NOVELTY - Fertilizer comprises 60-80 wt.% bio-carbon organic fertilizer, 2-6 wt.% urea, 12-25 wt.% monoammonium phosphate, 3-5 wt.% potassium sulfate, 2.5-4.5 wt.% calcium superphosphate, and 0.005-0.015 wt.% trace element.    USE - The fertilizer is useful for spring broad bean.    ADVANTAGE - The fertilizer supplies nutrient required for full growth period of the broad bean, provides enough humus soil, and improves soil texture.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for method for preparing the fertilizer, which involves (a) obtaining cattle dung, removing impurities, crushing the obtained dung, where the dust content is less than 4% after crushing, sieving the crushed product using 100-meshes sieve, maintaining moisture content at less than 50%, and granulating the obtained mixture, (b) refining rapeseed oil by existing method to obtain cake material, steaming the cake material, crushing the steamed material to 100 meshes to obtain oil meal, (c) crushing high-quality wheat straw and obtaining straw powder, (d) adding 0.05 wt.% urea and 0.01 wt.% sugar to the straw powder, and mixing and aging the obtained mixture for 25-35 days at 20-40 degrees C to obtain fermented wheat straw powder, (e) adding 1 kg fermentation agent to 30 kg maize flour (100 meshes), adding 20 kg oil meal, and mixing the obtained mixture to obtain fermentation agent, (f) layering 10-30 wt.% cow manure particles, 60-80 wt.% cattle manure particles, 3-7 wt.% fermented wheat straw, 3 wt.% calcium superphosphate, 0.5-1.5 wt.% urea, and fermentation agent (remainder) in order in a fermentation tank for 4 times to a maximum height of less than 1.2 cm, maintaining moisture content at 50-60%, ventilating the fermentation tank and naturally heating the tank, turning the stacked material when the indoor temperature reaches more than 60 degrees C or air humidity reaches more than 80%, after continuous turning for 3 times aerobically fermenting for 3 days at 55 degrees C, covering the mixed material with plastic thin film, performing aerobic fermentation during spring, summer and autumn three seasons continuously for 5-7 days or performing aerobic fermentation during winter for 15-25 days, where fiber toughness disappears obtaining black colored bio-carbon organic matrix, crushing the matrix to 100 meshes, and naturally drying the product.