There are 2 things that I instinctively do when I arrive at an unknown piece of land. I verify and test my water sources and look at the historical use of it. And I then start observing and analysing the soil health on the farm. This gives me an indication of the kind of productivity I can expect from the land and what my input must be to be sustainable. Since I started this routine, the soil food web has intrigued me far beyond what I thought could be possible. It is your number one asset on your farm, no matter what you farm with or what farm activity you want to persue. Before you even think of bringing in the very expensive technology that comes with precision farming today, go back to the basics of your soil life. You wont be dissapointed.

What is the Soil Food Web?

The Soil Food Web refers to the community of organisms living all or part of their lives in the soil, interacting with one another in a complex network of relationships. This intricate system comprises bacteria, fungi, protozoa, nematodes, arthropods, and other microorganisms, as well as larger creatures like earthworms. These organisms, in their myriad interactions, play vital roles in decomposing organic matter, cycling nutrients, improving soil structure, enhancing water retention, and controlling pests. They support each other in various ways: for instance, bacteria might break down organic matter, releasing nutrients that benefit plants, while protozoa might feed on these bacteria, releasing excess nitrogen that is then available for plant uptake. Originating from the continuous evolution of life in soil over millions of years, the concept of the Soil Food Web gained prominence in the latter half of the 20th century, particularly through the work of researchers like Dr. Elaine Ingham, who have emphasized the importance of understanding and nurturing this web for sustainable and regenerative agriculture.

A Deeper dive into soil’s Microbial Marvels

Soil Bacteria

Bacteria, though minuscule, have an oversized impact on soil health. Some, like the Azotobacter, are free-living nitrogen fixers, turning atmospheric nitrogen into forms plant can use. Others, like the Actinomycetes, give the soil its characteristic earthy smell and play a role in decomposing thougher organic substances.

Fungi

Beyond the common mushrooms, the realm of fungi is vast. Arbuscular mycorrhizal fungi penetrate plant roots, creating a symbiotic relationship where plants provide sugars and the fungi offer water and nutrients. Saprophytic fungi, meanwhile, break down dead organic matter, recycling vital nutrients.

Protozoa

While they may feed on bacteria, protozoa play a role in maintaining a balanced microbial ecosystem. Their activities ensure that the soil doesn’t get overrun by bacterial populations, and in the process, they release nutrients in forms plants can assimilate.

Nematodes

Contrary to the notion that all nematodes are plant pests, many are actually beneficial. Predatory nematodes can keep pest populations in check, and decomposer nematodes help break down organic matter.

Other Micoorganisms

The micro-arhropods, although not microscopic, play roles in aerating the soil and breaking down organic materials. Algae, on the other hand, can be involved in binding soil particles and even in nitrogen fixation.

The Interconnectedness of Soil Life

These microbes and microorganisms don’t operate in isolation. The soil food web is a complex, intertwined network of feeding relationships, where the waste of one organism becomes the food for another and where disturbances in one link can reverberate through the entire chain. This intricate dance ensures that nutrients are cycle efficiently, soil structure is maintained and plants find a supportive environment to thive in.

Why Soil Life is the cornerstone of Agriculture

In essence, healthy soil is the lifeblood of a farm. The nutritional quality of the crops, the yield, the resilience of the plants to diseases and even the flavor of the produce can trace their roots back to the condition of the soil. If the soil is teeming with beneficial microbes, if it’s well aerated and if it’s rich in organic matter then the plants above ground will undoubtedly flourish.

What is the connection between poor soil health and disease?

Poorly nourished soil can have profound implications for plant health, particularly in making plants more susceptible to diseases. It can set up a cascade of vulnerabilities that pathogens are all too eager to exploit. Let there be no question that improved plant immunity improves yield and thus income. And the opposite is also true. Here is a detailed explanation as to why:

Imbalance of Essential Nutrients:

Healthy soil provides plants with the essential nutrients they require for growth. In poorly nourished soil, there’s often an imbalance of lack of these vital nutrients. Without proper nutrition, plants can’t develop the neccessary cellular structures or metabolic pathways to support healthy growth. This physiological stress can make plants more vulnerable to pathogens.

Weakened Plant Defense Mechanisms:

Plants have natural defense mechanisms to ward off diseases. These defenses range from physical barriers like thicker cell walls or waxy cuticles to the production of antimicrobial compounds. When plants are malnourished, their ability to muster these defenses is compromised.

Compromised Root Systems:

Healthy soil supports the development of robust root systems. In contrast, poorly nourished soil can lead to stunted or malformed roots. A weak root system not only limits the plant’s ability to uptake nutrients but also becomes an easy target for soil-borne pathogens.

Direct Support for Pathogens:

Soil that is out of balance in terms of nutrients can sometimes directly support the growth of pathogens. An excess of certain nutrients might fuel the rapid multiplication of harmful microbes.

Disruption of the Soil Food Web:

Healthy soil is not just about nutrients, it’s also about the complex web of microorganisms that is named the soil food web. These organisms play roles in suppressing harmful pathogens. For instance, certain beneficial bacteria and fungi form symbiotic relationships with plant roots, protecting them from pathogenic microbes. When the soil is poorly nourished, this balance can be disrupted and thus allowing harmful pathogens to proliferate.

Reduced Microbial Diversity:

Microbial diversity is a sign of soil health. A diverse microbial community can compete with, inhibit or even consume potential pathogens and thus reducing the chances of disease. Poorly nourished soils often have reduced microbial diversity, removing this natural protective barrier.

Stressed Plants emits signals:

Research has shown that plants under stress, including nutritional stress, emit specific signals. Some of these might be volatile organic compounds or exudates from roots. These signals can attract pests and pathogens.

Poor soil structure:

Poorly nourished soil often has comprised physical properties. It might have poor aeration, leading to conditions that favor anaerobic pathogens. Or it might retain too much moisture, promoting fungi that thrive in wet conditions.

Embarking on a Soil Health assessment journey

Soil Testing

Beyond basic pH and nutrient profiles, advanced soil tests can now provide insights into microbial populations and offering a window into the soil’s biological health.

Observation

Regularly walk your fields. Look for signs of soil erotion, surface crusting or poor water infiltration. Often, these are indicators of underlying soil health issues. Walking your field could be the best time spent on your farm.

Use of Compost and Organic Matter

Well-decomposed compost introduces not just nutrients but also beneficial microbes into the soil. It’s like giving your soil a probiotic boost.

Minimize Tillage

Tilling can disrupt the soil structure and harm the microbial communities. Consider no-till or reduced till farming.

Cover cropping

Cover crops, like rye of clover, can prevent soil erotion, suppress weeds, and even fix atmospheric nitrogen. They act as a living mulch, supporting soil health even when main crops aren’t in season.

Diverse planting

Monocultures can be hard on soil. Planting diverse crops or practicing crop rotation can prevent the buildup of pests and diseases and can promote a balanced soil ecosystem.

Deepening your Soil Knowledge

Elaine Ingham’s Soil Food Web Course:

This is a masterclass in soil biology. Learn the relationships between different soil organisms and how to harness their power for better farming. You learn how to help farmers restore their soil biology, increase their profits and grow food in harmony with nature. This could be an excellent new career opportunity and to be part of a new movement.

Book: “Dirt: The erosian of Civilizations” by David R. Montgomery

This book beautifully captures the history of soil management and its impact on civilizations.

USDA’s Soil Biology Primer:

An authoritative guide on soil biology, with detailed sections on various microbial groups.

Documentary: “Kiss the Ground”

Narrated by Woody Harrelson, this documentary paints a compelling picture of how regenerating the world’s soils can impact climate change, water scarcity and food security.

Wrapping up

From the humble bacteria to the intricate fungi, from the tiny protozoa to the minute nematodes, the soil beneath us is alive and buzzing with activity. By recognizing, respecting and nurturing this life, farmers can tap into nature’s wisdom, ensureing sustainable, productive and harmonious agriculture.