Growing miscanthus: making the right choices

Although easy to grow, miscanthus cultivation requires a good understanding of the plant and its behavior, particularly when it comes to planting. As miscanthus specialists, the Novabiom team is here to help you make the right choices.

What yield can be expected from a miscanthus crop ?

The yield of mature miscanthus is 10 to 20 gross tons at 15% moisture content per hectare per year, depending on the soil and climate characteristics of the plot.

The best yields are obtained on deep soils with good water reserves.

Miscanthus has a C4 metabolism: good water availability (useful reserves and rainfall) and high temperature sums will promote the yield of a plot.

The quality of planting is also a key factor in yield, with steps that must be carried out with care: preparing the plot, planting, tamping, and weeding.

During the establishment phase, crop yields increase each year, reaching a plateau after 4 to 6 years. The oldest crops in Europe are over 25 years old and still produce high yields.

Choose your plot

In France, miscanthus is suitable for most arable land in low-lying areas with a minimum rainfall of 500 mm/year. To obtain economically viable harvests, shallow or excessively compacted soils should be avoided. Miscanthus giganteus grows in a wide range of soils, with a pH of 5.5 to 8.

Previously fallow or old grassland areas present a risk of wireworm damage (soil pests) that must be taken into account. In this particular case, it is better to delay planting and grow an annual crop in the meantime.

You also need to be aware of risk factors: very clayey soil that is difficult to prepare in spring, excessive stones, white soil, dry soil.

Preparing the ground: a step to take care of

Miscanthus is planted in spring in loosened soil, at least 15 cm deep. Finely prepared soil is necessary for good soil/rhizome contact: this will promote rapid and even growth.

Important: Miscanthus should be planted on clean land, free of residues and with prior management of perennial grasses such as couch grass or bent grass. Weeding in the fall and false sowing before planting will reduce weed pressure on the miscanthus.

Planting Miscanthus

Miscanthus is planted using a specific planter, such as the Novabiom model, or a manual vegetable planter used for potatoes, for example. Unless there are special conditions, the miscanthus rhizome is positioned between 8 and 10 cm deep, then covered with loose, compacted soil to allow for the best possible soil-plant contact.

Depending on the soil and climate conditions, planting density will vary from 18,000 to 20,000 rhizomes/ha. It may be reduced for land development projects.

Weeding: intervening at the right time

Miscanthus is sensitive to competition from weeds in its first year, so it must be planted in clean soil. Weeding, either chemical or mechanical, can be carried out before and/or after emergence, mainly during the first three months after planting. Please contact us for any information on organic or conventional farming practices.

Winter maintenance can be carried out to limit weed competition: please contact us for more information on this subject.

Successful harvesting

Harvesting takes place every year starting in the second winter after planting. It is carried out using a conventional forage harvester equipped with rotating blades (Kemper type) and corn knives, between late March and April, when the moisture content of the stalks is below 17%. The ensiled miscanthus is then ready for use: it is stored in bulk and does not require drying. The quality of the miscanthus cut can be significantly impaired by inappropriate settings or worn parts on the forage harvester; please contact us for more information on this subject.

In some cases, it may be advisable to mow and bundle the miscanthus canes.

The issue of pests and diseases

The wireworm issue must be carefully considered during the establishment phase: if pressure is too high, it is recommended that strategies be put in place to promote rapid and vigorous growth of the miscanthus. The aim of this principle is to shorten the period during which the crop is susceptible to wireworms. In some cases, it may be advisable to delay planting miscanthus in favor of an annual crop.

During the first few months after planting, large populations of rabbits or hares can cause significant damage to miscanthus. Temporary protection should therefore be put in place to protect the plantation.

Fertilization: only in case of proven deficiencies

Miscanthus is a relatively self-sufficient crop, as it is harvested at the end of its cycle, and complete senescence allows nutrients to return to the rhizome, which serves as storage for the next cycle. The leaves fall during the winter, returning to the soil and potentially being remobilized by the plant.

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.

Si votre pH est bas (<6), ou a tendance à baisser, un chaulage avant installation ou tous les 3 à 4 ans pour l’entretien, reste nécessaire.

For more information:

Novabiom has published a best practices guide that we provide to our customers to support them through every stage of setting up their crop, right up to harvest time.

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