Growth of Turfgrasses as Affected by Soil Phosphorus and Arsenic

Abstract

Abstract The influence of soil phosphorus (P) level on the growth of turfgrasses and on the Bray P 1 extractable arsenic (As) were investigated. In the first study five rates of As (0, 0.44, 0.88, 1.76, and 3.53 kg As/100 m 2 ) and four rates of P (0, 1, 2, and 4 kg P/100 m 2 ) were applied to a soil low in natural P. In the second study four rates of As (0, 0.88, 1.76, and 3.53 kg As/100 m 2 ) were applied to a soil collected from a long‐term P study. Several cool season turfgrasses were seeded in each study. Arsenic had no effect on seed germination of any of the grasses when the As was applied and incubated 7 weeks prior to seeding. Increasing As levels decreased the growth of all grasses regardless of P level. Poa annua L. was most affected by As. Phosphorus had little or no effect on As toxicity as exhibited by turfgrass growth even at very high P levels. Adding As increased the Bray P 1 extractable As fraction. The Bray P 1 extractable As level was negatively correlated to turfgrass growth. Phosphorus had no effect on As activity as measured by the Bray P 1 extractable As. However, As markedly increased the P soil test results due to interference.