Soil Biology

Plants are one of the most successful forms of life on earth, despite their inability to move about. Since they can’t flee inhospitable conditions, they have evolved numerous physical and biochemical coping mechanisms, enabling their own pollination and seed dispersals, combating variations in climatic conditions, deploying herbivore deterrents, creating barriers to pathogen invasions, and mitigating biotic and abiotic stresses.

Primary metabolites are involved in nutrition and the basic essential metabolic processes inside the plant. Secondary plant metabolites (SMs) help the plant adapt to changing conditions. Secondary metabolites may also inhibit the growth of competitor plants (allelopathy). Pigments (such as terpenoid carotenes, phenolics, and flavonoids) color flowers and, together with terpene and phenolic odors, attract pollinators. It makes sense for growers to promote the production of secondary metabolites to naturally make the plant more “bulletproof.”

The DTN Fertilizer Index, a weekly survey of more than 300 retailer prices, showed dry urea averaging $873 per ton in the first week of December 2021. With 920 pounds of nitrogen provided to a crop from each ton of urea, that’s $0.95 per pound of nitrogen. With liquid UAN-32 fertilizer priced at $661 per ton and 640 pounds of nitrogen available from each ton, that’s $1.03 per pound of nitrogen.

These prices don’t seem to have any chance of declining, but there are viable options for reducing synthetic fertilizer costs by incorporating biological products into your crop program. The integration of biological products can deliver a greater ROI by reducing the cost of inputs and increasing quality crop yields.

Today’s biofertilizer market is $1.2 billion to $1.5 billion. Biologicals are projected to have a growth rate that’s two to three times faster than the traditional crop protection market. Bio-controls and bio-stimulants will have global sales of more than $15 billion by 2027!

I'm proud to introduce From the Ground Up, a book comprised of five years of essays, organized by topic or category, about leading-edge agricultural practices. Since 2016, Andaman Ag has been sharing research in twice a month newsletters to educate the agricultural...

Many of the biological farming practices that we are just now implementing today were very much a part of the landscape as far back as 12,000 years ago. Climate change at the end of the last glaciation produced thick forest soils. Over thousands of years the soil grew several feet thick depending on the region. Soil erosion began only after the introduction of the plow.

The ancient Greeks and Romans knew that manure spread on fields helped crop production. Early Arabic civilizations collected written knowledge about farming complementing nature. By 1815, England was importing bones from around the world, as bone meal had been recognized as a benefit to agriculture. This included many human bones, from the Empire’s brutal colonial wars. Bird droppings, known by the Spanish name guano, became popular fertilizers in the U.S. in the 1800s. Darwin discovered that worms not only helped make soil, but they also helped move it. Francis Chaboussou, an agronomist at the French National Institute of Agricultural Research, in 1985 wrote “Healthy Crops: A New Agricultural Revolution.” In reviewing numerous studies stretching over nearly 50 years, he demonstrated that the nutrient balance of crops affects their susceptibility to pests and disease, and increases in diseases were tied to heavy nitrogen fertilization.

Mycoremediation, sometimes referred to as fungi remediation or mushroom remediation, uses fungi instead of bacteria to break down waste. Mycoremediation can be an economical and effective strategy to degrade various recalcitrant, persistent and toxic pollutants like polyaromatic hydrocarbons, antibiotics, herbicides, insecticides, antifungal drugs, algal bloom, cyanotoxins, detergents, heavy metals, and plastic.

Fungi consume organic debris that no other organism we know about will, and they create soil. They can be used in filtration systems, and in fact fungi mycelium are being released throughout burn zones in California to trap toxic waste before it reaches our waterways and to accelerate the recovery of the burn areas. Mycelium can help to structurally bind together particles, which slows runoff and helps to keep soil in place. Some fungi are so tolerant of toxicity that they even grow on the site of the Chernobyl power plant.

Overindulgence in synthetic fertilizers, especially nitrates, can weaken plants and expose them to greater disease problems. Applications of products like calcium ammonium nitrate, or CAN17, kill the soil biology and set up the plants for a host of problems including downy mildew and soil-borne diseases like fusarium, phytophthora, etc. Soil-borne diseases are among the most destructive threats to crop production. The intensive use of pesticides further depletes soil biology. Yet for the last century, food production has heavily relied on chemical controls for the management of pathogens and pests.

Our drought continues to challenge our daily farming practices. Finding new and advanced ways that can save water can add up. When we flush our irrigation lines or sand filters there’s a tremendous waste of water. By reducing this practice and making it more efficient, we can save money. In addition, spending labor dollars on cleaning filters, screens, regulators, etc. is a less productive task than other priorities on the farm. I’ve mentioned our bio-catalyst product in previous newsletters but thought it was particularly important this season given the high mineral content of our water in drought conditions. As we’re avid promoters of soil health, the product must enhance soil biology versus destroy it.

I think the easiest way to think about soil biology is to think about our own gut microbiome. As defined by molecular biologist Joshua Lederberg, the gut biome is the totality of microorganisms — bacteria, viruses, protozoa, and fungi — and their collective genetic material present in the gastrointestinal tract (GIT). Hey, wait a minute, that sounds like a soil profile! Furthermore, when we have a broken or impaired GIT, it impacts our total health. This is no different from how poor soil health impacts the total health of the plant. It’s really that simple.

There is considerable discussion in the market about new regulations coming out of the California Department of Food and Agriculture requiring less use of nitrogen on crops. While this can be disturbing news for many growers, the fact is there are a host of ways to get more from less in nitrogen applications, and we’ve been doing it for years.

When plants are exposed to environmental stresses like drought and elevated temperatures, they produce reactive oxygen species (ROS) in response. This is problematic, as these excited ROS molecules cause the oxidation of cellular biomolecules such as nucleic acids, proteins and lipids, and they eventually destroy the cellular structure. Simply put, the plant begins to break down. However, when plants start to accumulate ROS, they respond by producing significant secondary metabolites to counter the ROS and head off the breakdown. Secondary metabolites are organic compounds which are not primarily involved in the plant development but accomplish specific functions under specified situations, for example, stress conditions.