By John Lewis, Otage Daily Times – Thu, 14 Aug 2008
A new dairy-effluent pumping system invented by a Southlander could be the answer to the problem of effluent leaching from paddocks into waterways.
Dairy farmer turned electrician Lindsay Lewis has invented the system which allows farmers to fertilise their farms with stock effluent without polluting waterways with nitrates and faecal coliforms.
Until now, farmers have been using travelling irrigators or podline systems, which spread a higher quantity of effluent, for distribution.
However, many farmers were limited in the way they disposed of their effluent because of predominantly wet conditions in the region.
Mr Lewis said his Clean Green Effluent System used materials similar to those in portable irrigators to spray stock effluent on to farm paddocks.
But unlike other methods, the system used water pressure and timers to stop the flow of effluent from one paddock and redirect it to another before the pastures become saturated.
Some farmers did not favour podline technology because it was difficult and time-consuming to set up in farm paddocks.
However, Mr Lewis has incorporated the technology in his design and set it up so it is easily and quickly moved.
“We estimate it would take two people half an hour to move the K-Line pots once a month. Normally, they can take up to one and a-half hours to move every day.”
He said the system applied just enough effluent on a paddock to give the grass root system nutrients, but not so much that it leached into the water table or ran off into nearby waterways.
The idea was born out of friendship and necessity, he said.
“A friend converted his sheep farm into a dairy farm on the banks of the Mataura River and he asked me to design something, because he was concerned about the environmental impact on the river.
“There was nothing on the market that was man management free.”
After four years of development, Mr Lewis came up with the automated Clean Green Effluent System and installation of the prototype is almost complete on his friend’s Southland farm.
An average cow produces between 50 and 70 litres of effluent a day and disposing of it was difficult, he said.
“I think farmers get a huge rap for pollution.
“Present application systems cannot necessarily be monitored from the farm that is creating the damage. Once the effluent gets into the water table, it might not reappear for several miles and another farmer down the road gets the blame.”
Dairy farmers can be fined up to $200,000 and jailed for discharging dairy effluent to land in circumstances where it enters water.
Several Southland landowners and sharemilkers were prosecuted in the Environment Court recently and fined up to $20,000.
Mr Lewis hoped his system would revolutionise the dairy industry and have a significant impact on the health of the environment.
Environment Southland approved the installation of the Clean Green prototype but land sustainability officer Nathan Cruickshank declined to comment on it because it had not been proven in practice yet.
However, Otago Regional Council land resources manager Susie McKeague said the system had potential, on paper.
Some of the systems operating on Otago dairy farms applied large quantities of effluent in one go and, when the soils were wet, there was a limited amount of space for the effluent to go.
“A system that puts on a small amount of effluent like this one is a good choice, because you’ve got less chance of getting to field capacity or beyond.”
Having a choice of paddocks to spread the effluent was also valid, she said.
Invermay Agricultural Centre senior soil scientist Ross Monaghan said for farmers with land on sloping topography or with mole-tile drainage systems, the Clean Green Effluent System could be a useful tool.
Dr Monaghan said staff were studying the system in a controlled environment on a test plot in West Otago and water draining from the plot would be tested.
“On paper, it has the potential to be a best practice method for managing farm effluent,” he said.