The invention discloses a method for preventing and controlling acidification of a sugarcane field and promoting
nitrogen fixation of sugarcanes. The method comprises the following steps: preparing soil; a
soil conditioner is applied before sugarcane planting, and the
soil conditioner is prepared from, by weight, 40-70 parts of waste
papermaking pulp, 0.03-0.05 part of
fermentation complex microbial inoculants, 10-20 parts of mineral clay, 20-30 parts of
organic matter fertilizer, 10-20 parts of
inorganic fertilizer and 3-5 parts of pyroligneous liquor; alfalfa and
sesbania are interplanted, alfalfa planting rows are formed between sugarcane rows, after alfalfa is sown for 30-40 days,
sesbania planting rows are formed between the alfalfa rows, and after alfalfa is sown for 90-110 days, alfalfa and
sesbania are turned and pressed into soil; a slow-release water absorbent is applied in the tillering stage and the elongation stage of the sugarcane, and the slow-release water absorbent is prepared from, by weight, 20-30% of
polypropylene, 30-40% of shell
powder, 20-45% of
vermiculite and 5-10% of
straw residues. The
fertilizer effectively prevents and controls acidification of a sugarcane field, promotes
nitrogen fixation of sugarcane, improves
soil structure, reduces hardening of acidified soil, improves air permeability of soil, improves microbial activity, reduces poison of aluminum and
manganese, improves yield and quality of sugarcane, and promotes
nitrogen fixation of sugarcane.