INFLUENCE OF MUNICIPAL SEWAGE SLUDGE ON TOBACCO PLANTS’ (Nicotiana tabacum L.) GROWTH AND CROP

The effects on the developmental stages and biomass production of tobacco plants, after amending the cultivation soil with sewage sludge, were investigated. The development of all plant organs and their major morphological features as well as the crop production of tobacco plants was investigated. Five different treatments, including inorganic fertilizer (11-15-15) / at a rate of 2 g/6 kg soil corresponding to 16 P units, 16 K units, and 8 N units) and various concentrations of sludge (0,6 kg dry sewage sludge per 5,4 kg soil or 1,0 kg sewage sludge per 5 kg soil), were utilized. The number of leaves, the leaf area and leaf tissue development as well as the total dry weight of the leaves, which constitute the commercial part of the tobacco plant, were recorded. The results strongly support the use of sludge, in any proportion, for promoting plant growth, in terms of more in number and wider in size leaves, elaborated leaf histology, and up to 30% increase in total crop. All the above benefits are succeeded without the surcharge of the fertilizers. The biomass of the seeds of plants grown in sludge-amended soil, was also significantly higher than that of the controls.