CONCENTRATION OF SODIUM AND MACRONUTRIENTS IN THE LEAVES OF CULTIVATED PLANT SPECIES IN INTERCROPPING AND AT DIFFERENT LOCATIONS IN WETLANDS

Abstract

This study was done to evaluate the concentration of nutrients and sodium in the leaves of different plant species grown in consortium in constructed wetlands (CWs) used for domestic sewage treatment. The system consisted of 4 CWs of subsurface flow with the dimensions of 0.35 m deep x 1.0 m wide x 24.0 m long and impermeated with a polyvinyl chloride geomembrane. Each CW was filled with fine stones to 0.30 m thickness and planted with cattail, tifton-85 or alternantera, at four different locations. The organic load application rate and daily flow was 200 kg ha-1 d-1 and 1.6 m3 d-1, respectively, which allowed for a hydraulic retention time of 1.8 days. Only shoot phosphorus concentration was influenced by the plant location. The highest concentrations of nutrients, except potassium and sodium occurred in alternantera regardless location on the CWs. The tifton-85 grass should not be grown in the first third of the CWs, because of its intolerance to the environmental conditions.