Solubilization of Phosphorus in Phosphate Fertilizers after Treatment with Different Organic Residues

Phosphorus is an element of low mobility in soil. It is combined with iron compounds, aluminum and calcium, and organic matter. Phosphorus inorganic compounds found in the soil are conditioned by pH, type and quantity of minerals present in the clay fraction. This study aimed to evaluate the influence of three types of organic waste and the incubation time in the solubilization of three sources of P in the soil of the northeastern semi-arid region. The treatments were arranged in a 3 x 3 x 7 factorial arrangement, and a solo, 3 sources of phosphorus (P), 3 organic waste and 7 incubation times. The treatments were arranged in a randomized block design with three replicates. All soil samples were determined: pH, Ca and P concentrations, 10, 20, 30, 40, 50, 70 and 90 days of incubation. Data were submitted to ANOVA and Tukey test to compare the treatment averages. For the incubation time factor, regression equations were set at the level of 1% probability. The most efficient organic waste in reducing pH and solubilizing phosphate was Leucaena; The biofertilizer was the most efficient source of phosphate in making phosphorus available for soil.