Fertilizer Requirement for Native Perennial Plants Harvested for Biomass
Study author(s): Craig Scheaffer, University of Minnesota, Department of Agronomy and Plant Genetics
Years of study: 2008 – 2009
Location(s): Lamberton MN, Rosemount MN, Austin MN
Important: for the complete report, including all tables and figures, please download using the link(s) to the right.
Field research evaluated the effect of N, P2O5 or K2O fertilizer on native prairie biomass yield, energy yield, and nutrient content. At the initiation of the trial, unfertilized biomass yields were 2.7, 1.8, and 3.0 ton/acre at Austin, Lamberton, and Rosemount, respectively, and were increased 45, 27, and 43% respectively by N fertilization. Ethanol yield per ton averaged 108 gallons/ton and decreased slightly with nitrogen fertilization. Ethanol yield/acre ranged from 211 to 323 ton/acre and was increased with nitrogen fertilization. Response to K2O and P2O5 application was less consistent and dramatic compared to N fertilizer. Concentration and content of N, P, K, and S in biomass harvested in the fall were low. Short-term harvest should not deplete soil nutrients. Producers will be able to use nitrogen fertilizer as a management tool to optimize biomass and ethanol yield.