The invention relates to a water-soluble
plant growth
nutrient solution and a preparation method. In the
plant growth
nutrient solution, the content of small molecular weight water-soluble
chitosan accounts for 8-120g / L, the sum of the content of
nitrogen,
phosphorus and
potassium is larger than or equal to 60g / L, the sum of the content of medium trace elements accounts for 3-30g / L, the content of
organic matter accounts for 30-200g / L, the content of
plant growth regulator accounts for 0.01-5g / L, and the content of spread penetrating agents is larger than or equal to 0.2g / L; the small molecular weight water-soluble
chitosan is obtained through the preparation steps that
chitosan is firstly subjected to alkalization of strong base, then subjected to carboxyl
chemical modification, degraded through strong oxidant after carboxyl
chemical modification and finally neutralized through acid. The water-soluble
plant growth nutrient solution integrates the effects of nutritional complement,
growth promotion,
antibiosis,
virus resistance, stress tolerance and the like and has multiple functions and effects of improving soil, preventing hardening, increasing
ground temperature, resisting to
disease, being tolerant to stress, resisting to
continuous cropping, supplementing
nutrition rapidly, raising the yield and improving fruit quality and the like.