Low intensity harvest management of reed canarygrass

High K grass forage increases risk of animal metabolic disorders, and forage management of perennial grass grown under K-limiting soil conditions needs further study. Our objective was to evaluate forage nutritive value, yield, and stand persistence of reed canarygrass (Phalaris arundinaceae L.) under two-harvest management and low availability of soil K. Three N and three K fertilizer treatments were applied to reed canarygrass for 5 yr at two sites in central New York state with Niagara silt loam (fine-silty, mixed, active, mesic Aeric Epiqualfs) and Williamson silt loam (coarse-silty, mixed, active, mesic Typic Fragiudepts) soil types. Reed canarygrass persisted under all treatments throughout the experiment, although K deficiency symptoms appeared in the high N, low K fertilizer combination. At the high N fertilizer rate, dry matter (DM) yield increased linearly (P < 0.05) with increased K fertilizer rate, while K fertilizer did not influence yield in the absence of N fertilizer. Recovery of K fertilizer was low and increased linearly (P < 0.05) with increased N fertilizer rate from 6 to 42%. Soil test K increased to 59.9 mg kg(-1) with no N fertilization and decreased to 34.9 mg kg(-1) with 224 kg N ha(-1). Under high N fertilization with no K fertilization, grass forage K concentration averaged <12 g kg(-1) in the spring and <8 g kg(-1) in the fall. Sufficient yields of grass forage with reasonable quality and low concentrations of K were possible through high N, low K fertility management in a two-harvest system.