Soils are a fundamental part of what drives our life on Earth. It is estimated that 95 per cent of all of our food is produced directly or indirectly in soil, not to mention it is a major component in providing food security and nutrition. Soils are so important for our basic functions that the UN have designated 2015 the International Year of Soils. Healthy soils maintain diverse ecosystems of essential soil organisms that can be very effective in controlling disease and pests, they form mutualistic relationships with root systems, help recycle nutrients and increase crop yields. Furthermore, healthy soils can have a huge impact on mitigating climate change via their ability to store organic carbon.
Yet, despite all this, we have been treating soils appallingly. This is often fuelled by cheap, quick agricultural practices and the false idea that soils are a renewable resource. Although our global demand for agricultural production needs to increase by 60 per cent by 2050, soils actually only form at a rate of 1cm every 1,000 years. It is therefore essential that we learn to ensure sustainable practice, for example by reducing tilling, improving nutrient-holding capacity through composting and by rotating crops with legumes, such as clover.
New methods are springing up in labs around the world, as scientists scour lessons from history to combat the increasing pressure felt by farmers, as the climate warms and population levels continue to soar.
One of the most promising examples of this is biochar, a hark back to 2,000 years ago in Central America, where indigenous tribes would add organic material to their soils to improve fertility. Biochar is the carbonised material created from agricultural waste by heating biomass in the absence of oxygen to produce a porous, fine-grained charcoal.
It enhances soil by increasing its nutrient and water-holding capacity, as well as its ability to lock in carbon for thousands of years, prompting many to label it as a key tool in combating climate change.
It is hoped that, by introducing such methods, as well as a gaining a deeper understanding of soil health, we will be able to provide nutritious food for the world’s population in the decades to come.
Photograph: Colette Kesler