Excreted antibiotics can poison plants
Patrick K. Jjemba was curious about the interplay of protozoa and the bacteria they eat in soil. As part of his research, he began altering the organisms' environment. When he applied large amounts of protozoan-killing antibiotics to dirt around the roots of soybeans, Jjemba was amazed at what happened. The drugs—widely used in human and veterinary medicine—did far more than subtly alter the balance of microbial predators and prey. One drug stunted soybeans, and another killed the plants.