Hytönen, J. 2005. Effects of Liming on the Growth of Birch and Willow on cut-away Peat Substrates in Greenhouse. Baltic Forestry, 11 (2): 68-74

The effects of liming (doses 0, 6, 12, 24, 48 tonnes/ha of dolomite lime) on the growth and nutrition of birch (Betula pendula Roth, Betula pubescens Ehr.) and short-rotation willows (Salix x dasyclados, Salix viminalis) were studied in a greenhouse on peat obtained from two cut-away peatland areas. Peat was NPK-fertilized using either raw phosphate or superphosphate as phosphorus source. An increase in liming dose up to 48 tonnes/ha increased peat pH asymptotically from 3.5 to 6.0 and from 3.9 to 6.7 in the two peats. The substrate’s pH did not affect the biomass production of silver and downy birch. Willows did not grow at all in the acidic Aitoneva peat without the substrate being limed. Willow growth was best when substrate pH was higher than 5.0. Liming decreased the foliar phosphorus and boron concentrations in birch and boron concentrations in willow. Rock phosphate and superphosphate gave almost equal results in birch growth, but willows grew significantly better when fertilized with superphosphate. Downy birch had significantly higher foliar potassium, calcium, magnesium and boron concentrations than silver birch. Salix viminalis had significantly higher foliar concentrations of phosphorus, potassium and boron than S. x dasyclados.

 Key words: Cut-away peatland, liming, downy birch, silver birch, willow, Salix, phosphorus