Abstract:
The investigation was conducted to study the potential utilization of wastewater treatment sludge (WTS)
in combination with coir dust as a growing medium for leafy vegetable Ipomoea aquatica(L) and
ornamental plant Tagetes patula (Antigua Yellow). Wastewater treatment sludge was obtained from
wastewater treatment plant situated in Moratuwa, Soyzapura, Sri Lanka. Five different potting media
were prepared by mixing WTS and coconut coir dust (CCD) at ratios of 10%WTS+90%CCD,
25%WTS+75%CCD, 50%WTS+50%CCD, 75%WTS+25%CCD and 100%WTS. A mixture of top soil,
compost and river sand ratio of 1:1:1 was used as the control. Then bulk density, true density, porosity,
mean weight diameter, pH, organic matter, nitrogen, C:N ratio, electrical conductivity, phosphorous and
potassium content of developed media were analyzed. Formulated 10%WTS+90%CCD potting medium
gave the best growth and yield performance for Ipomoea aquatic and Tagetes patula which were not
significantly differed compared to commercial potting medium (control). The highest plant height, shoot
fresh weight and shoot dry weight of the Ipomoea aquatica were 116.5cm, 91.89g and 29.99g, respectively
while the same parameters were recorded as 45.6cm, 69.84gand 16.46g, respectively for Tagetespatula.
Therefore, formulated 10% WTS + 90%CCD potting medium can be recommended as an alternative
substrate for the extensively used control.
