nor education 10 min read

By TerraCare

Natural Organic Reduction Soil vs. Cremation Ashes: What Families Actually Receive (colloquially referred to as human composting)

Direct Answer

The most fundamental difference between natural organic reduction soil and cremation ashes is what they are: one is living, the other is mineral. Through natural organic reduction (NOR) — the process legally known as terramation — a person’s remains are transformed over several weeks into approximately one-half cubic yard of nutrient-rich Regenerative Living Soil™, capable of supporting plant life and returning carbon to the earth. Cremation, by contrast, produces three to nine pounds of processed bone minerals — calcium phosphate and calcium carbonate — that are sterile, highly alkaline, and not directly beneficial to most plants without amendment. Both represent a meaningful physical return; what they give back to the earth differs considerably.

What is the difference between terramation soil and cremation ashes?

Terramation produces roughly one-half cubic yard of biologically active soil rich in nitrogen, phosphorus, potassium, and carbon — material that supports plant growth and sequesters carbon. Cremation produces 3–9 lbs of sterile calcium phosphate ash with a pH of 10–12.5 that contains no organic matter and can actually inhibit plant growth in concentrated amounts. One is a living soil amendment; the other is an inert mineral residue.

  • Terramation yields approximately one-half cubic yard of biologically active, nutrient-rich Regenerative Living Soil™ — compared to 3–9 lbs of sterile ash from cremation.
  • Cremation ash has a pH of 10–12.5 (similar to bleach) and sodium levels 200–2,000x what most plants tolerate, making it harmful to plants in quantity.
  • NOR soil sequesters carbon in stable organic matter; cremation converts body carbon directly to CO2 during combustion.
  • Terramation soil can go directly into a garden bed; cremation ash requires significant amendment before most plant use.
  • Families receive meaningful choices with NOR soil — garden amendment, memorial tree planting, conservation donation — that aren't possible with a small urn of ash.

Two Very Different Returns

When families begin comparing disposition options, one of the most personal questions is also one of the most concrete: What will we actually receive?

Terramation and flame cremation each produce something tangible — but the physical nature, volume, and ecological character of what families receive are profoundly different. The sections below compare them directly across the dimensions that matter most.

1. What It Is Physically

Terramation (natural organic reduction soil)

Through natural organic reduction, a person’s remains — along with organic materials like wood chips, straw, and alfalfa — are placed in a vessel where microbial activity, warmth, and carefully managed airflow facilitate transformation. Washington State’s RCW 68.04.310 defines natural organic reduction as “the contained, accelerated conversion of human remains to soil.” That definition is precise: what emerges is soil — dark, earthy, and biologically active.

Families typically receive approximately one-half cubic yard of Regenerative Living Soil. That is a substantial physical volume — roughly the size of a wheelbarrow load, often delivered in a bag or sturdy box. The material looks and smells like rich garden soil: dark brown, textured, with the characteristic earthy scent of healthy ground.

Cremation ashes (cremated remains)

Flame cremation exposes the body to temperatures of 1,400–1,800°F for approximately two to three hours, reducing soft tissue and bone to mineral fragments. What remains is colloquially called “ashes,” but the term is slightly imprecise. Cremated remains are primarily processed bone minerals — not ash in the agricultural sense. They are gray to off-white in color, coarse and granular in texture, and completely sterile.

An adult’s cremated remains typically weigh between four and six pounds, with a range of roughly three to nine pounds depending on body size. They occupy approximately 200 cubic inches — enough to fill a standard urn, typically presented in a sealed plastic bag inside a temporary container or urn of the family’s choosing.

The contrast in scale is significant: one-half cubic yard of terramation soil versus a small urn of mineral fragments.

2. Nutrient Content and Biological Activity

Terramation soil

The soil produced through natural organic reduction is biologically active. The NOR process generates heat that sterilizes pathogens while preserving beneficial microbial communities, leaving a final product rich in the core building blocks of plant nutrition: nitrogen, phosphorus, potassium, and organic carbon.

Washington State’s regulatory framework under WAC Chapter 246-500 requires NOR facilities to test the final soil product for physical contaminants, heavy metals, and pathogens — the same standards applied to finished compost. The result is a material that genuinely functions as soil amendment: it feeds microbes, supports root systems, and participates in the carbon cycle.

The nutrient density of terramation soil is examined in depth in our article on NOR soil nutrient density, which covers the nitrogen, phosphorus, and potassium profile compared to standard topsoil.

Cremated remains

Cremated remains are primarily calcium phosphate (roughly 47.5% phosphate and 23.3% calcium by composition), with smaller amounts of sulfate, potassium, sodium, and chloride. They contain no organic matter, no microbial life, and no carbon compounds available to plants.

While plants do need calcium and phosphorus, the issue with cremated remains is not simply what they contain — it is what else they contain, and at what pH. Cremated remains are highly alkaline, with a pH typically between 10 and 12.5. For context, that is in the range of bleach. At that alkalinity level, most plant roots cannot absorb the nutrients already present in the soil. The sodium content in cremated remains compounds this problem: sodium levels can be 200 to 2,000 times higher than what most plants tolerate, limiting water uptake and disrupting soil microbiology.

One study found that 90% of seedlings died when planted in soil that contained untreated cremated remains. In small quantities, scattered widely, cremated remains pose minimal harm. Used in concentrated quantities in a garden bed, they can inhibit growth rather than support it.

Cremated remains can be used in gardens with proper amendment — mixing with compost, organic matter, and lime-neutralizing agents — but this requires intentional effort. They are not inherently garden-ready.

3. Environmental Character

Terramation soil

The soil produced by natural organic reduction is a carbon-sequestering material. The organic carbon in a person’s body — which in flame cremation would be released as CO₂ — is instead integrated into the soil structure, where it contributes to long-term carbon storage. Evergrove, an NOR provider, cites estimates that the nutrient-rich earth produced through terramation can sequester approximately 100–500 kg of CO₂ depending on how the soil is applied.

The terramation process itself is estimated to produce less than 50 kg of CO₂ — a fraction of the roughly 535 pounds (approximately 243 kg) of CO₂ that a single flame cremation generates.

In addition to carbon, the NOR process avoids the mercury emissions that arise when dental amalgam fillings are vaporized during flame cremation, along with the nitrogen oxides, sulfur dioxide, and particulate matter produced by high-temperature combustion.

Cremated remains

Cremated remains themselves are inert and produce no further emissions once the process is complete. They do not decompose, leach toxins, or interact with the surrounding environment in most typical scattering or urn scenarios.

However, the environmental cost of cremation occurs during the process: temperatures maintained at 1,400–1,800°F, typically fueled by natural gas, for one to three hours per cremation. The emissions occur upstream of what families receive, not in the remains themselves.

For a deeper comparison of emissions data across disposition methods, see our article on CO₂ and environmental comparisons for terramation, cremation, and burial.

4. What Families Can Do With It

Terramation soil

The scale and biological activity of terramation soil opens a wide range of meaningful uses:

  • Home garden: Incorporate into an existing garden bed as a rich soil amendment. Because the soil is processed and tested to meet regulatory standards, it is appropriate for use around plants, trees, and flowers.
  • Memorial tree planting: Place at the root zone of a newly planted tree as a living tribute that grows over years and decades.
  • Scatter on meaningful land: With appropriate legal permissions (which vary by jurisdiction), families may scatter terramation soil on private property, conservation lands, or other meaningful places. Rules around scattering soil differ from rules around scattering cremated remains, so families should consult with their NOR provider.
  • Donate to conservation: Several NOR providers, including The Natural Funeral, offer families the option to donate any portion of soil they do not wish to keep — directing it to organic flower farms, forest restoration projects, or land conservation partners.

Because families receive approximately one-half cubic yard, many choose to split the soil: keeping a portion for a personal garden or memorial planting, and donating the remainder.

Cremated remains

Cremated remains offer their own range of meaningful options, shaped by their small volume and durable, mineral character:

  • Scatter: Scattering on land, at sea, or from the air is the most common choice. Most jurisdictions permit scattering on private land with the landowner’s permission and at sea beyond a certain distance from shore. Public lands have varying rules.
  • Urn: Keeping cremated remains in an urn at home or in a columbarium niche remains a common choice for families who want a fixed, permanent place for remembrance.
  • Memorial jewelry and keepsakes: A small portion of cremated remains can be incorporated into glass art, jewelry, or other memorial objects — options that are not feasible with the large volume of terramation soil.
  • Reef balls: Cremated remains can be incorporated into artificial reef structures placed in the ocean, contributing to marine habitat.
  • Space scattering: Several services offer to carry a small portion of cremated remains on a spacecraft for a memorial flight.

The smaller volume of cremated remains is, for some families, a practical advantage — it is more portable, more easily divided among family members, and compatible with smaller living spaces.

Natural organic reduction is currently legal in 14 states: Washington, Colorado, Oregon, Vermont, California, New York, Nevada, Arizona, Maryland, Delaware, Minnesota, Maine, Georgia, and New Jersey. Availability of active NOR services varies within those states; California, New York, and New Jersey have passed legislation but services are not yet operational in all areas. Families outside these states may need to consider transportation of remains to a state where NOR is available.

Flame cremation is available nationwide and is currently chosen by approximately 63.4% of American families, according to the National Funeral Directors Association’s 2025 statistics.

Making the Decision

Choosing between terramation and cremation involves more than logistics — it involves what a family believes about where a person goes after death, and what role, if any, the body plays in the world that continues.

Terramation offers a physical return to the living earth: soil that can grow things, feed ecosystems, and sequester carbon. Cremation offers a mineral permanence — a durable, portable remainder that families can keep close, scatter widely, or memorialize in other forms.

Understanding the difference between natural organic reduction soil and cremation ashes — not just symbolically but physically — gives families the foundation to make a decision that genuinely reflects their values.

For more on how terramation soil compares to standard compost and what makes it distinctively nutrient-rich, see Regenerative Living Soil vs. Compost (and what sets it apart). For a broader introduction to the terramation process itself, visit our guide to how terramation works. For a full overview of terramation’s environmental credentials, visit our terramation soil quality and environmental impact hub.

Ready to Learn More?

Learn more about terramation services near you

Ready to explore terramation? Contact TerraCare Partners

Sources

  1. Washington State Legislature — RCW 68.04.310: “Natural organic reduction” definition. https://app.leg.wa.gov/RCW/default.aspx?cite=68.04.310

  2. Washington State Legislature — WAC Chapter 246-500: Natural Organic Reduction facility regulations, including soil testing and contaminant standards. https://app.leg.wa.gov/wac/default.aspx?cite=246-500&full=true

  3. Washington State Legislature — SB 5001 (2019): Bill authorizing natural organic reduction in Washington State, effective May 1, 2020. https://app.leg.wa.gov/billsummary?BillNumber=5001&Year=2019

  4. The Natural Funeral — Natural Organic Reduction (Body Composting): Process description, soil yield (~1/2 cubic yard of Regenerative Living Soil), and family options. https://www.thenaturalfuneral.com/natural-organic-reduction-body-composting/

  5. Evergrove — Environmental Impact of Terramation: Terramation process produces less than 50 kg CO₂; soil can sequester 100–500 kg CO₂ depending on application. https://www.evergrove.life/impact

  6. cremation.green — What Are Cremation Ashes Made Of: Mineral composition (47.5% phosphate, 23.3% calcium), sodium content. Note: pH levels and seedling mortality data are from source 7 (Living Legacy Forest), not this source. https://www.cremation.green/what-are-cremation-ashes-made-of/

  7. Living Legacy Forest — Cremation Ashes Composition: Full Breakdown: Alkalinity range (pH 10–12.5), composition breakdown, and plant interaction effects. https://livinglegacyforest.com/blog/cremation-ashes-composition-full-breakdown/

  8. National Funeral Directors Association — Statistics: 2025 projected cremation rate of 63.4%; 2045 projection of 82.3%. https://nfda.org/news/statistics

  9. Wikipedia — Terramation: Overview of natural organic reduction process, legal status in 14 states, soil yield (one-half cubic yard), energy use comparison with cremation. https://en.wikipedia.org/wiki/Human_composting