Container production of ericaceous plants requires maintenance of a long-term substrate pH of 4.0 to 5.5. The objective of the study was to examine the effects of incorporated elemental sulfur, ferrous sulfate, and aluminum sulfate on long-term pH suppression in an acidic container substrate irrigated with highly alkaline water. ‘Northcountry’ blueberry liners were planted into a peat/pine bark based container substrate containing one of six different commercial amendments for pH reduction at three different rates of actual sulfur: 0.89 kg S/m3 (1.5 lb S/yd3), 1.78 kg S/m3 (3 lb S/yd3), and 2.67 kg S/m3 (4.5 lb. S/yd3). After fourteen weeks, only one elemental sulfur treatment had a substrate pH significantly lower than untreated substrate pH. Elemental sulfur particle size played a role in ability to control substrate pH.
Minnesota Experiment Station #041210140. This research was funded in part by Bailey Nurseries, Inc. and the Minnesota Nursery and Landscape Association.
2Horticultural Research Scientist and Associate Professor, respectively.