Copper in carrots by soil type and area in Japan: a baseline study

The copper content in carrots cultivated in the Japanese archipelago was assessed and compared by area and soil type. 373 carrot samples were collected from 232 cities, towns and villages. According to geographical features and vegetation, the sampling sites were divided into 9 provinces and 7 soil types. Copper was measured by flameless atomic absorption spectrometry. There was a significant difference in the mean values of copper in carrots by provinces, but not by soil type. Although the content of copper in the soil was different among soil types, the difference did not influence the content of copper in the carrots. The authors speculate that the low solubility of copper in the soil and the low intake into plant roots from the soil are related to this soil-plant discrepancy.