Transpiration replaces oxygen and water vapor in the air. Just 2,500 square feet can produce enough oxygen to support a family of four. Soil Soil types affect how often and how long you need to water. Sandy soil absorbs water fast but can lose it just as quick. Loam soil is ideal because it has a good absorbing rate and can also hold water well.
Clay soil can be hard to water because it absorbs the water very slowly.
Clay also holds water well and dries slower than sand or loam type soils. The average turfgrass consumes about one inch of water a week. If there isn't enough rain to meet the need, then watering is the only answer. Soil dries out from the surface downward. By deep watering you encourage deeper rooting of the grass.