1. Joan Harrison Saskatchewan Waste Reduction Council
Value of Compost
Joan Harrison
Saskatchewan Waste Reduction Council

2. Why is compost valuable?
Mature compost is fast food for soil.
It is a mixture of soil microbes and slow to break down organic materials on their way to becoming humus.
Dirt + Compost= Soil
Soil keeps the earth green and us fed!

3. Why bother to make compost?
Composting reduces the weight and volume of materials (50% or more).
You can handle many different types of materials in one system.
The end product is moveable and can be placed where needed.
Weed seeds and plant disease organisms are killed if the there is a prolonged heating phase.

4. Benefits of compost use
Biological
Chemical
Physical

5. Biological
Boosts beneficial bacteria and fungi populations in the soil
Helps prevent plant diseases – the beneficial microbes out compete the problem ones.
Bacteria
Fungi

6. Chemical
Compost acts as a slow release fertilizer. Most of the nutrients are stored in the bodies of the microbes and are released as wastes by larger organisms that eat them.
The slow to degrade ‘humus’ material can hold onto positively charged nutrients like ammonium (a plant useable form of nitrogen).

7. Physical Compost improves soil’s Water and air holding ability
Structure—easier to till or dig while still having soil particles hold together in small clumps

8. Main Uses Soil amendment
Lawn and golf course establishment and maintenance
Revegetating ditches
Part of potting soil mix
Mulch
Compost tea

9. Soil Amendment Incorporate up to 2” (5cm) into cultivated topsoil.
Most common use for compost.
Incorporate up to 2” (5cm) into cultivated topsoil.
Use to enrich soil in specific planting holes for transplants or trees.

10. Lawns, sports fields and Golf courses
Use compost as a soil amendment when lawns or greens are established
Used as a top dressing in established areas

11. Revegetating ditches
Compost and seed mixtures are sprayed on the dirt surface of ditches and steep slopes.
Can be very effective in establishing fast growth.
Texas: 8 months from application to picture of vegetated ditch

12. Potting soil mix Use mature, unsterilized compost
Helps prevent damping off
Use as approx. ¼ of mix
Compost/soil recipe collection at

13. Compost as Mulch
Coarse woody composts can be applied as surface mulches around trees and shrubs.

14. Simple Compost Tea Compost, mesh bag, dechlorinated water
Steep for 30 minutes, use soon
Tea has water soluble nutrients and antibiotics but few microbes
Use to water plants
Can be made in small or large volumes

15. Aerated Compost Tea Microbes extracted from compost
Populations grown out in aerated water with carefully chosen foods
‘tea’ is brewed in aerated brewer for hours
Sprayed on soil or plant material within 4-6 hours of completed brewing
Complex process but can be very helpful to renew soil microbes or prevent plant diseases.

16. Sample Commercial Brewers
5 gallon KIS brewer
55 gallon KIS brewer

17. Compost Extractors
Extracts microbes from compost but does not enlarge population
Allows microbes to be sprayed onto plant material
Avoids some potential problems with pathogens
Microbes in compost= microbes in solution

18. End