Effect of Two Types of Phosphates on Phosphorus Efficiency and Phosphorus Absorption and Distribution in Cotton Field

In this paper,the effect of two types of fertilizer and different phosphorus concentration on phosphorus efficiency and dry matter accumulation in the whole growth period of cotton was studied by field experiment.The results showed that application of phosphorus could significantly increased soil available phosphorus and total phosphorus content as well as phosphorus activation coefficient,but also could increase the phosphorus absorption and dry matter accumulation.Comparison results showed the effect of single super phosphate(SSP) on soil total phosphorus content,phosphorus activation coefficient,dry matter accumulation and phosphorus uptake in cotton field was the same as di-ammonium phosphate(DAP),only the effect of SSP on soil available phosphorus content was significantly superior to DAP,the soil available phosphorus content of seedling stage,bud period,flowering and bolling stage and boll-opening stage of SSP were respectively 7.95,4.35,2.81 and 2.95 times as big as DAP.