Growing miscanthus: making the right choices

What yield can be expected from a miscanthus crop ?

The yield of miscanthus at maturity is 10 to 20 tons/ha/year, depending on the pedoclimatic characteristics of the plot. Its PCI is 5 MWh per ton of dry matter.
The best yields are obtained on deep soils with a good useful reserve.
Miscanthus metabolism is of C4 type: a good availability of water (useful reserve and rainfall) and high temperature sums will favour the yield of a plot.
During the establishment phase, crop yields increase every year, reaching a plateau after 4 to 6 years. The oldest crops in Europe are more than 20 years old: they still produce high yields.

In France, Miscanthus is adapted to most lowland arable land with a minimum rainfall of 500 mm/year. To obtain economically exploitable crops, superficial or excessively asphyxiating soils should be avoided. Miscanthus giganteus grows on a wide range of soils, with a ph of 5.5 to 8.
Previous fallow land or old grassland present a risk of damage by wireworms (soil pests) that should be taken into consideration. In this particular case, it is better to postpone the planting and to plant an annual crop in the meantime.

Miscanthus is planted in spring on a loosened soil, on at least 15 cm. A soil with a fine preparation will allow a good contact soil/rhizome: it will support a fast and regular emergence.
Important: Miscanthus should be planted on a clean plot, cleared of any perennial grasses such as couch grass or bentgrass. A weeding in autumn and false seeding before planting will reduce the pressure of weeds 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 sensitive to competition from weeds in the first year: it must therefore be planted on clean soil. Weed control, chemical or mechanical, can be done before and/or after emergence: essentially during the first 3 months after planting. Consult us for any information on organic or conventional farming.
It is possible to carry out a winter maintenance to limit the competition of the weeds: consult us for any 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.

Novabiom advises against fertilizing miscanthus if no deficiency is found in the soil analysis. Nitrogen fertilization would favour the development of weeds and it has been observed that Miscanthus productivity is not increased by nitrogen fertilization during the first years. It is nevertheless advisable to monitor the mineral reserves of the plot every 5 years by a soil analysis.