Managing micronutrient deficiencies in cropping systems of eastern Australia
This project will address these increasing concerns and speculation in a three pronged approach for all six micronutrients named in the tender (Mn, Zn, Cu, B, Mo, Fe) for all cropping regions in Australia except for those in WA. This project will liaise closely with a separate bid being prepared by Dr Ross Brennan of DAFWA to address issues in WA specifically, should that bid be successful. This project will produce clear guidelines for management of micronutrient disorders for the major crops in the southern and northern regions of GRDC based on existing knowledge which has been objectively tested for its relevance to modern cropping systems and modernised for current technologies and economic circumstances where necessary.
IPNI-2014-AUS-020
2016 Annual Interpretive Summary
During 2016, another group of ten micronutrient field experiments were undertaken across southeastern Australia predominantly on wheat. There were three copper (Cu) trials, two zinc (Zn) trials, one boron (B) trial, and three manganese (Mn) trials. An additional trial with Cu applied to field beans was abandoned due to excessively wet conditions. Soil and plant tissue sampling has been completed along with final yield analyses, although the collated results will not be available until April 2017 as the project reaches its conclusion.
Prior to 2016, the project undertook five Zn trials, three Cu trials, and four Mn trials. The comparisons within each experiment aimed to investigate the sources, rates and timings, and as well as the placement of micronutrients for optimal wheat production. Even though the sites were screened for low soil micronutrient concentrations and the history of the sites were evaluated, few significant yield responses have been seen. The overall results from these experiments showed one small but significant response to applied Zn, one spectacular response to Cu, and no responses to Mn. The preliminary conclusions are that critical soil concentrations for Zn are below 0.2 mg/kg DTPA-extractable Zn, critical concentration for Cu are below 0.2 mg/kg DTPA-extractable Cu and the concentration for Mn are unable to be assessed from this work. In general, the wheat tissue critical concentration seen were within the ranges proposed by Reuter and Robinson.