Irrigation Water Requirements of Lawns

Irrigation water requirements for lawn grasses can be estimated by an empirical formula when adequate climatological data are available. The modified Blaney-Criddle formula can be used for this purpose. This procedure is explained and recommendations are made for the use of the results in accordance with the lawn condition desired. Most lawns can be subjected to drought conditions for short periods; if this is done, the irrigation water requirements can be materially reduced. An analysis of the available research data indicates that when the soil is near wilting point, light frequent irrigations at a rate of approximately one-half the normal consumptive use will maintain an appearance rated from fair to good. On certain types of turf, such a practice is allowable if not prolonged too long and if the turf is given good growing conditions at other times. Under these conditions it is believed that common lawn grasses seldom require irrigation to maintain appearance when the monthly net irrigation requirement is less than one-half the consumptive use computed for maintaining a full supply of moisture.