Corn production in soil containing in natura tannery sludge and irrigated with domestic wastewater

• Tannery sludge, helped increase pH and P, K, Mg and Ca concentrations in soil.
• The irrigation with wastewater is an alternative for the disposal of these waters.
• Wastewater and tannery sludge not completely replace minerals fertilizers.

This research was developed with the objective of assessing chemical alterations in soil and corn (Zea mays L.) yield (plot area BG 7049H), using Haplic Plinthosol treated with tannery sludge and irrigated with domestic wastewater. Dried and sieved in natura tannery sludge was added to the soil in concentrations of 9 Mg ha−1 and 18 Mg ha−1. Pots kept in a protected environment during 150 days were used in the experiment. The treatment arrangement consisted of a 2 × 6 factorial—two irrigation types and six fertilization treatments in completely randomized design (CRD), with 5 repetitions. By the end of the experiment, the total ear weight, 100-grain weight and productivity, were assessed. Additionally, soil samples of each experimental unit were collected for determination of pH and K, Ca, Mg and Cu concentrations. The results showed that the 9 and 18 Mg ha−1 doses, plus irrigation with domestic wastewater, caused an increase in pH and P, K, Mg and Ca concentrations, which attested increased soil fertility. On the other hand, the application of such doses, even if together with irrigation with wastewater, did not promote a yield of the corn culture equivalent to that obtained with mineral fertilizers. New studies using tannery sludge together with wastewater or other organic substrates are recommended, in order to offer to rural producers the opportunity to use relatively small doses of tannery sludge, so that the reuse of such residues become viable from the economical, agricultural and environmental points of view.