Changes were evaluated in concentration and saturation of exchangeable sodium of a soil cropped with tifton-85 grass, submitted to different rates of municipal solid waste leachate (MSW). For this research, a 5000 L reservoir was filled with fresh MSW in order to produce leachate. Leachate rates of 0 (control), 250, 500, 750 and 1000 kg ha-1 d-1 of BOD5 were applied to the field. In the control treatment, which did not receive any leachate, potable water from the municipal supply network were applied at the same depth as for the 500 kg ha-1 d-1 of BOD5. Water and leachate was applied to tifton grass daily during an eight month period. The applied MSW leachate provided sodium accumulation in all soil profile layers, however, without any damage to quality. MSW doses of less than 1000 kg ha-1 d-1 of BOD5 caused no problems to soil during the research period and, therefore, it can be used to dispose such effluent. At the end of trial, one could note that exchangeable sodium percentage (PST) remained lower than the 15% limit. However, for longer applications, one would expect the limit to be exceeded in the superficial soil layer (0 to 0.10 m) after 1.2 years of MSW leachate application.
landfill leachates; sanitary landfill; fertirrigation
