By Brian Brus STILLWATER, Okla. – Oklahoma State University has received more than $2.6 million to research ways to improve agricultural production while reducing environmental impacts, said Kevin Wagner, director of the Oklahoma Water Resources Center at Oklahoma State University. It will require a holistic approach, Wagner said. Climate, livestock grazing, crop rotation, hydrology, regional economics and more – the systems in regenerative agriculture are just too large, complex and intertwined for a simple solution. To that…