Modern traditional farming practices that incorporate deep tillage destroy earthworms and their habitat. Tilling lowers soil moisture, reduces surface plant residue, and outright kills soil organisms including earthworms and protozoa.
In the short term, tilling in crop plant residues accelerates the decomposition process of soil organic matter. This leads to excess carbon dioxide and nitrous oxide emissions as microorganisms mineralize more soil organic carbon.
When there is an ample food supply, microorganisms multiply rapidly. But active microorganisms have a short life span, on average just 12 hours in undisturbed soil. Most soil organisms don’t live that long and become prey to larger single-celled organisms.
Farm management practices that include tilling disrupt natural soil nutrient cycles. This increases risk factors such as soil compaction, soil erosion, and infiltration capacity. In other words, loss of topsoil and damage from floods and drought.
Synthetic inputs have negative impacts on all soil organisms, including protozoa and earthworms. Insecticides are toxic to earthworms and cause “…immobility, rigidity and also show a significant effect on biomass reduction, growth, and reproduction by disturbing various physiological activities…”(1)
Although the intent is to only affect targeted pests with pesticides and insecticides, the reality is the entire ecosystem becomes contaminated. Often, modern traditional farming techniques use fumigation as a preventative measure, believing it is better to kill off the pathogenic microorganisms before they begin to hurt crop production. But do pathogenic microorganisms always decrease? Are ‘cides a short-term solution that won’t hold up in the long term?
This chemical contamination and the resulting change in soil pH cause adverse reactions across the entire soil food web. Most soil microorganisms and earthworms are unable to survive both tillage and the chemical ecosystem change caused by synthetic inputs.
Without the aid of living microorganisms, soil becomes dead dirt, leading to land degradation and possible desertification. But there is a way to farm that maintains, and even increases, the beneficial populations of earthworms, protozoa, and other microorganisms.
Pesticide residuals change the microbial diversity, biochemical reactions, and accumulation of toxins over time. Soil organisms ingest inputs and if it doesn’t kill them it often changes their morphology.
There’s always the chance that an increased bio-concentration of pesticides will impact the mammals (including humans) who eat plants grown in contaminated soil.
In a National Library of Medicine article written in 2022 the author stated “One of the fundamental determinants of our health is the food we eat. ..the risks associated with chemical contaminants are severely under-researched.” (2)
The Impact of Regenerative Farming and Ranching On Soil Health
Soil health starts with living beneficial soil organisms. Farm practices that include no-till and cover crops create hospitable environments for earthworms and protozoa, among other microorganisms. Living critters means you have better water infiltration, fewer pest problems, and improved plant growth.
The Benefits of Earthworm Burrows
Some earthworm tunnels go deep through hardpan and into the subsoil. Stormwater infiltration rates are higher so drought and flood aren’t as difficult on your farm or ranch. Your operation is more resilient.
Their tunnels act as natural drainage systems, allowing rainwater to penetrate the soil, and reducing the risk of erosion or waterlogging. Water soaking into the ground results in better crop production and higher nutrient levels. When water infiltrates through earthworm tunnels it becomes rich with plant-available nutrients.
Earthworm castings are rich in nitrogen, phosphorus, and other micronutrients essential for plant growth. Their castings also have a stable structure that improves soil aggregation and tilth.
Other microorganisms are stimulated by the activities of earthworms. They provide food, as well as prey on, single-celled organisms in the soil. But all this activity is only possible when there is the right amount of food, at the right time.
This is also appropriate for protozoa and other microorganisms. Too much food and they multiply too fast, too little and they starve or go into a resting phase until conditions are right. Why should you care about protozoa?
Protozoa – Premier Soil Nutrient Cyclers
Earthworms alone are an unbalanced food web. When protozoa feed on bacteria, fungi, and other protozoa they release unneeded nutrients back into the soil in plant-available forms. The nitrogen that was locked up in bacteria is released by protozoa as ammonium. And because the majority of bacteria (their prey) are in the rhizosphere (plant root zone), ammonium is secreted near plant root hairs for plant nutrient uptake.
Protozoa don’t just prey on bacteria, although that’s a primary part of their diet. They also prey on fungi and other protozoa. Their actions regulate the population and diversity of microorganisms in the soil, preventing any one species from dominating or depleting soil resources.
Pathogens don’t have a chance on farms or ranches with a balanced soil food web. Protozoa suppress pathogens by competing with them for food and space. They also directly consume pathogens or their spores. This reduces the risk of plant disease and improves plant health.
Agriculture Can Be Part of the Climate Crisis Solution
Farm practices that incorporate cover crops and crop rotation, as well as no-till, have higher soil organic matter. The carbon cycle is foundational for all living things and it starts with organic matter.
The more complex the aboveground biomass the more diverse the underground microbial population. Mixed cover crops create root structures that impact different layers of the soil structure. Perennial and annual covers, along with crop rotations, lead to less topsoil loss through wind and water erosion and more beneficial populations in the soil food web.
Microorganisms are constantly dying and being replaced by new ones, creating a dynamic and diverse soil community. Earthworms and protozoa are essential members of that community, performing many functions such as decomposing organic matter, cycling nutrients, suppressing pathogens, and enhancing plant growth.
By benefiting the soil food web, sustainable agriculture also benefits the environment and human well-being. Farming or ranching management practices can help regulate the climate, water cycles, and biodiversity, and provide food security, health, and a good livelihood.
To find out how your farm or ranch could be a part of the climate crisis solution contact our team at STBiologicals.com.
