[en] Sustainable non-food cropping systems for arable land are being studied intensively both in Scandinavia and elsewhere in Europe to find alternatives, in which the need for economic subvention would be lower than the export subsidies for grain or other food products. The area of arable land available for non-food cultivation is about 1 million hectares in Finland and 20 - 30 million hectares in the European Communities. In addition to conventional crops and afforestatation, it is possible to grow energy plants (willow, poplar, miscanthus, etc.) and agrofibre plants in these areas. Cultivation of energy willows or other corresponding plants of less than 5 m in height is usually not considered afforestation, as a willow field can easily be retaken into agricultural use with certain reservations (e.g., covered drains can be clogged) This article gives a survey of the alternatives for the utilization of non-food cropping systems

[en] An overview is given of bottlenecks and solutions with regard to Dutch sustainable energy supply policy, focusing on biomass experiments

[en] A study was carried out to: determine the factors affecting the cost of energy conversion feedstocks in short rotation intensive culture plantations of trees; determine the factors influencing biomass yield; identify interrelationships between the previous two objectives; present estimates of potential biomass yields and associated economics; and to identify gaps in the knowledge of the economics and yields of biomass production and their interrelationships. Reported costs for most aspects had a wide range. Currently, yields of 10-15 dry Mg/hectare/y are readily achievable. Using the cost and yield data, and assuming a biomass price of $40/dry Mg, a series of cash flow analyses were performed. For the low cost inputs, all scenarios were marginally profitable. For the high cost inputs, none of the scenarios were profitable. A current scenario, using figures for contract farming, was not profitable, however this system would break even with a yield of 23.3 dry Mg/hectare/y, within the range of some production clones. A future scenario using farm labour with increased productivity, product values, and machinery efficiencies yielded a profit-making situation. The addition of incentives increased profitability. There is great potential for the production of woody biomass in Canada as a feedstock for energy and other products. Continued and more intensive breeding and selection to develop high yielding stress tolerant clones, cost efficient harvesting systems, continued research into optimization of planting density, rotation length and cultural techniques, and characterization of promising clones with respect to nutrient-use efficiency, site requirements and pest/disease resistance are important areas for further work. 81 refs., 3 figs., 13 tabs

[en] An update is presented of a study carried out to: determine the factors affecting the cost of energy conversion feedstocks in short rotation intensive culture plantations of trees; determine the factors influencing biomass yield; identify interrelationships between the previous two objectives; present estimates of potential biomass yields and associated economics; and to identify gaps in the knowledge of the economics and yields of biomass production and their interrelationships. Developments in economics and yields in short rotation intensive silviculture for the production of biomass energy since 1991 are documented. The most substantial changes have been: the introduction of new clones in Sweden with a 20% increase in yield; illustrating the potential genetic gains achievable through selection and breeding; and halving of harvesting costs with new machinery. Harvesting costs with chipping incorporated have fallen to $51.21/dry tonne. The twin row ESM and Frobbester harvesters have lower estimated costs of $36.62 and $ 33.69 respectively. Agricultural based machines have further reduced costs to $19.42 and $26.12/dry tonne. Using these new data, three new scenarios were developed for cost of production analysis, using contract labour, farm labour or farm labour plus a subsidy. A contracted operation is now viable with an annual equivalent net value (AENV) of $35/ha. With the use of farm labour for most operations and omitting land rent, profitability increased to $127/ha. With a subsidy of $75/ha, the AENV increases to $205/ha. 25 refs., 1 fig., 3 tabs

[en] Short communication

[en] Precommercial thinning and plantation cleaning offer opportunities for increasing the availability of wood fuel in Canada. In 1992, approximately 130 000 ha were treated with precommercial thinning or stand cleaning. Manual methods predominate in these silvicultural activities; however, at stand densities greater than 10 000 - 15 000 stems/ha, mechanized systems are more economical. Recovering this biomass for wood fuel would require changes to silvicultural systems and harvesting technology

[en] The main objective of the present work, is to study the effect of the addition of different nutrients and irrigation doses on the chemical and energetic characteristics of the Sorghum bicolor (L.) Moench ssp. bicolor biomass. The effect of compost addition is compared with the mineral fertilisation in two different irrigation doses . The experimental parcel, is located at CIEMAT-CEDER (Soria), at 1000 m above sea level, with a extremely weather and a loam sandy soil texture. The results obtained in the tested conditions show: a) the average biomass productivity was 9.81 d.m./ha, and no significant differences between treatments were observed. b) Mean values of the proximate analysis were 72.6 volatile matter, 6.2% ashes and 21.2 % fixed carbon. The volatile matter increases (1.1 %) and the ashes decreases (1.4 %) for the highest irrigation dose both in plots with no addition and in plots amended with compost. c) The N, S and Cl contents decreases for the highest irrigation dose in the same cases above mentioned. Mean values of the elemental analysis were: 45.0 % C, 6.3 % H, 1.4 % N, 0.15 % S and 0.49 % Cl. d) The average High Heating Value was 18071 kJ/kg d.m. and no significant differences between treatments were observed e) For the highest irrigation doses, a reduction in the K₂ O, P₂ O₅, Mg and Si content, and a increase in the Al, Fe and Ti in ashes were detected. (Author) 13 refs

[en] Breeding of clover grass on fallow areas as a resource for methane generation has several important advantages. It does not require any additional nitrogen fertilizer as it can fix the atmospheric nitrogen.Herbicides are unnecessary as most weeds are one-year plants, while clover is perennial. From methane generation data for clover-grass the gross energy generation has been calculated to 11.08 MJ per kg dry matter. Net energy generation (with account for electric power) is calculated to 14.00 MJ/kg dry matter. (EG)

[en] In this study a bottom-up scenario analysis of the global bioenergy production potential is carried out, with specific attention for the impact of underlying factors, existing outlook studies on demand and supply and gaps in the knowledge base that explain the large range in estimates. Key variables are the demand for industrial roundwood and fuelwood, plantation establishment rates and natural forest growth. Key uncertainties are the supply of wood from trees outside and the impact of sustainable forest management (SFM) of yields. Results show that the world is capable of meeting the future demand for industrial roundwood and fuelwood, without further deforestation. The total potential of bioenergy from surplus forest growth and residues is estimated at 27 to 140 EJy^-1 in 2050

[en] During last years, energy crops have been envisaged as an interesting alternative to biomass residues utilization as renewable energy source. In this work, main parameters used in calculating the energy balance of an energy crop are analyzed. The approach consists of determining energy equivalents for the different inputs and outputs of the process, thus obtaining energy ratios of the system, useful to determine if the energy balance is positive, that is, if the system generates energy. Energy costs for inputs and assessment approaches for energy crop yields (output) are provided. Finally, as a way of illustration, energy balances of some representative energy crops are shown. (Author) 15 refs