Relationship of Turfgrass Growth and Quality to Soil Nitrate Desorbed from Anion
Kelly L. Kopp* and Karl Guillard |
Anion exchange membranes (AEMs) are a potential method for determining the plant available N status of soils; however, their capacity for use with turfgrass has not been researched extensively. The Theremain objective of this experiment was to determine the relationship exchange between soil nitrate desorbed from AEMs and growth response and quality of turfgrass managed as a residential lawn. Two field experiments were conducted with a bluegrass–ryegrass–fescue mixture receiving four rates of N fertilizer (0, 98, 196, and 392 kg N ha-1 yr-1 ) with clippings returned or removed. The soils at the two sites were a Paxton fine sandy loam (coarse-loamy, mixed, active, mesic Oxyaquic Dystrudepts) and a variant of a Hinckley gravelly sandy loam (sandy, skeletal, mixed, mesic Typic Udorthents). Anion exchange membranes were inserted into plots and exchanged weekly during the growing seasons of 1998 and 1999. Nitrate-N was desorbed from AEMs and quantified. As N fertilization rates increased, desorbed NO3-N increased. The relationship of desorbedNO3-N fromAEMsto clippingyield and turfgrass quality was characterized using quadratic response Suplateau (QRP) and Cate-Nelson models (C-Ns). Critical levels of meadesorbed NO3-N ranged from 0.86 to 8.0 g cm2 d1 for relative dry matter yield (DMY) and from 2.3 to 12 microg cm-2 d-1 for turfgrass quality depending upon experimental treatment. Anion exchange membranes show promise of indicating the critical levels of soil NO3-N desorbed from AEMs necessary to achieve maximum turfgrass quality and yield without overapplication of N. Link to Research document (PDF)
*Corresponding author (kellyk@ext.usu.edu). |
