RESULTS of a three-year Western Dairy study at Vasse Research Station have prompted a re-think on recommended pasture application rates for potassium.
Western Dairy said last week the results could help produce more cost-effective pasture and reduce the risk of over-fertilising with potassium.
The study set out to define the minimum critical potassium level required in leaf tissue of annual and Italian ryegrass, in order to achieve 95 per cent of the plant's maximum yield.
Western Dairy's Bunbury research, development and extension hub science team proved the critical plant concentration in ryegrass is 1.5pc potassium - significantly lower than the industry standard 2pc potassium recommendation for both clover and ryegrass pastures.
Agribusiness team leader Kirk Reynolds, together with research scientists Martin Staines and Ruairi McDonnell, tabled the findings with CSBP and Summit Fertilizers.
CSBP South West district manager Reid Carter welcomed the results.
"It's great to get on-ground local research specific to the dairy industry and on our soil types in WA," Mr Carter said.
"It is paramount this work is done locally and CSBP will use these findings in its decision support tools to make fertiliser recommendations.
"We are fortunate in WA to have the calibre of these researchers working with the dairy industry and the fertiliser companies, to ensure that we are all on the same page."
Summit Fertilizer's South West manager Ralph Papalia had a similar view.
"It is great for Western Dairy to be able to provide such useful, local and relevant science and I have been using the information to inform my clients on how to better apply potassium fertilisers," Mr Papalia said.
As WA dairy farming systems have intensified, most are ryegrass dominant and so the refined recommendation is highly relevant to the industry, Mr Reynolds said.
The study followed previous local research for nitrogen and phosphorus application recommendations.
"In an industry where monitoring margins at every turn is critical to profits, the opportunity to refine potassium rates when applied to ryegrass pastures is an opportunity to reduce cost without impacting yield, or improve yield by lowering the cost of production," Mr Reynolds said.
"It is an important one-percenter and during tight times in the industry, every single one-percenter counts."
Another key finding identified that soil testing for potassium is not a reliable indicator for dry matter response in ryegrass, so dairy farmers seeking optimal ryegrass pastures management should conduct plant tissue tests to accurately assess potassium levels.