Miscanthus: Planting and Growing (PB5421)

Where will Miscanthus Grow Well?

More experience is needed of yields under a wide range of soil conditions, but current information suggests that most lowland agricultural sites in England should be suitable for miscanthus cropping, with the highest yields coming from deep,moisture retentive soils.

Key determinants of yield are sunshine, temperature and rainfall. The old maize growing zone; south of a line drawn between the Bristol Channel and the Wash, will satisfy the environmental requirements for high yield, but many lowland sites north of this line will also be suitable. Within these areas, annual rainfall levels will effect yield.

Soils

Miscanthus has been reported growing, and producing high or reasonable yields on a wide range of soils - from sands to high organic matter soils. It is also tolerant of a wide range of pH, but the optimum is between pH 5.5 and 7.5. Miscanthus is harvested in the winter or early spring and therefore it is essential that the site does not get excessively waterlogged during this period, as this may cause problems with the harvesting machinery.

Temperature

The potential cropping zones for miscanthus are quite widespread. Photosynthesis, and therefore plant growth, is not achieved at very low temperatures. However, the threshold for miscanthus photosynthesis (6oC) is considerably lower than for maize and, therefore, the potential growing season is longer. The major constraint to long season growth is late spring frosts which destroy early spring foliage and effectively reduce the duration of the growing season.

Yield as plants mature

The yield from the first seasons growth, 1-2 t/ha, is not worth harvesting. The stems do not need to be cut and so the stems may be left in the field until the following season. From the second year onwards the crop is harvested annually. The second year harvestable yields may range from 4-10 t/ha (occasionally up to 13 t/ha), and those in the third year would be between 10 -13 t/ha or more. Peak harvestable yields of 20 t/ha/yr have been recorded at a number of sites. The reason for the variation depends on planting density, soil type and climate. At sites where moisture supply or exposure limit yield, there may be a longer yield-building phase.

Long term yield

The long-term average results from a multi-site study in England show that harvestable yields from good sites, including clay, clay loam and peaty soils, exceed 13 t/ha/yr.Yields from sites at 300 m altitude in the Yorkshire Wolds (ADAS High Mowthorpe) and on free-draining sandy soils (ADAS Gleadthorpe) have been much lower at 9 t/ha/yr or even less.

ADLib logo Content provided by the Agricultural Document Library
© University of Hertfordshire, 2011