What is Living Soil?
Understanding Sustainable Soil
Structure Management and Fertility.
What is living soil? It is the key to sustainable soil structure management and fertility!
A primary goal of sustainable living on a small farm is obviously to produce an abundance of safe nutritious food – enough to meet your needs as well as a surplus to barter with others or value add for addition income.
To achieve this goal, you must first understand how soils work, then get to know your own soil and take appropriate steps to optimize its fertility and productivity.
Here you’ll find hands-on information about soils you can apply to your own small farm or backyard:
• What is living soil?
• Types of soil
• Soil structure
• Understanding soil pH
• Soil testing
• Using organic soil amendments
What is Living Soil?
The goal of sustainable soil management is living soil. So what is living soil? It is perhaps easiest to start by considering situations where the soil ecosystem is dead.
Hydroponic systems have essentially dead soils – plants grow in soil media that merely provide the roots with something to hold onto while being loose enough to allow air to get to them.
Nutritional needs of hydroponic plants are met not from the “soil”, but from fertilizers dissolved into their irrigation water. Similar soluble fertilizers are also used in conventional farming systems whose soils are often only barely alive due to chemical use.
The plants are forced to intake the soluble nutrients whenever they drink, and as a result grow rapidly and produce hefty crops. The farmer gets paid, the consumer gets attractive looking food, and all seems well. So what’s wrong with that?
Dead Soil – Farming Outcomes
Here are some of the problems of plants grown this way:
• Poor vitality:
Force-fed plants are inherently weak and need protection from pests, diseases and weeds via chemicals and poisons.
The soluble fertilizers leach away and contaminate rivers and streams causing eutrophication and algal blooms.
• Low nutritional value:
Force-fed plants have low nutritional value, and taste like it too!
• Low drought tolerance:
Force-fed plants are highly dependant on moisture to maintain a comfortable dilution of the fertilizer salts dissolved in their cells. So the plant dies as soon as soils start to dry out.
• Climate unfriendly:
Agricultural crop chemicals and fertilizers require a large amount of energy to produce, contributing to the greenhouse effect.
What is Living Soil?
Living soil on the other hand is full of life. What is living soil but a functional ecosystem of soil critters and microbes that interact with plants to naturally promote healthy growth. For those of us aspiring to sustainable living, eating vibrant plants and animals is a cornerstone to sustainable health.
Living Soil – Farming Outcomes
The benefits of living soil are many:
Produce delicious, nutrient-rich foods.
• High vitality:
Naturally grown plants are inherently strong and need less protection, allowing organic food production methods to be used.
• Drought tolerant:
As their food is in colloidal states rather than being soluble, naturally grown plants only feed when they want to, are not overloaded with chemical salts, and can continue to grow under drier conditions.
• Low pollution:
Fertilizers used are not soluble so stay in the soil where they are needed rather than leaching away and causing pollution.
• Greenhouse friendly:
Does not require energy intensive inputs of agricultural crop chemicals and fertilizers.
What Lives in Soil?
Because it’s hard to make a dollar from all the amazing ways that soil life enhances the vitality and productivity of the entire soil/plant system, there has been very little study into soil biology. However we do know that a diverse range of creatures and microbes contribute to what is living soil including:
• Macro-fauna such as earthworms, slugs, nematodes, termites and earth-mites
• Micro-flora including a range of varieties of soil fungi, molds, yeasts and algae
• Micro-fauna including many types of bacteria and protozoa in soil
• Other microbes such as actinomycetes which are in between bacteria and algae and break down tough organic material even under tough conditions
The weight of all these critters in a healthy living soil combined is as much as that of the livestock that grazes above the surface! They are integral to a healthy soil system that supports healthy plant growth.
What is living soil contributing to productivity?
Soil life works in beneficial relationship to plants, both directly and indirectly. Consider these examples:
• Worms good for soil:
Earthworms benefit soil by bringing surface nutrient materials into the soil where they can be accessed to feed the soil ecosystem.
They make use of low grade wastes and excrete and recycle them as nutrient rich worm castings. These castings also have a high capacity to bind and hold soil nutrients in a colloidal (non-soluble) state.
The slime-lined tunnels they make create channels for the movement of air and water through the soil.
• Soil fungi are amazing:
Have you ever lifted up a rock and seen a delicate network of filaments and threads lacing the soil underneath? These are the hyphae of soil fungi. Some types of fungi live symbiotically with plants.
They attach to plant roots and take in sugars that plants are able to make from photosynthesis of sunlight.
In return the fungi reach out with their long hyphae and scout the surrounding area for nutrients that the plant needs. It’s amazing that the presence of symbiotic fungi can increase the availability to plants of some nutrients by nine-fold!
• Soil bacteria are tops:
There are many types of bacteria in soil that perform life enhancing and unique services that benefit plants. One that is well-known is nitrogen fixation.
Nitrogen (N) fixing bacteria have the ability to grab and make use of N from the very air. Some species have a symbiotic relationship with particular plants where they make this N available to those plants in little nodes that form on the plants’ roots especially for this purpose.
• Soil algae are essential:
Soil algae are capable of photosynthesis. So like plants, they can convert sunlight into carbohydrates and sugars. They have an important role to play in working symbiotically with fungi to form a skin of lichen to protect soils that are too degraded to support higher plant life.
• Soil microbe complexes are cool:
In addition, complexes of soil microbes work on grosser rock and mineral complexes to break it down so that it becomes available as essential minerals to the wider soil/plant ecosystem. In a similar way they also break down gross organic materials and convert them to useful nutrients.
These complexes build up the humus and colloidal organic material in the soil and hold soil particles together in crumbs that provide plant accessible nutrients and create pores for the penetration of water and air into the soil.
• Soil life adds life:
The only reason existence can resist the universal trend towards disorder and disassembly (entropy) is because of life. Life re-uses, recycles and restores itself from the spent disarray of dead matter.
In soil this is particularly striking. The life in soil makes use of dead organic material and exhaled atmospheric gases to rebuild itself. It deposits the results into a bank that enriches the soil.
The action of soil organisms in living soil under ideal conditions is to convert organic wastes into humus. Humus provides good structure and available plant nutrients to soils. Humus is dark brown so soil color is a good indicator of its organic matter content. High humus, dark soils have:
• High fertility
• Low erosion potential
• High available Nitrogen
• Good aeration
Because soil life activity tends to be concentrated in the top layer of the soil profile, soil is usually darkest at the surface, becoming progressively lighter with depth.
You can check on the balance of the account by measuring the amount of organic matter in your soil. Ideally the soil is 3% or more organic material.
The organic matter has several functions: acting as a buffer to prevent changes in pH; absorbing and retaining moisture in the soil; and holding onto free nutrients, that might otherwise be washed out of the system, until plants need them (“soil cation exchange capacity”).
What About Harmful Soil Life?
While normally only a very small part of soil life, harmful varieties of fungi, nematodes and macro-fauna may proliferate and cause problems when the soil system is stressed and out of balance.
Meeting the Needs of Soil Life
Apart from very specialized creatures, most life on Earth – from bacteria to humans – has these same basic needs in common:
Water is the basis to all life on Earth. The soil ecosystem will only function at peak productivity if adequate moisture is available to support cell function within its biota.
Because of the integral relationship between plant health and soil health, when you feed the soil you feed the plants. So what does soil life need? The same nutrients that we need – proteins, carbohydrates and essential minerals and trace nutrients.
A rarely appreciated fact is that both plants and soil critters need air! Well structured soils provide this air via soil pores that exist around small clumps of soil held together by soil life. Such soils will have a crumb-like feel to them. Sustainable soil structure management promotes soil life as the key to maintaining healthy soil structure.
All life has an acceptable range of pH and temperature within which constitutes a comfortable environment in which they can function at their optimum. If conditions become too hot or cold, too acidic or alkaline, life energy is compromised or if extreme, extinguished. This is the basis of the disinfecting qualities of strongly alkaline substances such as bleach, designed to kill life.
Knowing what is living soil’s ideal conditions and ensuring they are met allows you to optimize the productivity of your small farm system.