The invention relates to the technical field of
saline-
alkali soil improvement, in particular to a compound
microorganism-loaded
saline-
alkali soil conditioner as well as a preparation method and application thereof. Compound microorganisms loaded on the
saline-
alkali soil conditioner comprise
Ralstonia sp.
Ralstonia Bul-1 and
Bacillus sp. Bacillus Zn-B. The preparation method of the saline-alkali
soil conditioner comprises the following steps: (1) pretreating straws by using a
zinc chloride solution, and carrying out
hydrothermal carbonization on the pretreated straws; (2) respectively preparing a
Ralstonia seed solution and a bacillus seed solution, and then mixing to prepare a compound bacterium seed solution; and (3) compounding the
zinc-modified hydrothermal carbon and the compound
bacteria seed solution to form a
composite material, and then mixing the
composite material with decomposed
mushroom dregs or an
organic fertilizer and a
calcium magnesium phosphate fertilizer for
granulation to form the saline-alkali
soil conditioner. During application, the composite
soil conditioner is applied to saline-alkali soil, and the dosage per mu is 300-500 kg. Through the synergistic effect of
biochar,
organic fertilizer, microorganisms and the like, the pH and
salinity of the saline-alkali soil are remarkably reduced, the content of
organic matter and aggregates is increased, the
soil structure is improved,
plant growth is promoted, and remarkable economic, ecological and
social benefits are achieved.