Field balances of trace elements at the farm level on crop and dairy farms in Finland in 2004

Summary

This study was part of a three-year (2004-2007) project entitled "Assessment and reduction of heavy metal inputs into Finnish agro-ecosystems" that was funded by the Ministry of Agriculture and Forestry in Finland. The main aim of this study was to estimate field balances of trace elements at the farm level on typical crop and dairy farms in Finland in 2004.
Field balances estimated at the farm level showed that the balances of the harmful heavy metals, Cd and Hg, were often slightly positive leading in accumulation of these metals into the soil on the crop and dairy farms. Selenium indicated a highly positive balance resulting in enrichment of this element in the soil in both farming systems. Also, the Cu and Zn balances were positive on the dairy farms but on the crop farms, clearly negative showing a depletion trend in the soil. In general, inputs and outputs of As, Cr, Ni, Pb and V were rather well balanced. However, if steel slag was used on the farm, accumulation of V into the soil was even 400 times that on the farm not used steel slag.