Potencial de utilização de resíduos de construção civil na correção da acidez do solo

Abstract

Inadequate waste construction deposition represents a socio-economic and environmental problem due to the responsible bodies and society neglect. Looking for new ways to waste use, this study aimed to verify the agricultural potential use of construction waste (Class A). The study was conducted at the Soil Chemistry and Fertility Laboratory of the Federal University of Fronteira Sul, Campus Cerro Largo, Rio Grande do Sul State, Brazil. Nine samples from different waste strands were collected from the Mattiazzi Construções company from Santa Rosa - Rio Grande do Sul. Neutralizing power and reactivity rate were evaluated, estimating the effective calcium carbonate (ECC). Three waste with the highest ECC were incubated with 300 gr of soil for 70 days, in a 3x4 factorial design with a randomized design, seeking to rise up the pH of a soil (5.2) to 5.5, 6.0 and 6.5. The results of waste showed appropriate reactivity rate values (68.7 to 81.6%) but reactivity rate low (9.9% to 17.5%). As a result, ECC values were low (6.8 to 14.1%), not reaching the minimum of 45% required by law for material to be considered as lime. In the experiment incubation, the three waste tested (ECC 14.1, 12.5 and 11.7%) reported a similar linear response with doses calculated to increase pH. However, pH values of only 5.5, 6.0 and 6.5 were not reached after 70 days of incubation, with final values of 5.0, 5.2 and 5.4, respectively