NZ Dairy Summer 2021

36 | nzdairy DAIRY PEOPLE » Dr Ian Scott: Oraka Deer Park Research, science underpin farm management Sue Russell For Dr Ian Scott, large animal veterinarian, cropping, dairy, bull and deer farmer, every decision underpinning farm management practices comes from a thoroughly researched and informed science-based perspective; looking through an enquiry-focussed lens to inform tweaks and adjustments on a continuum of constant improvement. Oraka Deer Farm is nestled on pristine Waikato land, at Okoroire, between Tirau and Matamata and is a superb example of a highly evolved, intensely integrated farming system, where every activity involving stock, every decision regarding what is grown and every piece of infrastructure used, attempts a positive environmental, animal health, productivity, people and financial outcome. Mixed wapiti and red deer numbers total about 2000, and include 600 hinds, 700 velvet stags plus young stock. The dairy herd peak milks 400 Friesians with 25% autumn calvers. To reduce bobby calves, all autumn and later-calvers are mated to Herefords. This means 200 beef destined calves are reared and taken to yearlings on the recently acquired Langlands Road property. This year’s cropping activity will cover 80 plus hectares. The home farm at 71 Bayly Road has a footprint of 108ha, while Lake Rd farm, used as the enginehouse maize and rye-grass production, measures 66ha. Deer and cows are integrally managed on the the home farm at critical times to enhance pasture quality and stock energy uptake, all fuelling production. The dairy herd is shifted off the home milking platform to spend their 40-to-50-day dry period on annual ryegrass at Lake Rd, awaiting calving. With calving near, they return to the home farm. Ian innately understands that improvement in performance of just one part of a farm’s activities, doesn’t necessarily result in sustainable gain. While Ian is the majority shareholder of the business Oraka Farms, joining him in more recent times is Dr Jacqueline Rowarth CNZM, who has an Agricultural Science degree in Environmental Agriculture and a PhD in Soil Science from Massey University. Jacqueline’s research is on nutrient cycling – phosphorus, nitrogen and carbon, in particular. She is currently a farmer-elected director of Dairy NZ and Ravensdown and adjunct professor at Lincoln University, among many notable academic positions. Together Ian and Jacqueline bring a wealth of rigorous academic understanding into farm management practice decisions. • to page 38 When the dairy herd began contributing to the winter milk quota, a herd shelter was built. This, of itself, created the opportunity to reduce N leaching by recycling released animal nutrients captured in the floor’s woodchips, into soil nutrient improvements and carbon capturing opportunities on any of the other farms, growing combinations of maize, fodder beet, and rye-grasses. “We turned a potential nutrient loss and cost, directly into production gain, simply by removing the woodchips from the shelter periodically and digging them into the soil on the Lake Rd etc farms. This dramatically improved the organic profile of the soil,” Ian explains. Improving the farm’s effluent system has been a recent focus, given Ian’s view for many years that the focus on anaerobic effluent storage ponds does not fully deliver potential environmental benefits. While these traditional ponds reduce N from leaching, the process can further increase greenhouse gas emissions. “We wanted to treat effluent in a similar way to how urban sewerage systems operate; storing aerobically after separating out the water content from the solids.” To assist, Ian sought the input of Ian Jamieson, senior sales and mechanical engineering expert from Kliptank, a Bay of Plenty company that designs and manufactures above ground dairy effluent tanks and treatment systems. Using a predominantly in-ground Taranaki Precast Concrete storage tank and solids bunker, the system uses a Plucks Engineering rotary screen separator (incorporating a 1mm laser cut, wedge wire screen). This removes larger solids and particularly the wood chips, which had previously frequently blocked travelling irrigator nozzles, despite sediment traps and various screens. The large storage tank is then kept aerobic using a kliptank venturi system which also keeps remaining solids stirred and in suspension. The system delivers the following benefits: • Effluent is stored without smell and with minimal GHG losses. It doesn’t crust or sediment to the bottom requiring major stirring equipment and episodes. Rats can’t chew concrete! • Travelling irrigators and stationary cannons operate blockage free and a large capacity delivery pump means multiple application systems can work at once. • The large solids storage bunker allows for safe storage of screen separated solids, sediment trap cleanings and also allows for partial herd shelter clean outs when ground soil conditions are not ideal. • Trials are being planned to see if soil structure advantages accrue from aerobically stored effluent and the system may potentially be used to provide summer irrigation options. Dr Ian Scott with a stag at Oraka Deer Farm. Leaders in Sustainable Dairy Farm Infrastructure TARANAKI PRECAST CONCRETE LTD Talk with our specialist team on 0800 777 5636 Or email: