Calibração e validação dos modelos Century, APSIM e NDICEA de decomposição de materiais orgânicos e mineralização de N para a Mata Atlântica

• Autor(a) principal: Nascimento, Alexandre Ferreira do
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5398
• topic: Modelo Century; Agroecologia; Manejo do solo; Century model; Agroecology; Soil management; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

A high number of agricultural systems depends on nutrients coming from decomposition of organics materials applied into soil. The decomposition rate of these materials is controlled by intrinsic factors as chemical and biochemical composition and extrinsic factors as temperature and moisture. Hence, the decomposition is a complex and dynamic process, which can be represented and examined within a framework, the mathematical models. Thus, the goal of this work was to make the parameterization and validation of Century, APSIM and NDICEA models for tropical conditions, working with different organic materials and to evaluate the capacity of these models to simulate N uptake mineralized from the organic materials. The information for model parameterization and calibration were collected in Matos (2005) and Chacón (2006). From this database it was utilized eight green manure residues evaluated in Araponga for 150 days and four in Pedra Dourada for 360 days, both municipalities situated in the Atlantic Forest of Minas Gerais State. For validation of the models it was utilized data from an experiment carried out in Seropédica (RJ), with four green manure residues, evaluated in the winter and summer seasons. The models were also calibrated to decomposition and N mineralization of four animal manures and four composts. To the N uptake, the calibration of the models was performed in order to assess the growth of Brachiaria plants with application of five organic materials as fertilizers. The calibration using the default of the Century and APSIM models overestimated the decomposition rate and N release of all the vegetable residues and, the NDICEA, underestimated those processes to the more recalcitrant materials. Thus, the calibration was essential to improve the accuracy level of these models. After calibrate the models, the NDICEA presented higher accuracy level than the Century and APSIM, simulating with lower error the decomposition and N release of the green manures in the winter and summer seasons. The calibration of the decomposition and N mineralization of the animal manures and composts was done individually, all models presented high performance in simulating those processes. The models overestimated the N uptake by Brachiaria plants when working with the calibration done to N mineralization of the organic materials. To increase the accuracy of the models in estimating the N uptake it was essential to do a specific calibration. After of this calibration, the NDICEA model presented the highest accuracy in estimating the N uptake by Brachiaria plants. After testing the accuracy of the models, the NDICEA presented the best performance in the environmental conditions of our study, showing potential to be a tool to be used in optimizing the use of organic materials as a source of N in the agroecosytems. However, future works are necessary, incorporating more organic materials and environments to improve the models in estimating the decomposition of organic material and N mineralization and its uptake by plants.