Choose methods for manganese properly
Like all nutrients, manganese (Mn) can be supplied in different forms.
Research has shown that manganese is ineffective banded in a liquid stream at seeding, irrespective of whether it is banded as a sulphate, oxide or chelate.
On the other hand, foliar applications can be quite effective but responses may not be as reliable as banding manganese in a granule at seeding.
Deficient crops may need two or three foliar applications to be fully effective.
CSBP field research manager James Easton said this year CSBP had been investigating the need for manganese in trials across the State.
Some of these trials are investigating the effectiveness of manganese oxides (MnO and MnO2) to the manganese sulphate supplied in all of CSBP’s manganese products.
“Our biggest responses to manganese have been at a trial at Bolgart where there responses to 4kg of Mn/ha supplied by Agstar Manganese and Agflow Manganese, but no response to 4kg of Mn/ha supplied by the oxide (coated on to Agstar),” he said.
Plant tests showed that none of the manganese from the oxide had become available (figure 1).
At Badgingarra, plant tests indicated that yield responses were unlikely but indicated that the sulphate form (supplied by AgMn and K-Till Manganese) is more effective than oxides coated onto K-Till Extra Plus (figure 2).
“Both trials highlight the importance of using effective fertiliser sources,” Mr Easton said.
Crops using Agstar MnO2 (4kg of Mn) on the left performed better than crops with Agstar Manganese (2kg of Mn).