The real cost of dairy

During the past few decades we have wrought the most massive changes to New Zealand’s environment since fire was used to burn forests and clear land many centuries ago.

Driven by the explosion in dairy farming, particularly in Canterbury and progressively in parts of Otago and Southland, our once pure drinking water supplies are now threatened by the rising levels of nitrates running off the land into soils, rivers and aquifers from nitrogen-rich fertilisers and cow urine.

This huge and increasingly concerning ecological state of affairs is coming home to roost in tainted water and gunged-up rivers and swimming holes.

Consumers are understandably irked by the price of dairy products in supermarkets. Why is one brand of milk in a different shaped plastic bottle to another more expensive? How can butter prices be so variable? And who on earth can afford to buy a kilogram of cheese these days – not even particularly flavoursome cheese – without cutting back on other goods?

These are, on the face of it, the apparent costs of dairying. But dig deeper and look wider, and you will see that the damage done to the countryside to produce those goods is the real cost to the nation and New Zealanders of dairy farming.

Until about 30 years ago, the Canterbury Plains was recognised as the bread basket of New Zealand, with farmers there producing all types of grains and crops and rearing a small amount of beef cattle and sheep.

Back then, the sight of a vast herd of black-and-white Friesian cows stretching across flat paddocks would have left one incredulous. Seeing the same in the rocky, desiccated landscapes of Central Otago would have seemed even more incredible.

Victoria University of Wellington scientist Dr Mike Joy and colleagues around the world recently set out to discover just how badly milk production is polluting Canterbury’s groundwater and whether it is possible for rain and river water to dilute those contaminants to make the water safe to drink.

They calculated that for every litre of milk produced in Canterbury, between 433 and 11,110 litres of water would be needed to dilute the pollution coming from its production.

This figure, the nitrate grey-water footprint, varies widely depending on the water standards in each area of production. The Australian Journal of Environmental Management study found the region’s groundwater drinking supplies could be heading to extreme nitrate contamination levels of 21 milligrams per litre, almost double the allowed level of 11.3mg per litre.

Overseas studies have linked such high levels of nitrates in drinking water to colorectal cancer and birth defects.

Dr Joy says dairy farming of such intensity is totally unsustainable and "could pose a significant risk to human health and the market perception of the sustainability of the New Zealand dairy industry and its products".

Farmers are, of course, partially to blame, but not entirely or even that significantly, compared with others. While there are many in the community who simply point the finger at dairy farmers, that is a lazy and overly simple way of looking at matters.

Dr Joy quite rightly saves his wrath for the bureaucrats and politicians in central and local government who allowed this to happen, through laissez-faire planning, piecemeal legislation and poor oversight.

Regional councils are especially culpable and he told RNZ he is particularly critical of Environment Canterbury and its "utter failure" in this work, as well as the environment ministers who have stood by and watched a "hands-off approach" to agriculture.

The Otago Regional Council, especially some councillors, would do well to read Dr Joy’s latest research and ponder on the benefits to the country of allocating more river water to allow for dairying in places where it should never be permitted.

New Zealand has more than enough dairy farms and too many cows. We need to be investing in ways to improve our water and reducing herd sizes. There is absolutely no need for any more dairying.

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