The invention discloses an organic-inorganic environmentally-friendly
pollution-free compound
fertilizer and a preparation method thereof. The compound
fertilizer comprises the following components, in percentages by
mass: 20-25% of harmless
livestock and
poultry manure, 5-10% of
earthworm excreta, 10-15% of
humic acid, 25-30% of
urea, 14-24% of monoammonium
phosphate, 8-18% of
potassium chloride,and 5-8% of
calcium dihydrogenphoshate. The preparation method comprises the following steps: removing
heavy metals in the
livestock and
poultry manure, performing harmless treatment on heavy
metal ions through earthworms and preparing the high-quality
organic fertilizer raw material earthworm excreta, removing
antibiotics of the
livestock and
poultry manure by adopting physical, chemical and biological methods, wherein the above steps solve the problems that the
heavy metals and the
antibiotics pollute the environment and endanger
human health, and performing composting
fermentation, whereina secondary
granulation technology is adopted to improve a
granulation rate of the material, clay for promoting
granulation does not need to be added, a large amount of
liquid vapor or water does notneed to be supplemented, so that the problem of difficulty in granulation of an organic-
inorganic fertilizer is solved. The prepared product provided by the invention has the following advantages: 1,the product has a high
nutrient content, a low
moisture content, good particle strength and low costs; and 2,
organic matter sources of the product are the livestock and poultry
manure, the earthwormexcreta and the
humic acid, compared with other organic-inorganic fertilizers, the
fertilizer provided by the invention has diversified and
pollution-free
organic matter sources, facilitates being absorbed and utilized by crops.