In 1937, Franklin Roosevelt, then president of the US, wrote to state governors in the wake of the “dust bowl” catastrophe, where drought across the Southern PlainsThis led to devastating famines and dust storms. “The nation that destroys its soils destroys itself,” he wrote, highlighting what remains a fundamental truth: that the state of the Earth’s soil is a vital indicator of the planet’s health.
As a society, it is not possible to place sufficient valueon the ground below our feet. The use of the word “dirt” to denote inferiority is an example of this disrespect for our land. Yet societies succeed and fail in direct. consequenceThey place great value on their soils.
Our soil not only directly or indirectly provides most of our food, but it’s also central to our planet’s life-support system. Soil is an integral part the carbon, water and nutrients cycles, which allow organisms to thrive of all sizes.
Plants and animals are able to release nutrients into the soil as a result of their decomposition. This allows future generations of organisms and plants to use and recycle these nutrients. The soils store, filter, and purify water to protect us. flash floodingBy absorbing rainwater. Soils are also important. carbon storagethereby helping to buffer the climate from the effects of human-driven CO2 emissions. It is estimated that there are approximately three times more carbon in our soils than in Earth’s atmosphere.
These ecosystem services are fragile and easily can be destroyed. Mistreating soil can lead to soil failure. deep ploughing(which can damage soil structure) and using harsh chemicalsMany of our soils are now in decline due to the destruction of important microbe communities. It’s estimated that one-thirdOver the past 40 years, most of our agricultural soils were lost.
This can reduce our ability to produce high quality food. Poor soils may require more fertiliser because they are unable to trap nitrogen and phosphorous. This is a significant source to carbon emissions. 600g of CO₂This is the amount of carbon dioxide produced when making a 800g loaf of bread. 43% of these emissions are due to nitrogen fertiliser.
On top of this, degradation can also lead to soils releasing their stored carbon as CO₂, amplifying the climate crisis. When I spoke at the UN climate conference in 2015, COP21 in Paris, I warned of impending disaster if we don’t protect our soils from degradation with techniques which reduce soil erosion, such as planting cover crops.
I was at that time described as a “peddler of university disaster pornography” by climate change deniers. My testimony was not a fanciful prediction. The dust bowl is a reminder that the repercussionsToday, soil degradation is still a problem.
The UK’s soils have been affected by intensive agriculture, making them more vulnerable to erosion from extreme weather. Degraded soils became ineligible to store water during heavy rainfall, which led to flooding of the UK’s spring 2014. widespread floodingand soil erosion. Earth observation centre is open during that month. NEODAAS in Plymouth released a satellite image of the UK “bleeding” its soils into the ocean.
We know why this happens. Ploughing removes conglomerations of soil particles, such as clay or sand, that are bound together by a cohesive force. organic materialThese include dead roots, fungal filaments, and bacterial or earthworm secretions. These substances store organic carbon and help to build soil structure. Without them, soils will be more easily washed into our rivers or estuaries.
Recent research from Leeds, York, and Sheffield has shown how to fix this problem. By using no or shallow ploughing and rotating land for agriculture, and by planting cover crops, we can all help our soils. rest and recover. This allows beneficial soil organisms such as earthworms, fungi, and bacteria to grow when combined with limiting fertilisers.
This evidence supports growing calls towards embrace regenerative agriculture, which calls for supporting – rather than fighting – biodiversity within the agricultural landscape.
In South America, for example, the popular method of “slash, burn and move on” agriculture – where forests are felled, burned to release nutrients and then farmed until those nutrients are depleted – has been criticised for its destruction of biodiversity. In contrast, regenerative agriculture’s focus on increasing biodiversity has been shown to be a successIt is important to protect and even increase soil health in the area.
Regenerative agriculture also involves reducing soil pressure, which can be difficult when considering the growing global population. Our researchIt has been shown that more food can be produced in the urban environmentThis could be a great way to achieve it.
You can grow crops in crowded citiesHighly efficient hydroponic systems that use less water, less fertilizer, and require no soil. These can operate on top of flat-roofed buildings – or even in refugee campsA place where farming improves food security as well as community resilience. We can eliminate the need for food to be shipped around the world by planting crops close to people’s homes. This makes our food systems more sustainable.
Almost 20%Most greenhouse gas emissions today are caused by agriculture. This means that carbon from our soils is being leaked out all over the globe. If we want to preserve a functioning agricultural ecosystem for future generations, we must embrace technologies that are soil-centric in food production.