Biossólidos em algodoeiro herbáceo: modificações no crescimento, no desenvolvimento e no ambiente edáfico.

Abstract

Through two experiments taken in vegetation house condition at Centro Nacional de Pesquisa do Algodão - EMBRAPA/CNPA ( National Center for Research on Cotton) increasing doses effects were studied, which were 0, 60, 100, 200, 250, and 350 kg.ha-' for the fírst experiment, and 0, 150, 250, 350, 450, and 550 kg.ha-' for the second experiment, of sewage sludge limided ( at 50%ST - biosolid), on the growth ( plant hight and stalk diameter), on the development ( fírst flowerbud and fírst cotton capsule), on a production ( production o f stone cotton, weight o f 1 capsule, number of capsules, percentage of fibre, plumage weight, weight of 100 seeds, aerial part phitomass, root phitomass, and relation phitomass of aerial part/root phitomass) of a cotton plant, on the physical features of the plumage (how thin, resistence, lengh, lengh uniformity, short fibre rate, stretching, spiness, reflectingness, and yellow degree) and finally on the edaphic environment: chemical features, ( contents of N , P, K, Ca, Mg, organic matter and pH) and physic features ( real density, global density, total porousness, field capacity, permanent wither point, and capacity for water storage) from a typical ground in the region ( Regolitic Neosoil ). Besides ali those, parasitologic analyses have been done with the aim to detect helmint eggs in stored water of each experimental unit. Herbaceous cotton plant, variety BRS 187 8H has been choosen as test plant. The experimental design used, for both experiments, was in casual blocks, wich 6 treatments and 5 replications, in a total of 30 experimental units for each case. Each experimental unit to establish vase plastic of 90 dm3 . The limimg eliminated the pathogens organisms of the sludge and, according to estimated results obtained by models of linear and non-linear regression, we could come into the conclusion that the cotton plant represented by the crop BRS 187 8H, responded in a favorable way to the biosolid aplication, as long as this waste can be added to the soil in proper doses, since from the equivalent dose to 450kgNha-', there has been some decreasings in ali varieties studied. The averall analyses of studied varieties allow to affirm that the best results, in terms of growth, production and fibre technologic quality were obtained with the equivalent biosolid dose of 300 kgN.ha-' . The biosolid doses increased linearly the contents of N, P, K, Ca, Mg, organic matter and indice Ph, as well as the total porousness, field capacity and permanent soil wither point. Helmint eggs presence in stored water for each experimental unit hasn't been noticed.