Fertiliser Responses

Summary

All samples of clover taken for tissue testing indicated adequate levels of magnesium. Results from clover tissue tests in spring 2002 indicated that magnesium deficiency was not present in either sub or white clover at the Bruthen and Orbost sites. The same result was confirmed for the Flynn site in 2003. Results from the 2002 tests also indicated that the trace elements boron and cobalt were at low levels in the clover herbage and were the probable cause of poor vigour. As a consequence cobalt and boron nutrients were applied to all sites in 2003. The cobalt and boron additives separately and together, improved the clover content at all sites, however the best overall result was obtained when both cobalt and boron were applied to the Flynn site. This area received normal levels of winter and spring rainfall, while the other sites only received 70 percent of normal rainfall. In 2002 a lime treatment used as a topdressing treatment significantly improved clover vigour at the Orbost site where boron had been applied. This lime was subsequently shown to have a cobalt impurity.