The Soil Wealth ICP demonstration site at Tarwin, South Gippsland in Victoria has now completed its fourth season. Hosted by Schreurs & Sons, the trial has investigated strategies to maintain soil carbon in a clay loam greenfield site which has been converted from pasture to a vegetable production system rotation (predominately celery, leek and spinach).
To achieve this, four combinations of cover crop, minimum till and compost treatments were trialled and compared to grower standard practice and a reference site on the property. This included:
- Composting and minimum till
- Cover crop (rye grass/oat/vetch/pea mix) and cultivation
- Composting and cultivation
- Cover crop (rye grass/oat/vetch/pea mix, and faba bean) and minimum till.
Key findings and grower benefits
- 33% reduction in diesel use due to less tillage
- 50% reduction in labour cost due to less tillage
- 50% reduction in irrigation in the first six weeks of crop establishment
- 3 out of 4 combinations (treatments) showed an increase in soil carbon due to cover crops, minimum till and/or compost, compared to grower standard practice (control).
- Approximately $2,300/ha net increase in profit in the trial area.
