Effects of Sod Type, Irrigation, and Fertilization on Nitrate‐Nitrogen and Orthophosphate‐Phosphorus Leaching from Newly Established St. Augustinegrass Sod

Nitrogen and P leaching losses from fertilized turfgrass remain an environmental concern. In the present study, we examined the effects of sod type, fertilization, and irrigation on turf quality, NO 3 –N and PO 4 –P leaching following St. Augustinegrass [ Stenotaphrum secundatum (Walt.) Kuntze] sod installation. Treatments included muck‐ vs. sand‐produced sod, no fertilization, fertilization with 4.9 g N m −2 at installation or at 30 d after installation (DAI), and routine irrigation or irrigation at stress from 30 to 60 DAI. Drainage was collected from lysimeters installed in each plot and analyzed for NO 3 –N and PO 4 –P to determine total leaching losses. Across all treatments, drainage averaged 290, 902, and 604 mm during each of the three trials. Fertilization at 30 DAI significantly reduced PO 4 –P leaching losses compared to fertilization at 0 DAI. Muck sod type significantly reduced the quantity of NO 3 –N leached. Muck sod also significantly reduced PO 4 –P leached and resulted in better turf quality in two of the three trials. In the context of minimizing nutrient leaching, these results support the use of muck‐grown sod established during low rainfall periods with fertilization delayed at least 30 DAI and with judicious use of irrigation.