Abstract:
Amending growing media with organic wastes may improve physical properties and enhance plant growth. We studied the physical properties of peat-based media amended with organic wastes and related these properties to the growth of three ornamental species. Four rates (55, 45, 35 and 25% v/v) of peat were mixed to four rates (10, 20, 30 and 40% v/v) of fresh and composted organic wastes and to a single rate (35%) of perlite. Wastes were both Fresh and Composted Bio-Filter (FBF and CBF), Sewage Sludge (FSS and CSS) and De-Inked Paper Sludge (FDP and CDP). Tagetes patula, Calceolaria herbeohybrida and Impatiens wallerana were grown in the media for four months. Physical properties of the media studied were saturated hydraulic conductivity (Ks), air-filled porosity (fa), relative gas diffusivity coefficient (Ds/Do) and pore tortuosity (τ). Ks (p = 0.0001) and Ds/Do (p = 0.0035) increased while τ (p = 0.01) linearly decreased with increasing rate of organic wastes. fa was not significantly affected. Plant dry weight (PDW) of Impatiens wallerana (p = 0.0001), Tagetes patula (p = 0.0018) and Calceolaria herbeohybrida (p = 0.0001) linearly decreased with increasing rate of organic wastes. PDW was significantly correlated with τ and Ds/Do with correlation coefficients (r) ranging form 0.70 to 0.90. These results suggest that measurements of pore space characteristics (τ and Ds/Do) in top of storage properties (water and air contents) of media may be useful in understanding the relationship between plant growth and the physical properties of growing media.
Nsalambi V. Nkongolo , Fabienne Gauthier and Jean Caron , 2007. Effects of Fresh and Composted Organic Wastes on Media Physical Properties and Growth of Three Ornamental Species. International Journal of Soil Science, 2: 235-246.
Subscribe Today 
