Soil Physical Properties of Aging Golf Course Putting Greens

ABSTRACT United States Golf Association (USGA) specification putting greens are designed to limit excess soil water and compaction; but these soil properties change over time. Objectives were to define soil physical properties of sand‐ amended rootzones as affected by (i) rootzone mixture, (ii) establishment treatment, and (iii) putting green age. The USGA specification rootzones were built and established with Agrostis stolonifera L. in four sequential years. Rootzone treatments were 80:20 (v:v) sand and sphagnum peat and an 80:15:5 (v:v) sand, sphagnum peat, and soil. An accelerated establishment treatment applied 2.5, 3, and 2.5 times N, P, and K, levels, respectively, than the control treatment. Data were collected on rootzone particle size distribution and saturated hydraulic conductivity (Ksat), bulk density, total, air‐filled and capillary porosity for 8 yr, infiltration rate for 10 yr. All soil physical properties changed with age, but were not influenced by establishment treatment. Infiltration declined 73% but remained adequate (≥0.15 m h−1) for location precipitation. Capillary porosity and bulk density increased 32 and 7%, respectively, while air‐filled porosity decreased 38%. Capillary and air‐filled porosity still met USGA specification after 8 yr. Addition of soil to the sand‐based rootzone mixture had no negative effect on soil physical properties. Fine sand from topdressing and surface organic matter accumulation were thought to account for these changes.