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 main objective of this experiment was to determine the relationship 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 fromAEMs and quantified. As N fertilization rates increased, desorbed NO3-N increased. The relationship of desorbedNO3-N from AEMs to clipping yield and turfgrass quality was characterized using quadratic response plateau (QRP) and Cate-Nelson models (C-Ns). Critical levels of NO3-N ranged from 0.86 to 8.0 _g cm_2 d_1 for relative dry matter yield (DMY) and from 2.3 to 12 _g cm_2 d_1 for turfgrass quality depending upon experimental treatment. Anion exchange membranes show promise of indicating the critical levels of soil NO - N desorbed from AEMs necessary to achieve maximum turfgrass quality and yield without overapplication of N.
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