Wetting agent effects on physical properties of mature green waste compost

Wettability of growth media is an important practical factor in soilless culture. The study was conducted to improve the water absorbing ability for green waste compost (GWC) as growth media with wetting agent. The experiments were divided into two sections. First, compost maturity assessment was performed by germination bioassay using Lepidium sativum L. (cress) as an indicator and germination index (GI) was calculated. Subsequently, five treatments were established based on the addition of wetting agent to GWC (0 %, 2 %, 4 %, 6 %, 8 %, v/v). Physical parameters (e.g. total porosity, air volume, easily available water, water buffering capacity and less readily available water) were analyzed. Results from the experiments indicate that 45 days after rapid composting GWC could be considered to be mature. And 2 % is more adequate wetting agent concentration in GWC.