Background Paper. Sustainable Bioenergy cropping systems for the Mediterranean. Expert Consultation

Transcription

1 Background Paper Sustainable Bioenergy cropping systems for the Mediterranean Expert Consultation Introduction Bioenergy is a key issue in the context of policies to mitigate global warming, to reduce fossil-fuel imports, and to foster regional development 1. Besides biomass residues from various sources, the dedicated bioenergy production is possible on land not longer used for conventional agriculture products like for food and feed 2. At the same time it is also possible that in future biomass becomes a viable alternative for food and feed production under influence of changes in prices for both energy and agricultural products, which might lead to an increasing pressure on the land. The last years have shown an increasing interest for such bioenergy crops, and some knowledge is available on their productivity, costs, and environmental impacts. However, growing bioenergy crops on agricultural land can create additional pressure on biodiversity, soil, and water resources. These can be limited if the right farming practices and bioenergy crops are used, and environmental guidelines are respected. Aim of the workshop The aim of the workshop is to collect information and to identify knowledge gaps in exploring sustainable bioenergy cropping systems for the Mediterranean. It is meant to provide more input to the discussion on high-yield, low input bioenergy crops suitable for the semi-arid and arid climates of the Mediterranean region. For this, existing experiences and new ideas for such crops (especially perennials, short-rotation coppice) and agro-forestry concepts in Southern Europe are to be collected, and discussed. In addition, the approach of the risk matrices which was used by the European Environment Agency in a recent project (see section background), and the relative ranking of bioenergy crops should be discussed critically, and developed further with special emphasis on the Mediterranean. The workshop is thus structured into 4 sessions: 1 See e.g. the EU Biomass Action Plan COM(2005)628 2 Similarly, bioenergy might be available from marginal land as well, but with typically lower yields, and different environmental, and biodiversity impacts than biocrops from former agricultural land. With an increase in energy prices, a competition to food production may occur when the prices paid for energy crops exceed the commodity prices.

2 Session 1 will look into practical experiences regarding cultivation of bioenergy crops in the Mediterranean, focusing on yields as well as the environmental performance, e.g. their ability to reduce soil erosion, their need for irrigation, pesticide and fertilizer input, etc.. Session 2 aims at collecting information on experiences gained with and possibilities for dedicated bioenergy crop combinations as well as agro-forestry options which promise to combine high yields with relatively low environmental impacts. Session 3 will analyse the environmental impact of different crops in the broader context of the agroenvironmental characteristics of the Mediterranean. Finally, session 4) will add economic, social and technical considerations to the discussion and will analyse the sustainability component of bioenergy in the Mediterranean. Background The European Environment Agency has in a recent project estimated the amount of environmentallycompatible biomass that is available for bioenergy production in the EU 3. The environmentallycompatible potential is the quantity of biomass that is technically available for energy use based on the assumption that this places no additional pressures on biodiversity, soil, and water resources, and that it is in line with other current and potential future environmental policies and objectives. Within this project, an initial selection of environmentally favourable bioenergy crop mixes was prepared with respect to the suitability in different environmental zones of Europe (classified by soils, topography and rainfall patterns). The prioritization was done by specifying matrices in which the different crops are rated according to the following environmental and ecological pressure indicators: 1. erosion 2. soil compaction 3. nutrient inputs into groundwater and surface water 4. pesticide pollution of soils and water 5. water abstraction 6. increased fire risk 7. farmland biodiversity 8. (diversity of crop types) On this basis, an environmental prioritization was made of bioenergy crops per environmental zone 4 by combining information on agri-environmental pressures per environmental zones described in former projects such as Mirabel I and II and IRENA and further reference based knowledge on the present land use and dominant farming systems in the different environmental zones. This bioenergy crop ranking led to the following general conclusions: Perennial bioenergy crops show a significantly lower risk of environmental impacts than most arable plants. Nevertheless, a direct comparison based on the risk matrices is not feasible. So, a percentage of the land in each country could be considered to be dedicated to perennials, foe 3 See for preliminary results a final report is scheduled for publication in May The environmental zones for Europe relevant in this context are Mediterranean North, Mediterranean South and Mediterranean Mountains.

3 example taking into account the current amount of forestry (in order to preserve a diverse landscape structure and create acceptance among the regional population). The data on the cultivation of perennials in the different environmental zones is insufficient. In contrast with annual plants, a detailed assessment could not be done. Therefore, only a differentiation between short-rotation coppice and energy grasses is to be addressed now. Annual bioenergy crops could enlarge the spectrum of cultivated plants, and allow to introduce extensive cropping systems (e.g., double cropping systems). The study concluded that for the Southern European regions, further research is needed into the suitable biomass crop mixes as the study found only few suitable crops for arid regions. Arable biomass crops may increase water abstraction, which is undesirable in regions where water is the main agronomic constraint. Most perennial biomass crops are either not suited for bioenergy production in the very arid summers, or increase the risk for fires in regions where fires are a serious risk already. On the other hand, problems with land abandonment, erosion and the need for alternative rural activities are also creating opportunities to introduce biomass crop production that may provide synergetic solutions for multiple problems. The aim of the workshop is to provide more input to the discussion on high-yield, low input bioenergy crops suitable for semi-arid and arid climates of the Mediterranean region and to discuss the environmental impact of different traditional bioenergy crops in the Mediterranean. Session 1) Objective: Gather practical experience gained with the cultivation of traditional bioenergy crops in the Mediterranean with respect to their environmental pressure, and yields. Practical experience with cultivating bioenergy crops in the Mediterranean region is needed to better estimate their environmental impact. Moreover, discussion on practical experiences will be valuable for selecting pressure indicators for this region. Within a recently completed EEA project, the selection of pressure indicators was based on a qualitative analysis of the main pressures exerted on the environment by different crops as described in existing literature. The starting point was an ecological prioritization of energy crops for German conditions 5, from which due to restrictions in time and resources - only a first step in the direction of an environmentally sound approach to biomass crop production could be made. This will have to be checked against practical experiences made with these crops in the Mediterranean, which should include a discussion on the link between crop mixes and farming practices, as the farming practice strongly determines the environmental impact of biomass crop production 6. The preliminary risk matrices for the Mediterranean zones are shown below 7 : 5 See IFEU/IUS (2004): Nature protection aspects of the use of renewable energies, study supported by the German Ministry for Environment, FZK , Heidelberg/Potsdam (in German) 6 The EEA work did not include farming practices nor the selection of crop varieties. 7 The risk matrices of the crops is only a rough indication of best crop mixes in terms of environmental benefits since in general differences in environmental pressures imposed by different crops are gradual rather than fixed within and between environmental zones and depend strongly on the farming practices applied.

4 Risk Matrix for Mediterranean North Medit. North Other Cereals cultivated grass Clover. alfalfa Sorghum Wheat Sun flower Sugar beets Potatoes Erosion A A A A A B/C C C C soil compaction A A/B A/B A A A C C B nutrient inputs groundwater A B B A A A/B B B C nutrient inputs in surface water A B B A A A/B B/C B/C C pesticide pollution of soils and A A A B/C A B B B C water water abstraction A A A A B B B C A/B increased fire risk --- C --- A diversity of crop types B A A B C A (B/C) B A/B B/C Link to farmland biodiversity B B/C B B B/C A/B B B/C C Risk Matrix for Mediterranean South Medit. South Other Cereals cultivated grass Clover. alfalfa Sorghum Wheat Sun flower Sugar beets Potatoes Erosion A A A A A B/C C C C soil compaction A A/B A/B A A A C C B nutrient inputs groundwater A B B A A A/B B B C nutrient inputs in surface water A B B A A A/B B/C B/C C pesticide pollution of soils and A A A B/C A B B B C water water abstraction A A A A B B B C A/B increased fire risk --- C --- A diversity of crop types B A A B C A (B/C) B A/B B/C Link to farmland biodiversity B B/C B B B/C A/B B B/C C Note: A means low risk, C high risk Maize Mai ze Session 2) Objective: Identify dedicated bioenergy crop combinations, and agro-forestry options for the Mediterranean which promise to combine high yields with relatively low environmental impacts The EEA study previously mentioned suggests that dedicated bioenergy crops such as perennials, short rotation coppice, and double cropping system can combine high yields with relatively low environmental impacts in Northern and Central Europe. However, data and information about the cultivation of perennials in the different environmental zones of Europe is still rather limited. In the Mediterranean, a higher share of the more drought resistant perennial bioenergy crops was assumed, especially reed canary grass, and switch grass. On the other hand, an increased fire risk will have to be taken into account as well as landscape considerations.

5 Another option of high energy-low yield bioenergy production based on annual crops was suggested for some Northern European regions. One example of such a specific farming practice is the double cropping practice. This is a cropping system that has been specifically designed for environmentally friendly bioenergy production and that has given good results in Germany until now. The fundamental characteristics of this system are: no ploughing needed, year round crop coverage, at least 2 crops and 2 harvests a year on the same field; green (wet) crop harvesting reduces the growing period of one crop, leaving time for cultivating a second crop; nearly closed cycles of nutrients by using fermentation residues (energy use: anaerobic fermentation); no (or very limited) pest management necessary as weeds can be used. Furthermore, double cropping could be integrated in the conventional crop rotation schemes. It could have a positive effect on biodiversity because of structural diversity in the fields (growing of numerous different crops e.g. cereals, rapeseed, poppy seed, hemp, sunflower, alfalfa, maize) but also negative impacts because of harvesting twice a year. The double cropping system described above is used to illustrate the principle of dedicated energy crop cultivation compared to traditional arable crops. It is meant as a starting point for the discussion and creation of other extensive alternatives in energy cropping. In particular, this cropping system does not appear suitable in Southern European countries, as it requires availability of sufficient water throughout the year. It will thus be of interest to identify which dedicated low-impact, high-yield bioenergy cropping systems are suitable for the Mediterranean. Session 3) Objective: Analyse the environmental impact of different crops in the broader context of the agroenvironmental characteristics of the Mediterranean The environmental pressures by crops will have to be reviewed in relation to the main environmental characteristics of the regions which make up the context within which the bioenergy crop rating needs to be determined. The characteristics to be incorporated are: a. Climatic suitability b. Present land use c. Present farming systems d. Present environmental problems The Northern and Southern Mediterranean Zones are among the zones with good climatic conditions for agriculture; they have the longest growing seasons but precipitation is a limiting factor. Water abstraction problems are thus typical for the Mediterranean zones as well as the risk for fire. This is associated with a high risk for soil erosion, particularly in South-western Spain, Northern Portugal, Southern Greece and Central Italy 8. The Mediterranean zones are characterised by a relatively low share of arable land in the utilized agricultural area (UAA), and a high share in irrigated arable land. Farming systems are to a large extent medium-to-low intensive, often high nature-value (HNV) farming. Often, a combination of intensive farming and extensive farming, as well as land abandonment can be found. Land abandonment is particularly a problem in areas where soil, topography and rainfall patterns are more limiting to agriculture such as in mountainous areas in the Mediterranean Mountains zones and in drier/arid areas in the Mediterranean zone. 8 Agriculture and environment in EU-15 - the IRENA indicator report; EEA 2005

6 An increase of biomass crop production in the Mediterranean zones could therefore put an additional pressure on farmland biodiversity, as there is a large probability of intensification. On the other hand, these zones also show a larger problem with land abandonment which could be countered by using cuttings (eg. on some semi-natural grass lands), or using extensive forms of bioenergy crops such as perennials. The choice of the bioenergy crop mixes is therefore very important for the environmental impact. For the choice of the right crop mixes it is important to realise that landscape diversity should be maintained (or increased), and specific bioenergy crop types need to be chosen which do not increase the risk for fires. One advantage of introducing bioenergy crops in these zones could be, however, that they may help to counter land abandonment and erosion risks if introduced carefully. Session 4) Objective: Analysis of the sustainability component of bioenergy in the Mediterranean. Add economic, social and technical considerations to the discussion on sustainable bioenergy crops for the Mediterranean. Sustainable crop mixes will have to take into account environmental considerations in the context of the environmental problems of the region, but also the yields of the crops, which can be seen as a rough proxy for economic efficiency. Furthermore, the availability of bioenergy conversion technologies, transport infrastructures, and the development of the demand side for different bioenergy products need consideration, as well as regional economic development impacts, and employment options. A sustainable bioenergy strategy must also factor in the future development of energy and CO 2 permit prices. If a CO 2 permit price to 60 /t until 2030 is assumed, this would create an economic value in addition to the normal market price from competing energy carriers such as oil, or natural gas (for which prices also might increase due to a crude oil price level of some 50 /bbl in 2030). Under these assumptions, from 2020 onwards the sum of energy and CO 2 certificate prices leads to higher revenues for bioenergy crops than for most food and feed products, even if their price increases in parallel (but at a lower rate). This reflection is underlined by the development of the European oil seed markets which shows that the biofuel demand will be the future driver for rape seed prices (DG Agriculture, 2005). In that respect, bioenergy crops could also create economic benefits. Overall outcome The Workshop aims at collecting the state of knowledge and at identifying the possible need for further research with regard to low-impact bioenergy crop production in the Mediterranean. A Technical Report will be prepared on the outcome of this meeting. The sessions will focus around technical discussions among the participants of the workshop, introduced by a brief a presentation held by the chair person (or co-chair or an expert invited by the chair person). The closing session on the second day will wrap up the discussion and come up with some general conclusions.