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Sustainable intensification - changing paradigm in forage production

In recent years, grass and forage research in Europe has been subjected to a substantial shift in the scien- tific and social paradigms in terms of identifying the optimum intensity. In the 2000s, European grassland science focused predominantly on ecosystem func- tioning beyond production functions, as suggested by key topics of the General Meetings of the European Grassland Federation (EGF); e.g., in 2002 (Multi-func- tion grasslands - quality forages, animal products and landscapes), in 2006 (Sustainable grassland productivity) and in 2008 (Biodiversity and animal feed - future chal- lenges for grassland production). However, more recently, the EGF General Meeting of 2010, Grassland and globalization, highlighted grassland production functions in the context of globalized feedstuff mar- kets and intensified production of forages. Production functions of grasslands and forage-crop areas in Eur- ope are gaining in importance because the global demands and increased prices for animal feedstuffs are rising continuously, predominantly due to the increased purchasing power of a steadily increasing world population, as well as the boosting use of bio- energy and the climate change induced threat to agricultural production (Gerber et al., 2010; Godfray et al., 2010). The forage production area has now become a very limited global resource, and thus, agricultural research in general and grass and forage science in particular will have an important part to play when meeting the challenge of an intensified but sustainable production. The sustainable development of agriculture and food systems has recently been addressed by the Standing Committee on Agricultural Research (SCAR, 2009) and the Royal Society (Royal Society, 2009). To meet upcoming challenges, such as increasing demands for products of animal origin, we cannot avoid the need for increased global agricultural pro- duction; i.e. forage production faces the challenge to meet a globally increasing demand that is estimated to double by 2050 (FAO, 2009). In this context, the term 'sustainable intensification' has recently been defined (Royal Society, 2009) and further discussed in the 'Food Security' special issue of the journal Science (e.g. Godfray et al., 2010) and from the Food Climate Research Network, University of Surrey (Garnett and Godfray, 2012). Sustainable intensification aims for the production of more food, feed, fibre and fuel on the same, or even less, area of land while at the same time reducing environmental impacts. So, how and where can more forage be produced sustainably, and more dairy cattle be raised sustainably, to meet the increased demand for dairy products with respect to the situation on the European continent? Regarding the 'where', it has to be considered that intensive dairy systems are dominating the north-western part of Europe, while the livelihood of widespread small farm enterprises in Central and Eastern Europe is more or less based on self-sufficiency. In terms of sus- tainable intensification, it can be concluded due to these different backgrounds that Eastern Europe is fac- ing the challenge to enhance productivity, while north-west Europe is facing the challenge of enhanc- ing efficiency. Overall the challenge of sustainable intensification requires fundamental changes not only in production, but also in the way products are pro- cessed, stored and distributed. Globally, around one billion people still suffer from malnutrition and do not have access to sufficient protein and energy supply, while roughly 30-40% of food is lost as waste (God- fray et al., 2010). The waste of food resources applies to both developing and developed countries, although reasons for the high losses are very different between countries. In developing countries losses are mainly attributable to the poor processing and transport infra- structure and the lack of knowledge and funds for storage technology. In contrast, losses in the devel- oped world are predominantly attributed to waste at the retail and home stage (Godfray et al., 2010). Thus, technical advances notwithstanding, agricultural research will hardly be able to overcome all the above-mentioned challenges without a substantial change in consumer behaviour, e.g. patterns of con- sumption. So, what are the implications of the above-men- tioned trends for grasslands worldwide? Metabolic conversion rates of feed energy into food are relatively low in beef production systems; much lower than that in pork or poultry production systems (FAO, 2006). However, cattle have the advantage that they can be fed solely on fibrous feed because their rumen func- tions as a large fermentation vat. It contains billions of microorganisms, including funghi, bacteria and proto- zoa, and allows ruminants to digest fibrous feeds (e.g. fresh grass, hay, silages), which cannot be utilized effi- ciently by monogastric organisms. This specific charac- teristic of ruminant nutrition provides the opportunity for using obligatory grasslands (i.e. land that is suitable only for grassland use rather than potentially usable for arable cropping) as the exclusive feed resource. Thus, land-use conflicts could be defused because the conversion of obligatory grassland into arable land is mostly constrained by economic and ecological factors, e.g. insufficient or excess water availability during the growing season. Conversely, increasing the proportion of livestock fed on grain may further aggravate land- use competition between the production of food, energy and forage. More than 70% of the agricultural land area worldwide is occupied by grasslands, whereas only around 30% of the agricultural land area in Europe is classified as grassland (FAO, 2008). In global terms, the relatively low-production arid and semi-arid grass- land ecosystems, such as the Eurasian steppe and the South American Cerrado, contribute to the vast area of grasslands. These areas are not only important feed resources for domestic livestock but also highly valu- able regarding their multiple ecosystem functions. For example, they contribute to the global carbon cycle by having huge carbon sequestration potentials through the fixation of atmospheric CO2 in plant biomass. Grasslands thus play an important role in GHG mitiga- tion strategies (Soussana et al., 2010). It is estimated that about 634 Gt of carbon is sequestered in global carbon stocks of temperate and tropical grasslands (IPCC, 2001). Furthermore, temperate grassland bio- mes are important drivers of biodiversity, providing valuable habitats for hundreds of species of plants and animals.

Background | Global grasslands under threat

Abstract | Materials and methods | Results | Discussion | References | Abstract | Land-use changes in the steppe ecosystem of Inner Mongolia Autonomous Region, P.R. China | Land-use change in the tropical savannah (Cerrado) of South America | Sustainable intensification of dairy farming - the specific role of grassland- based forage production | References |

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