Influência da adubação com lodo do tratamento de esgoto doméstico no cultivo de feijão e milho

Abstract

In the biological stage of sewage treatment, part of the organic matter degraded by microorganisms is converted into biomass, which constitutes the biological sludge or secondary sludge. Currently, the most used alternative for final disposal of sludge in Brazil is sending it to landfill, due to the low operational cost involved. However, this technique does not include the nutritive and/or energetic potential of the sludge. That said, this study evaluated the use of sludge from domestic sewage treatment in the cultivation of cowpea bean seedlings (Vigna unguiculata (L.) Walp., Cultivar IPA 206) and corn (BRS Gorotuba), compared to the use of chemical fertilizers. The experimente for each culture was conducted in a greenhouse and set up in a completely randomized, with 4 treatments and 3 repetitions, using pots containing 10 kg of soil. The two cultivations were carried out in parallel. The 4 treatments applied were: without fertilization, chemical fertilizer (NPK), lime sludge and composted sludge (T0, T1, T2 and T3, respectively). Among the performance parameters analyzed, in both crops, T1, T2 and T3 treatments presented plants with equivalent physical aspects (plant height and stem diameter). With regard to beans, the treatment T3 stood out for the amount of pods per plant, being about 125% higher than others, and for the higher performance in the weight of 100 beans (29.67g). For corn, treatments T1, T2 and T3 achieved equivalent performance. However, T3 obtained the highest numerical averages in all parameters of this cultivation. Finally, it was observed that the treatment with the greatest influence, in both crops, was T3, reaffirming the great potential of composted sludge