Nitrogen management strategies for maize production systems: Experimental data and crop modeling

Maize (Zea mays L.) is an important crop among Brazilian smallholder farmers,who are also responsible for 40% of the poultry and egg production in the country.Although poultry litter is considered a potential pollutant, if properly stabilized anddistributed in the field it can be used as a source of nitrogen for maize production.In this study, the response of maize to mineral fertilizer and poultry litter as sourceof nitrogen was evaluated and the results were then used to parameterize a processbased model. For both sources of nitrogen used in the second trial the averageobserved yield was higher than the average yield obtained by farmers during thepreceding years, indicating that there is a potential for improvement of maize yieldin the region. A rate of 195 kg ha-1 of nitrogen as poultry litter provided a slightlyhigher yield than a rate of 145 kg ha-1 of nitrogen as mineral fertilizer. Afteradjustments in the CSM-CERES-Maize cultivar-specific coefficients the modelsatisfactorily simulated maize anthesis, physiological maturity and yield. Poultrylitter has the potential to be an alternative source of nitrogen for maize productionin smallholder farms. The CSM-CERES-Maize model properly simulated maizegrowth, development and yield for both, mineral fertilizer and poultry litter sourcesof nitrogen.