Fertilizer prices spiked over the past few years amid supply and demand issues, and that’s when Katie Lewis, Ph.D., Texas A&M AgriLife Research soil scientist in Lubbock, took on several projects to examine manurebased fertilizers and their management in cropping systems.Producers are looking for environmentally and economically sustainable management strategies, Lewis said, and they want to determine how manure fits in as a possible fertilizer source.In a five-year project funded by a USDA National Institute of Food and Agriculture grant, Lewis is determining the value of manure in relation to carbon sequestration, greenhouse gas emissions and cover crops with on-farm ...