Boron and cobalt in beef pastures - Research

Summary

The first recorded pasture responses to boron in Australia were on the Southern Tablelands of New South Wales in 1948. This was three years after the trials were established in 1946. (Jn. Aust. Inst. Ag. Sc, Sept. 1952). In part this is due to boron deficiency impacting the seed production of annual legumes and thus its density in pasture. Old top dressed paddocks that have acidified and then limed were identified as underperforming compared to more recently developed pastures on 16 beef producing properties across East Gippsland.
Results from Producer Research Support project 2002/V04 indicated that the issue was most likely due to a deficiency of boron and cobalt caused by the calcium applied in lime. These nutrients are important for the growth of legumes and the process of nitrogen fixation. Past research on legumes has identified these nutrients as likely to be deficient if in marginal supply and large amounts of calcium were applied to the soil. The observed pasture impact has been severe nitrogen deficiency caused by the inability of legumes to thrive and fix adequate levels of nitrogen thus enabling vigorous grass growth.