Ag Biz News Column
By: Chad Gulley
County Extension Agent–Ag/NR
Irrigation for the Home Lawn
Water is a limited resource in Texas and it becomes more limited as the population grows. Watering the home lawn properly can improve grass quality yet still conserve water for future generations. Many times, home lawns are over-watered and over-watering can harm lawn quality more than under-watering.
Several factors need to be considered when staring a home lawn water program. Soil type, grass variety, management practices, and environmental conditions all can impact the irrigation plan for a home lawn. What type soil do you have in your lawn? Clay soils tend to retain the most water and thus need watering less often. Sandy soils retain less water but less water is needed to properly wet sandy soils. A loamy soil is a soil with a mixture of clay and sand together. Loamy soils retain a moderate amount of water.
The proper grass species is also important in the home lawn for water management. Grass species vary significantly in their water needs and drought resistance. Bermudagrass, zoysia japonica, and seashore paspalam are more drought tolerant than St. Augustine, centipede, ryegrass, or zoysia matrella.
Water can be conserved in the home lawn by proper fertilization, mowing, controlling thatch, reducing soil compaction, and considering the salt content of the water in the area. Proper fertilization promotes healthy plant shoot and root development. The deeper the root system the plant is better able to use water held deep within the soil. Proper mowing is also important. Frequent mowing produces thicker, denser turf.
Water your lawn by adjusting the watering schedule according to the weather. Irrigate deeply and a deeply watered lawn should generally be able to go 5 to 8 days between watering. Again, all the above mentioned factors should be considered in watering every 5 to 8 days. Early morning is the best time to water. Wind and temperatures are usually at the lowest of the day early in the morning. Late evening watering or at night causes leaves to remain wet for extended periods of time which can increase opportunity for disease in the lawn. Mid-afternoon watering may cause uneven distribution from high winds.
When watering the home lawn, thoroughly wet the soil to a depth of 6 inches. Shallow watering produces weak, shallow-rooted grass and is more susceptible to stresses. To determine how long to run your sprinkler or irrigation system, set 5 to 6 open top cans (tuna or cat food cans work great for this) randomly on the lawn. Turn on the sprinklers or system for 30 minutes. Measure and record the depth of the water caught in each individual can. Calculate the average depth of the water from all the cans. Add the depths together and then divide by the number of cans used. Use a garden spade or soil probe to determine how deeply the soil was wet during the 30 minute time period. From the amount of water that was applied in the 30 minute cycle and the depth it wet the soil, you can determine how long the sprinkler or system needs to run to wet the soil to a depth of 6 inches. In some soils it is more difficult to water to 6 inches deep. Never apply water to the point of run-off.
Many different irrigation systems are available for you to purchase and install. Routinely inspect the system to make sure irrigation heads are working properly and the water is being evenly distributed over the lawn. Proper pressure is important for the system. Install rain sensors to shut off the system during periods of rainfall. Sprinklers should be turned so they do not water sidewalks, driveways, and streets. Replace any part of the irrigation system that is in need of repair such as broken lines, clogged sprinkler heads, or realign sprinkler heads to provide a more even distribution of water. Remember that in water conservation, every drop counts.
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