By Donald Stotts STILLWATER, Okla. – Livestock producers need to continue to test their pastures for nitrate toxicity levels, even though they may have done so weeks ago and the results showed no reason for concern, said Oklahoma State University Extension experts. “Oklahoma has experienced a relatively mild summer but now we’re seeing hotter, drier conditions that can lead to nitrate issues in forage plants for areas that receive a sudden rainfall event,” said Alex…