Water is such a big deal that it is the No. 1 reason for the decline of life on this earth that has been recorded by human beings. The animal and plant kingdoms share a “Goldilocks Principle” of being in a “just right state” (having necessary boundaries and good measures): not too little water, not too much water—more is not always better!
To get a bit technical: Soil aggregates are groups of particles that bind to each other more strongly than to neighboring particles; the space between the aggregates allows for water retention. There’s a large range in the size of the spaces and in the size of the aggregates, and these spaces provides zones through which plant roots can grow and interconnect with soil microbes, conserving their own water.
The interdependence of roots and soil microbes forms and sustains what are known as water-holding soil aggregates. This relationship is supplied and supported by the top of the plant, where energy is captured from sunlight to charge nutrients absorbed in water-soluble form by the plant’s root system in the soil. These charged nutrients create food. Plants make their own food and share a portion with the soil microbes, which, in return, supply plant roots with mineral nutrients to be charged for mutual food trust. It’s a wonderful design in nature that is self-sustaining. Do we fertilize forests?
Let’s dig further down: Soil bacteria have enzymes to decompose organic matter and parent materials that make up soil. They produce a sort of glue that helps hold soil particles together in those water-holding aggregates mentioned earlier. They store nitrogen in their bodies and release it to plants when they’re consumed by other organisms. The plant releases food that keeps the predator/prey relationships active. Biodiversity in soil is the key to maintaining these water-holding aggregates.
Now, even further: Soil fungi grow in long, threadlike structures, the length of which directly relate to the amount of aggregation in the soil. Fungi help to form aggregates by netting soil particles and building bridges between them. Certain fungi have a relationship with plant roots and colonize fresh organic matter. They’re considered to be the most important for helping with stabilizing soil particles into aggregates.
Soil bacteria and fungi both store needed plant nutrients inside their microscopic bodies until a predator eats them and releases the right amount of nutrients delivered at just the right time with no leaching to the plant’s root systems. This symbiotic relationship happens in nature when plants have freedom to be in control. We humans can assist by providing favorable environmental management practices that increase soil foodweb activities that contribute to soil’s water holding capacity. Does learning to manage the soil foodweb as a water conservation idea make good common sense?
A common soil management practice, though, is to take control of a plant’s needs by applying chemical fertilizers in amounts that hinder the process that forms soil aggregate and disrupts the sustainable relationship with microbes. Continued applications of harmful amounts of chemical fertilizers cause the water-holding capacity of soil to weaken and collapse. This requires adding more water to the plant root system due to leaching. And what ability do soils have to hold those chemical fertilizers without soil aggregates? Very little ability, so they leach with the water into our rivers and our fresh water supplies.
Now what is a solution? I like Dr. Arden B. Andersen and his book Science in Agriculture—Advanced Methods for Sustainable Farming: “A sophisticated professional farming system designed to enhance biological activity in the soil provides energy to the crop and builds internal resistance to pests and diseases.” He goes on to state, “Biological farming is a ‘best of both worlds’ mix between organic and conventional farming practices, involving careful monitoring of crops and soils to ensure production is of high quality.”
Dr. Andersen is an agricultural consultant to farmers, farm consultants, and product companies around the world. As a medical doctor, he practices full-service family medicine, integrating both conventional and complementary medicines emphasizing nutrition, diet, detoxification, and food quality/selection.If you’d be interested in hearing what I’ve been doing in the local SLO County area to increase soil aggregation, I invite you to join me on Jan. 28 for the meeting of SLO Permaculture Guild at the SLO Grange, 2880 Broad St, San Luis Obispo. At 6 p.m., there’s a potluck meal and conversation. There’s no admission charge; bring food to share. My soil foodweb talk starts at 7 p.m.
I will close my piece with this fact: SLO County faces significant water problems! As Albert Einstein said, “We cannot solve the significant problems we face at the same level of thinking we were at when we created them.”
Kevin Stitt owns Stitt Plant Care and is working on the Caltrans’ Estrella Riverbank Restoration Project for the Upper Salinas-Las Tablas Resource Conservation District in Templeton. Most recently, he accepted the See Canyon manager position of caring for and maintaining 20 acres of orchard for the Food Bank Coalition of San Luis Obispo County. Send comments to the executive editor at firstname.lastname@example.org.