A positive valorization way of sludge compost: recycling it to turfgrass instead of partial conventional substrate

Abstract

Sludge is known to be a suitable amendment material to substrate used for horticultural products because of its soil-like physical and nutritional characteristics. Replacing a portion of substrate used for turfgrass with sludge has been shown to have positive effects, such as improved biomass productivity, root length and density as well as persistence of vegetation cover. Although the effects of adding sludge compost to turfgrass substrate have been widely investigated, the characteristics of commercial qualitative indicators of the generated turfgrass, substrate and sod products have been reported separately or incompletely. Therefore, this study was conducted to assess the effects of recycling composted sludge to turfgrass on commercial qualitative indicators. The results revealed positive and negative effects of sludge compost on the investigated parameters, with some factors showing positive responses to addition of sludge compost to a threshold, above which negative responses were observed. For example, water-holding porosity, biomass and chlorophyll content increased in response to sludge amendment, but increased salinity and weed density, as well as decreased tensile strength and intactness were also observed. Overall, sludge compost in moderate dose is a suitable material for replacement of partial turfgrass substrate, but excessive dose results in adverse effects.

Keywords

• compost
• sludge
• sod
• substrate
• turfgrass