IMPROVING NUTRIENT AND MOISTURE RETENTION IN PINE BARK SUBSTRATES WITH ROCKWOOL AND COMPOST COMBINATIONS

T.E. Bilderback, W.C. Fonteno
Cotoneaster dammeri Schneid. ‘Skogholm’ were potted into combinations of pine bark (PB), horticultural rockwool (RW), composted municipal yardwaste (CYW), composted turkey broiler litter (TBL) and washed builders sand (S). The objective of the study was to characterize the physical and chemical properties and subsequent plant growth and foliar tissue levels of the resultant substrates. Of the physical parameters tested the three component substrates PB:RW:CYW and PB:RW:TBL (70:20:10 by v) appeared to have the most consistent favorable physical properties with higher total porosities and available water content, equivalent air space and container capacity and lower unavailable water content than the pine bark control substrate. Electrical conductivity (EC) was extremely high the first day after initiation (DAI) in the substrates containing TBL but was not different for other sampling dates. Leachate pH initially ranged from 4.9 to 6.1 but through most of the study ranged from 5.2 to 5.8. As with EC all nutrient levels were very high one day after initiation. Leachate phosphate levels were maintained at recommended levels in the substrates containing TBL throughout most of the study while other substrates were generally deficient. The same was true for foliar tissue phosphate levels. The greatest top dry weight was yielded in the PB:RW:TBL (70:20:10, by v) substrate and least in the PB:S (80:20) substrate.
Bilderback, T.E. and Fonteno, W.C. (1993). IMPROVING NUTRIENT AND MOISTURE RETENTION IN PINE BARK SUBSTRATES WITH ROCKWOOL AND COMPOST COMBINATIONS. Acta Hortic. 342, 265-272
DOI: 10.17660/ActaHortic.1993.342.30
https://doi.org/10.17660/ActaHortic.1993.342.30
air space, bulk density, particle size distribution, available water capacity, unavailable water

Acta Horticulturae