ABSTRACT
Phosphorus (P) is commonly applied to turfgrass areas as a fertilizer. It has been associated with detrimental effects on the environment by causing eutrophication of surface waters. The objective of this study was to investigate the effect of irrigation regimes on the movement of P when applied to undisturbed soil columns with intact soil macropores. The soil columns were collected by encasing undisturbed soil columns 20 cm in diameter by 50 cm deep, in concrete. Two irrigation treatments that included one 2.54-cm application compared to four 0.64-cm applications over a 7-day test period were applied to the column surface, after a 33 kg P ha−1 application. Fifty-four percent more P was transported below 20 cm and P leaching was increased from 0.0 mg to 1.0 mg with the one 2.54-cm irrigation treatment than the four 0.64-cm irrigation applications. Whereas heavy irrigation or rainfall events can potentially move P through the macropores in the soil profile, carefully controlled irrigation practices can prevent P movement.
