Functional crop production models and mega-trends of climate

English. Crop production models may be grouped by their application: Research, Farm Advisory, Industrial, Analytical, and Process. Research and Process models are usually used to evaluate options and processes in an agricultural system during a growing season. Industrial and Advisory models usually minimize inputs, have specific applications, have a definitive output and deal with a risk over an operational time period. Analytical models are used to evaluate trends. Trends in agriculture include inter-annual variability of yield and long-term yield trends. Mega-trends in climate are modeled to anticipate impacts on agricultural production. The three recognized mega-trends of climate are global warming. El Nino, and the 18-20 year cycle

Portuguese. Os modelos de producao de culturas podem ser agrupados pela sua aplicacao: Investigacao, Aconselhamento ao nivel da exploracao, Industrial, Analiticos, e de Processos. Modelos de Investigacao e de Processos sao usados geralmente para avaliar opcoes e processos num sistema agricola durante uma estacao de crescimento. Modelos Industriais e de suporte ao Aconselhamento, geralmente, minimizam as entradas, tem aplicacoes especificas, tem uma saida definitiva e trabalham com um risco num periodo de tempo operacional. Os modelos analiticos sao usados para avaliar tendencias. Tendencias em agricultura incluem variabilidade inter-anual das producoes e tendencias de longo prazo das producoes. Mega-tendencias climaticas sao modeladas para antecipar impactos na producao agricola. As tres mega-tendencias climaticas reconhecidas sao o aquecimento global, El Nino, e o ciclo de 18-20 anos