Effects of Humic Acid and Biomass Carbon on Phosphorus Activation and Inorganic Phosphorus Form Transformation in Soil

Abstract

【Objective】The study was conducted to explore the effects of humic acid and biomass carbon on soil phosphorus activation and inorganic phosphorus form transformation with a view to providing theoretical basis for the research and development of synergistic phosphorus fertilizers.【Method】Taking humic acid and biomass carbon as the test materials, with the ratio of 1 g/kg and 2 g/kg soil and phosphate fertilizer and fully mixing with the test soil, a soil culture test was carried out for 60 days to study the effects of humic acid and biomass carbon on the activation of soil phosphorus and the transformation of various forms of inorganic phosphorus.【Result】Compared with CK2 and CK1 treatments, soil available phosphorus content, phosphorus activation coefficient and Fe-P and Al-P contents of soil inorganic phosphorus components increased, while the contents of Ca-P and O-P decreased to varying degrees. On the 18th, 30th and 45th day of the soil culture test, each treatment had a significant effect on the content of soil available phosphorus compared with CK2 and CK1. The content of available phosphorus in P2S2 treatment was significantly higher than that in CK2 treatment by 20.67%, and that in P1F2 treatment was significantly higher than that in CK1 treatment by 69.83%. On the 30th, 45th and 60th day of the test, the content of soil Al-P in P2S2 treatment was significantly higher than that in CK2 treatment by 61.40%, 14.79%, and 17.77%;. Correlation analysis showed that soil available phosphorus had a very significant positive correlation with phosphorus activation coefficient and Al-P. Under the action of different ratios of humic acid and biomass carbon, the proportion of inorganic phosphorus in each form ranked as Fe-P>Ca-P>Al-P>O-P.【Conclusion】Under two phosphorus application levels, both humic acid and biomass carbon can increase the content of soil available phosphorus and phosphorus activation coefficient, promote the contents of Fe-P and Al-P of inorganic phosphorus components in soil, and activate the fixed phosphorus in soil, which is conducive to the conversion of O-P to the available state and significantly improves the availability of soil phosphorus.

Keywords

• humic acid
• biomass carbon
• soil available phosphorus
• phosphorus activation coefficient
• phosphorus component