Benefits to Sharing Soil Test Calibration Data: Australian Experience.

Soil testing remains a valuable tool for assessing fertilizer requirements of crops. The data that supports the interpretation of soil test value and crop response are generally fragmented, sometimes held corporately or privately, and applied using a range of strategies. The Better Fertilizer Decisions for Crops (BFDC) project developed and now curates a national database of 5662 trial treatment series undertaken at 2724 sites. These span five decades of 1780 N, 2380 P, 365 K and 286 S experiments with soil test values and crop responses on cereal, pulse and oilseed crops. Minimum data requirements from past, present and future experiments for inclusion are soil type, a recognized soil test and that an estimate of crop yield with nil fertilizer and the maximum yield could be obtained.

The BFDC has provided traceability of critical soil test ranges, including the publication of these in refereed journals. The use of the “Interrogator” allows users to target specific soil type, crop and nutrient combinations. This provides substantiation of recommendations made to growers.

The project also provided an audit of the information available, and developed a set of protocols for data, including meta-data, that is required from future experiments. The gaps identified from this audit is now being addressed by targeted nutrient rate experiments.

This core part of this project was supported by the Grains Research Corporation and virtually all the state government agricultural agencies, fertilizer companies and private researchers. This group was drawn from all states and so provided a formal platform for collaboration, with a large amount of time and effort contributed by the participants. With a declining cohort of researchers dispersed across agencies, this aspect alone was a major benefit as it facilitated data sharing in an unprecedented way. The financial support that enabled the platform development then allowed participants to enter and rate data from various sources – including the grey literature and unpublished field experiments. Without this platform, these data would have been lost.

This database is now in its second iteration, with on-line registration and training, data entry by users and the incorporation of a protocol to analyse long-term fertilizer experiments. This project has enabled data to be preserved, accessed, interpreted and added to, so supporting the evidence-based approach to soil test interpretation. The authors commend this approach to other precincts where current and legacy data awaits capture and systematic interrogation, and to identify knowledge gaps to guide future research.