THE AG SIDE Water conservation in the landscape
A s our lack of rainfall persists, many homeowners continue to irrigate home lawns and landscapes. While irrigation during times of inadequate rainfall is essential, it is important to ensure that you are applying the appropriate amount of water in an efficient and judicious way.
First, if you have an automatic irrigation system, monthly checks to the system should be performed to ensure that the system is functioning properly. Broken and misaligned sprinkler heads can waste water and hinder performance. Making sure that your system applies the appropriate amount of water where it is needed is essential to performance as well as to a conservation effort. Know how to operate your system, how to make adjustments, and how to suspend its function if there is adequate rainfall.
New advancements in irrigation controllers have made systems more accurate and user friendly. Also, the use of rainfall sensors, freeze sensors, and evapotranspiration (ET) sensors will help the system intuitively adjust to water application. If it has been raining, the system will not run. Or it will reduce output. The ET sensor calculates weather situations such as humidity, temperature, and soil moisture and automatically adjusts output to provide a more accurate application of water as it determines water use and water loss from the yard. These new advances are helpful, but the system should still be reviewed to ensure proper function of the heads.
For manual systems, remember that you should know how to determine the water output of water from each type of sprinkler that you use. For hose end sprinklers, the easiest way is to run each sprinkler for 15 minutes, with 4-5 straight sided cans, such as tuna cans, under the spray of the sprinkler. At the end of the 15 minutes, use a ruler to measure how much water was caught in the cans.
Average the volume of water captured in each can and multiply this amount by 4. This will provide you with the gallons per hour (GPH) per each device. With that information, you can determine how long you will need to run each sprinkler to apply the needed water to the lawn. Remem- ber, the amount will be varied among different sprinklers, so it is important to test each one.
With either system, it is essential that you apply water deeply and infrequently to ensure solid root development and decrease in stress during periods of dry weather. Water applied frequently will cause turf roots to stay closer to the soil surface, causing more rapid stress, and hinder access to moisture and nutrients held deeper in the soil. Also do not water so long that the water becomes saturated and does not allow additional water to be absorbed.
Additionally, a break between watering may be necessary to allow water to soak in. Make sure you water during the early morning hours, 5-9 a.m. Watering during the afternoon will cause evaporative loss resulting in water leaving the landscape before it can be absorbed. Watering at night can promote plant disease development.
The best time to water is just before the plant stresses. When the leaf blades fold up, dull, and turn a bluish hue or footsteps across the lawn will cause the leaf blades not to rebound quickly, are signs that the lawn needs water. Managing the application of water to provide the required amount at the appropriate times will help to provide necessary supplemental water to landscapes while not wasting natural resources and saving you money. JMgersbach@ag.tamu.edu