Response of Container-Grown Nursery Crops to Raw and Composted Paper Mill Sludges

Abstract

Growth and nutrient uptake of three container grown nursery crops were compared using different potting media, including bark mixed with varying amounts, 0, 33, 67, and 100% by volume, of raw paper mill sludge and Phase I (fresh) and Phase II (aged) sludge composts. Species grown were: Tartarian dogwood (Cornus alba L.), Coral Beauty cotoneaster (Cotoneaster dammeri C. K. Schneid.), and Variegata Nana weigela [Weigela florida (Bunge) A.DC.]. Each compost consisted of ca. 40% paper mill sludge. Despite differences in response of species to the amount and source of sludge, plants grew well in media containing Phase I and II composts and produced plants of marketable size at harvest. Media with >33% raw sludge resulted in fewer marketable plants and had a greater volume reduction with increasing amounts of sludge. This was also accompanied by declining shoot and root dry weight. Media containing Phase I compost showed less volume reduction than those with raw sludge, and yielded growth comparable to that obt...