Microplastics in waterways and soil are fueling calls to reduce the pervasiveness of plastic in agriculture.By Liza GrossFarmers have relied on plastic since the 1960s, when the mass production of affordable agricultural tools derived from petrochemicals made them widely accessible. Plastic mulch quickly became a cornerstone of crop production, helping farmers boost yields of everything from corn to tomatoes by stabilizing soil temperature and controlling diseases and weeds with fewer pesticides.