Compost and Composting

Compost and Composting


Composting animal manures and agricultural waste is not a new process, but is one which has regained focus around the world. This is because environmental issues are forcing the reduction of use of raw manure and we have rediscovered that there are good scientific reasons why compost is a better form of nutrients for our agricultural crops. The use of composted manures in sustainable agricultural systems results in good yields and equivalent or improved quality produce.

The compost process is the combination of materials (manures, straw, green waste etc) that are then digested by naturally occurring microbes into a material that is available to plants for use as a nutrient source. The process relies on the right combination of carbon (wood, straw) and nitrogen (animal manures), the right moisture content and an ability to blend and aerate the materials.

By closely managing the composting process, we develop high levels of humus and consequently the compost has an ability to hold nutrients and water reducing the leaching of nutrients, particularly nitrogen, during the growing of crops.

Ref: Sustainable Farming Solutions:

Compost recipe:

45% Grove Processing Waste

45% Chipped grove prunings / spoiled grass hay or cereal straw

10% Animal Manure (Cow, sheep, pig or chicken)

Plus 1 tonne water / tonne of dry compost mix

It will be necessary to turn the compost. Over a period of 12 weeks it would need to be turned 4-6 times, plus plenty of mixing during preparation. I would suggest 12 weeks is a good time period, but 6 weeks with 3 turns could produce something useful. Going longer is never a problem for the compost, it just gets better over time.

How much compost?

According to John Barton, there’s unlikely to be a response with less than 5 m3/ha. 100 m3/ha would be the upper end of a positive response, but is probably uneconomic. 20 m3/ha is probably a good balance. For a traditionally spaced 6m X 8m (208 trees / has) this equates to around 100 lit / tree, or around 1 wheelbarrow / tree.

How often?

Annually is good, but every two years is also fine. If you’re applying compost for the soil health benefits, as opposed to nutrition supply (which would need to be yearly), sometimes you can go even longer if you combine it with good all round management. If you were a purely conventional grower, with little ground cover and lots of chemical fertiliser, I’d say do it every year  to help repair the soil from the year’s wear and tear. If you’re right into regenerative farming and have living plant cover all year round and organic sources of nutrients, then after a first application of good quality compost it might not be necessary for years afterwards.

Useful soils / compost references:

The following is a list of useful references provided as background and preparation for the 2021 Healthy Soils & Productive Groves field days.

Soils and soil moisture:

Interpreting soil and leaf analysis test reports:

Compost and composting:

General references on olive growing:

Links to some useful soil and grove management presentations:

AOA 2020 Virtual Conference presentations:

Click on the links below to access the conference session recordings. You can choose to watch the session in full or per presentation. Viewing the full session will provide access to the Q&As, which in itself is invaluable content.

Passwords are required to access the videos. You should have received an email with the relevant passwords recently if you had registered to attend the Virtual Conference. If not, please email

  • Soil management, presented by John Barton and Andy Gulliver

Dynamic presentations to assist delegates in understanding soil biology and improve soil health. Topics include composting, soil carbon, the soil biome, and how to harness them in your grove to better manage tree nutrition, available water, and tree health to improve grove productivity.

AOA 2021 grove management video presentations

  • Andrew Taylor: (Pendleton Estate) Principles of Canopy Management
  • Tree Pruning Video (7.5 mins):
  • Jon Lockwood & Tass Peters (OneTemp) with Mel Hollock at Nangkita Grove
  • Weather Stations, Remote Sensing and Automation Video – Nangkita Grove / Peninsula Providore, SA (14 min)
  • Peter Wadewitz (Peats Soils)
  • Making Compost Video (7 min)