Management Factors Affecting Establisment and Yield of Bioenergy Miscanthus on Claypan Soil Landscapes.

Bioenergy crop Miscanthus x giganteus has been well studied for its establishment and yield in Europe and certain parts of the US Midwest but little has been done to investigate these properties when grown on degraded soils, which are typified as being less productive, and consequently, economically marginal in traditional agricultural settings. Two independent studies were conducted to (1) determine nitrogen (N) requirements and yield potentials of M. x giganteus in degraded claypan soils and (2) determine how rhizome quality and claypan soil landscape impact initial growth and establishment of M. x giganteus. In the former study, the effects of N fertilizer rates were investigated at four different locations in central Missouri on a Mexico series soil (fine, smectitic, mesic Aeric Vertic Epiaqualfs). The latter study investigated the relationship between rhizome quality (metrics of mass, length, diameter and active number of buds) and topsoil depth of a claypan soil during first-year establishment. This study was conducted at a research site near Columbia, MO uniquely constructed of 16 blocks that range in topsoil depth from 0 to 40+ cm, characteristic of a claypan soil landscape. In 2013, treatments of 0, 34, 68 and 134 kg/ha had no effect on the yield at all locations. Higher N rates correlated with increased SPAD readings early in the growing season; however, little difference was observed in these readings by September. No yield response to N fertilizer could be due to the ability for miscanthus to recycle nutrients from previous year’s growth, along with its ability to re-partition N into the most photosynthetic-active upper leaves throughout the growing season. In the second study, the hypothesized larger, longer, and more active rhizomes in combination with deeper topsoil depth did not result in higher yields. A replicate year of both studies will be conducted in 2014.