Antibiotic uptake by plants from manure-amended soils.

Antibiotics are extensively given to livestock to promote growth and reduce diseases. Therefore, animal manure often contains antibiotics. Once manure is applied to agricultural land to improve soil productivity, crops would be exposed to antibiotics which may persist in soils from a few to several hundred days. The objective of this study was to evaluate the uptake of gentamicin and streptomycin by carrot (Daucus carota), lettuce (Lactuca sativa) and radish (Rhaphanus sativus) from manure-amended soil. The treatments were 0, 0.5 and 1 mg of antibiotic kg−1 of soil. Two pot experiments were carried out in the greenhouse. The first was conducted on the three crops and the second exclusively on radish. In radish, the increase in the concentrations of gentamicin was significant between the 0 and both of 0.5 and 1.0 mg kg−1 treatments, but not significant between the 0.5 and 1.0 mg kg−1. The average values were 35.5, 60.0 and 57.4 μg kg−1 for the 0, 0.5 and 1 mg kg−1 rates, respectively. However, the increase...