Soil and its Functions

Why Do Soils Matter?

We overlook it. We walk all over it, trample it, everyday. Yet we need it like the air we breathe. It's about time, that we talk about soil and certainly about time, that we start protecting it. There can be no life without it. It feeds us. And we are responsible for it.

Soil is formed from rocks that decomposed slowly by the sun, the wind and the rain, by animals and plants. In this way, 10 cm of fertile soil are created in 2000 long years, only 10 cm in 2 millennia. Soil that we deplete in few years, gone forever. Forests and Plants protect the soil but every year, 13 millions hectares of forests are cut down. Fields are cultivated inadequately. Added to that mono cultures and farming on slopes. After the harvest, fields are left naked and unprotected. All this greatly accelerates erosion. And so, gone with winds, washed away by water. 24 billion tons, of fertile soil, were lost - in 2011 alone. A loss of 3.4 tons per person worldwide.no matter what age. Erosion costs each person 70 dollars per year - a worldwide cost that amounts to 490 billions dollars, an astronomical amount.

But fertile soil is infinite and therefore invaluable. Investors and states have realized this. The race for soils of world has already begun: Land grabbing, often with questionable means, for questionable purposes. They destroy the forests because they need land - to survive. We need healthy and fertile soil, now more than ever. Projections say, the available arable land per earth inhabitant will be reduced by half by 2050. But already today, 1 billion people go to bed hungry night after night. And this number will increase everyday, if we do not distribute soil fairly, if we not increase yield dramatically on every piece of land - Or simply discover a second Earth. But we might not rely on this option.

Soil and land issues rarely get our attention or that of our policy makers. We see the full supermarket shelves and believe that things will stay like this forever. We live on credit at the expense of soils. But they are not inexhaustible.

But there is good news! We have long known that what we must do in order to preserve soils for our children. Let's remember - soil is a sensitive living being, who wants to taken care of - it is not a factory. Everyone one has right to soil - this right must be safeguarded by law. And, we cannot afford to bury out our livelihood under the layer of asphalt. Now it is up to us. We must find ways to apply our knowledge. So, we don't ended up losing the ground under our feet.

Soil Functions:

Soil is the medium for plants to grow. All kinds of vegetation are cultivated or managed in soil to provide the food that we and many animals eat. The same holds for fiber used in textile production, such as cotton. Plants are also used as fuel, as firewood, or ethanol fuel. Soil is the basis of most food production. And healthy soil is the basis for healthy food! Soil material itself is also used for many purposes; for example in construction. 30 percent of the world's population uses earth as a building material. Either as sand, or bricks made from clay, or peat. And nearly all of us use wood, which again, comes from trees that grow in soil.

This grass pavement may not appear very attractive, but it shows another important aspect of soil: They can absorb and store a lot of water. For example in case of severe droughts, or just the opposite, in the form of floods. Since this storage function helps to buffer extremes like drought and floods, it is also called the buffer function of soils.

Managing soils properly and on a landscape level helps to avoid floods, especially in downstream urban areas. Soil is also vital when it comes to water quality. As water infiltrates into the ground and moves toward the groundwater, soil acts as a giant “bio-filter” with the potential to retain harmful substances. That’s why it is possible in many places in the world to drink groundwater without any significant treatment, isn't that great?

In order to judge the filtering capacity of  a soil it is important to know more about the particular soil type and its properties. Scientists use “Lysimeter” to study this soil function.

Yet another aspect of soil: Soils are 3D archives! They keep and protect archaeological treasures. These can be artifacts from ancient civilizations, or prehistoric finds like this one, reported from Poland in 2010. This shows you how amazingly old soils are, and how important time is as a factor in their formation.

But soils are not important for humans and terrestrial animals alone. An incredible diversity of organisms lives in the soil. They range in size from the tiniest one-celled bacteria, to more complex nematodes and earthworms, like the one on the soil surface next to me, and finally small vertebrates such as the mole.

Soil provides massive support to our planet's biodiversity and hosts a full quarter, or 25%, of the total global biodiversity. Soil organisms also contribute to services that directly benefit people. For example, the genetic resources of soil microorganisms can be used for developing novel pharmaceuticals. A famous example is the anti-bacterial substance penicillin which in the 1930’s became the "wonder drug" which saved millions of lives. It’s discoverer, Alexander Fleming, received the Nobel Prize for this discovery in 1945.

Soil organisms as the ‘engine of soils’ are also behind a more abstract function: the cycling of nutrients. This function, which is vital for all life on earth, ensures that dead organic material entering the soil is broken down and degraded. This process is called “mineralization” and it releases fresh nutrients, which can be taken up by plants, animals and us! When we die, we become part of the subterranean nutrient cycling ourselves! You could say that we are only temporarily not part of the soil.

And one more thing… During the UN Climate Conference in Paris in December 2015! Soils were big on the agenda there. That’s because soil plays such a key role in the carbon and nitrogen cycles, and can thereby help to combat and adapt to climate change. Sustainable soil management can contribute to greater storage of carbon from the atmosphere in the soil, and lock it up there in the form of soil organic matter. In the next 25 years this process could help to fix, or “sequester”, some 10% of the man-made Carbon dioxide emissions. By the way, it is this soil organic matter that gives soils their dark, chocolate-brown color.

To summarize: Soils have a wide range of functions that are of vital importance for man and nature. They are the basis for food production. We are dependent on their storage and filter functions for food security and water quality. One quarter of all the earth’s biodiversity resides in the soil. Through wise land management we can use soil to alleviate the effects of climate change.