Under greenhouse conditions at the National Center for Cotton Research (CNPA/ EMBRAPA) effects of increasing doses of sewage sludge (biosolids) equivalent to 0, 150, 250, 350, 450, and 550 kg ha-1 of N, limed at 50%ST were studied, on the variables of the production (production of cotton, weight of capsule, number of capsules, percentage of fibre and plumage weight) and components (aerial, root and total phytomass and the ratio between phytomass of aerial parts to root) of herbaceous cotton variety BRS 187 8H. The experimental design used was in random blocks, with 6 treatments and 5 replications. Each experimental unit, constituted of a plastic recipient of 90 dm³. According to the results obtained significant effects were observed by F test at 1% level of probabililty of the biosolid doses on the variables studied, except for the weight of capsule and percentage of fibre. With the regression analysis, linear increase of the variables was observed for the weight of cotton, plumage weight, aerial parts and total phytomass and the relation phytomass of aerial parts to root while a quadratic equation for the number of capsules per plant and root phytomass was found, the regression equations estimated biosolid doses equivalents to 441 and 231 kg N ha-1, respectively, for the maximum values for these variables.
sewage sludge; revenue; cotton plant
