Envision supporting the billions of microorganisms present in the top 6 inches of soil of the acreage you farm. What would that look like?
The idea is to “support plants in manifesting their full potential,” said Dan Kittredge, founder of the Bionutrient Food Association.
Farmers can learn how to do that by looking to nature, Kittredge said in a recent meeting of the Virginia Association for Biological Farming.
For example, in nature, plants never receive fertilizer. Instead, they have the ability to feed themselves because of a symbiosis with soil microbes.
Therefore, in Kittredge’s view, soil microbes must be the focus for plants to flourish. A healthy soil microbiome can reduce agricultural inputs, he said.
There are five requirements in order to have a healthy soil microbiome: air, water, organic matter, minerals and diversity of microbes.
Soil microbes are aerobic organisms that need oxygen to breathe. Soil compaction is equivalent to asphyxiation for them. Kittredge said farmers can perform a simple compaction test on soil simply by seeing to what depth they can reach down into their soil.
Keeping living roots in soil for as many months of the year as possible also helps to aerate soil. This can be achieved by cover cropping any fallow field.
Keeping the soil covered also helps with water retention. If a cover crop isn’t possible, at least use a mulch.
Even in irrigated fields, Kittredge said farmers should considers the safeguards nature has against drought.
One of these safeguards is the principle of tidal force, which is often only associated with the ocean. However, this force also effects groundwater, which rises and lowers with the tides daily.
Using a pond to stockpile water uphill can also create the gravitational force to raise the water table, Kittredge said.
Organic matter is the main food source for soil microbes, so it is important to feed microbes 12 months of the year, Kittredge said.
This can be achieved through cover cropping or allowing residual plant matter to remain on fields.
Soil mineral levels can be monitored through regular soil testing, and many different amendments are available.
Even if all of these requirements are achieved, it is still possible that a field could lack microbial diversity because of frequent tillage and pesticide use.
If this is the case, a farmer may want to inoculate seed to reintroduce soil microbes to the land.
Kittredge’s organization, the Bionutrient Food Association, is studying how agricultural practices affect nutrient density.
The first step is to build a database and establish minimum and maximum nutrient potentials for different crops. From there, the causes of the variation can be investigated.
The Bionutrient Food Association is working with laboratories in Michigan, California and France that receive sample crops and samples of the soil they grew in. Participants in the study also answer a questionnaire about their agricultural practices.
“Nutrition should be the objective,” Kittredge said.