Potential biogas and methane yield of maize stover fractions and evaluation of some possible stover harvest chains

With a yearly global production of about 75 million tonnes of dry matter (DM), maize stover remains a major untapped agricultural resource. While its use as a feedstock for biogas production has been well studied, the methane potential of separate single stover fraction begs further analysis. This study evaluated the composition of maize cobs, husks, leaves, and stalks and the potential of those components to produce biogas and methane. These analyses allowed an estimate of the preferred maize stover harvest chain conditions for quantity and quality. Methane yields from the fractions ranged between 206.6 and 307.0 l N kg-1VS, with husks being the most productive. In total, our estimates suggest that these fractions produce about 3000 m3 ha-1 of methane from the biogas conveniently collected by different harvest chains.