ABSTRACT
KEYWORDS. Vaccinium angustifolium, paper mill biosolids, wood ash, ground bark, foliar nutrient concentration
INTRODUCTION
In the Saguenay-Lac-St-Jean area (Québec, Canada), soil degradation severely limits wild blueberry (Vaccinium angustifolium Ait.) fruit production. Excessive burning decreased soil organic matter (SOM), which has a direct impact on soil fertility and water retention capacity. The loss of SOM also increased wind erosion risk. Residues of the paper mill industry are abundant in the area and can be used to restore the SOM under the wild blueberry stand. The mixture of primary and secondary sludge was found to be sources of plant nutrients (N and P) (Cabral et Vasconcelos, 1993; Simard et al., 1997) and organic matter for crop production (Philips et al., 1997). Wood ash is primarily used as a liming amendment but it also adds plant nutrients to soil (Huang et al., 1992; Naylor and Schmidt, 1989). Ligneous materials, such as ground bark, are used as organic amendment in agricultural crops but N immobilization remained the main factor on crop production (Beauchemin et al., 1992). The objective of this study was to assess paper mill biosolids (PB) mixed with wood ash and ground bark as a soil amendment/fertilizer for wild lowbush blueberry.
