Field Research & Agronomy

SUM20.30: Form and Efficacy of Manganese Supply to Coromup Lupins, Regans Ford

Aim

This trial aims to assess the long-term response and carryover effect of manganese (Mn) fertiliser at a sandy soil site north of Regans Ford. With uncertainty surrounding best practice Mn fertiliser strategies, this trial has incorporated a number of combinations of common practice Mn and phosphorous (P) rates, with hopes to provide further insight into the decision making when using Mn sources at seeding while also assessing the efficacy of various chemical forms of Mn fertilizer.

Trial Details

Location: Regans Ford.

Trial Size: 2.2m x 10m, 7 treatments x 6 reps = 42 plots.

Soil Type: Sand.

Crop Sown: Coromup Lupin, sown 07/05/2020 at 100kg/ha.

Season Rainfall: 379 mm, BOM Lake Nammen, 112 mm below long-term average.

**Figure 1:** Pre-trial Soil nutrient analysis.

Results

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**Figure 1:** Concentration of manganese in young lupin whole tops collected at the five-leaf stage on the 24/06/2020. Mn concentration increased with increasing rates of applied Mn fertilizer, with form also affecting concentration. The dashed line represents the deficiency benchmark.

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**Figure 2:** Concentration of manganese in lupin stems collected at the podding stage on the 13/08/2020. Differences in concentrations between applied treatments had lessened compared with whole shoots the first sampling time. The dashed line represents the deficiency benchmark.

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**Figure 4:** Individual harvest yield displayed as the mean across six reps. There were no observable trends in yield between the treatments.

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Key Messages

Whole top plant sampling testing showed Mn concentration was significantly affected by the rate and form of applied manganese.
Yield was not significantly affected by the different forms and rates of Mn fertilizer. Yields ranged between 3.2-3.5 t/ha.
Under 2020 conditions at this site, the most profitable treatment was applying 3kg Mn/ha as a MAP:MnSO4 blend, returning $1340/ha.

For further information about this trial please get in touch with local Area Manager Brett Beard Bbeard@summitfertz.com.au.

Grain Legumes