November 26, 2021

Investigating Manganese Application Strategies in Wheat

An overview of our SUM21.19 trial to date, investigating different manganese rates & chemical forms.

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Summit Area Manager, Mark Ladny (right), has helped organise this trial which has been set up at Gunwarrie, east of Frankland River and west of Cranbrook. Mark discusses trial progress with Don Pentz (left) from Gunwarrie.

The best possible manganese (Mn) application strategies in cereal crops is under investigation in the Frankland region under the watchful eyes of Summit Fertilizers Area Manager Mark Ladny.

Mark has a Mn trial at Gunwarrie. Located east of Frankland River and west of Cranbrook on a forest gravel soil type, this trial is one of a series set up by Summit this year.

SUM21.19 examines:

  • a range of Mn rates
  • Mn applied in different chemical forms
  • supplied within MAP based granules (full compound) or blended with MAP.

The trial also includes some foliar Mn applications.

Mark said Mn deficiencies can appear on a range of soils and is intensified where soil pH is either naturally alkaline (above pH 6.6 CaCl) or where the soil has been limed, improving soil pH to a mild/neutral soil acidity status.

An arial overview of SUM 21.19 at Gunwarrie, Frankland River, image taken on November 3rd 2021. The trial aims to further investigate the best manganese strategies in Kinsei wheat.

“Soil testing for Mn, while it may provide a rough guide is unreliable because Mn can be present in the soil and yet unavailable to the plant. Plant tissue tests are always the preferred method for diagnosing Mn deficiency,” said Mark.

“Mn in the soil can take on various chemical forms with availability to plants dependent on oxidation state. Manganese sulphate, as supplied in Summit Fertilizers full compound product MAP & Mn, breaks down in the soil to release Mn2+ ions. Mn2+ is the only plant bio-available form of Mn and is readily transported into root cells. Oxide forms are insoluble and unavailable.

“In any soil there will be a balance between soluble Mn2+ and insoluble Mn oxides. In alkaline soil conditions, the oxidisation of Mn2+ to unavailable Mn oxide is favoured, which explains the lack of Mn uptake in high pH soils.

“Mn is also relatively immobile in the soil, which explains why top dressed Mn is so much less effective than when this element is placed with the sowing fertiliser below the seed.

“We feel available Mn applied in seeding fertiliser has some potential advantages and may relieve the necessity to apply it as a foliar spray,” said Mark.

“Plant testing during the season has indicated increasing plant tissue Mn concentrations with increasing Mn rates in this trial. Grain yield will be assessed. Retained seed will be analysed for Mn as well as assessing any quality benefits from the various Mn applications,” he said.

Mark covers the shires of Albany (West) and Denmark, Tambellup, Cranbrook, Plantagenet, Broomehill. For more information on Summit Fertilizer products or trial results, local growers can contact him on 0498 223 421.

View video interviews for more information on this trial.