The invention discloses a rice 
seedling substrate, a rice 
seedling substrate board and a preparation method of the rice 
seedling substrate. The rice seedling substrate can meet all 
nutrient elements required by rice seedlings, is simple and convenient in seedling operation, and meanwhile, solves the problem of difficulty in taking soil and the problem of 
seedbed weeds. A 
microorganism bacterium agent in the rice seedling substrate can kill 
pathogenic bacteria, change the rhizospheric 
microorganism environment and improve 
disease resistance of rice. The rice seedling substrate contains a compound slow release 
fertilizer and can meet the requirement of seedlings for nutriment in 40 days. Meanwhile, the rice seedling substrate is added with an efficient, low-toxic and low-residual green 
pesticide, does not propagate 
disease pests and weeds, is green, environmental-friendly, healthy and safe, and can increase 
soil organic matter and enhance 
land productivity when being used for long time. Moreover, according to the rice seedling substrate board, a seedling 
seedbed is good in air permeability; seedling roots grow vigorously; seminal roots and secondary roots are long in service life; roots are long; the number of the roots is great; a entangle 
root effect is obviously better than that of soil seedling; cultured rice seedlings are high in 
disease resistance and can effectively prevent and treat 
bacterial wilt and 
damping off in the rice seedling stage.