Nutrient and chemical characterization of aging golf course putting greens: Establishment and rootzone mixture treatment effects

Nutrient retention and dynamics with time in turfgrass sand-based rootzone mixtures (RZMs) are not well documented. This study was conducted to determine chemical properties of putting greens as impacted by (i) EZM, (ii) establishment (EST), and (iii) putting green age. United States Golf Association (USGA) specification greens were constructed and established with creeping bentgrass (Agrostis stolonifera L.) sequentially from 1997 to 2000. Treatments included two RZMs [i.e., 80:20 (v-v) sand and sphagnum peat mixture and an 80:15:5 (v-v-v) sand, sphagnum peat, and soil] and two EST procedures (i.e., accelerated vs. controlled). The accelerated treatment received 2.6-, 3.0-, and 2.6-fold N, P, and K, respectively, when compared with the controlled treatment during the EST year. Soil samples were taken and analyzed annually. The RZM generally had no effect on soil chemical properties during the EST year or beyond. All but five of the chemical properties investigated were significantly greater for the accelerated treatment compared with the controlled during the EST year. Soil pH in the accelerated treatment was lower than the controlled treatment, pH 6.7 vs. 7.4. Establishment treatments did not have an effect on chemical properties beyond the EST year, except for Bray1-P. All soil chemical properties investigated, excluding pH and available K, decreased after the EST year, but began to increase several years later.