Pyrolysis of mixtures of agricultural plastic waste in the form of polyethylene hay bale covers (PE) (4-37%) and switchgrass were investigated using the US Department of Agriculture's tail gas reactive pyrolysis (TGRP) process at different temperatures (400-570 degrees C). TGRP of switchgrass and plastic mixtures significantly reduced the formation of waxy solids that are produced during regular pyrolysis. Under an atmosphere of approximately 70% recycled tail gas, mostly noncondensable gases were produced along with highly deoxygenated and aromaticized pyrolysis oil. When the atmosphere was diluted further to a recycled tail gas concentration of about 55%, higher yields of liquid product were achieved but with less deoxygenation. TGRP of low plastic mixtures (4-8%) produced oils with increased carbon and reduced oxygen content compared to the fast pyrolysis of switchgrass alone. Noncondensable gas fractions containing high concentrations of H-2, CO, ethylene, and other light hydrocarbons remained a significant portion of the product mixture at temperatures above 500 degrees C.