Controlled Release Nitrogen Fertilization of Turfgrass1

Abstract

AbstractTwo experimental urea‐impregnated petroleum wax products and prilled urea with a petroleum‐based coating were evaluated as turfgrass fertilizers over a 2‐year period. They were compared with prilled urea, process tankage, and urea‐form. Applications were made to replicated plots of Kentucky bluegrass (Poa pratensis L.)‐red fescue (Festuca rubra L.) lawn turf at rates equal to 0.9, 1.8, and 2.7 kg N per 92.9 m2 in June of 1964 and 1965. Visual turf score ratings were taken every 2 weeks through mid‐October of both years. During 1964 clipping weights were taken each week and the clippings were analyzed for N content. Percent recovery of applied N during a 21‐week period was determined.Based on turf quality, yield and N content of clippings, and efficiency of N usage, as measured in 1964, the experimental products were superior to the standard materials. One of the urea‐impregnated wax products, X‐419‐68, was superior to all other test products. Plots fertilized with this material, particularly at the heaviest rate, showed improved quality even 11 months after application. Although second‐year results were less dramatic, the experimental products performed well during 1965. Little difference was evident among the experimental materials and urea but they did provide better quality turf than was obtained with most rates of process tankage and all rates of urea‐form.