Organic Fertilizer Production from Tobacco Stem by Microbial Fermentation

Producing of organic fertilizer from tobacco stems by aerobic fermentation was tested in an in-house fermentation apparatus.The temperature,moisture content,pH,organic matter,germination index(GI) in fermentation were tested and the major nutrients in the fertilizer were analyzed.The results showed that with no exogenous nutrient,the temperature of tobacco stems raised quickly and up to its highest value in about 10 days.The process was accelerated by microbial agent application.The maximum temperature of pile was 67℃ and the longer duration of high temperature(≥ 50℃) might shorten the fermentation period by 5 days.At the end of fermentation,the fertilizer's moisture content,pH and organic matter were 40.28%,7.3 and 65.05%,respectively;GI was 86.67%,which was higher than the critical point of compost maturity index(80.00%).Fertilizer sample was dark brown in color and free of tobacco smell.It offered an earthy odor and contained rich nutrients,including nitrogen(2.59%),potassium(6.75%),phosphorus(0.48%),iron(338.10 mg/kg) among others.