While the internet and social media can’t be entirely to blame, they do seem to speed up the widely held belief that if someone repeats something often enough, people start to believe that it’s true.

This has been seen in many walks of life, though farming seems to be on the receiving end of an awful lot of these urban myths which often seem to be dreamt up simply to do our industry down.

Sometimes these stories – such as the ‘cows are killing the plant’ mantra – are the result of lazy, inappropriate or malicious thinking and while they can be irritating but harmless, it's not unknown for such lies –which is effectively what they are – to be deliberately manipulated to promote the underlying agenda of specific groups.

One which could be a bit of an issue for the arable sector is the oft- repeated claim that the world’s soils will only be able to sustain another 60 harvests – or, in some headlines, it’s 100, or even 30.

Now scare stories proclaiming this sort of line have popped up pretty regularly over recent years, warning that modern farming practices are leading to our soils becoming so degraded that in three score years we could be facing what can only be described as an agricultural Armageddon.

Apart from spelling the end of mankind, it would certainly make you think twice about splashing out on a new combine. But, just in case you have been thinking about doing that, a recent piece in a scientific journal might help put your mind at rest.

For, while there are undoubtedly many threats to our soils – the most precious of mankind’s resources – across the entire globe and despite the fact that it has appeared in many newspaper headlines, indeed quoted by UK Government ministers (including Michael Gove) and even widely broadcast by the United Nations, no one has ever been able to find any peer-reviewed scientific paper which draws such a conclusion.

Even an oft-quoted piece of work from Sheffield University apparently made no mention of any 60-year threat, so no one has yet found any hard scientific evidence to back up the claims that our soils will only support another five dozen harvests.

Make no mistake, though, the issue shouldn’t be ignored – for some soils are indeed degrading and eroding quickly, with around 16% of soils estimated to have a lifespan of less than 100 years.

But others are going to be around for a good deal longer. A great deal of research points to the fact that half have a lifespan greater than 1000 years; and one-third have more than 5000 years and 18% were likely to have one in excess of 10,000 years – long enough to challenge the longevity of any combine.

A summary of some of the science included in a paper in ourworldindata.org showed that more than 90% of conventionally farmed soils had a ‘lifespan’ greater than 60 years, with the median for thinning soils standing at 491 years.

Where soil formation rates exceeded erosion rates, some soils are actually thickening, with around 7% of conventionally managed soils improving and building up.

But the work pointed out that with some thought and the adoption of sensible practices, the lifespan of most soils could be extended considerably – and working on the old 'live like you’ll die tomorrow, farm like you’ll live forever' adage, that’s probably something we should, indeed, be thinking about.

Research led by Dan Evans – who produced the first globally-relevant estimates of soil lifespans – found that using approaches such as contour cultivations, which stops direct run-off and changing management to reduced tillage, plus a wider use of cover crops to leave less soil bare over either wet winters or dry summers, along with forms of conservation agriculture, could substantially reduce the threat of soil erosion and degradation.

While the work indicated that allowing soils to revert to grassland and forestry could be the most effective ways of achieving both of these outcomes, given the need to meet the world’s growing demand for food, cover cropping – which was only slightly less effective at conserving soils – was arguably the more attractive option.

The work also found that, in general, conservation practices extended soil lifespans and could also promote soil thickening, increasing the potential for water, carbon and nutrient storage, and thereby soil conditions which could enhance crop yields.

Whilst there is a wide distribution of soil lifespans globally, this was at least in part due to major differences in the underlying driving variables such as climate, slope and soil texture. This, in turn, played a significant role in the efficacy of soil management techniques.

However, what was slightly more sobering was the fact that soils with lifespans shorter than 100 years were indeed present in all of the observed regions, including many of the world’s wealthiest nations.

All this caused Evans to conclude that this clearly demonstrated that soil erosion is one of the most critical threats to soil sustainability globally and that urgent action worldwide by land managers, policy makers, and society in general, was imperative to prevent the collapse of soil ecosystem service provision.

So, while it’s obviously not true, could the shock-tactic of the ‘only 60 harvests left’ headlines actually help us to realise and address the threat?

Hannah Ritchie – who wrote the ourworldindata.org piece – said that while some might believe that this sort of approach is justified, in the long run such scare tactics more often than not tend to be counterproductive. “Firstly, it forces some people towards solutions that are ineffective, or counterproductive. Some blame the decline in soil fertility on the use of fertilisers and other chemical inputs,” she said.

And the '60 harvests' claim from the UN senior official has been used many times to argue for a switch to organic farming systems – and Michael Gove said the UK had only 30 to 40 years of harvests left because it was 'drenching them with chemicals'.

But, as Ms Ritchie rightly pointed out, many effective soil conservation techniques have nothing to do with organic farming. In fact, shifting to a no-tillage approach often requires more pesticides and fertilisers, not less.

Since average yields tended to be only around 60% of those achieved under conventional management, it also required more agricultural land. “This is in obvious conflict with the best way to reduce soil erosion – that is to have as little crop land as possible. In some contexts, organic farming can play a role, but it’s not the ultimate solution. Misleading headlines convince people that it is.”

Of course, exaggeration can also lead to apathy, with the portrayal of the issue in such obviously erroneous and exaggerated cartoon terms being used as a justification for dismissing the fact that there is any problem at all.

So, although the headlines might be overblown, this shouldn’t detract from the fact that soil erosion is a serious problem. While it’s one we can’t afford to ignore, it is a problem that we can do something about – but let’s just make sure that it’s the right thing.