Efthymia Alexopoulou

New Insights into the Propagation Methods of Switchgrass, Miscanthus and Giant Reed

A general obstacle to the development of perennial grasses is the relatively high cost of propagation and planting. The objective of the present study was to investigate new propagation and planting methods of giant reed (Arundo donax L.), miscanthus (Miscanthus x giganteus Greef et Deuter) and switchgrass (Panicum virgatum L.). Field and open-air pot trials were carried out in four different locations across Europe: hydro-seeding of switchgrass was tested in field trials at the experimental farm of the University of Bologna, Italy; stem propagation and bud activation methods of miscanthus were evaluated in field experiments in Péteri, Hungary; giant reed rhizome and stem propagations were compared in a field trial in Aliartos, Greece; finally, an open-air pot trial was carried out in Catania, Italy, using single-node stem cuttings of giant reed. Hydro-seeding emerged as a feasible and promising technique for switchgrass to ensure prompt seed emergence and weed control during plant establishment. Direct stem plantings of miscanthus were successful, and activated stem-buds were able to sprout in field conditions; however, timely stem transplant was determinant for shoot density and biomass yield. In giant reed, rhizome propagation showed a higher stem density and biomass yield than stem propagation; however, the yield gap was not significant from the second year onwards. Single-node rooting was mainly driven by air temperature. Nodes from basal stems showed higher rooting rates than median and apical ones. Growth regulator pretreatments enhanced rooting rate only at transplanting times under suboptimal air temperatures. In general, these experiments provided insights into propagation strategies aimed at enhancing the establishment phase of perennial grasses.

New Insights from the BIOKENAF Project

This chapter summarizes the most important achievements of the European research project entitled “BIOKENAF—Biomass Production Chain and Growth Simulation Model for Kenaf” (www.cres.gr/biokenaf) that carried out for 2003–2007. The overall objective of the BIOKENAF project was to introduce and evaluate kenaf as a non-food crop through an integrated approach for alternative land use in South EU that will provide diversified opportunities for farmers and biological materials for the “bio-based industries” of the future. Several fields’ trials were carried out in South EU aiming to identify the appropriate crop management for yields maximization (sowing dates, plant densities, best varieties, irrigation and fertilization needs, harvesting time). A dynamic crop-growth simulation model was developed to produce quantitative estimates of the yielding potential of kenaf at regional level. The model was based on the detailed crop data that were collected from the field trials and were included in photosynthetic capacity, respiratory losses, phenology, dry matter distribution, and data on leaf area. The appropriate harvesting time for south EU countries that ensure the highest possible yields with the lowest possible moisture content investigated as well as best storage method in order to the minimum losses in the quality and quantity of the feedstock to be achieved. The suitability of kenaf for both selected industrial products (composites, building materials, nonwovens, paper, and board and absorption particles) and for thermo-chemical energy applications (combustion, gasification, and pyrolysis) was investigated. Following an environmental/economic assessment and market studies insight in the feasibility of kenaf for industrial and energy applications was provided that was used not only for comparison of the crop with other conventional crops with similar cultural practices but also for the development of scenarios for alternative land use and diversified opportunities for farmers in order to produce industrial bio-products that will supply the “bio-based industries” of the future.

Chapter 9 – Assessing the Potentials for Nonfood Crops

Given the ambitious EU targets to further decarbonize the economy, it can be expected that demand for lignocellulosic biomass will continue to grow. Provisioning of part of this biomass by dedicated biomass crops becomes an option. This chapter presents yields and cost levels that can be reached in Europe with different perennial crops in different climatic, soil, and management situations. The AquaCrop model developed by FAO was used and fed with phenological parameters per crop and detailed weather data to simulate the crop growth in all European NUTS3 regions. Yield levels were simulated for a maximum and a water limited yield situation and further converted to match with low, medium, and high input management systems. Low input systems are suitable for the lower quality soils often characterized as “marginal” because of their low suitability to be used for annual (rotational) cropping. In addition, suitability maps specific per crop were prepared according to important limiting factors such as killing frost, length of growing season, and slope. The cost productions were assessed with an activity-based costing (ABC) model, developed to assess the roadside Net Present Value (NPV) cost per ton of biomass. The yield, crop suitability, and cost simulation results were then combined to identify the best performing crop–management mix per region.

The Importance of Perennial Grasses as a Feedstock for Bioenergy and Bioproducts

Abstract This chapter describes the increasing importance of perennial grasses as a biomass source for both energy and nonenergy applications in Europe. Special emphasis is given to the current legislation on renewable energy and concerns regarding the use of food crops for first-generation biofuel production that led to food versus fuel debates, land use change scenarios, and other environmental concerns. Perennial grasses as the “ideotype” of bioenergy crops, bioenergy chains involving perennial grasses, environmental sustainability, and future research perspectives to bring these species into cropping systems are also underlined. Perennial grasses are lignocellulosic, low-cost feedstock, able to grow in variegate environments and to thrive on marginal lands. They have been indicated as the leading candidate feedstock for the modern biobased economy to produce a number of high added-value products (i.e., biopharmaceuticals, nutrient supplements, biopolymers), biomaterials (i.e., buildings, phonic insulating, mulching and biodegradable products for gardening and animal bedding), energy carriers (advanced biofuels, heat and power), and by-products (i.e., soil organic fertilizers, green chemistry products). However, research is still needed in breeding, agronomy, postharvest logistics, and bioconversion to deliver new elite varieties to expand the European market and allow potential yield and desired biomass quality to be reached, while maximizing resources and conversion efficiencies.