What is Living Soil?
Soil is so much more than dirt. Soil is a living ecosystem—a large community of living organisms linked together through nutrient cycles and energy flows. According to agricultural professor Dr. Higa, there are only four types of soils: Disease Inducing, Disease-Resistant, Zymogenic or Nutrient-sharing soils , and Nutrient - Synthesizing soil or Living Soils.
By observing simple clues about your soil, you will be able to identify what type of soil you have and take simple steps to create healthy soil, and enjoy greater yields from your plants.
STANDARD SOIL CLASSIFICATIONS
Before we dive into Dr Higa's soil classifications let's review some of the most common known soil classifications: "sandy", "clay", or "loamy". These classification help you understand drainage, nutrient availability, and what things you need to do, to amend the soil.
Sandy soils on are usually low in nutrients and drain and dry out very quickly. Clay soils are tight colloidal materials that have difficulty in draining. Clay soils contain lots of nutrients that are difficult for plants to access. Loamy soils, on the other hand, have good drainage, while retaining some moisture and they have a good amount of nutrients for plant growth.
Standard soil classification_soil texture
Another way soil is classified is by the pH, acidic or basis (alkaline). Soils tend to have various ranges in pH. The ideal soil pH for growing conditions is close to neutral, or close to 7.
In this article we introduce another classification, this one by soil microorganisms. The importance of microbes in soil science is being studied at great length as people begin to realize the connections between microbes and soil structure, nutrient availability, and plant disease.
DR. HIGA'S SOIL CLASSIFICATIONS
In Dr. Teruo Higa book Agricultural Utilization of Microorganisms For Environmental Conservation (only available in Japanese), he identifies four types of soils: Disease Inducing soil, Disease-Suppressive soil, Zymogenic soil, and Synthetic soil.
1. DISEASE-INDUCING SOILS
These soils tend to have a high percentage of fusarium. These soils have been poorly managed, tend to be compacted, drain poorly and support the growth of putrefactive microbes. Due to the high populations of putrefactive bacteria, they tend to put off foul odors such as ammonia from manures or high nitrogen fertilizers. These soils are conducive to pests, disease, and root rot and erode easily as there are little to no beneficial soil microbial communities to improve the soil structure. This is a very common classification for poorly managed agricultural soils that use high amounts of chemical fertilizers.
2. DISEASE-RESISTANT SOILS
These soils contain lots of soil microbial communities. Most of these microorganisms will be beneficial microorganisms including penicillium, Trichoderma, and Streptomyces genus. The texture is crumbly, where water can penetrate the soil easily.There is a low incidence of soil borne diseases in this soil, and plant yields are high. Due to high populations of beneficial microorganisms, the soil does not have any foul odors.
3. ZYMOGENIC or NUTRIENT-SHARING SOILS
The use of EM in various ways and forms introduces the fermentation pathway of organic-matter recycling. These soils tend to be dominated with fermentative microorganisms such as lactic acid bacteria and yeasts. Fermentation creates zymogens or enzymes, and a host of other beneficial substances which serve as food and substrates for other beneficial microorganisms. Populations of plant pathogens are low and disease suppression is high. Both population density and species diversity of beneficial microorganisms increase, including both aerobic types and beneficial anaerobic types (facultative anaerobic or fermentation types).
Earthworms and other soil micro-fauna increase even further in numbers, species diversity and activity. The soil starts to become a living soil. The soil structure is significantly improved and water penetration is even. Unavailable nutrients become available to plants for increased plant health. Microbial metabolites such as amino acids, polysaccharides, vitamins, bacteriocins, plant hormones, etc. are present. The soil is becoming more aerobic, teaming with life and bio-available nutrients for plants. Crop yields will be higher on these fields than on disease-suppressive soils.
4. NUTRIENT - SYNTHESIZING SOILS
"Nutrient Synthetic" microbes begin to dominate this soil. Unlike the meaning of "synthetic" when used for fertilizer or chemicals. This does not mean a "fake" or "manufactured" soil. It means a soil where things are synthesized or made. The soil naturally provides its own fertility from residues and natural processes, such as nitrogen-fixation by free-living and legume-symbiotic microorganisms. These microbes include algae, photosynthetic bacteria, and nitrogen-fixing bacteria. These are fusarium wilt suppressive soils as fusarium has a difficult time producing a strong population. Microbial metabolites are very high and Dr. Higa refers to this soil as being a "bacteria-cleansing type soil" and a natural biological control for soil borne pathogens such as blight.
HOW TO CHANGE YOUR SOILS HEALTH
This classification makes it fairly easy to identify soil microbe makeup by odors and incidence of pests and disease without going through the expense of taking soil samples and sending them to a lab.
To transition from disease-inducing soils to synthetic soils, populations of beneficial microbes need to be encouraged through proper management techniques and repeated microbial inoculation. The goal is to make soils teaming with beneficial microbial life. This will result in less disease, healthier plants, better drainage, and less pest damage.
Increasing beneficial microbial populations for increased plant health and increase disease suppression can be easy to do with a few basics.
- Maintain regular applications of EM-1® Microbial Inoculant. Dilute 1 oz of EM-1 to 1 gallon of water and water weekly.
- Add high-quality organic matter such as homemade compost or your food waste pre-compost.
- Foliar feed with EM-1® Microbial Inoculant. (1 oz to 1 gallon dilution)
- Use all natural, low-impact fertilizers only when needed.
- Use cover crops to add nutrients, even in your home garden.
- Practice crop rotation, even in your home garden. Some plants such as tomato and peppers are more susceptible to fungal pathogens and switching where things are planted can help.
- Be patient! Soil in poor condition can take time to transition to healthy, fertile soil.