Capeweed Control: Fix the Soil, Not Just the Weed

Can capeweed control start with rebuilding soil biology instead of simply treating the weed? Dr Mary Cole compares two neighbouring paddocks with very different capeweed pressure and explains what she believes the weed is telling us about the soil.

Then we follow the practical system — from thermal aerobic compost and temperature management to brewing aerated compost tea and getting it onto pasture without unnecessarily damaging the microbial component.

In this Farm Learning episode, Tim Thompson joins soil microbiologist and plant pathologist Dr Mary Cole in rural Victoria to look at capeweed as an indicator plant. Mary explains how soil disturbance, microbial balance and nitrogen cycling can influence the plants that dominate a pasture, and why her management focuses on changing the biological conditions beneath the pasture.

We then get practical.

Mary demonstrates how she produces thermal aerobic compost using green and woody material, manages the heating and turning process, allows the compost to mature, and then uses a relatively small amount of finished compost to produce a much larger volume of aerated compost tea.

You’ll also see:

• What Mary believes capeweed indicates about pasture soil
• Why fungal and bacterial populations matter in perennial pastures
• How thermal aerobic compost is constructed
• Why compost temperature needs to be monitored carefully
• When to turn a heating compost pile
• Why mature compost should be completely cool
• How a 1,000 L compost tea system works
• How to trial compost tea in a 20 L container
• Why aeration is important during brewing
• How Mary modifies a conventional pasture sprayer for compost tea
• Why pressure, filters and plumbing matter when applying biological products
• How rock dust is incorporated into Mary’s compost system
• The practical costs Mary calculates for producing and applying compost tea

This discussion covers capeweed control, pasture weed management, soil biology, soil microbiology, biological farming, regenerative agriculture, thermal aerobic compost, aerated compost tea, fungal-dominant soils, pasture microbes, nutrient cycling and practical biological inputs. It is particularly relevant to farmers and landholders trying to understand why weeds repeatedly return and what soil conditions may sit behind the problem.

The important question is not simply, “How do I kill capeweed?” It is also, “Why is capeweed thriving here?”

**Watch next on Farm Learning:**

• Soil biology and the rhizosphere — how microbes interact with plant roots
• Compost, compost extracts and biological inputs for farms
• Regenerative agriculture case studies showing changes in pasture and soil management

Subscribe to Farm Learning with Tim Thompson for practical agricultural education based around real farms, experienced farmers, researchers and field results.

If you have dealt with capeweed on your own property, tell us what management approach you used and what happened in the paddock.

Share this video with a farmer, contractor or landholder working through the same problem, and continue through the Farm Learning soil biology and regenerative agriculture videos for more on the system behind it.

Details

Guest: Dr Mary Cole
Location: Rural Victoria, Australia
Main topic: Capeweed and soil biology
System featured: Thermal aerobic compost and aerated compost tea
Enterprise context: Grazed pasture
Application: Pasture and farm soil biology management
Agpath Training https://agpath.com.au/education/courses-and-workshops/

#Capeweed #SoilBiology #CompostTea #RegenerativeAgriculture #biologicalfarming

00:00 Two paddocks, very different capeweed
01:03 Why weeds can be soil indicators
03:33 What capeweed may be telling you
05:25 Nitrogen, urea and soil biology
07:03 Building thermal aerobic compost
08:55 Why the compost needs turning
10:53 The critical compost temperature range
12:43 When compost is actually finished
14:29 Brewing 1,000 litres of compost tea
15:53 Making compost tea in a 20L bucket
17:19 Spraying compost tea without damaging microbes
19:02 Using rock dust in the compost
20:05 Fix the soil or just kill the weed?
21:16 What compost tea costs to apply
22:15 Do exported nutrients need replacing?
23:30 Learning more from Dr Mary Cole