Dairy farmers tell what it takes to

improve waterways

19 December 2019

Northland dairy farmer Andrew Booth. Photo credit: Northern Advocate.

Just about every dairy farmer is doing it these days – growing the good ‘weed’, that is.

Of course what they’re doing is entirely legal, has not required a referendum, and has a wide range of environmental benefits, in particular improving waterways.

Dairy farmers from as far flung as North Cape to Bluff are planting and nurturing veritable forests of the now coveted New Zealand native manuka.

Manuka was regarded by previous generations of farmers as a weed or pest plant, called ‘scrub’ by many and hand slashed and burnt to make way for pasture.

Today’s farmers, thanks to experience and the scientists who surround them, are passionate about growing manuka, including in the riparian strips created when they fence off waterways.

This once reviled shrub is one of the species that is highly adept at filtering and inactivating contaminants before they reach waterways. Compounds found in manuka can inhibit the conversion of ammonia into nitrate and nitrous oxide (a greenhouse gas), and also increase the die-off of pathogens that pass through their root systems. Manuka also helps to improve fish and invertebrate habitat by stabilising stream banks, providing shade, cooling water and therefore enhancing oxygenation.

Water quality scientist and DairyNZ’s environment manager, Aslan Wright-Stow, says together with fencing off waterways – 98 percent of waterways over 1m wide have dairy cattle excluded 1 – planting out the riparian strip between the water and the fence also does wonders for a farm’s biodiversity.

“The plantings attract bees – think manuka honey – other insects and birdlife, as well as enhancing the farm’s aesthetics. Of course, riparian planting is not limited to manuka – many other species help protect waterways and enhance biodiversity, including flaxes, sedges and cabbage trees. Even exotic species can be extremely beneficial if the right type is selected – for example,  hybrid, sterile willows.

“However, effective environmental management goes beyond riparian management and having fencing in the right place to protect waterways,” he says.

“It’s also vital that dairy farmers have good farm management practices in place across all aspects of their business. This includes ensuring there is sufficient on-farm effluent storage capacity so there’s minimal risk of overflows, as well as understanding what areas of the farm are prone to leaching, and how they should be managed to protect water quality outcomes.”

For dairy farmers, fencing off waterways, planting alongside them and maintaining the plantings is work they carry out in addition to their busy farming days.

Much of their work has been self-funded,  although there are various council and other funding sources they can tap into for a level of assistance, which they warmly welcome.

Many also involve local school children and community groups in walking the environmental talk, planting spades in hand.

As dairy farmers quietly take action to make things better, their work is being acknowledged by many.

Recent accolades include the Cawthron 2019 River Awards celebrating rivers and catchments making major efforts to improve river health.

Southland’s Waihopai, which drains into Foveaux Strait at Invercargill, took out the 2019 Supreme Award for Most Improved River, and third-generation Northland dairy farmer Andrew Booth was one of three finalists for the River Story Award.

The Waihopai is improving as a result of determined effort carried out over the past decade under the Living Streams project.  This has brought together farmers – including dairy farmers – industry, the local community, Invercargill City Council and Environment Southland.

As well as improvements in surrounding urban and industrial areas, over 90 kms of streambank have been fenced, stock crossings constructed and extensive riparian planting has taken place.

Farmers also apply fertiliser – including natural effluent waste from the farm – more efficiently to greatly reduce run-off and leaching, as well as better manage winter grazing to also lower risk.

Other on-farm initiatives have included restoring wetlands in important areas, and constructing new ones.  Farmers know these days that wetlands are the giant ‘kidneys’ of the landscape, helping to dilute and filter material that could otherwise harm waterways.

In Northland, River Story Award finalist Andrew Booth says his parents, Richard and Sharon Booth, took care to protect areas of native bush on the family farm he grew up on and now farms with his wife Vicky.

“They laid a great foundation and really the work we’re doing is building on this.”

The Booths milk 415 cows and with the five kilometres of farmland that runs along the Mangakahia River now fenced and planted, their attention has turned to installing and restoring wetlands.

An existing wetland, flourishing in an area of swamp Andrew’s parents left undrained when they developed the farm, catches nearly half of the farm’s run-off water.

It will soon be joined by a second wetland that’s under development.

Andrew says the best way farmers can help to improve water quality is by ensuring all water leaving the farm is clean.

In recent years he has invited pupils from nearby Maungatapere School, and others in the community, help out with planting and learn about water care.

Some of the thousands of native species planted on the farm have come from Northland Regional Council and The Integrated Kaipara Harbour Management Group.

The group is dedicated to improving and protecting the Kaipara Harbour.  It has the support of many dairy farmers in the region, including Earl Wright at Tapora.  With Andrew, he is a DairyNZ Dairy Environment Leader helping to inspire other farmers and others in the broader community.

Andrew’s advice: “always start with a smaller, more manageable area where the ongoing maintenance won’t get on top of you.  Once the riparian plants start growing the reward becomes infectious.  I promise it snow-balls, and it’s hard to stop”.

1 Sustainable Dairying: Water Accord Year 5 (dairynz.co.nz/wateraccord)



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