EFFECT OF LIMING ON YIELD AND NUTRIENT CONCENTRATION OF REED CANARYGRASS GROWN IN TWO PEAT SOILS

Abstract

A Typic Mesisol (woody peat) and a Humic Mesisol (sedge peat), from Ormstown and Farnham bogs (Que.), respectively, were mixed with calcitic agricultural limestone at rates of 0.5–30 tonne/ha to find a suitable liming rate for growing reed canarygrass on peat soils. Liming increased soil pH from 3.0 to 5.8. Average yields (eight cuttings) of reed canarygrass (Phalaris arundinacea L.) were not increased by liming beyond 6 tonne/ha (pH 3.6). At low lime rates, Cu concentration in the grass was higher in the seventh and eighth cuts while at high liming rates the Mg and P concentrations declined as Ca absorption increased. Considering that pH of the treated peats declined in the year following liming, one-time application of 10 tonne of lime per hectare was judged to be optimal for sustaining yields while providing balanced plant nutrition in the forage crops. It was also concluded that 100 ppm of Cu, both as a fertilizer and mitigator of subsidence, could be added to these soils at a stabilized pH of 3.4 to 3.6 without adverse effects on plant nutrition. At lower pH, the Cu concentration of the crop was found to increase from an optimal 10 ppm to 17 ppm. Key words: Liming, peat soils, nutrient concentration, reed canarygrass