Balance of basis in the soil and dry matter production in maze (Zea mays L.) in soils treated with sewage sludge, calcium carbonate and unslaked lime

Sewage sludge may have different uses, among which the agronomic use. In this case, it is necessary to know the characteristics of the sludge, the soil, the plant and its interactions, as well as the climate and the site where it will be applied. This work aimed at investigating the influence of sewage sludge, with or without addition of lime, in the balance of the soil and in the maize dry matter production. The experiment was carried out in pots under greenhouse conditions, utilizing two samples of soils, collected at a 015 cm deep layer: the first sample (S1), with clay texture, was collected from eutrophyc Red Latosol in direct seeding, and the second sample (S2), with sand texture was collected from dystrophic Red Latosol. The following treatments were used in soil S1: T1A - control; T2A - 9 t ha1 sewage sludge; T3A - 18 t ha1 limed sewage sludge (9 t ha1 sewage sludge + 9 t ha-1 unslaked lime); T4A - 9 t ha-1 unslaked lime; and for soil S2: T1B - control; T2B - 9 t ha-1 sewage sludge; T3B - 18 t ha-1 limed sewage sludge (9 t ha-1 sewage sludge + 9 t ha-1 unslaked lime); T4B - 9 t ha-1 unslaked lime; T5B - recommended liming. The maize dry matter shoot, cultivated at sandy dystrophic Red Latosol, increased with sewage sludge without lime. The application of limed sewage sludge increased the amounts of Mg and P (S1 e S2) and Na (S2). The increased pH contents may constitute a limiting factor for its application.

biosolid; basis saturation; liming; sewage sludge

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