Why Organic Matter Matters for Healthy Soil and Turf

Healthy turf begins below the surface. Organic matter plays a central role in building soil that supports strong, resilient grass without relying heavily on synthetic inputs.

Organic matter (OM) plays a vital role in improving soil structure and feeding the beneficial microbes that support healthy turf. According to the USDA NRCS, “One percent of organic matter in the top six inches of soil would hold approximately 27,000 gallons of water per acre”. That’s a powerful illustration of its importance in soil health and water retention.

Understanding its value helps guide better lawn care decisions.

What Is Organic Matter

Organic matter is made up of decomposed plant and animal materials. This includes compost, roots, and microbial biomass. Over time, these materials break down and become part of the soil structure.

Benefits of Organic Matter in Soil

Boosts microbial diversity and biological activity.
Enhances the soil’s water-holding capacity.
Improves nutrient retention and availability for plants.

Improves Soil Structure

Soils with adequate organic matter are easier to work and better able to support plant growth. They resist compaction and allow roots to move more freely. This creates a stronger, more stable turf system.

Supports Water Management

Organic matter helps soil hold moisture during dry periods while also improving drainage when rainfall is heavy. This balance is critical for consistent turf performance.

Feeds Soil Life

A healthy soil ecosystem depends on microbes. Organic matter provides a steady food source for beneficial organisms that cycle nutrients and improve soil function.

Enhances Nutrient Availability

Nutrients in soil are not always immediately available to plants. Organic matter helps store and slowly release them over time, making fertility more efficient and consistent.

Box Comparison: Organic Matter vs. Water Retention

(From The Art of Balancing Soil Nutrients by William McKibben)

Imagine two boxes of air-dried soil, each weighing 100 pounds:

Box A contains soil with 2% organic matter.
Box B contains soil with 4.5% organic matter.

How much water can each box absorb before it becomes saturated?

Box A (2% OM) can hold around 45 pounds of water.
Box B (4.5% OM) can hold nearly 150 pounds of water.

Key takeaway: Even a small increase in organic matter leads to a dramatic improvement in water and nutrient retention. This relationship isn’t linear—it’s logarithmic.

Ways to build organic matter in your lawn:

Organic matter is naturally depleted over time through microbial activity and decomposition. To maintain and improve OM levels, consistent inputs are essential.

Return grass clippings after mowing – they decompose and act as a natural fertilizer, equal to one nutrient application per season.
Mow high – taller grass promotes deeper roots, and as roots age and slough off, they add organic material back into the soil.
Apply organic fertilizers and soil amendments – including humates and compost, which support microbial life and contribute organic material.

Organic matter is not a quick fix. It is a long-term investment that improves soil performance year after year, leading to stronger, more resilient turf.

✅ Want to learn how to grow organic matter in your yard?
Check out our guide: 10 Steps to an Organic Lawn.

Remember: Organic matter matters—for your lawn and the earth.