NZ Dairy Autumn 2021

| 39 nz dairy DAIRY PEOPLE » Aokautere Farms Over 90 per cent of the water running through the farm to the Manawatu River is filtered through the new wetland, boasting over 12,000 plants. PROUD TO BE ASSOCIATED WITH AOKAUTERE FARMS Designing and implementing innovative and customised agricultural engineering solutions, Ag irst Engineering’s professional team have a strong focus on customer satisfaction and solution engineering for each client’s unique requirements. “We’re not just a sales company based on particular brands and products, we’re a solutions company,” says AgFirst Engineering director and agricultural engineering consultant Davieth Verheij. “We give our clients advice on water reticulation, dairy e luent and wastewater treatment, agricultural and pastoral irrigation, frost protection, and land drainage, and get the right it for their farm.” Aokautere Farms in the Manawatu had a 50,000L e luent storage tank and had to apply to pasture every day. For a new resource consent, this wasn’t going to comply. With a high water table on the farm, an in-ground tank or pond wasn’t an option, so Davieth and Aokautere Farms owner Grant Bell looked at the options and settled on a Balmoral tank, a concrete base with solid steel walls and no liner, and a volume of 4.2 million litres. Grant has a feed pad and his cows create a lot of solids, so when the tank needs to be de-sludged, there is no synthetic liner to get in the way. Grant didn’t want anything mechanical and he didn’t want solid separation, so a 9kW submersible stirring systemwas installed with the capacity to turn over 3.6 AgFirst Engineering million litres of e luent every hour. Next, Ag irst Engineering installed a Weta Irrigator at Aokautere Farms, the irst ever traveling e luent irrigator which applies the same application depth no matter where it is on the farm. “It’s driven by the low of the e luent and automatically maintains its travel speed and uniformity of nutrient application along its travel path.” The Weta Irrigator can spread 30,000L of e luent per hour, getting rid of 300,000L of e luent per irrigator shift. “The farm is right next to the Manawatu River, and e luent needs to be applied at high volumes and a low rate. Spreading that volume over a large area has a lower impact on the soil, lower nitrogen loading, and lower labour requirement, ticking all the boxes from a practical point of view and an environmental point of view,” Davieth says. He says Grant was also keen on using technology, and Ag irst Engineering provided a Harvest e luent monitoring systemwhichmaps GPS proof of placement andmeasures the travel speed of the irrigator, and if it stops for any reason turns o automatically, a pressure sensor so if a hose breaks the irrigator will stop. “With this system, Grant is completely covered,” Davieth says. “There is no risk of over-application of e luent. He has proof of placement and complete control of the system from his phone or computer. The value of that is amazing. He can move his irrigator, set it up, then press start on his phone.”