Growing up in provincial New Zealand, whether Whanganui, Manawatu or Golden Bay, I've had lots of connection to the land. Through friends and family, plus three years at Massey alongside agriculture students, I've been on a wide range of farms.

I've even had a romantic view of farming -- people connected to the land, caring for their animals, a special bond with their favourite dog, down-to-earth and honest. That's why I'm struggling to understand this practice of "spray and pray" that's just hit the media.

How can this be anything but Russian roulette with one of a farm's most critical and fundamental assets, the soil?

The spray-and-pray concept, as far as I understand it, is to grow a crop as extra feed. It involves clearing the pasture off hillsides by spraying herbicide from a helicopter, then planting up and finishing with adding fertiliser, again via the air. Then the praying kicks in with the hope the seed takes with just enough rain, but not too much, which would wash the seeds, fertiliser and topsoil down the slopes -- gravity in action.


Where has this risky business come from? Is it just creep with those who've been using it on rolling countryside, literally pushing it up hills, driven in part by increasing financial pressure? I'm not confident how close this practice gets to break-even, especially if the rain gets to it first, given the state of our sodden soils.

The gain is being able to host more livestock over winter months and the income associated with extra stock, or perhaps a better price for fatter animals. If not well managed and subjected to too many hooves pugging up the soil, particularly over winter, the land is likely to end up bare and exposed, so we're back at damaged soil structure and erosion.

Risk: Helicopter spraying of herbicide to kill pasture on erosion-prone hillsides to plant feed crops --
Risk: Helicopter spraying of herbicide to kill pasture on erosion-prone hillsides to plant feed crops -- "spray and pray" -- is environmental Russian roulette.Photo/file.

What I'm also told by a farmer who's observed this on his neighbour's property (outside the Whanganui region) is that, after the land has been through this cycle, successful or otherwise, the hillside comes back in higher numbers of weeds, triggering more dependency on spray.

It doesn't help that our current system doesn't put a market price on keeping soil on the hills or a market cost on allowing sedimentation of streams. These "externalities" are carried by the wider community who pay subsidies for erosion programmes through rates and taxes.

But it's not just sedimentation that's a problem here. Apparently, urine hitting bare ground increases the conversion of nitrogen to nitrous oxide, which is a much more powerful greenhouse gas than carbon dioxide or the farting (and burping) gas, methane.

What can be done? I'm asking that question around the council table. We invest significantly in managing erosion on steep land, so I'm hopeful there will be answers ready about whether this practice is a risk in our region. I'd like to be reassured that if it's happening, it's only a small minority and that when done badly, there is action taken to stop a repeat.

I'm also asking questions about feedlots, and we had a submission at last week's annual plan hearings emphasising the options Horizons has available.

One thing I know from my time working as an environmental adviser on road construction projects, inspecting many a sediment fence, we need to manage the very real erosion risk that bare land presents. Rain is inevitable, and if there are slopes without pasture, there is a risk of run-off. Once it's in the waterways, as reported last month in the Rangitikei, we have increased sediment.

There are growing public concerns about the impacts of intensifying agriculture. It's time to face up to the consequences of short-term thinking and I can't see "spray and pray" as anything but that.

Nicola Patrick is a councillor at Horizons Regional Council, a Sustainable Whanganui trustee and works for Te Kaahui o Rauru. A mum of two boys, she has a science degree and is the Green Party's Whanganui candidate.