Layflat poly pipe is a disposable plastic pipe that inflates with water during pumping. The pipe is designed to last about one growing season, assuming it remains in place. Poly pipe is a low-cost method used to distribute water from a lagoon onto cropland. The pipe will only handle 4 feet of head pressure before bursting. Therefore, it can not be used to move water uphill or downhill, and must be used on a level contour. Solid pipe or hose is used to move water from the pump to the poly pipe. The poly pipe may be laid on a terrace or placed in a 3- to 5-inch deep furrow to prevent rolling when filling. The pipe must be disposed of properly if it is damaged or filled with solids. Since the pipe is disposable, solids accumulation in the pipe is acceptable. Valves may be inserted as needed along the pipe. Each valve will discharge about 10 gallons of water per minute using a 1-inch opening. Irrigating into a standing crop or tall vegetation minimizes odors since the water exits at ground level and is not sprayed into the air. As with all lagoon pumping operations, the process should be monitored to insure that runoff does not leave the field or application area.
Before using this pumping method, an irrigation specialist familiar with flood or furrow irrigation should be consulted to determine if target field soil type and slope are appropriate for this type of irrigation distribution. Sands and loamy sands will allow large amounts of liquid to soak into the ground rather than moving very far laterally down the row or furrow. Lagoon liquid distribution and hence, nutrient distribution, could be unacceptable both from a fertilizer stewardship and environmental viewpoint.
