Soil Phosphorus and Corn Development Under Application of Phosphate Sources

Knowledge of the solubility of phosphate fertilizers is fundamental for phosphorus (P) recommendation management and for choosing the laboratory evaluation method of nutrient availability in the soil according to the history of fertilization. The aim was to evaluate the initial development of corn plants as a function of the application of triple superphosphate (TSP) and natural phosphate of Arraias (NPA) with and without liming and incubation time, as well as to evaluate the available P in the soil with the use the extractors Mehlich-1 and Mehlich-3. An experiment was installed in an 8 × 3 × 2 factorial scheme, being 8 fertilizer incubation times (180, 140, 100, 80, 60, 40, 20, 0 day(s) before planting), 3 P sources (control—without P, TSP and NPA) and 2 refers to the application of limestone (with and without limestone). Were evaluated the shoot and root dry matter, analysis of P, Ca, Mg, and Zn in shoot and P in roots. In the soil, P levels were determined by Mehlich-1 and Mehlich-3 extractors. There was a greater accumulation of P with the application of TSP with limestone in all incubation times. The application of the NPA allowed a greater accumulation of P in the plants without the application of lime. The previous incubation of the NPA did not favor the efficiency of this source, neither in the soil with corrected acidity nor in the soil with its original acidity. Mehlich-3 proved to be adequate to determine the phosphorus content in soil fertilized by NPA.