The use of specialised cover crops which are grown, mulched and incorporated into the soil prior to cropping is known as ‘biofumigation’.
The fumigation effect is caused by plant compounds called cyanogenic glucosides or glucosinolates. These are found in Brassica species such as cabbages, radish and cauliflowers; it’s the odour that you smell as you drive through the Lockyer Valley!
When these are broken down, these naturally occurring compounds from the biofumigant plants are effective in suppressing soil-borne pests, diseases and weeds. They can be particularly effective in getting the jump on nematodes. Other benefits of using biofumigant cover crops is the addition of rich organic matter and a consequential improvement of soil structure and fertility.
There are over 200 glucosinolates commonly found in Brassica species and work is currently underway in the region to identify more accurately, which species are most effective for specific pests and diseases. The Department of Agriculture and Fisheries have recently established a trial of different biofumigant crop types at the Research Facility in Bundaberg, and are also doing an on-farm demonstration with some local growers. They have developed a poster on their trial findings to date – download here.
For further reading on the benefits of incorporating a biofumigant cover crop into your vegetable crop rotation, download this factsheet which has been developed through the Soil Wealth Program.
- Biofumigation Fact Sheet – Soil Wealth and Integrated Crop Protection (VG16078) – http://www.soilwealth.com.au
- Queensland Department of Agriculture and Fisheries, 2018.
Post written by Michelle Haase – Vegetable Industry Development Officer (VegNET) with Bundaberg Fruit & Vegetable Growers – www.bfvg.com.au. Funding for the VegNET National Vegetable Extension Network program is from Hort Innovation with vegetable grower levies and funding by the Australian Government.