Sum14-04 K x Mouldboard Ploughing


To investigate the residual response of potassium rates applied pre and post mouldboard ploughing in 2014 to a rotation of wheat 2014, barley 2015 and canola 2016.

For further details contact your local Area Manager or the Summit Field Research Team

Table 1: Soil Analysis
Fig 1: Yields for 3 years of trial.
Fig 2: Compound yield 2014-2016

There was a positive yield response to K application in each season, although yield increase was progressively less in subsequent seasons and crops.
Applying K post mouldboarding had a yield advantage in 2014 and 2015; although by 2016 there was a yield advantage to K applied pre mouldboard.
The highly vigorous, deep rooting canola crop of 2016 was perhaps able to more readily access the K applied pre and buried by the mouldboard in 2014.

Pooled average K response for all timings indicated much less of a response to K in 2016 compared to 2014 and 2015.
This suggests that applied K has largely been used or leached out of the root zone since application in 2014.