Field Research & Agronomy

SUM20.07a: Form and Efficacy of Manganese Supply to Lupin Varieties, Eradu

Aim

This trial aims to assess the response of Barlock and Jurien lupins to manganese (Mn) fertilizer on sandy soils south-east of Eradu, while also assessing the efficacy of various chemical forms of Mn fertilizer, with hopes to provide further insight into the decision making when using Mn sources at seeding.

Trial Details

Location: Eradu.

Trial Size: 1.61m x 8m, 12 treatments x 4 reps = 48 plots

Soil Type: Sand

Crop Sown: Barlock & Jurien Lupin, sown 15/04/2020.

Season Rainfall: 255 mm, BOM Eradu, 25 mm below long-term average.

**Table 1:** Pre trial soil nutrient analysis.

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Results

**Figure 1:** Concentration of manganese in young lupin whole tops collected at the five-leaf stage on 23/06/2020.

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**Figure 2:** Concentration of manganese in lupin stems collected at the podding stage on 13/08/2020.

**Figure 3:** Individual harvest yield displayed as the mean of 4 reps. Jurien had a higher yield than Barlock across all treatments, but there were no observable trends in yield between treatments.

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**Figure 4: a)** Split seed count displayed as the mean of four replicates show Barlock had a higher rate of split seed than Jurien. b) The relationship between split seed and in-season stem Mn concentrations collected at the podding stage.

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Key Messages

Whole top plant sampling and stem sampling indicated Mn concentration in lupin tissue was affected by form and rate of Mn fertilizer. Supplying Mn in MnO2 form appears ineffective.
Plant testing for stem Mn proved reasonably useful in predicting split seed.
Different forms and rates of manganese fertilizer did not significantly affect yield or split seed counts in Barlock or Jurien.
Jurien lupins had greater yields than Barlock across the trial.
Under 2020 growing conditions, the most profitable fertilizer application was 3kg Mn/ha applied as a MAP:MnSO4 blend to Jurien, returning $1350/ha.

For further information about this trial please get in touch with local Area Manager Shane Turner, sturner@summitfertz.com.au.

Grain Legumes