'Success of miscanthus determined long before planting'

"When choosing a supplier of miscanthus rhizomes, you should consider the genotype, the emergence rate, the growth rate and the suitability for the Dutch climate," says Florian Ilias of miscanthus specialist Terravesta.

Who is Terravesta and what do you do?
We grow and supply the perennial biomass crop miscanthus, and we partner with farmers to cultivate high-quality crops. In addition to supplying rhizomes, we offer advice and long-term support to help growers make a profitable and reliable investment in miscanthus. We also offer soil carbon monitoring and carbon market services to create additional revenue opportunities for growers.

Is there a growing demand for biomass in Europe?
Over the past twenty years, demand for biomass has tripled. This demand comes primarily from biomaterials and energy production, while supply comes from waste and recycling, agriculture, and forestry. The fastest-growing segment is agricultural biomass. Overall, demand for agricultural biomass in Europe is expected to reach €30 billion annually by 2025.

Miscanthus is gaining popularity in the Netherlands, but results vary. Why?
Miscanthus has proven itself. The quality of the rootstocks, the genetics, and the way the crop is planted are important. Two fields can appear the same on paper, but perform very differently in twenty years.

How does the quality of the nursery translate into performance?
A key indicator is the emergence rate. With current technology, rhizomes should achieve an emergence rate of around 90%. Rhizomes should come from specialized nurseries where mother plants are replanted annually to keep the material fresh and vigorous. This makes the material particularly resistant to harvesting, transport, and planting.

Are the genetics themselves different?
"Our new generation of genotypes is bred for Northern European conditions, such as cold winters, wet springs, and hot, dry summers. They store nutrients more efficiently in the roots, which supports strong early root development."

What does this mean in practice?
These improved genotypes emerge weeks earlier. This allows for faster root development and faster nutrient storage. The result is a commercial harvest in the second year, as opposed to the third year for standard varieties.

Plant density is often overlooked. Where do farmers go wrong?
"Planting too thinly reduces costs, but limits long-term yield. Miscanthus plants have a diameter of 55 to 70 centimeters, so 15.000 to 18.000 living plants are needed for 1 hectare. Given the high emergence rate of 90% of new genotypes such as Terravesta With Athena™, this requires 18.000 to 20.000 rhizomes per hectare. Fewer than that leads to lower yields. Over a period of 15 to 20 years, even small reductions can have a significant financial impact. A tool exists that can analyze drone images, allowing any farmer to count the number of living plants in a field.

How should rhizome prices be compared?
"Look at the price per rhizome, not per hectare. Any price above €0,15 per rhizome (excluding transport and planting costs) indicates inefficient nursery management and is a poor long-term investment for farmers."

Many farmers judge based on stem height. Is this reliable?
What matters is what remains after the winter. The top 30 to 50 centimeters of the stem often break off during storms. Tall, thick stems that age prematurely are prone to lodging. The final yield depends on the number of stems and their chances of surviving the winter. Therefore, we recommend visiting the fields during harvest to compare the different varieties.

Miscanthus is good for soil carbon. How does that work?
As Miscanthus matures, it sheds most of its leaves, forming a thick mulch that is then absorbed into the soil. It continuously adds organic matter to the soil, improving its structure and retaining carbon in the form of humus.

How does carbon in the soil differ from carbon in products?
In many value chains, such as those for building materials, a large portion of the carbon is captured by the processor. However, carbon in the soil remains on the farmer's land and is entirely their property.