The effects of sewage sludge on growth and nutrient content of ornamental cabbage

In this study, five different growing medium made from sewage sludge and soil mixture were used for growth of ornamental cabbage; I) soil (control)-100%, II) soil-75%;sludge-25%, III) soil-50%;sludge-50%, IV) soil-25%;sludge-75%, V) sludge-100%. In the study, plant growth parameters (plant height, stem length, head height, root length, stem and root collar diameter, length and width of leaf blade, length and diameter of leafstalk, fresh weights of plant, shoot and root, dry weights of plant, shoot and root, the relative weights of shoot and root, root/shoot ratio, compactness), physiological parameters (SPAD, PSII, loss of turgidity, leaf relative water content-LRWC, ion leakage, injury), plant nutrient (N, P, K, Ca, Na, Cu, Fe, Mn, Mg, Zn and B) and some heavy metals on sludge (Zn, Cr, Ni, Cd and Mo) were investigated. It was concluded that, depending on various vegetative parameters, the highest results were taken from Medium III (with 50 % sludge), while the lowest were from Medium IV and V (with parallel to the increase in sludge by 75 and 100%). Moreover, PSII and YOSK were observed to decrease in media with high sludge (that is in 75% and 100%), whereas turgor loss, ion leakage and damage were seen to increase. Sludge, especially in the case of 25 and 50%, was found to be effective in nutrient uptake, such as P, Ca, Mg, Fe, Mn and Zn. As a result, sewage sludge to the extent of 50% was found to be useful for the growth of ornamental cabbage.