NEW Zealand covers about the same area as Great Britain but fewer than five million people live there, so it presents the visitor with many wide open spaces. It has as many cattle as human beings, and 10 times as many sheep. For all its green vistas, then, it must count as the world’s blackest sinner in terms of carbon emissions.

It also has a bad conscience about that, and some years ago introduced a levy on farmers to pay for research into the problem. This was more or less laughed out of court when it became known, with the earthy local sense of humour, as the Fart Tax. Today the relevant research is financed by other means.

Finance is an obsession in the world of New Zealand’s agriculture because, remarkably, it does not subsidise its farmers in any way: this despite the fact that their produce makes up three-quarters of exports and so is vital to the nation’s existence. They always used to be subsidised, like their counterparts elsewhere. But in 1984 a Labour government did away with the whole system in one fell swoop, on the argument that farmers spent more time chasing money from the ministry than they did breeding beasts. Since then they have been on their own, fully exposed to unstable global markets.

I raise the point in response to one of my readers, Dougie Gray of Dunbar, who wrote in a couple of weeks ago asking: “Can someone please explain to me why we pay so much for locally produced food from the agricultural sector? To put things in perspective – you have to lock in that currently and for the considerable future all our farmers and land owners receive very substantial government funding, without actually having to do very much at all for it. Yet somehow we can import butter and lamb from New Zealand, 11,500 miles away, and then sell it cheaper than that locally produced.” Dougie concluded his letter: “New Zealand should be the model that Scotland should be adopting in future government agricultural policy.”

You’ll not be surprised to hear I agree with you, Dougie, especially as the present set-up is due to dissolve in chaos when we leave the EU. For 45 years its Common Agricultural Policy has been the only such policy we have had, originally designed to supply the needs of European peasants. The CAP failed to save them, and now it rather supplies the needs of juggernaut European agribusiness. UK farmers never really fitted into either category, so we will have to make up a new policy of our own as we go along.

Whatever it turns out to be, I suspect this new policy is not going to be good news for Scotland. We will be brought face to face with the brutal truth that Scottish agriculture is unprofitable. The latest figures show the average farm earns £149,000 a year but carries costs amounting to £168,000 a year.

Dairy farming alone makes a reasonable profit but all remaining branches lose money, or would lose it without the subsidies they get, especially in the Highlands and other remote areas. The system is more generous to Scotland than to the rest of the UK. We have one-twelfth of the population but we get one-sixth of the subsidies.

The UK has had to go along with a structure of payments basically designed to serve continental interests through the sky-high prices we see in the shops. Now there comes by way of Brexit a chance to cut it back down to size. The payments have taken two forms in the main two forms. One is support for innovative investments in niche markets, in practice handed over to wealthy and progressive English farmers. The other is blanket subsidy – which is what skint Scots prefer. Put yourself in the place of a future UK government and ask which kind of payment you would cut back first if forced to. Assume this government can offer its farmers no assured consumer base, like now, but must drum up business for them in experimental trade agreements with the outside world – and I think the answer is obvious.

Things might still work for Scots if the agricultural powers returning from Brussels after Brexit alighted in Edinburgh. But, as we know, the UK government is plotting to have them land in London instead. Agriculture was one of the old Scottish Office’s responsibilities from 1906. In future, it would go back to being run at the UK level, on the excuse this is easiest for a sector in inevitable upheaval.

What could a government in Edinburgh do in such daunting conditions? It could acquiesce in English pressures, and do its best to prettify the ugly results. It could continue the CAP levels of subsidy out of its own resources, but only at eye-watering cost – and I wonder if that would ever find enough political support. Or it could aim, after Scotland’s Independence Day, to learn from our cousins in New Zealand.

Of course, there was a big upheaval when New Zealand abolished subsidies too, if perhaps no bigger than the one we face anyway. A lot of farmers went out of business, but it seems they left more capable people in charge who were better equipped to cope with the crisis. In fact most farming families held on to their properties and now have seen their incomes more than recover.

This is because their production has soared five times over, which was not a consequence originally forecast. Trying to figure it out, New Zealanders decided it was because the traditional subsidies encouraged inefficient farmers to grow unprofitable crops far beyond what consumers actually needed, secure in the knowledge that government would protect them from loss, and in particular keep out competitive imports from their rivals in poor countries.

By removing subsidies, New Zealand joined the ranks of a new global regime which liberates the best farmers anywhere in the world to produce what people really want. At the turning point, as capitalism came with full force into China, India and other teeming Asian countries, there appeared a vast market of hundreds of millions of people who had got rich quick and wished to ape western ways. An early indicator of rising living standards is consumption of dairy products, as families give up bean sprouts to feed their kids calcium – enough, for example, to turn the once diminutive Japanese into rugby players.

So a basic answer to Dougie Gray’s query is that there is no deep secret about all this. New Zealanders, forced to look out for themselves after the end of Commonwealth preference in 1973, decided the world would never owe them a living and coolly assessed what they had to do. They enjoyed certain advantages: their country is as wet as Scotland but somewhat warmer. So the beasts need not be held indoors in the winter and can feed on pasture, which makes them healthier and cuts out the cost of transporting hay. But otherwise it is a matter of keeping a sharp eye on the markets. Newly health-conscious Chinese, for example, no longer want to eat so much fat – OK, send them leaner lambs from fresh breeds.

In the back country of Dunedin and Invercargill, many farming families originally came from Scotland. Agricultural innovation was in their blood. For those who stayed at home, their profit-seeking genes seem meanwhile to have transmuted into subsidy-seeking genes, gladly gratified by our government’s subsidy-giving genes.

Is it too late to change? If not, I don’t see much future for agriculture in Scotland.