Farmers from across the Riverine Plains cropping belt were challenged by the practicalities of building soil carbon at a workshop and farm visits sponsored by the Murray Catchment Management Authority and GRDC, which was held in Mulwala on 31 August 2011.
Thirty farmers from the Riverine Plains group heard Dr Clive Kirkby from CSIRO explain the concept of growing soil humus as a “crop” to increase their economic productivity under cereals and in a mixed cropping/pasture rotation.
Dr Kirkby has conducted trials investigating ways to accelerate the breakdown of stubble for many years and advised that his research has shown that some incorporation of the stubble to give greater contact with the soil and soil organisms, builds up the level of organic matter in the soil, which sequesters carbon.
He also pointed out that nutrients and microbes drive carbon sequestration, so the levels of nitrogen, phosphorous and sulphur in the soil are critical and sulphur levels in cropping paddocks may well be a limiting factor.
The group then visited two farms to see first hand the issues of putting the theory into practice. At Lake Rowan they looked at a trial conducted in conjunction with Broken Landcare Network, using pasture cropping to build groundcover and root penetration in a heavy soil with clay subsoil.
At Youanmite, the group saw the effect of converting to biological farming and incorporation of stubbles in crops of wheat and field peas, using a Lemken multi-disc, and discussed the need to take a more long term view of building productivity under this system.
Some members of the Riverine Plains group are hoping to begin field trials using nutrients and tillage methods to increase organic matter by increasing the effectiveness of stubble breakdown.
Comments
Post has no comments.