VARIABILITY IN TURFGRASS WATER REQUIREMENTS ON A GOLF COURSE

Microclimates can vary significantly across a golf course, and directl y influence turf irrigation requirements. The objective of this study was to quantify the extent of this variability in water demand, and ev aluate the accuracy of weather station-generated evapotranspiration (E T) estimates for determining irrigation need for one Kansas golf cours e. Evaporation was measured using black Bellani plate atmometers place d on four golf tees and near the weather station at the Manhattan Coun try Club, Manhattan, Kans., in 1995 and 1996, Evaporation was measured on a total of 62 precipitation-free summer days in 1995 and 1996. Pro bably because the weather station was situated over nonirrigated turf, evaporation at the weather station was up to 22% higher than that at locations on tees. Evaporation varied by >20% among tees. Evaporation on a north-facing slope was 8% lower than that on a level surface or s outh-facing slope. Weather station-estimated empirical ET (Penman mode l) was consistently higher than ET estimated from atmometer evaporatio n, particularly when ET was >4 mm.day(-1). Superintendents should be a ware of the potential variability in water demand across a golf course , and that weather-station ET estimates may differ from turf ET primar ily because of microclimatic differences and potential inaccuracies in the empirical model employed by the weather station to estimate turf ET.