Why test soil for biology without genetics?

Overview of the Soil Food Web process

The Soil Food Web (SFW) process is a revolutionary approach to understanding and managing soil health that emphasizes the interconnection between all living organisms within the soil ecosystem. Developed through decades of research by Dr. Elaine Ingham, her husband Russel Ingham, and their collaborators, the Soil Food Web highlights how a healthy, biologically active soil can support plant growth, improve crop yields, and restore degraded land—all while reducing the need for chemical inputs.

At its core, the Soil Food Web is a dynamic system of interactions between microorganisms (such as bacteria, fungi, protozoa, and nematodes), larger soil fauna, plant roots, and organic matter. These organisms play critical roles in nutrient cycling, disease suppression, soil structure formation, and water retention. Rather than treating soil as an inert growing medium, the SFW process views it as a living, breathing ecosystem that thrives when its natural balance is maintained.

The Soil Food Web process provides practical tools and techniques for farmers, gardeners, and land managers to harness the power of soil biology. Key practices include using compost, compost teas, and organic amendments to foster microbial diversity and abundance. The process also incorporates soil testing and microscopy to assess the health of soil ecosystems, enabling tailored interventions to address specific challenges.

By working with nature rather than against it, the Soil Food Web process helps growers reduce their reliance on synthetic fertilizers and pesticides, improve the resilience of their crops, and contribute to long-term sustainability. This holistic approach is a cornerstone of regenerative agriculture and offers a path toward healthier soils, thriving plants, and a more sustainable future.

Applications of Simple Soil Microbiology Testing

Soil Food Web (SFW) School-style microscopy offers a practical and cost-effective way for both conventional and organic farmers to assess and manage soil health by directly observing soil biology. Here are the key applications:

Assessing Soil Health

• Identify Beneficial Microorganisms: Check for beneficial organisms such as bacteria, fungi, protozoa, and nematodes, which are essential for nutrient cycling and plant health.
• Diagnose Imbalances: Detect deficiencies or overabundances of specific groups, such as too much bacteria relative to fungi, which can indicate poor soil structure or fertility.
• Track Organic Matter Breakdown: Monitor microbial activity to understand how well organic amendments like compost or mulch are decomposing.

Compost and Compost Tea Quality Control

• Verify Microbial Diversity: Ensure compost and compost teas are biologically active and contain diverse microbes suited for their crop and soil needs.
• Avoid Harmful Pathogens: Check for potential pathogens or anaerobic conditions that could harm plants or soil.
• Optimize Application Timing: Use microscopy to identify when compost teas or extracts are at their biological peak for application.

Pest and Disease Management

• Detect Predatory Nematodes: Farmers can monitor populations of predatory nematodes that control root-feeding pests, reducing the need for chemical pesticides.
• Identify Early Pathogen Signs: Spot fungal pathogens or signs of imbalances that may lead to increased susceptibility to diseases.
• Improve Plant Defense: Ensure beneficial fungi (e.g., mycorrhizae) are present to enhance plants’ natural defenses.

Reducing Chemical Inputs

For conventional farmers, SFW microscopy can help transition to more sustainable practices by:

• Reducing Fertilizer Dependency: Understanding the nutrient cycling capabilities of soil microbes helps reduce reliance on synthetic fertilizers.
• Minimizing Herbicides and Pesticides: Healthy soil microbiology can outcompete weeds and suppress pests naturally, reducing the need for chemical inputs.
• Validating Biological Amendments: Assess the effectiveness of products like microbial inoculants or biofertilizers.

Soil Management and Regeneration

• Track Changes Over Time: Farmers can monitor soil health improvements or degradation with regular biological assessments.
• Guide Tillage Decisions: Observing fungal networks helps determine the impact of tillage and inform no-till or low-till practices.
• Tailor Crop Rotations: Use data on microbial populations to select crop rotations that promote desired microbial communities.

Enhancing Yields and Profitability

• Optimize Inputs: Save costs by applying fertilizers, compost, or biological amendments more effectively based on microbial data.
• Improve Crop Quality: Healthy soils produce higher-quality crops with better nutrient density and resilience to stress.
• Market as Sustainable: Farmers practicing SFW-based soil management can market their products as sustainable or regenerative, appealing to consumers who value environmentally friendly practices.

Educational and Certification Uses

• Training Staff: Train farm staff to use microscopy to routinely monitor soil health.
• Certification Requirements: For organic or regenerative certifications, farmers can use microscopy data as evidence of soil improvement and ecological farming practices.

Arguments for and against using SFW

It's completely natural and expected to be suspicious of anything not fully understood, let's assess the technique from both sides of the fence, for and against. 

Argument For Soil Food Web style testing

1. Cost-Effectiveness
   Soil Food Web (SFW) testing is a highly cost-effective approach compared to genetic testing. It provides actionable insights into soil biology without the high expense of DNA sequencing, making it accessible to small-scale farmers, gardeners, and land managers.
2. Focus on Functionality
   SFW testing emphasizes the ecological roles of soil organisms rather than their genetic makeup. Farmers need to know how effectively soil microbes are cycling nutrients, suppressing diseases, and improving soil structure—not necessarily their specific species or genetic identity.
3. Rapid Results for Immediate Action
   Microscopy-based SFW tests provide real-time results, enabling farmers to make quick decisions about soil amendments, compost applications, or management changes. Genetic testing often requires longer processing times, delaying actionable insights.
4. Accessible Training and Tools
   SFW testing can be performed with relatively simple tools (e.g., a microscope) and training, allowing farmers or consultants to conduct tests themselves. This democratizes access to soil biology monitoring.
5. Proven Results in Practice
   Many growers using SFW methods report significant improvements in soil health, crop yields, and pest resistance without needing genetic data. This demonstrates that understanding general biological activity can be sufficient for practical applications.

Argument Against Soil Food Web style testing

1. Lack of Specificity
   Microscopy-based SFW testing cannot identify organisms at the species or strain level, which can limit understanding. For example, some fungi or bacteria are beneficial while closely related species are pathogenic. Genetic testing provides precise identification to distinguish between these.
2. Limited Insights into Microbial Communities
   Without genetic data, it is difficult to quantify microbial diversity fully or identify rare but ecologically important organisms. This limitation may result in an incomplete understanding of the soil ecosystem.
3. Inability to Detect Non-Visual Organisms
   Many microorganisms, such as certain bacteria and archaea, are too small or lack distinguishing morphological features to be identified under a microscope. Genetic testing is necessary to detect these invisible contributors to soil health.
4. Missing Functional Insights from Gene Expression
   Genetic analysis can provide insights into microbial functions, such as nitrogen fixation, disease suppression, or organic matter decomposition, by identifying functional genes. Microscopy only reveals the presence of organisms, not their functional capabilities.
5. Potential for Misinterpretation
   Microscopy results rely heavily on the skill and experience of the tester, leading to variability in results. Genetic testing provides more consistent and objective data.

Conclusion

One of the Soil Nerd's most favourite expressions is "You can use a hammer to remove a screw, but it makes a horrible mess:". Thus, using the correct tool for the right job is important. Sure, you can test the field with the best (and most expensive) techniques but was there a return on investment? The power of this testing comes from the interchange of ideas revolving around challenges and desired states of outcome. 

We at Soil Nerd don't like to get into mud-slinging about right, wrong, correct, incorrect. We see everything as living, breathing process which involves being honest without ourselves and nature around us. The testing we offer can help top-line organic and regenerative farmers maintain that pole position. It can equally help those who struggle to regain momentum not seen in decades such as fertility, yield, quality, and profit. The SFW test is among the cheapest and fastest ways to gather data to help measure state. It's up to the farmer to decide how to interpret that information into an action plan, and that is why we are here to help.