Comparison of Heavy Metal(loid)s Contamination of Soil between Conventional and Organic Fruit Farms

Abstract

Organic amendments such as animal waste compost, lime-bordeaux mixture, and lime sulphur mixture containheavy metal(loid)s which are toxic to human being, animal, and plant. The objective of this study was to compareheavy metal(loid)s contamination of soil between conventional and organic farm. Soil samples were collectedfrom 10 conventional and 38 organic fruit farms. At each sampling point, top (0~15 cm) and sub soil (15~30 cm)were taken using hand auger. Total concentration for arsenic (As), cadmium (Cd), copper (Cu), nikel (Ni), lead(Pb), and zinc (Zn) in the collected soil were measured. The pollution index (PI) for heavy metal in organic farmsindicated it was unpolluted area. However, mean value of PI for organic farms (0.143) was higher than that forconventional farms (0.122). High Geoaccumulation index (Igeo) for Cu, Pb, and Zn implied that grape farms weremore polluted than others fruit farms because a lot of lime-bordeaux mixture and lime sulphur were applied inorganic grape farms. Especially, top soils showed higher level of contamination than sub soil. Based on the aboveresults, organic amendments might cause accumulation of heavy metals in soil. Therefore, particular attentionshould be paid for concentration of Cu, Pb, and Zn, when organic amendments are used in the organic fruit farms.