| Popis: |
Phosphate is an essential element for plant nutrition, and therefore it is important to know the dynamics of sources of phosphorus (P) with different solubility in soils that naturally have low levels of available P and that fixate or adsorb the aggregated P. For that purpose four doses of P were applied (0, 300, 600 y 1200 mg.kg -1 ) to an Andisol soil type from the IX Region (Chile), employing fertilizers that differ in their solubility, triple superphosphate (TSP) and Rock phosphate (RF), and afterwards they were maintained in controlled temperature and humidity conditions. Available P – (Olsen) was measured 1, 7, 14, 28 and 120 days after applications. The treatments that received TSP, showed a rapid increase in available P, followed by an initial rapid decrease on the first day and later by a slow steady decrease. When RF was applied the level of available P increase slowly in time, but never reaches the levels attained with TSP. The P adsorption after one day of applying TSP, was explained by a lineal regression, Available P=0.07xP applied + 0.64 (R 2 =0.99; P |
