World Soil Day: time to celebrate our most prized asset

"Let’s take a moment to think of our soils and how important they are. Look at your clothes, your food and the place that you live, and try to see how much of that would be impossible without soil.

Soil is our home. We breathe the air, we drink the water and we eat the crops, but we live on the soil. And without it, none of the rest would happen. Soil stores twice as much carbon globally as the vegetation above ground, and is a universe of microbial life working with plants to balance the carbon, nitrogen and oxygen levels in the air. When it rains, only a tiny amount of water lands in the rivers, lochs and lakes. Almost all of it lands on the soil, and is filtered and stored, released slowly and steadily back out. Without the soil, we would all be washed out to sea every time it rained heavily.

A lot of the UK’s soft fruit is grown in polytunnels on artificial substrates like coir (which is made from coconut husks), but that is only a fraction of the enormous agricultural output in this country. Around the world, 11% of the total land area is used to grow edible crops. Around three times as much is grassland, supporting herbivores – including cows, sheep and other animals.

The 5th of December has been designated as World Soil Day by the United Nations, and it is an opportunity for soil scientists around the world celebrate and promote their work and the importance of soil. Around the world, universities, research organisations and soil science societies will be holding events and sharing information on social media.

At the James Hutton Institute, soil scientists look at ways in which soil could store more carbon, to slow down climate change and to improve the soil’s ability to carry out a host of functions. They also investigate how to slow down water in the landscape, to store it in the soil for longer. This will improve water supplies in parts of the world with long dry seasons, and will reduce the risks of floods during wet seasons.

Hutton researchers work on crops, including plant breeding for different qualities like disease resistance and drought tolerance, but also on the effects of the soil on these qualities. How does a farmer maintain soil nitrogen levels to maintain yields, without spending too much on fertiliser and polluting waterways? What can we do to reduce soil erosion, flooding and crop loss by changing how those crops are planted? Which soil microbes increase nutrient availability to crop roots, improving their growth? All of these questions and more need answers to increase our food security, protect the environment and help drive our economy.

Next year the Institute will begin a large experiment across three farms in different parts of Scotland to examine the effects of lime on a whole host of soil properties and functions. Lime is important for maintaining the acidity level of soils, which for many reasons has a major impact on how plants grow. It affects the structure of the soil and the chemistry and biology that takes place below the surface, so it will also influence how much greenhouse gases are released and the numbers of invertebrates that wild birds feed on. 

A team of scientists, including ecologists, agronomists, chemists, physicists and biologists will investigate the many effects of lime application by focusing on multifunctionality - the ability of the soil to carry out several important functions at once.

Multifunctionality is an important concept in the soil, and in research at the James Hutton Institute. Components interact, each doing something different and contributing to the whole. Synergies are developed, with unexpected results. It is important to make use of these interactions and their potent effects, to understand them and enable them.

Let’s take a moment to think of our soils and how important they are. Look at your clothes, your food and the place that you live, and try to see how much of that would be impossible without soil.