The invention discloses a preparation method of a soil improvement agent for preventing and treating maize southern leaf
blight, and belongs to the field of soil improvement agents. According to the preparation method, a living cicada
pupa is first taken; an opening is scratched at the
abdomen of the cicada
pupa; afterwards, the cicada
pupa is put into honey for soaking; after being soaked, the cicada pupa is aired to obtain a
solid culture medium; a
paecilomyces lilacinus seed solution is uniformly sprinkled on the surface of the
solid culture medium to carry out
fermentation culture; an obtained substance is dried and ground until
lavender downy fungi fully grow, so as to obtain cicada pupa
powder covered with
paecilomyces lilacinus; subsequently, a waste crab shell is subjected to acid soaking and alkali soaking respectively; after being rinsed and dried, the waste crab shell is mixed with the cicada pupa
powder covered with the
paecilomyces lilacinus,
ammonium dihydrogen
phosphate,
milk vetch straw, grass carbon and a tea seed cake, so that the soil improvement agent for preventing and treating the maize southern leaf
blight can be obtained. The soil improvement agent prepared and obtained by the preparation method can obviously inhibit the growth of a
mycelium of helminthosporium maydis, and greatly decreases the morbidity of the maize southern leaf
blight; and compared with a conventional chemical insecticide, the soil improvement agent cannot pollute a
crop, does not generate
drug resistance and is long in prevention and
treatment time.