The residue of the process of parboiling rice contains high amounts of elements such as nitrogen, phosphorus and others which, once incorporated into the soil, could serve as a source of nutrients. Accordingly, the present study evaluated some properties of an Ultisol, the dry matter production and nutritional status of corn grown after applying an anaerobic sludge originated from the process of parboiling rice. The experiment was conducted in 4 kg pots filled with soil, in four replications. The following treatments were studied: control, NPK fertilization, 2.15, 4.31, 8.62, 12.93, and17.24 g kg-1 sludge. Sludge application from parboiled rice increased the maize dry matter yield, as well as pH, electrical conductivity and the concentration of N, P, K and Na in the soil. The sludge also increased the concentration of N, P and K and decreased Ca and Mg in the maize shoots.
Zea mays; biosolids; nutrients; waste disposal
