Establishment and yield of bioenergy miscanthus on clayplan soil ladscapes

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Bioenergy crop Miscanthus × 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, and consequently, less productive soils in traditional agricultural settings. Two independent studies were conducted over the 2013-14 growing seasons to (1) quantify how both rhizome quality and depth of soil from the surface to the first argillic horizon (or depth to claypan (DTC)) affected early growth and establishment of M. × giganteus and (2) determine nitrogen (N) requirements and yield potentials of M. × giganteus in degraded soils. In the former study, rhizome quality was assessed by measuring rhizome mass, length, diameter and growing buds. Soil was defined as: fine, smectitic, mesic Aeric Vertic Epiaqualf, and had various DTC. In the latter study, fertilizer total N rates applied over two years were 0, 64, 101, 134, 201 and 268 kg N ha-1 for young stands (2- to 3-yr-old) and 224, 314, 404, and 492 kg N ha-1 for the mature stand (8-yr-old) applied over 8 years. In the first study, rhizomes performed best on the most eroded parts of the landscape and larger rhizome length, mass, and diameter had the most positive effect on first-year establishment. In the second study, yield of the young stands and the mature stand was not affected by N rate in 2013. In 2014, yield of a young stand at only one location responded to N and increased by 7.4 Mg ha-1 over the control with the highest rate. Generally these findings demonstrate M. × giganteus resilient for establishment on even the most degraded parts of a claypan soil landscape. Additionally, it indicates that N fertilizer is not required to optimize yield for these degraded soils