The phosphorus compounds in the sediment of Sau reservoir have been analysed and related to the annual phosphorus budgets from 1965 to 1969 . With the increase of eutrophy, the phosphorus inputs leave the water in two ways : to the sediment and to the water outflow . The second way becomes more important throughout the eutrophication process .Of the three phosphorus forms studied, apatite-P is related to annual water flow, which is also directly related to sedimentation rate . By contrast, the other two phosphorus forms (organic-P and inorganic non apatite-P) are linked to phosphorus outputs . These relationships enable us to propose an historical sequence for the sediment . Finally, the dating of sediment allows us to develop an equation relating the total phosphorus in the sediment to the annual phosphorus inputs and water flow into the reservoir (r = 0 .94) .

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Duas variedades de soja, Santa Rosa e UFV-1 foram cultivadas em solução nutritiva deficiente em macronutrientes. Foi possível obter sintomas de carência, verificar o efeito das deficiências no crescimento, composição mineral e produção de vagens. Fez-se a diagnose foliar no caso de N, P e K e verificou-se o efeito do nivel de N na solução sobre a atividade da redutase de nitrato.