Objective: Oreochromis niloticus (Tilapia) meal was evaluated as a source of nutrients in agriculture, through a composting process mixed with a zero tillage soil. Design/methodology/approach: Two manures were formulated, mixing flour and soil at a 30:70 ratio (mass/mass w:w) respectively. Compost A was maintained at 60 days of composting (ddc), compost B at 30 days. The phytotoxicity of the manures was evaluated as percentage of germination in Solanum lycopersicum (tomato) seeds. Results: The N-P-K ratio (% dry mass) was 1.90-2.06-0.30 for manure A (60 ddc), and 2.60-2.24-0.34 for B (30 ddc). On germination, 100% concentration; manure A had 44.9% and B 19.6%, compared to the control. For concentration of 10% it was 93.7 and 111.4%, manure A and B, respectively. Limitations on study/implications: It is necessary to carry out more phytotoxicity tests. In this experiment, dilutions were made in the manures to increase germination. Findings/conclusions: The use of manure based on tilapia meal in agriculture is proposed in the future and in this way take advantage of the waste from fish processing.
