Better Fertilizer Decisions for Crops

This project concluded in 2012 with the completion and launch of the on-line interrogator tool (http://www.bfdc.com.au), which allows trained participants to investigate the response of grain crops to N, P, K, and S from over 5,000 field experiments in Australia. The outputs from the on-line database are soil test critical values that will allow advisers to check and substantiate their recommendations based on these values. The project results will also be published in a special edition of Crop and Pasture Science during 2013.

Using the trial data, soil test critical values can be derived online through the Better Fertiliser Decisions for Cropping Interrogator tool. A trained and registered user is able to filter the data by attributes that include crop type, soil type, soil test, yield, and growing season rainfall. Fertilizer response criteria are obtained by fitting an inverted plot of the natural logarithm for the soil test value and the arcsin of the square root of relative yield. From these curves, critical fertilizer response values and confidence limits are determined for 80, 90, and 95% of relative yield. The fertilizer response curve is presented to the user with the critical values for each of these relative yields. The outcome of the project is to provide easy access to field experiments on soil test and crop response, as well as a repository for future nutrition research. Protocols for experimental design, data handling, and recording of experimental metadata were also developed, and these will provide guidance for future research. ANZ-09