Abstract: With red soil, brown soil, and drab soil as test soils, a laboratory incubation test was conducted to study the effects of exogenous humic acids on soil phosphorus (P) adsorption and desorption. Comparing with the control, applying humic acids decreased the adsorbed amount of P in soils, with the sequence of drab soil > red soil > brown soil. Humic acid application increased the desorbed amount and desorption rate of P in red soil and brown soil, the increment varied with the kinds of exogenous humic acid, but had less promotion effect on the P desorption in drab soil. The effects of exogenous humic acids on soil P adsorption and desorption were most obvious in red soil, followed by in brown soil, and in drab soil. Applying humic acids could enhance the P utilization rate in red soil and brown soil.

Key words: Northeast China spring soybean, SSR marks, Genetic diversity, Core collection