A balance between profit and pollution

20:04, Apr 11 2012

Terry Parminter remembers his early days as an agriculture ministry farm adviser in the 1980s.

"We treated the environment in a care-free fashion. I thought, 'There's always another piece of bush, always another clean stream around the corner'.

"But there probably never was, even then, and there's certainly not now."

The Wellington-based consultant has long-since changed his thinking, but wonders if we are all guilty of taking our clean green environment for granted.

"We don't wake up in the morning and say, 'What am I doing good for the environment today?'

"We should think about the environment more as part of everything we do. For urban people, it could be, 'Where do we wash the car?' Is it on the side of the road where the detergent ends up in the wastewater system, ultimately helping pollute waterways, or do we do it on the grass where the water and detergent can be dispersed into the soil?"


For farmers, it's more complicated. They have to balance care for the environment with the need to make a living from it.

Parminter's job is to help them achieve that. He is the manager for DairyLink, a Tararua district project by local farmers, DairyNZ, Federated Farmers and Horizons Regional Council. The district is a dairying hotpoint, with 312 farms and 99,000 cows with numerous streams and rivers feeding into the Manawatu River before it funnels through the Manawatu Gorge.

The three-year project's aim is to promote good farming practice to improve the district's water quality. But Parminter and the other advisers from DairyNZ have set themselves an additional task. They want to show that at the same time as farmers are reducing the loss of phosphate and nitrogen off their farms into waterways they can also be increasing their profitability.

Three farmers have volunteered to be guinea pigs.

So far, two field days have been held on each farm and it is early days. The first task has been convincing farmers they can make a difference. Giving them the science on water quality and revealing that the Manawatu and Mangatainoka rivers' quality has improved over the past 10 years with the removal of shed effluent shows they can have an impact.

On the farms, several ideas have been floated and await further detail.

Central to the project is the Overseer computer program. Developed by AgResearch, it calculates nutrient flows and identifies the risk to the environment of phosphate and nitrogen run-off and leaching.

Parminter plans to use Overseer to fine-tune each farm's performance, putting each idea through the program to discover its impact.

At the southern end of Tararua, at Hukanui, are Geoff Arends and Ester Romp, with 470 cows owned by sharemilkers Chris and Dana Sutton.

According to Overseer, they are leaching 36kg of nitrogen per hectare a year, at the lower end of the industry average.

Arends says he would like to know exactly what happens to the nitrogen added to each paddock - "Where does it go in the soil, when is the best time to apply it, what weather conditions to look out for?"

Parminter says that can be answered, but the measuring instruments cost tens of thousands of dollars. "Is it worth it to spend that?"

He answers himself. "Yes. The cost can be borne by the industry because the whole industry will benefit."

One way the farm has been able to reduce its nitrogen load has been with a new effluent irrigator. Through the Dairy Link project, Arends has discovered his old irrigator distributed the effluent at a much heavier rate than was needed. The new irrigator, from Plucks Engineering in Rakaia, sends the effluent out in a fine spray that does not waste what is a natural fertiliser.

This efficiency means the farm can reduce its use of bagged nitrogen on its effluent paddocks.

Other measures still to be implemented are to plant riparian strips and create wetlands to filter runoff.

At the same time, recommendations of how to lift milk production include feeding cows better at calving, reducing replacement numbers and keeping cows longer in the herd. As production increases, an opportunity will arise to reduce herd numbers without affecting profitability.

All the farmers have received these ideas with reactions ranging from caution to scepticism. They want more information.

On Mike and Heather Burmeister's farm at Mangatainoka, they already have riparian strips, but climbing weeds are choking the willows holding the riverbanks from eroding.

Parminter admits finding a solution is testing him. "If I had to come up with action immediately, it would be to put in young stock to graze out the weeds. However, it would be a breach of the Clean Streams Accord."

One experiment that will be watched with interest is the creation of swales to take water from bogged paddocks. A swale is a wide shallow ditch that blends into the paddock. The water that drains into it is taken away through underground pipes to be filtered through riparian strips to the river.

They have a high cost but need no maintenance, unlike conventional ditches, and don't need to be fenced.

Burmeister has achieved high production with a high stocking rate on a flood-prone farm. He is dependent on regular small inputs of fertiliser and supplementary feed and his aim is to reduce his environmental footprint by using these inputs as efficiently as possible.

The farm leaches 27kg of nitrogen per hectare a year which is low for the industry and about average for the region.

Bruce and Joy Charmley, who with their son Scott milk 208 cows at Maharahara, near Dannevirke, have more clover than they have ever seen.

As part of the Dairy Link project, they have been carefully managing their pastures to encourage clover growth. A big part of that is mowing when the grass gets too long.

They have reduced cow numbers to 2.6 to the hectare and with the extra pasture feed expect to lift milk production among their high genetic value cows.

"We're trying to keep everything in balance," Bruce says. "We have a low cost structure and that's our advantage."

The farm straddles three winding streams and they have bridged four crossings with nine still to do. They are doing the work themselves and estimate it will have cost them $60,000 by the time they are finished. This compares with a $63,000 quote Bruce was given by a contractor for just one bridge.

A big patch of bush in the centre of the farm is a peaceful oasis and a useful nutrient filter, but is only there because they ignored the advice of the local Rural Bank manager when he was loaned the money to buy the farm from his parents in the 1970s.

"He said, 'Get the dozer in and bowl that bush'. But I couldn't do it. My father and grandfather had looked after it and so have I."

One of the project's recommendations is to put in more riparian strips to catch the 24kg per hectare of nitrogen that is being leached but he is reluctant to do so. "It will take too much land on a farm this size. It could be the difference between whether I stay or go." He would like to see the regional council offer compensation for the loss of land, possibly in the form of a rates rebate.

Parminter feels that one of the biggest problems is the lack of immediate feedback to show farmers how successful they have been in reducing their environmental footprint. "Like anybody else, farmers want to know that if it is costing them time and money it is going to be effective."

He is convinced Overseer will provide that feedback and enable them to prioritise what they can do to reduce nutrient losses from their farms. "It works out what nutrients are going on the farm and what are coming off in the form of production, and what cannot be accounted for."

And he is sure the programme can find ways to increase milk production while reducing nutrient losses.

"That will come once we have farmers using it from season to season, manipulating their fertiliser use, their grazing, drainage, tree planting, crops - everything that governs their nutrient use."

For filtering surface water and reducing leaching there are several options, such as riparian strips, wetlands and ditches filled with wood chips, and Overseer can give readings on all of them.

He expects to have examples for farmers at the next field days, due in July, although he is unsure of the reception it will get.

"Some farmers distrust black box technology, a computer that tells them the answers. They want to make their own decisions. We talk about Overseer being 'decision support'. We tell them, 'It's your choice, you're taking the risk'."

Taranaki Daily News