IPNI Helps Australian Farmers Make Better Fertilizer Decisions

Examples output identifying phosphorus fertilizer response trials matching user-selected criteria.

When testing soil to determine fertilizer application rates, critical soil test values are used to show the likelihood of a crop response to an added nutrient. To help crop growers and advisors make better fertilizer decisions, the Australian grains industry saw a need to make the data behind soil test critical values available for cross examination.

The IPNI Australia and New Zealand program joined forces with the government and private agencies to collect and scrutinize crop responses to fertilizer nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) at different soil test values from over 6,000 trials, creating a searchable national crop nutrition database (www.bfdc.com.au).

Using the BFDC database, soil test critical values for P, K, and S were revised for both winter and summer crops in Australia, with the results published in a special issue of Crop and Pasture Science. The data has also been used by proprietary fertilizer decision support systems, accredited through the national Fertcare ® industry stewardship program.

“This has been a great project for the Australian Fertilizer industry. It provides an accessible, authoritative data set that underpins good advice on nutrient management. The industry was involved from the start and is now ensuring that the data is used consistently by Fertcare Accredited Advisors,” said Nick Drew, Head of Fertilizer Australia.

Researchers also used the database to refine critical soil test values for cereals, based on the interactions between crop rotation and soil P immobilization, help discover that cereals following canola had a higher need for P compared to cereals following pulses, and help identify that organic carbon and P buffering capacity were important in determining soil test and yield response relationships.

Gaps in the databases were also identified, such as P and K for pulse crops, and K for wheat and canola in southern Australia, with subsequent field trials taken to address these. Since its creation, the database has proved an invaluable tool for supporting responsible nutrient management in Australia. Read more about the project here. You can also learn more about the Fertcare program here.