Soil biology is the mediator of life on Earth. It is the function of the biological systems acting as the “gut” of plants. In the soil-- bacteria, fungi, yeasts, protozoa and nematodes act as microbes in the gut biome to solubilize, sequester and digest the minerals from the sand, silt, clay, rocks, and crop residues into plant available nutrition. This is referred to as nutrient cycling and in symbiosis with plants, these microbes are critical for carbon cycling also.
The challenge with most conventional agricultural management is the soil biological system, the “gut”, has largely been ignored. The wrath of herbicides, insecticides, fungicides, soluble fertilizers and tillage have left soils void of some of these microscopic soil managers. Without them, growers are left to chemistry only paradigms that only function until the soluble nutrients are farmed out of the soil. Crop quality suffers without soil biology, soil health, and plant health.
Perhaps some of the most eye-opening information gathered from reading and listening to various educators and growers has been regarding the value of improving biological systems in soils. After planting the trees in the research farm, we side dressed with compost and inoculums. We then began a regiment of applying microbes extracted from vermicompost and from the soil in oak hammocks beneath wild citrus trees. This was done on a regular basis to continue inoculating more biology and specific families of microbes into the soil and onto the foliage of the trees. More recently bioavailable fertilizers and bio stimulants, primarily microbial produced organic acids including citric, lactic, malic etc. were added as a food source in a variety of ways to “feed the herd”.
This thought of building up the tree’s health through biology has been reinforced in a recent article in the Florida Citrus Industry magazine. In their California Corner section written by Len Wilcox, Carolyn Roper, an associate professor of plant pathology at UC Riverside is spotlighted for her work “studying bacteria that are naturally part of the microbial flora living in and on citrus trees. She discovered that one of them, cladosporol, kills the bacteria (CLas) that causes HLB.”
As our understanding of many of the “-cides” used in agriculture increased, it became clear how devastating these can be to the microbes. To address this, we have virtually eliminated all forms of insecticides and fungicides so as to not compromise the biodiversity that has been built.
“Interestingly, we didn’t find sting nematodes (which I’m pretty sure were there when you just planted)…, but mostly spiral nematodes, which are plant-parasitic nematodes, but tend to cause little damage. High counts for the non-parasitic nematodes which makes for a pretty healthy looking nematode population overall.”
Dr. Johan Desaeger, Nematologist UF/IFAS (4/13/21)
Wilcox, Len. “Citrus Day Updates Growers on UC Research.” Citrus Industry Magazine, 13 Feb. 2020, citrusindustry.net/2020/02/13/citrus-day-updates-growers-on-uc-research/.