Farmers tested the quality of their soil by burying a pair of underpants in the ground and seeing how quickly they rotted.
The idea is that the more healthy microorganisms there are in the ground, such as bacteria and fungi, the faster the tissue will be eaten away.
Bury the pants now and they may be dug up next year in pristine condition.
That’s because, according to experts, more than half of the world’s agricultural land is already degraded.
In India, soil degradation is one of the factors, along with debt, that is said to have led to the shocking statistic of nearly 30 people in the agricultural sector taking their own lives on average every day.
To try to make things better, a popular Indian guru called Sadhguru continues to lead a global campaign called SaveSoil, which calls for improved soil health around the world. It calls for farmers to be given incentives, such as financial support, to maintain a minimum of 3% organic content in their soil.
“If we remove that and the soil becomes sand, then it’s done,” he says. “If we don’t take care of our soil problem, we’re all going to be left with a desert.”
History has shown us the devastating consequences of poor soil.
“We all remember those images of the North American Dust Bowl from the 1930s and we’re really shocked by it,” said David Montgomery, a professor of geomorphology at the University of Washington and author of three books on soil, including Dirt: The Erosion of civilizations.
The reality of most soil degradation is a build-up over time, not a one-time catastrophic event, he adds.
“If you’re continually degrading the land faster than you’re restoring its fertility, you’re depleting its batteries, its ability to actually support agricultural production. Fertility is trapped in the topsoil that has literally been torn away from decades upon centuries of farming, and it just makes it that much harder to grow food.”
There are several causes of soil degradation, from overgrazing, to growing only one crop at a time, and excessive use of weed killers. But one contributing factor was a piece of technology that revolutionized farming—the plow.
All over the world, from small subsistence farms in Africa to the vast mechanized farms of North Dakota, this very old piece of technology is a typical part of farm life.
Modern plowing turns the soil to get rid of weeds, but in doing so exposes the microbes beneath the soil that are vital to its well-being. These microbes, now exposed to the sun, die and the soil loses its fertility.
The plow, along with other machines such as the combine, expanded the scale, speed, and productivity of agriculture, resulting in more land being cultivated more efficiently.
But Ben Raskin, head of agroforestry and horticulture at the UK Soil Association, says we need to rethink the role of technology in farming.
“We need to make sure the technology supports soil and plant health,” he says.
This could mean new tools. Farm equipment suppliers such as John Deere are now introducing “no-till machines” – farm equipment that is designed to cause minimal disturbance to the soil.
These include seed drills that drop seeds into small holes rather than using a large blade to dig a long trench.
Or it could mean using robots that can help with planting and weeding in a more gentle way. One such device is the Robotti, manufactured by Danish agricultural technology firm AgroIntelli. The development of this was aided by British musician-turned-organic farmer Andy Kato of the band Groove Armada, who tested early versions.
Meanwhile, cover crops—those that are not harvested but instead planted to prevent the ground from being left bare—help improve soil structure by increasing soil organic matter.
Ultimately, though, Mr. Raskin says, we may need to shift the focus away from above-the-ground solutions and dig a little deeper.
“Much of the technical focus in agriculture is on chemicals [pesticides] and physically [machinery]but now it’s time to start thinking about biology,” he says.
Currently, scientists are thought to have identified only about 10% of life in soil.
Prof Montgomery says that for too long “the whole world that’s underground has been kind of invisible to science”. He adds: “Soil is one of the last great frontiers of science – understanding what’s going on in it.”
Understanding the composition of soil can spawn whole new industries, such as biotechnology, which focuses on the genetic sequencing of soil microbes in an effort to provide farmers with the best nutrients for their land.
Going back to simple and old-fashioned techniques can also generate interesting and potentially radical ideas.
One experiment conducted as part of the Soil Association’s Innovative Farmers program used a mulch of willow shavings around trees to suppress weeds and disease. It was discovered that the acid in it actually stimulated an immune response in the trees.
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And the soil beneath our feet may hold the secrets to some much larger human medical breakthroughs.
Natural products from the soil microbiome are a promising source of medicinal compounds, according to an article in Chemistry World.
He points out that teixobactin – a toxin that could lead to the first new class of antibiotics in 30 years – was discovered by sieving soil samples.
For farmers who are concerned about the quality of their soil but don’t want to part with their pants, there are more modern ways to measure it.
Soil samples can be sent to a laboratory for testing, although this can be expensive and time-consuming. In the age of data and internet connectivity, smartphones can provide another solution.
Jack Ingle is a director of Harvest Agri, a British firm that sells a device called a soil test microbiometer. Farmers take a sample of the soil and add it to a tube of a special solution, which is then transferred to paper.
With a free app available for both Android and iPhone, the sample can be scanned to reveal a number that indicates how many fungal and bacterial microbes are present.
And it’s not just farmers who measure soil quality.
A group of scientists created a database of soil health measurements from sites around the world called SoilHealthDB. Last year, the EU established the EU Soil Observatory to collect and track soil data and to support soil research and policy development.
But much of the future of agricultural technology could be about learning from the past, Prof Montgomery believes.
“It’s taking some of the ancient wisdom, like crop rotation and cover crops, and fusing it in new ways with modern technology – sensors, robots and the search for microbial inoculants [beneficial micro-organisms],” he says.