Impact of rootzone construction and irrigation methods on soil moisture in sports fields under greenhouse conditions

This study investigated the effects of various root- zone construction methods and irrigation systems on soil moisture distribution and retention in sports field soils under greenhouse conditions. The goal was to identify how these factors can be harmonized to enhance irrigation efficiency and develop sustainable, environmentally resilient turf- grass areas. The experiment involved 2- and 3-layered root- zones, irrigated using both sprinkler and subsurface drip irrigation (SDI) systems. Eighteen plots were set up in a greenhouse, each receiving 10 L m-2-2 h-1-1 of water for 1 or 2 hours via SDI or sprinkler. Soil moisture was monitored at different depths and times to assess the distribution and retention patterns. Results showed that both the rootzone construction and irrigation system significantly influenced soil moisture behavior. Sprinkler irrigation led to a quick moisture increase followed by a sharp decline due to high percolation and low retention. In contrast, SDI caused minimal changes, especially in near-surface areas, due to insufficient upward water movement. The 2-layered SDI setup, even with doubled irrigation, did not enhance capillary rise or humidification in the main rooting zone up to 12 cm depth. However, the 3-layered SDI variant demonstrated a more effective capillary rise, resulting in even moisture distribution and better water retention. At 12 cm depth, the 3-layered SDI setup maintained higher residual moisture than other variants. This suggests that the benefits of SDI are most pronounced in 3-layer constructions or other setups that adequately account for capillary rise in the root zone. The findings indicate that a hybrid approach combining SDI and sprinkler systems could effectively meet the dual requirements of sports fields: sufficient near-surface humidification for turfgrass establishment and efficient water resource utilization.