No-till has been adopted more and more by farmers and research has generated much information on nutritional aspects, mainly related to organic matter, nutrients accumulation, especially macronutrients, and soil acidity. However, there is a lack of information on micronutrient dynamics in this tillage system. In an experiment installed fifteen years ago on an Ultisol (Argissolo Vermelho-Amarelo) soil samples were collected to evaluate the influence of six soil tillage systems: no-till (SD), moldboard plow (AA), disk plow (AD), tandem-heavy disk plow (GP), tandem-heavy disk plow + moldboard plow (GP+AA) and tandem-heavy disk plow + disk plow (GP+AD), on pH values and contents of organic carbon and micronutrients copper, manganese, zinc and iron in four depths (0-2.5; 2.5-5.0; 5.0-10.0 and 10.0-20.0 cm). Differences were observed for values of pH and contents of organic carbon, copper, manganese and zinc for tillage systems and soil depths, with the largest values being observed in the first 5 cm of soil depth under the SD system. Below the depth of 5 cm more similarity for the studied treatments was observed, with greater content reductions in the layer from 10 to 20 cm. Iron contents was negatively influenced by the organic matter in surface in SD and GP systems. Micronutrient contents correlated positively with organic carbon contents in the different tillage systems and depths. The treatments that involved greater soil turn-over showed larger homogeneity on organic matter and micronutrient contents along the sampled profile.
no-till; tillage systems and micronutrients
