Irrigation technology allows producers to apply adequate water to crops or grassland, without relying on annual rainfall. Though there are many different methods for irrigation, the center pivot and drip methods are the most commonly used in the Texas Panhandle.
Subsurface drip irrigation uses lines below the surface to precisely deliver water directly to the root of plants. There are several advantages to drip irrigation including reduced soil erosion, higher yields, decreased input costs, and safer and more efficient ways to fertilize. Drip systems are also very useful on oddly shaped fields and fields with higher slopes. Where the drip tape is located depends on the type of crop the producer grows. For example, cotton planted on 40 inch rows will normally have drip tape located 80 inches apart while corn planted on 30 inch rows will have drip tape 60 inches apart. The biggest disadvantage is the expensive initial cost. A drip irrigation system could cost as low as $700 per acre or over $1,500 per acre depending on the design of the system. Depending on what crops you grow, drip systems usually pay for themselves over the span of a few years.
A well maintained drip system can last over 20 years. There are several steps to keep your system well maintained. First, you must maintain your filters. Many people choose to use a combination of filters in their drip irrigation system. Next, you must flush all of the lines and manifolds. Flushing prevents very fine particles from clogging the emitters. Lastly, you need to inject chlorine and acid. A low concentration of chlorine (1-5 ppm) kills bacteria and oxidizes iron, while a high concentration (100-1000 ppm) will oxidize organic matter and remove it from the system. Injecting acid prevents buildup of calcium carbonate, magnesium, and other salts.
With pivot irrigation, there are several different techniques you can use. The first is Low Energy Precision Application or LEPA. With a LEPA system, applicators are placed in every other row. These applicators use bubblers, drag hoses, or drag socks to deliver water directly to the furrow, thus, cutting down on evaporation. In fact, LEPA is 95% water efficient. Also, because LEPA is low energy, it requires low pressure of approximately 6 to 10 psi. Because the applicators follow the furrow, the farmer’s crops under the pivot must be planted in a circle. Also, some areas are not suited for LEPA systems because the slope is too steep.
The next techniques for pivot irrigation are Low Elevation Spray Application (LESA), Low Pressure In Canopy (LPIC), and Mid Elevation Spray Application (MESA). These three systems are all low pressure sprinkler systems. Instead of using drag hoses, LESA, LPIC, and MESA utilize spray nozzles. The differences among these three techniques are how high the spray nozzles are located. LESA spray nozzles are typically located one to two feet above the surface, LPIC nozzles are located in the crop’s canopy, and MESA nozzles are above the crops canopy, ranging from 5 to 10 feet above the surface. Because LESA systems are the closest to the soil surface, they lose the least amount of water through evaporation and wind. On the other hand, MESA systems lose the largest amount of water since they are the highest above the soil surface.
For pivot irrigation, management should make sure the correct nozzles or applicators are always in use on the pivot. Failure to have the correct applicators can result in lower efficiency. Additionally, producers should grease swivels monthly and check gearboxes and center drives annually.