Investigations into the Agronomic and Economic Aspects of Using Peanut (Arachis hypogaea) as an On-Farm Biodiesel Feedstock.

Although farmers have benefited from the creation of transportation fuels from grain and oilseeds, little research has addressed single farm or community self-reliance on home-grown fuels.  The Peanut Biodiesel Project is designed to determine if peanut is suitable for just such a concept through field evaluations and a scale pilot refinery.  A total of 24 peanut cultivars were evaluated in 2006 and 2007 for performance under low input growing conditions.  Low input systems used neither fungicides nor insecticides and limited use of herbicides in order to minimize production costs, thereby making an oil feedstock of minimal cost.  Cultivars were subjected to as many as four different irrigation regimes depending on year.  Dryland peanut yield ranged from 480 to 2800 kg ha^-1 while fully irrigated yield ranged from 680 to 3240 kg ha^-1.  Both the 2006 and 2007 growing seasons exposed peanuts to higher than normal temperatures, drought, and moderate spotted wilt pressure, and 2007 included high pressure from both late leafspot and whitemold.  The cultivar DP-1 gave consistently high yields in all irrigation treatments both years (2620 kg ha^-1) and was among the highest in kernel oil content.  Irrigation increased kernel oil content versus dryland an average of 1.5%, however, both early and late season deficit irrigation regimes did not effect kernel oil content.  Dryland peanut yielded as much as 880 L ha^-1 of oil, while irrigated yields exceeded 1300 L ha^-1.  Average production cost per unit of oil was $0.52 and $0.41 L^-1 for dryland and irrigated, respectively.  Preliminary data from our biodiesel pilot refinery suggests processing biodiesel from farmer stock peanuts costs approx. $0.24 L^-1, thus biodiesel was produced at the farm level for as little as $0.65 L^-1, a 40% savings versus purchased petroleum diesel.