The goal of this study was to evaluate yield and net return of a maize crop fertilized with different rates of conventional mineral fertilizer and cattle manure. The CSM-CERES-Maize model was used to simulate the nitrogen (N) fertilization management scenarios. Twelve treatments were simulated as follows: T1, T2 and T3 were, rates of 90, 130 and 160 kg ha-1 of N as conventional fertilizer, respectively; T4a, T4b and T4c were 4.5 t ha-1 of air-dried cattle manure,

du 1 The authors and the participants of the PFOA discussion group at the workshop acknowledge Dr Maria José A. Sampaio of the Embrapa Secretariat for Intellectual Property Rights and Dr Ana Lúcia Assad of the Ministry of Science and Technology at the time of the workshop, for their contribution of ideas during the workshop.