Miscanthus
Miscanthus has been grown in the UK for a number of years, primarily as an energy feedstock for burning in power stations or heating systems. Under the Energy Crops Scheme, nearly 2,500 hectares of new plantings were established in 2006.
Miscanthus is a woody, perennial grass with the potential for high rates of growth and a lifespan of at least 15 years. Stems emerge annually in March/April and can reach 1-2metrs in height in the first season. Annual harvesting begins in the second year of the production cycle from February through to April, with crops reaching a height of 3-3.5 metres. Once established, crops can produce yields of approximately 12-14 dry tonnes/ha/yr.
Miscanthus is able to use nutrients very efficiently as it is capable of recycling nutrients into the rhizomes towards the end of the growing season, therefore only very small amounts are taken away with the harvested product. As harvesting only removes the stems with the majority of the leaves remaining in the field, only the nutrients removed by the stems need replacing each year.
Nitrogen use efficiency in C4 crops, such as miscanthus, is higher than in C3 crops and the nutrient requirement in established crops is not likely to exceed 75 kg/ha phosphate and 100 kg/ha potash on soils with nutrient reserves at normal levels for arable crops. Soil nitrogen supply should exceed 150kg N/ha in each of the first two seasons.