Antibiotics that are added to cattle feed have produced numerous benefits. However, when those antibiotics are excreted in manure and the manure is spread over cropland, plant growth and development might be affected. A series of greenhouse experiments were conducted to determine the effects of two antibiotics, chlortetracycline and oxytetracycline on plant growth and development in sandy loam and clay loam. In sandy loam, the antibiotic concentrations were either 0 or 160 ppm. Edible radish yields, and the nutrient uptake of wheat and corn were greater with either antibiotic than they were with the control treatment. Pinto beans were affected by both antibiotics. Bean yields, plant heights, top and root dry-weights, and the Ca, Mg, K, and N contents were all decreased by the antibiotics. Because only beans showed an adverse response in the sandy loam, they were the only plants grown in the clay loam. There were no antibiotic effects on the bean plants with either antibiotic in a concentration series of 0–160 ppm. The growth and development effects were related to soil characteristics and plant sensitivities.

Batchelder, A.R. 1982. Chlortetracycline and oxytetracycline effects on plant growth and development in soil systems. Journal of Environmental Quality 11(October):675-678.

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