The invention provides a method for quickly improving salt-resistant fertile soil in soda
saline-alkali dry farmland, which comprises the following steps: adjusting a low-salt organic material, mixing and stirring with
ferric sulfate powder, carrying out subcritical
hydrolysis carbonization, and respectively collecting
hydrolysate and
solid hydrolyzed carbon; after autumn crops are harvested, conventional
straw crushing and stubble cleaning treatment are carried out,
hydrolysate and
urea are mixed and then sprayed to
straw, volcanic
slag is spread, and then deep ploughing and field returning are carried out; hydrolyzed carbon and chemical
fertilizer are mixed to serve as base
fertilizer to be applied in furrows before
sowing in spring, and then dry field crops are planted. The number of
soil humus and water-stable large aggregates is synchronously and rapidly increased, the salt upward moving amount is reduced, the pH of the soil is reduced, the
utilization rate of the
fertilizer is increased, the soda
saline-
alkali soil is improved from the perspective of constructing healthy and fertile
plough layer soil, and the
grain yield is permanently guaranteed.