Inter-relação do magnésio na cadeia solo-planta-animal em áreas de campo natural na Serra do Sudeste - RS

Abstract

The objective of this work was to evaluate the seasonal dynamics of magnesium in the soil, plant and blood serum of the animals under natural pastures conditions over the year, in two soils in the Piratini-RS region, and to determine some factors that influence the passage of magnesium in the soil-plant-animal system. The research was carried out in two native field areas in the town of Piratini-RS, using undisturbed areas, which were being used for grazing cattle. For 12 months, soil, plant and animal blood samples were collected, and the magnesium levels in the soils, plant tissues and blood serum of the animals were analyzed. The experimental design was a randomized complete design in factorial scheme with two factors. Data were analyzed using analysis of variance and comparison of the means by F test (P <0,05) and Pearson's correlation. The data presented significant variation (P<0,0001) in the magnesium content (Mg) throughout the year in the soil, plant and blood serum of the animal. With lower levels in the soil and plant during winter in both areas. Mg was able to meet the requirements of growing cattle. The levels of Mg in the blood serum of the animals grew as they advanced their age, presenting levels at the limit of normality in the blood serum. There was a correlation between temperature and Mg concentrations in soil, plant and animal, however rainfall did not affect Mg levels in the soil-plant-animal chain links. There were positive and negative correlations among magnesium and other minerals in distinct links of the chain soil-plant-animal. It is concluded that the passage of Mg in the soil-plant-animal chain undergoes variation throughout the year, being influenced by the climatic conditions and the interactions with the other minerals.