Abstract
Incorporation of organic and inorganic amendments to turf root zones consisting of heavy clays presents a unique situation yet to be explored. Two Vertisols, Princes Town clay and Talparo clay were amended with coarse sand and sphagnum peat (SP) at different ratios to investigate the independent and combined influences of these amendments on the physical properties of modified turfgrass root zones. Bulk density (rho b), saturated hydraulic conductivity (Ks) and clipping yield (CY) were used to assess root zone physical conditions and turf response. A compaction pressure of 270 kJ m-3 was applied to the established turfgrass to evaluate root zone media resilience to vertical stress. Pre-compaction data indicate that sand and/or peat had no significant influence either on DM or Ks, whilst increasing sand content resulted in increasing rho b across both soils. There was a significant linear relationship for increasing sand and peat content on CY. Post-compaction data revealed decreased CY and rho b across all treatments. Peat and sand applied at 40 % by volume showed the lowest and highest rho b of 1.06 and 1.46 g cm-3 respectively. Ks values although higher with peat were appreciably low and not affected by applied amendments.
