Soil conservation: an alliance with fertilizers

Soil is an essential component of life on Earth. It contributes to water regulation and supply, climate regulation, biodiversity conservation, and carbon sequestration. As the UN reminds us, 95% of our food comes from soil and around 33% of the planet's soil is degraded.

Our soil is getting poorer. This is a consequence of exploitation for decades, taking away its most precious resources and giving nothing back. The soil of our planet is an organism full of life. It is composed of several mineral and organic elements.

In fact, soil is a thin layer of mineral and organic matter that allows the retention and circulation of water and air on the Earth's surface. This thin layer, which varies in thickness from a few centimeters to a few meters, supports practically all life on the planet. 

Different forms of life coexist and allow the soil to perform several essential functions:

• regulate the climate;
• regulate floods;
• maintain/sequester carbon;
• provide food, fiber and fuel;
• provide construction equipment;
• be a habitat for many organisms;
• purify water and reduce soil contamination;

Yes, our soil has superpowers! But their intensive exploitation causes their impoverishment, which leads to their erosion and desertification, which makes them even less capable of being used. 

Soil is an important non-renewable resource that, when subjected to strong erosion, is lost over millennia. While rain provides moisture for plant growth and human well-being, it is also undoubtedly a major cause of soil degradation, which seriously threatens the balance of our planet and all its occupants. Soil erosion reduces land productivity and mainly contributes to the silting of rivers, which is responsible for flooding.

The risk of erosion increases if the soil is not sufficiently protected by vegetation cover and/or the layer of harvest residue from the previous crop (straw). Waste and vegetation protect the soil from the impact of raindrops and water splashes. They also tend to reduce the speed of water flow and promote water infiltration into the soil.

The adoption of conservationist practices, such as the adoption of the direct planting system, with no return of plant remains, performing crop rotation and preserving straw on the soil surface, is a huge contribution to the system becoming balanced and sustainable. The straw over the system lowers the temperature and preserves soil moisture, creating a more favorable climate for the development of beneficial microorganisms.

The layer lost to erosion is the most fertile, alive and rich in organic matter. Plants will only be able to cover the soil quickly and efficiently the faster they develop. This is possible when the plant finds suitable conditions in the soil, especially the availability of nutrients. Because tropical soils have low nutrient availability, it is fertilizer that will contribute to the supply of essential nutrients for plant growth. 

The use of fertilizer favors greater production of plant mass, which will create a greater mass of residue, protecting the soil more efficiently against the impact of raindrops and, consequently, the soil's erosion process. Likewise, the greater the development of the plant, the greater the amount of plant residue that will remain on the soil. Thus, the use of fertilizer favors greater production of plant mass, which will create a greater mass of residue, protecting the soil more efficiently against the impact of raindrops and, consequently, the soil erosive process. 

The importance of fertilizer in the plant cover of the soil and the greater production of straw is evident. These two factors contribute to reducing the soil erosion process and conserving the soil's chemical, physical and biological properties. This preservation helps the soil maintain its productive potential, but above all it contributes to reducing the siltation of rivers and lakes and water conservation.

*Per Valter Casarin, general and scientific coordinator of Nutrientes Para a Vida