Effect of textile industrial effluent on tree plantation and soil chemistry

A field study was conducted at Arid Forest Research Institute to study the effect of textile industrial effluent on the growth of forest trees and associated soil properties. The effluent has high pH, electrical conductivity (EC), sodium adsorption ratio (SAR) and residual sodium carbonate (RSC) whereas the bivalent cations were in traces. Eight months old seedlings of Acacia nilotica, Acacia tortilis, Albizia lebbeck, Azadirachta indica, Parkinsonia aculeata and Prosopis juliflora were planted in July 1993. Various treatment regimes followed were; irrigation with effluent only (W1), effluent mixed with canal water in 1:1 ratio (W2), irrigation with gypsum treated effluent (W3), gypsum treated soil irrigated with effluent (W4) and wood ash treated soil irrigated with effluent (W5). Treatment regime W5 was found the best where plants attained (mean of six species) 173 cm height, 138 cm crown diameter and 9.2 cm collar girth at the age of 28 months. The poorest growth was observed under treatment regime of W3. The growth of the species varied significantly and the maximum growth was recorded for P. juliflora (188 cm height, 198 cm crown diameter and 10.0 cm collar girth). The minimum growth was recorded for A. lebbeck. Irrigation with effluent resulted in increase in percent organic matter as well as in EC. In most of the cases there were no changes in soil pH except in W5 where it was due to the effect of wood ash. Addition of wood ash influenced plant growth. These results suggest that tree species studied (except A. lebbeck) can be established successfully using textile industrial wastewater in arid region.