Cadmium in Brazilian Soil and Soybean Grains: Are There Any Risks Regarding Food Security?.

Food security has gained widespread attention on the global development and can be defined by FAO as the physical and economic access to food for all people at all times. In this sense, agricultural practices that supply plants with nutrients are important regarding food production and optimum yields. However, phosphorus fertilizers contain cadmium (Cd) as a contaminant and therefore represent a major source of Cd input into agricultural systems. Cadmium is a trace element (TE) that has attracted the most attention in soil science and plant nutrition due to its potential toxicity to plants and humans, as well as its relative mobility in the soil-plant system. In this scenario, the aim of this study was to quantify Cd contents in soils and soybean grains grown in areas with high P-fertilizers inputs and crop rotation history in the years of 2010, 2011 and 2012. The area is located in the state of Mato Grosso, Brazil. Higher levels of Cd in the cultivated soil were observed (up to 128 µg kg^-1) compared with the reference area, where levels up to 15 µg kg^-1 were found, for all three years evaluated. There were a range of Cd content among crop rotations as well as considering the three different years. The values ranged from 7 µg kg^-1 for the soybean/Brachiaria system to 21 µg kg^-1 for the soybean/corn+Brachiaria system. The results showed that Cd levels found in this study are considered to be safe regarding food insecurity since its contents are within the limits set by regulatory agencies according to the latest legislation for Cd in soil and grains. Sponsored by CAPES, FAPEMIG and CNPq.