Summary

Miscanthus (Miscanthus x giganteus) is a sterile triploid plant grown in the 80s of the 20^th century in Denmark as a result of crossbreeding a tetraploid species Miscanthus sacchariflorus and a diploid species Miscanthus sinensis. The optimal temperature for its growth is 28-32ºC. The transpiration coefficient of this grass is low, and amounts to about 250-340 l of water per 1 kg of d.m. Due to its high yielding it has high water requirements in the vegetation period, which ranges from 500-600 mm up to 700 mm of rainfall. The well-developed root system of Miscanthus allows cultivation on various types of soil, from sands with low level of ground water to soils with a high content of organic matter.

Nonetheless, Miscanthus should not be cultivated on excessively humid soils which do not freeze annually, as it may limit its yield. The maximum time for the commercial use of a Miscanthus plantation can range from 10 to 15 years. The preparation of the stand before establishing the plantation is a key factor which determines the success of cultivation. Depending on the condition of the soil culture on which the plantation is to be established, the soil should be well-prepared by means of various treatments. In order to gain the plant density of 10 000-15 000 cuttings per ha it is recommended to plant about 16 000 of rhizomes per ha. When establishing the plantation, the interrows are 1 m wide, and the distance between the rhizomes in a row is 0.7--1m.

Miscanthus rhizomes should be planted in early spring. It is often April, but with favourable weather conditions and proper storage of rhizomes the planting can be continued in May. The rhizomes of Miscanthus should be planted at the depth of 5-10 cm. After planting rolling with a smooth roller is performed, and in the case of long droughts the plantation should be watered. The level of fertilization is determined by the richness of the soil and the level of yield. With the yield 10-15 t d.m./ha, Miscanthus takes up about: 60-100 kg of nitrogen, 7-15 kg of phosphorus, 50-130 kg of potassium and 3-12 kg magnesium. The optimal pH for Miscanthus plants is within the range 5.5-7.5.

Miscanthus can be harvested in late autumn, after the vegetation period is over. Nonetheless, in this period Miscanthus has a high humidity, so in order to generate biomass of good quality the harvest is frequently performed in March or April. Biomass collected in this period is a fuel of better quality due to the lower humidity level, content of ash and minerals and the higher net calorific value.

In the European research, the yields of Miscanthus were highly varied, and ranged from 4 to even 44 tonnes of dry matter per hectares per year depending on the soil, weather conditions, the level of fertilization, the age of the plantation and other factors.

The costs of establishing a plantation of Miscanthus in Great Britain are even a half lower than in Poland. The costs of establishing 1 ha of Miscanthus plantation amount to around 2605 €, where the cost of cuttings is 1900 € (73%). The market price of Miscanthus biomass with the humidity of 20% amounts to about 60 €/t. On the basis of the calculations it may be concluded that in Great Britain the mean annual profit from Miscanthus cultivation can range from 230 €/ha in the third year of cultivation up to 658 €/ha after 20 years.

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