MANGANESE NUTRITION OF CEREALS AND FORAGES GROWN IN PRINCE EDWARD ISLAND

Abstract

Field experiments were conducted in Prince Edward Island to determine the effects of MnSO4 H2O applied as a foliar spray and to the soil and the effects of chelated Mn applied as a foliar spray and limestone applications on Mn concentration and yields of alfalfa (Medicago sativa, L.), timothy (Phleum pratense L.), wheat (Triticum aestivum L.) and oats (Avena sativa L.). The Mn concentration in forages and cereal grain was not affected by method of application. Soil-applied Mn at 5 and 10 kg ha−1 was generally ineffective in increasing tissue Mn concentration. The second cut of alfalfa and timothy contained more Mn than the first cut. Yields of forages and cereals were not affected by Mn applications. Manganese concentrations as low as 29–31 μg g−1 in forages and 22 μg g−1 in cereals were not related to Mn deficiency. In spite of some foliage burning at the 2 kg Mn ha−1 foliar application, no yield reductions were found on any of the crops investigated. Applications of limestone to raise soil pH to 6.6–6.9 decreased tissue Mn in forages and cereal grain. The sharpest decreases occurred in timothy and alfalfa but did not result in low enough tissue Mn to cause Mn deficiency. Key words: Tissue Mn, soil-applied Mn, foliar-applied Mn, soil pH