Information on the mineralization of residues are important for proper management of these materials in agricultural areas. The objective was to evaluate the mineralization of nitrogen from the residue of guava processing industry, applied in a Ultisol cultivated with guava trees. Soil samples and the residue were placed in polyethylene pots with a capacity of 0.25 dm³. Around 100 g of soil plus waste were weighed in each treatment (doses of residue: 0, 9, 18 and 36 t ha-1), with such a procedure being performed in triplicate. The maximum incubation period was 11 weeks, with analyses at 0, 7, 14, 28, 42, 56, 70, 84, 98, 112 and 126 days of treatment. The soil+residue humidity was adjusted to 70% of the soil water retention capacity and monitored daily by weighing the pots. The inorganic nitrogen was measured in each evaluation time. It can be stated that the N mineralization or release is slow and there is not rapid availability of nitrogen. Over the period of 126 days, the mean fraction of mineralization was 23% with the half-life of 73 days.
Psidium guajava; industry of food; organic fertilizer; by-product; seeds of guava
