Simulated yield and return of a maize crop fertilized with different sources and rates of nitrogen.

ANDRADE, C. de L. T. de; AMARAL, T. A.; DUARTE, J. de O.; GARCIA, J. C.; SILVA, D. de F.; MARTINS, P. C.

Simulated yield and return of a maize crop fertilized with different sources and rates of nitrogen.

Autores

ANDRADE, C. de L. T. de

Descripción

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, rated at 17.05, 22.73 and 34.09 US$ per ton, respectively; T5a, T5b and T5c were 6.5 t ha-1 of air-dried cattle manure, rated at US$ 17.05, US$ 22.73 and US$ 34.09 per ton, respectively; T6a, T6b and T6c were 8.0 t ha-1 of air-dried cattle manure, rated at US$ 17.05, US$ 22.73 and US$ 34.09 US$ per ton. It was assumed that the air-dried cattle manure has 2% of N. The conventional mineral fertilization with a nitrogen rate of 90 kg ha-1 (T1) resulted in an average yield of 4.812 kg ha-1 and average profitability of US$ 35.56 ha-1, while higher nitrogen rates caused economic losses. Profitabilities of US$ 120.90 and US$ 183.50 ha-1 were obtained with cattle manure rates of 6,500 and 8,000 kg ha -1, respectively.