North Texas corn growers with strip-till operations are seeing big yields after close spacing their LEPA sprinklers on center pivots.
In 2011, Texas farmers were left with bone-dry soils after a record breaking 7 month dry spell and record high temperatures soaring over 100°. The harsh circumstances lead to cracked soils and numerous other problems, but it gave farmers new motivation to really think about their irrigation methods and analyze what they were doing when applying water to their fields.
North Texas corn growers with strip-till operations switched their regular spray systems to LEPA (Low Energy Precision Application) bubble sprinklers, such as Senninger’s LDN Bubbler Pad, and strategically placed the sprinklers 30 inches apart on every row in a pivot. This closer spacing resulted in a more consistent distribution pattern, a wider wetted circle, water conservation and increased yields. Even with a lack of rain, some growers were able to yield around 260 bushels per acre – 30 bushels more than what farmer’s achieved with sprays.
LEPA bubble systems are generally used on every other row on a center pivot to ensure water conservation through a more restricted application. This method is ideal when farmers can expect some rain during the season, but in the face of a severe drought, modifications needed to be made. Texas farmers used the closer spaced bubbles to distribute water over most of the soil surface. This method increases the application rate and cools the soil – which translates to lowered evaporative losses.
For farmers, this means fewer irrigation cycles. Irrigation can be reduced from watering over a seven day cycle to watering over a two day cycle.
The theory behind this application method is the concept of “water on water” – the idea that the weight of standing water on a soil’s already wetted surface will push water deeper into the soil to fill the profile. For the tight clay soils in Texas, this seems to be a proven and effective method. Edwin Smith CID, CAIS, High Plains District Manager for Senninger Irrigation, notes that “It is important however, to monitor the application rate and ensure that water stays close to where you put it. You don’t want water running off into other parts of the field”.
Smith sees great promise in the use of close spacing bubble irrigation for corn growers. Irrigated soils in Texas generally dry out after being irrigated and lose half an inch of the water applied. He has found that farmers are now applying around two inches of water with bubblers on every irrigation trip, which means that one and a half inches of water is being taken in by the soil. “One producer wowed me by putting down over 3 inches per trip.”
The application method requires a lot of management as well as crop residue capable of holding the water until it soaks in – but farmers are already reporting continuing success. Many Texans have reported increased crop yields despite hot, dry conditions, and most have been able to recoup their equipment change costs in one year.
Smith notes that there are certain aspects farmers need to be aware of though, before making a switch to this method. “We understand that some sandy soils need water a lot more often”, he says. Sandy soils do not have a large water capacity, so irrigation will need to be performed more often in these cases. Also important is considering which crop was previously grown in the field. Root channels vary by crop, so the channels left over by crops such as peanuts may not be effective in helping water flow into the soil. Corn’s long, deep roots provide great channels for water.
The success of close spaced bubbler sprinklers in no-till fields has been a great boon to Texas farmers. Corn crops have been more resilient and the soils structure of fields has been preserved, but more important to farmers, the modification in their irrigation methods has led saved energy, water and money.