Characteristics of Soil Heavy Metal Contamination in the Intensive Livestock Farming Watersheds

Abstract

Soil contamination of agricultural watersheds can increase to deteriorate water quality, human health, crop production and aquatic ecology. In particular, it is important to understand the impacts of soil heavy metal contamination from livestock excretion because the excretion has been gradually increasing due to the rapid growth of the livestock industry. In this study, to analyze the characteristics of soil heavy metal contamination in intensive livestock farming watersheds, we selected intensive livestock farming watersheds where livestock heads and amount of livestock excretion by species were spatiotemporally surveyed. We also investigated the characteristics of five soil heavy metals (As, Cd, Pb, Cu, Zn) contamination. The Cheongmi Stream watershed in Anseong, Kyungi-do and Gwangcheon Stream watershed in Hongseong, Chungcheongbuk-do, Korea were one of the most intensive livestock rearing regions where there were very large amounts of livestock excretion. It was also found that Cu and Zn among heavy metals exceeded the soil contamination concern standard at two of the sampling points in the Gwangcheon Stream watershed. Compared to the national soil measurement network data, it was showed that the concentrations of Cd, Cu, and Zn in the intensive livestock farming areas such as both Cheongmi Stream and Gwangcheon Stream watersheds were higher than in other areas. Thus, we suggested that the soil in intensive farming watersheds was contaminated by heavy metals compared to other areas. Therefore, it is necessary to manage not only livestock excretion, but also animals’ welfare, humans, and the environment to use less heavy metals in their feeds. We also believed that various impacts of livestock excretion on the environment need to be studied soon.