Miscanthus-complemented grassland in Europe: Additional source of biomass for bioenergy

Abstract

Grasslands are estimated to cover over 40 % of the Earth’s land surface. Due to the large areas occupied and environmental effects, grasslands are important for bioenergy and biofuel. In Europe, most grasslands are maintained by regular mowing or grazing. For those on nutrient-poor soils, such maintenance is especially important to avoid species succession and loss of biodiversity. Many European grasslands, particularly semi-natural grasslands growing on nitrogen-poor and stony shallow soils, do not produce high biomass yields, making their maintenance economically unattractive for farmers. However, these poor-soil grasslands usually maintain the highest plant and animal species diversity. The introduction of C4 grasses into C3 grasslands has been investigated as an option to increase biomass yields and economic attractiveness of grassland management. Here, the options of establishing miscanthus into C3 grasslands are discussed. Miscanthus is currently the most productive perennial C4 grass in temperate climates and one of the strongest energy crop candidates. Practical examples of the use of natural miscanthus-dominated grasslands for biomass production can be seen in Asia. In Europe, no-till planting of miscanthus on marginal grassland and use of miscanthus-complemented grassland biomass could increase the productivity of these grassland areas while maintaining biodiversity. As part of the EU-funded project OPTIMISC, field trials with several miscanthus genotypes were established and maintained for 4 years on undisturbed grassland in south-west Germany. Based on the results of these trials and scientific literature review, the following aspects are discussed here: distribution and use of natural miscanthus grasslands; how miscanthus can support biodiversity; and opportunities and potential benefits of miscanthus establishment on semi-natural grassland in Europe.