The Arizona Republic provides a lawn watering guide each day on its weather page. To determine how much water should be applied to a lawn, a UA Meteorological Network (AZMET) lawn watering guide that supports the weather page guide provides information about determining the amount. First thing to do is make sure that all of the sprinkler heads in the automated system are fitted with the same type of nozzle that delivers the same amount of water across the lawn. This can be confirmed by using the “catch can” technique. This will ensure that there will not be dry spots or “donuts” caused by inefficient coverage. Once the uniformity and distribution is determined, the amount and frequency can be applied following the daily guide. Generally, about one-half pound per 1000 sq ft of nitrogen can be applied monthly during the actively growing months (May-Sept). That will be about 2-1/2 lb of ammonium sulfate (21-0-0) or 1 lb of urea per 1000 sq ft of the lawn.
