Converting to mobile drip irrigation could be financially beneficial for some growers.
Along with more efficient water delivery and lower energy costs, this system can improve crop health by reducing leaf burn and disease issues.
Mobile drip uses specially designed drip lines that drag on the ground and deliver water directly to crops to reduce evaporation and eliminate wind drift. Compared to a traditional drop tube system, mobile drip systems can cut water use by half. And because water is dispersed behind the wheels, the equipment will move forward smoothly on a dry path.
Savings on energy bills is another advantage. Low-horsepower engines allow mobile drip systems to run at around 10 to 12 pounds of pressure (versus 30 to 35 pounds of pressure for sprinklers on drop tubes).
Growers wanting to change to mobile drip can convert their centre pivot or linear move irrigation systems by securing drip lines to their current system. The standard cost to convert to Precision Mobile Drip Irrigation (PMDI) is approximately $30,000 per quarter section centre pivot.
However, the cost can be higher because investing in good filters is a must, said Roger Holm, president of the Canadian National Committee on Irrigation and Drainage (a committee of the Canadian Water Resources Association).
“Filtration is an issue with these,” he said. “To put a proper filtration system on, we’re probably talking $40,000 plus.”
Whether it’s worth spending that kind of money depends on a grower’s situation, he said.
“If you’re going to look at this, look at it for the right reasons,” said Holm. “If you’re an alfalfa seed producer, and you want to increase the flying time of your bees, this might be a product to look at.
“If you have a crop that leaf disease is going to be an issue, this may be the product.”
Mobile drip irrigation “is also great if you have row crops,” he said, but be prepared to begin farming in circles.
“If you’re going to put this on a centre pivot that goes around, and you’re farming back and forth, it is going to ride up on top of the crop,” he said.
With straight rows, the hoses will easily ride up on plants because they are so light. “We’ve seen them on top of corn ears,” he said.
The system can be used on both tall and short crops. The spacing between drip lines will vary by soil and crop type, but is designed to range from 20 to 80 inches between lateral lines.
It is also crucial when using a mobile drip system to deliver enough water on the ground to meet the crop’s needs. Most systems are designed to emit about 400 to 600 gallons per minute, which is not feasible for all crops. Holm said he has heard of some irrigators getting up to 800 gallons per minute, which would be close to six millimetres of water per day.
Private irrigators will benefit from this system because they will be able to take the water they save and add it to more acres. Those who belong to an irrigation district will not benefit directly, as their conserved water will go back to the district as a whole.
A mobile drip system can be valuable for some irrigation farmers but it depends on a producer’s needs.
“Do it for the right reasons,” said Holm.