Special controlled-release microbial fertilizer for peanuts in continuous cropping field and preparation method thereof

A controlled-release microbial fertilizer for peanuts in a continuous cropping field, comprising an outer layer, a middle layer and an inner layer;

• wherein
• the inner layer consists of active bacteria, inorganic matter, an additive, 10-15 parts by weight of sodium carboxymethyl starch and 10-20 parts by weight of modified starch, wherein the active bacteria consist of:
• 200-300 million/g of Bacillus subtilis, 100-200 million/g of Bacillus thuringiensis, 50-100 million/g of Aspergillus niger, and 50-100 million/g of streptomycete with respect to a weight of the inner layer;
• the inorganic matter consists of:
• 5-8 parts by weight of calcium nitrate, 1-3 parts by weight of magnesium sulfate, 1-3 parts by weight of zinc sulfate 35, 1-3 parts by weight of borax, 0.5-1 part by weight of ammonium molybdate and 1-3 parts by weight of ferrous sulfate;
• the additive in the inner layer consists of:
• 60-80 parts by weight of fulvic acid, 15-20 parts by weight of alginic acid and 10-12 parts by weight of amino acid;
• the middle layer is composed of 30-50 parts by weight of urea formaldehyde powder, 15-20 parts by weight of polyethylene glycol and 30-40 parts by weight of natto powder;
• the outer layer consists of active bacteria, inorganic matter, and an additive which are the same as the active bacteria, the inorganic matter, and the additive in the inner layer, 10-15 parts by weight of sodium carboxymethyl starch and 10-20 parts by weight of modified starch, and additional 10-12 parts by weight of rice husk carbon as well as 8-10 parts by weight of cellulose.