A teaspoon of healthy soil contains billions of microbes.
Microbes feed the plants, strengthen their roots, and increase their yields. A plant sends signals to attract the microbes it needs at any given moment. In chemical-free agriculture, there is a good marriage between plants and microbes. In a complex, self-regulating system, plants and microbes work harmoniously, nourishing each other.
The chemistry of a plant sends specific nutrients to attract microbes to strengthen its immunity. The plant is not only capable of diagnosing its needs, it also makes its own medicine. When chemicals interfere with self-regulation, the plants are weakened. What should you do to improve the health of your plants? Build your microbial biomass by building your soil. Soil structure is the microbial home. A couple ways to build your soil structure are composting and cover crops. The roots in the soil are home to microbes. In nature, soil is covered, not fallow. The global soil degradation and desertification affects us all.
The microbes found in soil are also found in our gut. The health of the soil impacts the nutritional value of our food and our health. The immunity of a plant impacts our own immunity. What we eat is essential to our own wellbeing. By taking care of the land and our agriculture, we are also taking care of ourselves. In this interview with Dr. Judy Fitzpatrick, microbiologist and diagnostic developer, we deepen into the importance of microbial biomass, the ratio of fungi to bacteria, plant – and human – immunity, and how to build soil
structure.
This article was featured in the April 2022 issue of Heart & Soil Magazine Rooted in Wisdom.
Click here to listen to the full interview on Heart & Soil TV.
The microbial population or microbial biomass (MB) reflects soil fertility. For over 2 million years, plants and soil microbes have worked together to create what we call fertile “soil”.
How do they work together? The plant supplies the microbes with carbon rich food. The microbes then mine the soil for the required minerals. Microbes can actually manufacture nitrogen and antibiotics that protect the plant from pathogens in return creating carbon stores that build soil structure and sequester carbon.
Like all good partners, what is good for one is good for the other, i.e., a healthy MB predicts a healthy plant. Therefore, supplying NPK directly to plants disrupts the plant microbe relationship – plants no longer feed the microbes and the MB decreases accordingly. Soils with low MB suffer from erosion, compaction, and poor structure. Sadly, this is how we have lost 50% of the earth’s soil.
Soil microbes, like all living things, need food. They need to be fed carbon and nitrogen from plants or organic matter so they can mine the minerals, P, K, Mg, Cu S etc. from the soil. If there is not enough of any nutrient, including the minerals that should be in the soil, it negatively affects the number of microbes; just as humans do not thrive when we are deficient in a critical nutrient.
Oxygen, water, and an agreeable pH and temperature are also important for soil microbes. Compacted soil is low in oxygen and microbial biomass. As soil dries, microbes die or become dormant. MB is much lower in low and high pH soils than in those that are in the neutral range. This is because most enzymes work best at neutral pH and all metabolism is enzyme dependent. MB also contracts during intense cold and heat. Plant roots require these same conditions
Microbes also need shelter to survive. Soil aggregates provide small cubbyholes that accommodate oxygen and water. It is in these areas where microbes attach themselves to be protected from predators. These predators are larger than they are; think of how little fish hide in coral. Not only are soil aggregates homes for microbes, they are homes built by microbes. The capsular material that microbes secrete to attach themselves to soil particles is long lasting. It binds the soil particles, therefore, creating aggregates that build soil structure and prevent erosion. These aggregates provide the water, oxygen and wiggle room needed by plant roots.
Furthermore, soil microbes build up carbon in the soil by producing humic matter. When microbes die, their bodies become stored carbon. This is good for microbes in the way that a savings account is good us. It is important for the soil as well because the humic matter increases soil structure. This allows more oxygen and water storage. It is also a resource that microbes can take a loan from before harvest when plant material is not being released to microbes. For too long we have relied on microbes borrowing from this humic carbon source and have released ½ of the soils stored carbon to the air as carbon dioxide. This has contributed to climate change and loss of 50% of earth’s soil. Microbes have always worked well with plants to create soil and they can help us restore exhausted soils back to fertility.
