Compost vs. Manure

Composting Garden Waste: Benefits, Drawbacks, and Comparison to Animal Manure Inputs

Composting garden waste is the process of aerobically decomposing plant residues—like leaves, grass clippings, and vegetable kitchen scraps—into a nutrient-rich amendment for soil. It closes the nutrient loop in your garden while diverting organic material from landfills.

Benefits of Composting Garden Waste

• Keeps organic waste out of landfills, cutting methane emissions by promoting aerobic decomposition.

• Turns garden waste into a living soil amendment that boosts plant health and growth.

• Saves money by reducing or eliminating the need for purchased manure and premium soil mixes.

• Enhances soil biodiversity, supporting beneficial microbes, fungi, and insects.

• Improves soil structure, water retention, and erosion resistance, leading to stronger root systems.

Drawbacks of Composting Garden Waste

• Can attract pests if greens-to-browns balance or aeration is mismanaged.

• May produce off-odors when too wet or rich in nitrogenous scraps.

• Requires regular attention—turning, moisture checks, and feedstock balancing—to keep the process on track.

• Takes up space.

• Sensitive to weather extremes: rain can waterlog a pile, and cold snaps slow decomposition.

Composting Styles: Compost Pile vs Lasagne Gardening

Compost Pile

A traditional compost pile involves alternating “green” (nitrogen-rich) and “brown” (carbon-rich) layers in an open or enclosed bin. Regular turning introduces oxygen, accelerating breakdown and producing finished compost in as little as 2–4 months under hot-compost conditions. This method gives you control over temperature, moisture, and pest management.

Lasagne Gardening

Lasagne gardening (or sheet composting) is a no-dig, no-turn approach that builds beds by layering cardboard or newspaper, then alternating brown and green materials directly on the ground or in a raised-bed frame. Over time (typically six months), the layers decompose into a nutrient-dense growing medium with minimal effort and fewer weeds. You can plant immediately by topping the sheeted layers with a thin layer of finished compost.  However, newspaper and Cardboard are not permitted inputs in our gardens.  Straw and dried tree leaves are a suitable substitute for cardboard and newspaper.

Compost vs Animal Manure as Soil Inputs

Compost and animal manures both enrich soil but differ in stability, nutrient release, and risk profile:

• Stability and Pathogens

  • Compost is a stabilized product with low pathogen and weed-seed risk.

  • Raw manure may carry pathogens and viable weed seeds unless properly aged or composted.

• Nutrient Release

  • Compost releases roughly 60% of its nutrients in the first year as organic matter continues to break down.

  • Manure typically releases closer to 30% in year one, with higher immediate nitrogen availability but greater leaching potential.

• Soil Structure

  • Compost excels at improving soil aggregation, water retention, and aeration.

  • Manure adds organic matter but can compact soil if over-applied when fresh.

Typical NPK of Garden Compost and Manure Comparison

Input Type	Nitrogen (N %)	Phosphorus (P %)	Potassium (K %)
Average Compost	1.0	1.0	1.0
Cow Manure	0.6	0.4	0.5
Chicken Manure	1.1	0.8	0.5
Sheep Manure	0.7	0.3	0.9

Average compost NPK is roughly 1-1-1, reflecting its balanced, slow-release nature. Manures vary by animal source and tend to deliver higher nitrogen percentages but carry more management considerations.

Composting garden waste offers an eco-friendly, cost-effective way to boost soil health, sequester carbon, and improve plant vigour. Traditional compost piles and lasagne gardens each have their place depending on space, effort, and timing. When compared to animal manures, compost is more stable, safer, and better at building long-term soil structure, while manures can supply a quick-acting nitrogen punch if handled properly. Both amendments have strengths—combining them can deliver the best of steady nutrient release, improved soil texture, and robust microbial activity.

Temperature Plays an Important Role in the Composting Process

Decomposition occurs most rapidly between 43C and 71C. Within two weeks, a properly made compost pile will reach these temperatures. At this time, you will notice the pile settling which is a good sign that the pile is working properly.

Now you must decide how you want to compost. Do you want to add to the pile or just let it continue as is? If you want to add to the pile, you can do so throughout the growing season and into the winter months. As you add fresh material, you will need to turn and water the pile more often. Monitoring the temperature and turning whenever the pile temperature dips below 43C keeps the pile active at its highest level, and you will have the fastest breakdown. This means turning the pile more often, like once a week.

There are different types of aerobic bacteria that work in composting piles. Their population will vary according to the pile temperature.

Psychrophylic Bacteria work in the lowest temperature range. They are most active at 13C and will work in the pile if the initial pile temperature is less than 21C. They give off a small amount of heat in comparison to other types of bacteria. The heat they produce is enough however, to help build the pile temperature to the point where another set of bacteria, Mesophilic Bacteria, start to take over.

Mesophilic Bacteria rapidly decompose organic matter, producing acids, carbon dioxide and heat. Its working temperature range is generally between 21C and 38C. When the pile temperature rises above 38C, the Mesophilic Bacteria begin to die off or move to the outer part of the heap. They are replaced by heat-loving Thermophilic Bacteria.

Thermophilic Bacteria thrive at temperatures ranging from 45C to 71C. Thermophilic Bacteria continue the decomposition process, raising the pile temperature 54 to 71 degrees C, where it usually stabilizes. Unless a pile is constantly fed new materials and turned at strategic times, the higher temperatures typically last no more than 3 to 5 days. Thermophilic Bacteria use up too much of the degradable materials to sustain their population for any length of time. As the Thermophilic Bacteria decline and the temperature of the pile gradually cools off, the Mesophilic Bacteria once again become dominant. The Mesophilic Bacteria will then consume the remaining organic material with the help of other organisms.

To determine where the pile is at it is advisable to use an accurate compost thermometer.

This section on compost temperature was authored by:

Duane Friend

Extension Educator, Natural Resources Management, University of Illinois Extension

Martha Smith

Extension Educator, Horticulture, University of Illinois Extension

Holly Johnson

Waste Recovery Specialist, University of Wisconsin Extension

Sources:  homesandgardens.com, thespruce.com, farmonaut.com, almostzerowaste.com, allotment-garden.org