RESPONSE OF RED CLOVER TO KIMBERLEY ELECTRIC FURNACE IRON SL4G AND OTHER LIMING MATERIALS

Abstract

Yields, together with K, Ca and Mg concentrations and uptake, were determined for 10 consecutive harvests of red clover in growth-chamber experiments comparing electric furnace iron slag with commercially available agricultural lime, marl and dolomite, as well as reagent-grade magnesium carbonate, as liming materials at two rates of application on the acid Alouette silt loam and Pitt silty clay soils.On the Alouette silt loam, slag was the most effective treatment in increasing yield, while on the Pitt silty clay soil, slag was not significantly better than dolomite, marl or agricultural lime. Magnesium carbonate was the least effective liming treatment in increasing yield on both soils.All liming agents except magnesium carbonate increased Ca uptake. With the exception of dolomite on the Pitt soil and magnesium carbonate on both soils, Ca concentration in red clover tissue was increased by the liming materials.Content of Mg in red clover tissue was increased by slag, dolomite and magnesium carbonate on the Alouette soil and by the latter two sources on Pitt soil. Marl reduced Mg concentration in red clover harvested from Alouette soil, and both agricultural lime and marl decreased Mg in tissue from the Pitt soil. On the Alouette soil, all liming materials except marl and agricultural lime resulted in significant increases in uptake of Mg, while all liming treatments increased Mg uptake from the Pitt soil.Concentration of K in red clover was reduced by liming, whereas K uptake was increased by all liming agents.