Characterization and dynamics of phosphorus fertility on a silvopastoral system

The dynamics of phosphorus fertility was studied in a five-year trial on a silvopastoral assay. The treatments were follows: natural vegetation, Encal yptus sp., mixed pasture and Melia azedarach. Total phosphorus, organic and inorganic phosphorus, fraction of the procedu re of Bowman and Cole (1978) as well as various extractable forms were dete rmined, No significant differences were found for the organic and inorganic phosphorus, whereas differences were reported, in autumn only, for the ass imilable forms, Significant seasonal differences for the extractable P were found, particularly for the Melia and pasture treatments, the two systems with maximum return to soil of dry matter.