Effects of Phosphorus Activator on Absorbability of Phosphorus in Red Soil

The effect of zeolite (Ze), humic acid (HA), citric acid (CA) and ammonium oxalate (AO), on absorbability of phosphorus in red soil was studied in order to understand the influence of phosphorus activator on absorbability of external phosphorus resource. The results showed that HA, CA and AO could effectively reduce the absorption and fixation of phosphorus by the red soil. The capacity of phosphorus absorbability by the red soil was reduced by 902%-11.75%, 1742%-21.74%, and 987%-3610% respectively by adding HA, CA and AO into the red soil. It was showed that Ze would increase phosphorus absorption amount by 11.04%-1754%, and promote phosphorus adsorption rate by 954%-1708%.