Growing your fertiliser management skills

08 July 2016

Fertiliser is, for many producers, the single biggest on-farm investment they make each year.

How to get the greatest return from that investment is a key element in running a profitable grazing enterprise.

To help producers hone their skills, MLA is running several Fertiliser Decision-Making Workshops (part funded through Making More from Sheep and More Beef from Pastures) in northern NSW this month, presented by Dr Lewis Kahn, of Agricultural Information and Monitoring Services.

“As part of the workshops we’ll be looking at how different pasture options and identifying priority areas of the farm influence the fertiliser plan," Lewis said.

With a focus on practicality, Lewis recommends producers don’t overwhelm themselves with science but start with the basics – use a soil test to identify limiting nutrients and form short and longer term goals based on the results.

“The key limiting factors, in order of importance, are phosphorus, sulphur, potassium and pH for the damaging role acidity plays by increasing the solubility of aluminium in the soil,” Lewis said.

“Following that, organic carbon content, which is a key indicator of the impacts of land and grazing management.”

A range of tests are available for each of the trace elements.

“It’s important producers compare the results with the critical levels specific to each test as they do differ depending on which test is used,” Lewis said.

The critical values of plant-available nutrients in the soil (the recommended levels producers should be aiming for) are included in soil test results but some interpretation is often required.

“For example, the critical range of an Olsen test for available phosphorus in soil is 15-20 mg/kg but that critical range is most applicable for temperate pastures with reasonable legume content such as clovers which have a higher phosphorus requirement,” Lewis said.

More information: David Brown T: 0439 448 159 E:  


25 July – Armidale Bowling Club
26 July – Glen Innes Bowling Club


$148 per business (limit two participants)
To register visit

Resources to help with fertiliser decision making

Visit The Five Easy Steps phosphorus tool and booklet Visit More Beef from Pastures at
Visit Making More from Sheep at

Back to News

Join myMLA today

One username and password for key integrity and information Systems (LPA/NVD, NLIS, MSA & LDL).

A personalised online dashboard that provides news, weather, events and R&D tools relevant to you.

Customised market information and analysis.

Learn more about myMLA

myMLA Sign Up

Already registered for myMLA?

Sign in here