Otakeho farmer Mark Washer says an effluent system installed on his property by Southern Dairy Solutions will pay for itself within three years due tothe reduction in fertiliser costs.
Mark estimates he will save $20,000 a year by irrigating an area previously out of reach of the shed. The system went in along with a new cowshed last year, replacing a facility built around 1980.
A farm effluent assessment was done by accredited designer Allan Crouch of Hi-Tech Enviro Solutions and Paul Gibson from Southern Dairy Solutions. The assessment looked at the farm contour, the soil types and infiltration rates, along with the hydraulics and application equipment.
The irrigation system carries the effluent from the shed to a 47-hectare block of free-draining, low-fertility coastal land divided from the main farm by State Highway 45. To reach the area being irrigated, a main line had to be run through an existing underpass under the road.
“Effluent is gravity-fed to the 110,000-litre tank, where it is then pumped around the farm,” explains Mark. “The paddocks are irrigated once a day with a mobile rain gun, which is shifted around the block. It’s a small tank for the size of the operation, but the system suits the soil type and low rainfall of the area.
“We decided to spend the money on an irrigation system instead of a hole in the ground,” he adds. “It’s giving us extra pasture and we’re very pleased so far.”
The system uses a large-bore pipe to carry the effluent, which is dispersed through 80mm laterals, enabling them to use a 15hp pump. “It produces good pressure, 90psi, at the end of the laterals. The paddocks on the irrigated side of the road still have a tinge of green at present while the rest of the farm was looking very dry,” says Mark.
“Another good feature of taking the effluent away from the shed is to reduce the potassium levels of pasture in the paddocks where newly calved cows are grazed during calving time. We won’t have as many metabolic problems with colostrum cows in the springtime that can be caused by high potash levels in the soil."
“I’m very happy with our new effluent system,” Mark says. “Paul and Allan have done an excellent job of the design and installation. We’ve just done a soil test six months in and we are looking forward to seeing the results of that. I expect a definite lift in fertility after 12 months.”