Growing Innovation: Issue 10, June 29, 2016
Integrating sustainable soil health practices into commercial vegetable farming
As part of the Soil Wealth initiative, Hort Innovation has announced the findings of a project to integrate sustainable soil health practices into commercial vegetable farming operations which looked at ‘softer’ soil management practices such as reduced tillage, cover crops, compost and controlled traffic.
The trials at Mulyan Farms, in Cowra NSW, provided commercial scale validation that ‘softer’ soil management practices can be integrated into large-scale vegetable production.
The project demonstrated that combining cover cropping with controlled traffic and reduced tillage sustainably improved the soil condition, which can maintain or improve yields, and reduce input costs.
Vegetable growers in Australia mainly use conventional cultivation methods including pre-plant ripping and rotary hoeing. Aggressive cultivation is expensive and damaging to soils and is typically used to bury crop residues, relieve compaction, control weeds and prepare seed beds.
This general decline in soil condition from these energy-intensive cultivation practices, leads to reduced yield, and to reduced eating and keeping quality of leafy vegetable crops such as lettuce and baby leaf salad lines.
Integrating sustainable soil health practices into commercial vegetable production helps to reverse the decline in soil health and to maintain, or improve the productivity and profitability of vegetable enterprises.
This project studied the effect of a range of cover crops on paddocks that have been in a reduced till and controlled traffic regime since 2009. The soil quality of these paddocks had been heavily degraded from decades of intensive cultivation, and the farm owners were intent on restoring the soil quality of the land.
Working with vegetable growers Ed and James Fagan to document their soil management practices and trial new ones, the project highlighted a commercially validated and sustainable leafy vegetable production system for Australian conditions resulting in high productivity and soil restored to a sustainable condition.
Further, the project saw improved profitability and sustainability for the vegetable industry and an objective assessment of impacts of minimum tillage involving mulches, legumes and controlled traffic on productivity, soil health and carbon sequestration.
According to Gordon Rogers of Applied Horticultural Research, “The project has contributed to the knowledge base which will allow the vegetable industry to achieve the outcomes listed above. In particular, the project has provided solid evidence for the use of cover crops and reduced tillage in the vegetable production systems of western NSW, the target region for the project”.
“The trials at Mulyan Farms, Cowra NSW, have provided commercial scale validation that “softer” soil management practices can be integrated into large-scale vegetable production. For example, all varieties of cover crops produced a more profitable spinach crop, compared to a traditional fallowed system.
“Increases in profitably of 36 and 48 per cent were obtained following the legume cover crops of Morgan Field peas or Balansa clover, respectively. The project has successfully demonstrated and communicated that combining cover cropping with controlled traffic and reduced tillage will allow for sustainable improvement to the soil condition and which can maintain or improve yields, and reduce input costs”, he said.
Reduced till can deliver some significant benefits to vegetable growers, including reduced input costs, better soil health and yields as good as or better than via conventional tillage. Challenges include costs of machinery modifications and new equipment, paddock rotation planning and the possibility of new pest species. In this five-minute video, Ed Fagan explains why he is using reduced till and some of the great results he’s getting – while saving money.
An eight-minute video feature Ed and James Fagan explaining how to implement reduced tillage and cover crops, what machinery to use, the synergies with cover cropping and timing of spraying out cover crops, incorporation and sowing of a cash crop. After 12 months the video has received 884 views.
Download Soil Wealth factsheets here:
- Carbon storage in vegetable soils
- Reduced till in vegetable production
- Nitrous oxide emissions from vegetable soils