To the naked eye, it looks like there’s not much going on when it comes to soil. But beneath our feet there is an unseen interplay between organic and inorganic matter, creating a diverse ecosystem that helps grow our food.
Each year, World Soil Day reminds us of the vital role of soil while also encouraging sustainable soil management. While dirt is ubiquitous, soil is a limited and non-renewable resource characterized by its inability to fully replenish within our lifespan.[1] We can’t have efficient agriculture without soil, which is why soil health is crucial. Soil is crucial to maintaining a strong agriculture sector—but what goes into healthy soil?
Soil health refers to how it is managed and taken care of. There are three pillars to soil health—chemical, biological, and physical. Fertility and pH levels are related to the chemical components of soil. A high concentration of nutrients like nitrogen and magnesium are what make soils fertile. Neutral pH levels in soil ensures nutrient solubility which means plant roots can absorb nutrients with ease.
Soil structure or tilth is one of the physical attributes and it refers to how soil aggregates together. Ideally, soil structure should be porous, so water and air can flow easily throughout the ecosystem.
Micro-organisms and insects account for the biological components of soil which are especially important for producing organic matter. Each of these components interact with one another in order to create a diverse ecosystem.[2]
Maintaining these three pillars comes down to organic matter, which is the decaying waste from living organisms. Through processes like composting, natural waste biologically degrades into organic matter, contributing to the soil’s overall health—it reintroduces nutrients that are crucial to plant growth, preserves the soil’s structure, and also boosts moisture-holding capacity levels.[3]
As soil is the foundation to our food and agriculture systems, there are certain threats to its health, and sustainable soil management practices are needed to address them.
This year for World Soil Day, the Food and Agriculture Organization organized a campaign to “Halt soil salinization, boost soil productivity.”
According to the United Nations, there are over 833 million hectares of salt-affected soils around the world. Soil salinization and sodification are growing concerns. In soil salinization there is an excess of soluble salts, affecting a plants ability to absorb water and nutrients. Soil sodification disturbs the composition of soil, preventing plant growth.[4]
Human activity has increased soil salinization and sodification in croplands, resulting in an unsustainable ecosystem for agriculture production. It poses a threat to issues such as food security and environmental sustainability—problems that agriculture tries to solve every day.[5]
Over the years, agriculture has adopted various sustainable soil management practices in order to offset the negative impacts affecting our productive land.
For instance, no-till farming has been practiced by farmers for decades. No-till farming leaves most of the topsoil undisturbed, aiming for only 10-40 per cent soil disturbance.[6] Topsoil is where most of the organic matter and micro-organisms are found so tilling it would disrupt the natural processes that keep nutrients in the land for next year’s crop.
Crop rotation also improves soil health—integrating different crops every season can strengthen soil’s resiliency, and as a result, it increases the concentration of organic matter. Pulse crops have proven to be extremely beneficial to a farmer’s rotation—pulses add nitrogen back into the soil, revitalizing its fertility levels.
These are only a few practices that agriculture implements to ensure the future of our soil. Every day, people are working towards improving and developing sustainable management practices. By taking care of our soil and addressing its key threats, we can support our agriculture while also ensuring food security for future generations.
[1] Food and Agriculture Organization of the United Nations—Soil is a non-renewable resource https://www.fao.org/3/i4373e/i4373e.pdf [2] Real Agriculture— Soil School: What makes a healthy soil? https://www.realagriculture.com/2021/11/soil-school-what-makes-a-healthy-soil/ [3] Recycling Council of Alberta—An Introductory Guide to On-Farm Composting https://recycle.ab.ca/wp-content/uploads/2021/07/An-Introduction-to-On-Farm-Composting-F8-July-2021.pdf [4] Food and Agriculture Organization of the United Nations—Salt-affected soils: discovering a missed reality https://www.youtube.com/watch?v=kQcax3Rv4oA [5] United Nations— Soil salinization: a threat to our global pantry https://www.un.org/en/observances/world-soil-day [6] Government of Alberta—Beneficial Management Practices https://www.alberta.ca/beneficial-management-practices.aspx