Miscanthus Productivity and Nutrient Export on 22 Producer Fields.

On-farm assessments of Miscanthus × giganteus growth and nutrition across a wide range of management and environmental conditions are needed to determine how this crop performs and where it should be placed on the landscape. Therefore, Miscanthus growth and nutrition were monitored during 2014 and 2015 at several landscape positions within 22 commercial production fields in central and southwestern Missouri and northeast Arkansas. Miscanthus shoot density and/or yield were best when it was grown: i) following pasture converted to annual row crops or following row crops; ii) on soils with colluvium parent material; iii) on north-facing backslopes or footslopes; iv) on soils with medium to fine texture; and v) on well-drained/high runoff/low available water soils. Factors influencing nutrient concentrations varied by nutrient, but all concentrations consistently decreased as stands matured and most were more influenced by weather than were yield or nutrient export. Most effects on nutrient export were similar to effects on yield, but some nutrient exports were also influenced by manure history and weather conditions. Overall, cropping history prior to Miscanthus, landscape position, and soil properties such as parent material, soil textural class, and drainage class had the largest influence on Miscanthus growth and nutrition. Weather conditions and inferior soils did not strongly influence Miscanthus production, but excessive soil moisture caused by various soil and weather factors often limited its growth. Thus, Miscanthus may be especially well-suited for vulnerable backslope positions otherwise prone to erosion under annual row crop production. These results will assist with the optimal placement and cultivation of Miscanthus on Midwest landscapes.