The know-how of soil fertility
Soil fertility relates to the capacity of soil to support agricultural plant growth.
image credit- shuttershock.com
Soil fertility and sustainable agriculture experts know that most soils today need their health and endurance restored. Soil fertility relates to the capacity of soil to support agricultural plant growth. But if this were indeed the case anywhere at all - especially the sustained and consistent bit measured over a few decades, then the level of inputs added to the soil that agriculture requires across the world today!
On the other hand, for millennia, soil grew life, more soil, and more life in perpetual cycles, all over the planet. Without any external help!
Factors like cultivation, grazing, composting, soil remineralization, fertilizer priorities, fossil humates, soil conservation, green manuring, soil testing, and visual soil assessment all play a crucial part in establishing fertile soils.
Nutrients in the soil
Plants need nutrients just like people do. Plants depend on carbon, moisture, nitrogen, phosphorus, potassium and a bunch of trace minerals. Each of these is cyclic in nature - the water cycle which ensures there are enough of them everywhere, and similarly, there’s a carbon cycle, nitrogen cycle, phosphorus cycle and so on.
Additionally, to provide for this living carbon in the soil, the conditions need to be right. Sunlight falling directly on the ground, and the lack of organic matter on and in it destroy the habitat in which these thrive. Keeping the soil covered is absolutely critical for healthy, fertile soils! Our farming methods - clearing the land of all vegetation, tilling and more recently, dosing it with harsh chemicals in large quantities - all contribute to the living constituents of the soil that help keep these processes and cycles going.
According to the United States Department of Agriculture too, good healthy soil is 45% minerals, 5% carbon, 25% water and 25% air! This is likelier to be soil in sync with these numbers, and stay healthy as well.
Raising soil fertility
What commonly referred to as fertility is not a point in time measurement of a few things, but a process that keeps the ecosystem ideal for easy growth of plant life. And soil’s innate ability to support plant life, it has to be considered as over a period - if it supports this less and less innately, the fertility reduces.
There are natural processes that sit at the intersection of these various cycles that keep the soil “fertile” and moisture-rich. In a sense, fertility can be described in terms of the health of these processes in the soil itself!
Fertility is something the forest both nurtured over eons and depended on for its own sustenance and growth. It is something that was inadvertently disrupted and destroyed as humans started farming about 12000 years ago, and accelerated a century ago as the world acquired superpowers and scaled energy through oil.
This is where the ecosystem of bacterial colonies, nematodes, larger insects and various fungi - most notably mycorrhizae - play a significant role. There are millions of these around root ecosystems and strike a symbiotic relationship with the roots and play a variety of different roles that are unearthed only to an extent today. All of these life forms, in turn, need other forms of carbon in the soil, as well as a diverse set of roots producing sugars and carbs for them. They also burrow and loosen the soil, helping absorb and retain moisture to greater depths. And having moisture in the soil is excellent for plants!
Obviously, great soil needs to have the moisture as well as all the macronutrients and micronutrient. What is more important is that these need to be in a form that the plants can use. And the cycles that make these available and replenish in various forms are in motion.
Fertility is what nature had created as its method to grow and sustain life in a variety of conditions, and that can be achieved again. Even in severely degraded landscapes. A helping hand is what nature needs, and it will do the rest!
Sameer Shisodia, Co-founder & Chief Farming Officer, Beforest