Healthier soils will give us – and the planet – a healthier century
The dirt beneath your feet is teeming with life. In any given tablespoon of soil, there may be more than 50 billion microbes – bacteria, fungi, nematodes, mites, and more. Ninety percent of all the organisms on earth live underground. In a handful of healthy soil, there is more biodiversity than there is among all the above-ground animals in the Amazon Basin
Author: Robert T Fraley. Source: Huffington Post
Until fairly recently, the human race has been largely uninformed about this vast ocean of uncatalogued life. Although farmers have always valued their soil and understood the importance of maintaining it, science offered little detail about the organic material within it, let alone how that material interacts with crops to give us our food.
Now, however, advances in biotechnology have begun to exponentially advance our understanding. As a result, we are on the cusp of making major strides in sustainable agriculture that will benefit both humanity and our ecosystems.
These advances are clearly coming just in time. By the year 2050 we will have 2 billion more people to feed on this planet, and global food demand will be about 70 percent higher than it is today.
Meanwhile, our key resources are threatened. Fresh water – our single most precious resource – is finite in supply and fast being depleted. Topsoil – which is literally the foundation of our food supply – is being stripped or degraded faster than Nature can replenish it (new topsoil is made at the rate of 0.025 mm to 0.125 mm per year).
And now climate change – to which agriculture itself is making a contribution – is threatening crops and livestock with a variety of new challenges, including withering heat, drought, and new pressures from bugs and diseases.
For these and other reasons, the United Nations Food and Agriculture Organization (FAO) explained recently, the world needs a “paradigm shift” to more sustainable methods. It’s no exaggeration to say that if we don’t think more holistically about agriculture, the 21st century could be grimmer than any of us want to imagine.
The good news is we can do this. We can enable a more sustainable and productive agriculture. And in part we can do that through the development of new frontiers that, not surprisingly, coalesce around soil.
In 2003 Craig Venter and a team of scientists set out to demonstrate that advances in genomics and computing power could enable the mapping of microbial life all over the planet. Beginning in the Sargasso Sea and then circumnavigating the globe, Dr Venter and his team were able to uncover the secrets of microbial life and diversity throughout the oceans. Over the last few years many other scientists have followed, leading to the description of the microbial life in the soils, permafrost, deep-sea vents, and even geysers.
As a result, humanity is now finally learning about what lies below. At the same time, we’re learning how different crop plants interact with the biological communities, or micro-biomes, in the soil. We’re learning how some organisms help a given plant and some hinder it, not unlike the ways of micro-organisms in our own bodies.
For example, just as the “good” microbes in our gut help us digest our food and maintain our immune system, “good” microbes in the soil form symbiotic relationships with plants and help them absorb nutrients through their roots as well as resist bugs and diseases. “Bad” ones do things like triggering the outbreak of plant diseases. There is growing evidence that “good” microbes added to the soil can provide health benefits to crops just like “probiotics.”
All of this is leading to a day when farmers will be able to use the tools of genomics and precision agriculture to analyze their fields in an unprecedentedly detailed way. They’ll then be able to introduce or reintroduce the kinds of beneficial microbes found in the most productive soils. We may even be able to restore fertility to some of the lands – for example, in sub-Saharan Africa, or even areas of our own rich bread basket in the United States – where management practices driven by a variety of forces have rendered the land less productive.
By doing below ground what we’ve done above in reintroducing endangered species, we’ll achieve great benefits. Specifically, healthier organic life in the soil will bring us:
- Healthier, more resilient plants. Crops will have less need for some of the chemical fertilizers and pesticides we now rely on for production. They’ll need less irrigation too, because the soil will retain water better and the plants will absorb it more efficiently.
- Climate change mitigation. Healthier soils lead to lower rates of greenhouse gas emissions, as I’ll discuss in a moment.
- Increased biodiversity. The more beneficial microbial life in the soil, the more life there will be of all kinds.
- Better ecosystem “services”. By many calculations, the living soil is the Earth’s most valuable ecosystem. Besides mitigating climate change, it protects against soil erosion, filters our water, and performs other functions worth trillions of dollars each year.
To make this future work best, however, it will also be important for farmers to keep adopting better soil management practices, such as conservation tillage and cover cropping. Conservation tillage is a broad term to describe any method of cultivation that leaves the previous year’s crop residue – corn stalks or wheat stubble, for example – on fields before and after planting the next crop. Cover cropping involves planting a secondary crop after the main one is harvested, to stop erosion or replenish nutrients in the soil.
These practices, which have indeed been gaining popularity, stand in contrast to tilling – the process of breaking and turning over the soil while ploughing under the residue for the purpose of hampering weed growth. Tilling is a time-honored practice, but it disrupts the soil’s sponge-like structure and disturbs the balance of its microbial life, decreasing the land’s capacity to absorb water as well as nitrogen and phosphorus from artificial fertilizers. The result is excessive runoff of water and nutrients, leading to the infamous dead zones that afflict places like Lake Erie and the Gulf of Mexico and larger releases of nitrous oxide, a potent greenhouse gas.
By rebalancing the microbial community in the soil toward air-loving organisms, tilling also leads to the more rapid decomposition of the organic matter buried in the soil – and thus to the release of the carbon sequestered within it. And astonishingly, there is more carbon in the soil than in all the plants and the atmosphere combined. Only the oceans contain more.
Biotechnology – herbicide-tolerant crops, in particular – has helped farmers move away from till farming by giving them another way to control weeds. This USDA report is only the latest of many to make that point. In other words, biotechnology has proved to be a foundational technology for the new advances we anticipate in improving the soil biome.
Even more advances in soil management are on the way. Right now, for example, our company [Monsanto] is partnering with the National Corn Growers Association and partners in conservation and academic science to gain a more systematic understanding of the economic and environmental benefits of different soil management strategies on a region-specific and crop-specific basis. The Soil Health Partnership, as it’s called, has already established demonstration farms in the Midwest where innovative management practices are aimed at improving soil health. The partnership aims eventually to publish its findings and to encourage farmers to adopt them as appropriate.
Much more such research needs to be conducted. Success will take partnerships and collaborations among all of us -public and privately funded research groups, farmers, ecologists, and many others. My own company has partnered with Novozymes, a world leader in the use of microorganisms. We expect that marrying their insights into microbes with our knowledge of agriculture can accelerate much needed solutions to the problems we face in feeding a growing population.
The soil clearly must be protected, and to do that, we need to understand it. But we’re making great strides now, and they’re going to make agriculture more productive and sustainable – better for us and the earth.
About the author: Dr Robert T. Fraley is Executive Vice President and Chief Technology Officer, Monsanto