The effect of yellow–brown and black soil on the germination of the peanut

Yellow–brown soil, which is a type of soil most productive for peanuts (Arachis hypogaea L.), was compared with black soil which is typically not productive for peanuts. In this study, the effect of the two types of soil on the germination of peanuts was investigated. Pots filled with these two types of soil and different mixtures of them were used to test peanut germination. Both sterilized and unsterilized yellow–brown soil were compared to evaluate the effect of microorganisms on the germination. Twenty fungal strains and 19 bacterial strains isolated from yellow–brown soil were propagated to inoculate the black soil for germination testing. Yellow–brown soil, covered or mixed with black soil, was tested for its effect on germination. Microorganisms from the yellow–brown soil, separated into two parts by rinsing one part in water suspension and the other in rinsed soil sediment. Both parts were amended into the black soil for the germination test. The above-ground biomass of the peanut seedlings was weighed 20 days after sowing. Compared with the treatment of black soil only, the above-ground biomass of the peanut seedlings markedly improved when treated with yellow–brown soil covered with black soil. Sterilized or mixed treatment with yellow–brown soil resulted in a loss of improvement. Thirty-nine strains of microorganisms isolated from yellow–brown soil failed to promote peanut germination. Neither the rinsed yellow–brown soil amendments nor the rinsed soil suspension irrigation recovered the improvement of peanut germination in black soil. Black soil inhibited peanut germination. Peanut germination was rapid and uniform in black soil covered with 2 cm of yellow–brown soil. Yellow–brown soil steam sterilized or mixed with black soil makes the germination difficult. Inoculation with isolated microorganism formulations failed to promote the germination. Yellow–brown soil, including chemicals and microorganisms, is a system that benefits peanut germination.