Author
Shelver, Weilin | |
DESUTTER, THOMAS - North Dakota State University |
Submitted to: Journal of Environmental Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/9/2015 Publication Date: 3/9/2015 Publication URL: http://handle.nal.usda.gov/10113/62192 Citation: Shelver, W.L., Desutter, T.M. 2015. Ractopamine up take by alfalfa (Medicago sativa) and wheat (Triticum aestivum) from soil. Journal of Environmental Science. 34:86-92. doi: 10.1016/j.jes.2015.03.010. Interpretive Summary: In this study, plants (alfalfa and wheat) were grown in soil containing different concentrations of ractopamine with soil containing no ractopamine as a control. The prime objective was to measure the uptake of ractopamine by the plants and a secondary objective was to determine if ractopamine affect plant growth. Two diverse types of agricultural soils obtained from the Midwestern North America were used to determine if the type of soil affected plant uptake of ractopamine and plant growth. Plant growth was unaffected by the concentrations of ractopamine used in these experiments (up to 10 µg/g) demonstrating the presence of ractopamine had no effect on the weight of the plants. This was observed in both soils. As expected, the weight of the plants was affected by the soil type with higher growth in the higher organic matter soil. The recovery of ractopamine from the soil after the experiment was greater from the low organic soil. Ractopamine was taken up by both plants, with greater uptake by alfalfa than wheat. Furthermore, greater uptake was observed from lower organic matter soil than higher organic matter soil. As would be expected the ractopamine uptake was increased by increasing the concentration of the ractopamine. Generally, the amount of ractopamine taken up by the plants was sufficiently low to not present food safety problem. Technical Abstract: Ractopamine is a beta adrenergic agonist used as a growth promoter in swine, cattle and turkeys. To test whether ractopamine has the potential to accumulate in plants grown in contaminated soil, a greenhouse study was conducted with alfalfa (Medicago sativa) and wheat (Triticum aestivum) grown in two soils having different concentrations of organic matter (1.3 and 2.1%), amended with 0, 0.5, and 10 µg/g of ractopamine. Plant growth ranged from 2.7 g to 8.8 g dry weight (dw) for alfalfa, and 8.7 g to 40 g dw for wheat and was generally greater in the higher organic matter content soil. The uptake of ractopamine in plant tissues ranged from non-detectable to 897 ng/g and was strongly dependent on soil ractopamine concentration across soil and plant tissue. When adjusted to the total fortified quantities, the amount of ractopamine taken up by the plant tissue was low, < 0.01 % for either soil. |