Growing miscanthus: making the right choices

What yield can be expected from a miscanthus crop ?

First of all, miscanthus yield at maturity is 10 to 20 tonnes/ha/year, depending on the pedoclimatic characteristics of the plot. Its ICP is 5 MWh per tonne of dry matter.
The best yields are obtained on deep soils with good useful reserves.
Miscanthus has a C4 metabolism: good water availability (useful reserve and rainfall) and high temperature sums will boost a plot's yield.
During the establishment phase, crop yields increase each year, reaching a plateau after 4 to 6 years. The oldest crops in Europe date back more than 20 years: they still produce high yields.

Secondly, in France, miscanthus is suited to most lowland arable land with a minimum rainfall of 500 mm/year. For economically viable harvests, superficial or excessively asphyxiated soils should be avoided. Miscanthus giganteus grows on a wide range of soils, with ph levels from 5.5 to 8.
The risk of damage from wireworms (soil pests) should be taken into consideration in the case of fallow land or old grassland. In this particular case, it's best to postpone planting and plant an annual crop in the meantime.

Miscanthus is best planted in spring on loosened soil, at least 15 cm deep. A finely prepared soil will ensure good soil/rhizome contact, promoting rapid, regular emergence.
Important: miscanthus should be planted on a clean plot, cleared of any perennial grasses such as couch grass or bentgrass. Autumn weeding and false seeding before planting will reduce weed pressure on miscanthus.

Planting Miscanthus

Miscanthus is planted with a specific planter, such as the Novabiom planter, or a manual vegetable planter used for potatoes for example. Except in special conditions, the miscanthus rhizome is placed at a depth of 8 to 10 cm, then covered with loose soil and re-compacted, to allow the best possible soil-plant contact.
Depending on the soil and climate conditions, the planting density will vary from 15 000 to 20 000 rhizomes/ha.

Weeding: intervening at the right time

Miscanthus is also sensitive to weed competition in the first year, so it must be planted on clean soil. Chemical or mechanical weeding can be carried out before and/or after emergence, essentially during the first 3 months after planting. Consult us for information on organic or conventional farming.
Winter maintenance can be carried out to limit competition from weeds: consult us for information on this subject.

Harvesting takes place every year from the second winter after planting. They can be carried out with a conventional forage harvester, equipped with rotary nozzles (Kemper type), between the end of March and April, when the humidity of the canes is lower than 17%. The ensiled miscanthus is thus ready to use: it can be stored in bulk in a shed or covered silo and does not require any drying. It is also possible to mow and bale miscanthus canes.

During the first few months after planting, large rabbit populations can cause significant damage to miscanthus. It is then necessary to install a temporary protection to protect the plantation.
Wireworms should also be taken into consideration: if the pressure is too high, it is recommended to delay the planting of miscanthus in favor of an annual crop.

Finally, Novabiom advises against fertilizing miscanthus if no deficiencies are identified by soil analysis. Nitrogen fertilization would encourage weed development, and it has been observed that miscanthus productivity is not increased by nitrogen fertilization during the first few years. Nevertheless, the mineral reserves of the plot should be monitored every 5 years by soil analysis.

For further information: contact us