Why go with SDI over LEPA?
Freddie Lamm, Kansas State University agricultural engineer and irrigation researcher in Colby, says the primary reason is probablybecause more acres can be irrigated when water supplies are sufficient. "For example, if you’re installing a pivot on a full 160 acres, it will cover about 125 acres," he says. "With SDI, you can irrigate about 155 acres.
“That's over 20% more acres. With today’s corn prices, that's quite a bit more in production and return per farmed acre."
In that case, an extra 30 acres at a yield of 200 bu./acre could generate an extra $42,000 in gross return based on $7 corn.
Lamm notes that if growers can control runoff, then a LEPA system, with its extended drop lines and more precise nozzles, can be virtually as efficient as SDI, other than watering fewer acres.
However, when slopes are too great, the use of both LEPA and SDI may be limited. And as with Anthony and his odd shaped fields, there could circular system issues.
Lamm notes that if a grower uses deep tillage that may interfere with
Drip line buried 12-18 in. deep, field operations also could be limited. "However, growers are likely using GPS, so if they need to rip between drip lines, they should be able to do without disturbing the drip line," he says.