Mineral content of the natural range in the southern Brazil. II. Sodium, sulfur, zinc, copper, iron and manganese

Foram analisadas 33 amostras de solo e 275 amostras de pastagem natural em onze Unidades de Mapeamento de Solo (U.M.) do Rio Grande do Sul, em diferentes estações do ano, objetivando conhecer os teores de minerais, comparando-os com a necessidade dos bovinos. Nos solos, os teores de Na variaram de 20 a 130 ppm, com média de 66,4 ppm, e os de Mn de 14 a 669 ppm com média de 183. Nas pastagens, os teores médios de Na variaram de 0 a 924 ppm, com média de 269 ppm na matéria seca (MS), enquanto os de Mn oscilaram entre 189 e 605 ppm, com média de 364 ppm, os teores médios de S variaram de 0,07 a 0,48%, com média de 0, 17% na MS, e os de Zn variaram de 11 a 30 ppm, com média de 20 ppm; a média de Fe foi de 319 ppm, variando de 53 a 1.338 ppm na MS, e a média geral de Cu foi de 11 ppm, com teores médios entre 5 e 16 ppm. Os teores médios de Na e Zn mostraram-se insuficientes para bovinos, em todas as épocas e em várias U.M. de solo, e os de Cu, apenas no verão.Thirty three soil samples and 275 samples of native pastures were collected from eleven different soil classes in Rio Grande do Sul, Brazil, in different year seasons, to determine the levels of different minerals and compare them to beef cattle requirements. Soil levels of Na ranged from 20 to 130 ppm, with 66.4 ppm, on average, and Mn levels ranged from 14 to 669 ppm with 183 on average. In the pastures, the levels of Na ranged from zero to 924 ppm, with average of 269 ppm in the dry matter (DM), while those of Mn ranged from 189 to 605 ppm with average of 364 ppm. The S values ranged from 0.07 to 0.48% with an average of 0.17% in DM, while those of Zn varied from 11 to 30 ppm with an average of 20 ppm. Fe levels varied from 53 to 1338 ppm with an average of 319 ppm. The average of Cu was 11 ppm, ranging from 5 to 16 ppm. The levels of Na and Zn were deficient for cattle in all seasons in most of the soil types, while Cu was only deficient in Summer