Oftentimes, the focus in farming is on the plants above the ground, how tall they grow, how lush their leaves are or how bountiful the harvest will be. But what many farmers may not realize is that the real magic happens beneath the surface. The soil is alive with a vibrant ecosystem of organisms, both big and small, working tirelessly to create conditions perfect for healthy crops.

Why Soil Organisms Matter

Soil organisms are the backbone of healthy soil. They perform critical functions that synthetic fertilisers and chemicals  cannot replicate.

Here is why they are so important:

1. Nutrient Cycling: Soil organisms break down organic matter like dead plants and animal waste, turning them into nutrients that plants can absorb.
2. Soil Structure Improvement: Creatures like earthworms create tunnels that improve water infiltration and air circulation in the soil.
3. Pest and Disease Control: Some soil organisms protect plants by preying on harmful pests or competing with disease-causing microbes.
4. Carbon Storage: Healthy soil ecosystems store carbon, helping to mitigate climate change.

Without these tiny helpers, soils become lifeless and unproductive. With the right care, soil organisms  can turn even the most degraded land into a thriving farm.

Types of Soil Organisms and Their Functions

Soil organisms come in all shapes and sizes, including earthworms and microscopic bacteria.

Here’s a breakdown of the key players and what they do:

1. Earthworms

• Function: Earthworms are nature’s plows. They burrow through the soil, creating tunnels that improve aeration and water infiltration. They also digest organic matter, producing nutrient-rich castings that fertilize the soil.
• Benefit: Improved soil structure and nutrient availability.

2. Fungi

• Function: Fungi form vast networks of hyphae (thread-like structures) that help plants absorb water and nutrients. Some fungi, like mycorrhizae, form symbiotic relationships with plant roots.
• Benefit: Enhanced nutrient uptake and drought tolerance.

3. Bacteria

• Function: Bacteria decompose organic matter and fix nitrogen from the air, making it available to plants. Some bacteria also produce compounds that protect plants from diseases.
• Benefit: Increased soil fertility and plant health.

4. Springtails and Mites

• Function: These tiny arthropods break down organic matter into smaller pieces, making it easier for microbes to decompose.
• Benefit: Faster decomposition and nutrient cycling.

5. Millipedes and Slaters (Woodlice)

• Function: These larger decomposers feed on dead plant material, breaking it down into smaller particles.
• Benefit: Improved organic matter breakdown and soil fertility.

6. Nematodes

• Function: Some nematodes are beneficial, feeding on harmful pests and decomposing organic matter. Others can be harmful, attacking plant roots.
• Benefit: Natural pest control and nutrient cycling.

How to Support Soil Organisms on Your Farm

1. Add Organic Matter: Soil organisms feed on organic matter like compost, mulch, and crop residues. Regularly adding these materials will keep your soil ecosystem healthy.
2. Avoid Over-Tilling: Excessive tilling can destroy soil structure and harm organisms like earthworms. Use minimal tillage or no-till practices to protect them.
3. Reduce Chemical Use: Pesticides and synthetic fertilizers can kill beneficial soil organisms. Switch to organic alternatives whenever possible.
4. Practice Crop Rotation: Rotating crops helps maintain a diverse soil ecosystem, preventing the buildup of pests and diseases.
5. Keep Soil Covered: Use cover crops or mulch to protect soil from erosion and extreme temperatures, creating a stable environment for organisms.

Download the free knowledge product “Soil Organisms: Living Things in the Soil That Make Soil Strong” developed by the Namibian Organic Association & Namibia Nature Foundation

Author: Rabecca Mwila

Rabecca Mwila is a passionate advocate for sustainable agriculture and environmental stewardship. With a background in climate change and communications, she has spent years telling the untold stories of the realities of climate change, environmental and climate injustices and how they affect vulnerable communities in Africa and beyond.