'Spray and pray' farming method too risky: Massey's Peter Kemp

One of the regions where 'spray and pray' occurs is the Rangitikei, with a subsequent impact on the quality of the water ...

One of the regions where 'spray and pray' occurs is the Rangitikei, with a subsequent impact on the quality of the water in the Rangitikei River.

OPINION: In the past few months, the "spray and pray" farming practice has received attention as a looming threat to water quality and as a source of contamination of waterways in Rangitikei and Southland. If the practice was to catch on, I think it would be, but I suspect that this practice will lose steam on its own.

Spray and pray is an old term that summarises the optimism of broadcasting seed onto uncultivated land. It has been reprised to describe the practice of spraying herbicide on the pasture on hillsides and broadcasting brassica seed from the air to establish winter feed crops. The farmer risks economic loss if crop establishment is poor due to unpredictable weather after sowing, and risks environmental damage through soil erosion.

Before we get into why this practice won't catch on, it is interesting that this is being touted as new, as it has been around for many years, and for many years it has been labelled high risk. Soil erosion is a problem. New Zealand underwent large scale clearance of forest for farmland without the foresight to see what impact that would have on water quality. This is not new news to scientists, agriculture or the farmers themselves and we are actively trying to combat it.

Peter Kemp believes 'spray and pray' is too risky.

Peter Kemp believes 'spray and pray' is too risky.

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If spray and pray catches on it will cause sediment build-up in the rivers. As soon as you strip vegetation from a slope, you are prone to erosion, and if you have nutrients in the soil, they will get into the waterway.

So why are some farmers doing it? The simple answer is they are taking a gamble trying to get enough quality feed for winter. They are working hard to increase production. We can all understand why, while not condoning their actions, because there are other methods that can be used. For example, the intensive use of all the pockets of cultivatable land on the farm for crops, and the application of N fertilizer in autumn to increase winter pasture cover.

Some claim that the resurgence of the practice may be happening because of cheaper costs of aerial farming methods. The argument that the risk lowers because of the lower cost of the gamble doesn't fly with me, because ultimately it is still a gamble.

If we take the extreme worst case scenario of this becoming common practice, I can't see it carrying on long-term as each farmer will eventually be burned when the crop fails and they will ultimately abandon the process as a loss. The risk is not just causing soil and nutrients to flow into the river, but the risk that the farmer loses the crop they have planted.

Southland farmer Grant Weller recently said the behaviour was coming "from a new generation of farmers straight out of the universities", but that claim is absurd. Massey University certainly doesn't teach this kind of thinking, as it is not economically or environmentally sustainable.

Fifty to 100 years ago the attitudes were different and grazing on hillsides without a dense pasture may have been seen as a viable option, but farmers are getting smarter – this new generation, especially university graduates, are more likely to condemn than condone this risky practice.

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There has been no solution developed to conduct this process sustainably – both environmentally and economically. Knowledge on how to spray and pray smarter is difficult to come by because it involves "praying" for good weather - too much rain and the fertiliser and seed washes into the waterways, too little and the seeds can't establish themselves. Even when you get everything right, the risk remains when you graze.

We simply can't see the long-term sustainability in the practice and farmers see this too. Which is another possible reason why it hasn't caught on in the past.

So why hasn't the government acted? Well, governments move slowly. Some councils are proposing changes and will act if the practice catches on, but I suspect it will burn itself out before it becomes a serious problem.

Tree planting is an effective and proven tool used to negate the negative effects of hillside erosion, so why not steer the conversation that way?

Farmers are thinking of alternative uses for erosion prone land. Research is going into these areas from manuka honey to forestry. Farmers are innovative, but they are also business savvy. They are not going to adopt something long-term that carries such risk.

The problem won't gain momentum and smart farming will win in the end.


Professor Peter Kemp is Head of the Institute of Agriculture and Environment at Massey University.


 - Stuff

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