, Potassium Use Efficiency And The Yield, Quality Of Tobacco

In this study, a randomized block experiment was conducted to study the effects of tobacco-specific slow-release fertilizer (Kim Zheng Da producer) on the growth characteristics of flue-cured tobacco, leaf nitrogen and potassium fertilizer use efficiency and yield and quality, try to reveal the possibility of slow-release fertilizer in the tobacco production practice, and to facilitate an efficient fertilization model. The main conclusions are as follows:1. The initial release rate of nitrogen and potassium of tobacco-specific slow-release fertilizer in water was less than 15%, the cumulative release rate of nutrients within 28 d was no more than 75%, confirming national standards for slow-release fertilizer. The nutrient release rate was slow in early, fast in late, long release cycle, with the synchronous release of nitrogen and potassium.2. Tobacco-specific slow release fertilizer may preserve the nutrients in it, it maintain the level of soil total nitrogen, available nitrogen, phosphorus, potassium content, improve soil fertility, promote the nutrients absorption of flue-cured tobacco.3. Tobacco-specific slow-release fertilizer can promote the growth of flue-cured tobacco. Tobacco-specific slow-release fertilizer application could improve the agronomic characters, dry weight, root activity, leaf SPAD value, leaf nitrate reductase activity from vigorous growth stage to maturity; raise leaf net photosynthetic rate, stomatal conductance, intercellular CO2 concentration; enhance the content of leaf total soluble sugar, reducing sugar, nicotine, total nitrogen, total potassium and other chemical ingredients.4. Tobacco-specific slow-release fertilizer can improve the N, K fertilizer use efficiency of tobacco, but the effects decreased with the increase of fertilization level. In the low fertilization level, the increasement of nitrogen, potassium use efficiency were 24.13%,25.08%; in the high fertilization level, only 8.74%,8.58% increasement respectively.5. Tobacco-specific slow-release fertilizer can improve the yield and quality of tobacco leaf. In the high and low level of fertilization, the yield and output value increased by 155.65 kg/hm2,4524.42 yuan/hm2 and 176.45 kg/hm2,2876.72 yuan/hm2 respectively. And the leaf total soluble sugar, reducing sugar, nicotine, total potassium content is suitable, and the chemical compositions were in harmonious, corresponding the requirements of fine quality tobacco...