Environmental Assessment and Management in the Food Industry (eBook)

Life Cycle Assessment and Related Approaches

J Berlin, U Sonesson, F Ziegler (Herausgeber)

eBook Download: PDF | EPUB

2010 | 1. Auflage
432 Seiten
Elsevier Science (Verlag)
978-0-85709-022-5 (ISBN)

Infos

Life cycle assessment (LCA) of production and processing in the food industry is an important tool for improving sustainability. Environmental assessment and management in the food industry reviews the advantages, challenges and different applications of LCA and related methods for environmental assessment, as well as key aspects of environmental management in this industry sector.Part one discusses the environmental impact of food production and processing, addressing issues such as nutrient management and water efficiency in agriculture. Chapters in Part two cover LCA methodology and challenges, with chapters focusing on different food industry sectors such as crop production, livestock and aquaculture. Part three addresses the applications of LCA and related approaches in the food industry, with chapters covering combining LCA with economic tools, ecodesign of food products and footprinting methods of assessment, among other topics. The final part of the book concentrates on environmental management in the food industry, including contributions on training, eco-labelling and establishing management systems.With its international team of editors and contributors, Environmental assessment and management in the food industry is an essential reference for anyone involved in environmental management in the food industry, and for those with an academic interest in sustainable food production. - Reviews the advantages, challenges and different applications of LCA and related methods for environmental assessment - Discusses the environmental impact of food production and processing, addressing issues such as nutrient management and water efficiency in agriculture - Examines environmental management in the food industry, including contributions on training, eco-labelling and establishing management systems

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1

Improving nutrient management in agriculture to reduce eutrophication, acidification and climate change

C. Cederberg,     SIK – the Swedish Institute for Food and Biotechnology, Sweden

Abstract:

The present organisation of our food production leads to significant alterations of the global nitrogen cycle and this is an important cause of increasing emissions of reactive nitrogen into ecosystems and the atmosphere. In this chapter, important environmental themes related to the mismanagement of the nitrogen cycle – eutrophication, acidification and climate change – are discussed. The prospect of a doubled consumption of animal products in 2050 globally means a giant challenge for stakeholders in the food chain to improve production and to find new innovative ideas in order to substantially reduce nutrient losses from the food chain.

Key words

reactive nitrogen

surplus phosphorous

livestock production

animal products

1.1 Introduction

Eutrophication, acidification and climate change are impacts ranked high on the policy agenda, and today’s food production has a profound influence on these environmental themes. Human alteration of the global nitrogen cycle, which is very much associated with food production, is an important cause for emissions of reactive nitrogen into ecosystems and the atmosphere. Through land clearing, production and use of fertilisers, increasing animal production accompanied by increasing manure production, and discharges of human waste, nitrogen has been mobilised at an unprecedented rate in the 20th century. The role of food production is unquestionable in this context and the task of feeding an increasing world population in the 21st century with less disturbance of the global nitrogen cycle is one of the greatest challenges for all stakeholders in the food chain.

Nitrogen is essential for everything that grows; one hundred years ago, before the introduction of the Haber-Bosch method to synthesise nitrous gas into ammonia, the nitrogen problem was regarded as a shortage problem in food production. Now, at the beginning of the 21st century, the problem is the opposite. There is overwhelming evidence of several serious environmental consequences due to excess nitrogen from human activities. This chapter describes the environmental impact of eutrophication, acidification and climate change, with a focus on the nitrogen issue which is a common problem almost exclusively linked to the food chain.

1.2 Eutrophication and acidification

1.2.1 Aquatic eutrophication

Aquatic eutrophication can be defined as nutrient enrichment of the aquatic environment. Excess input of nutrients increases the primary production of fast-growing algae such as phytoplankton, and as this algae biomass grows, the water becomes turbid. Slow-growing vascular plants (e.g. eelgrass) that are best adapted to low-nutrient environments decrease and the fish community shifts due to habitat changes (less light, changes in plant species). In tropical waters, nutrient enrichment stimulating production of macro-algae can lead to overgrowth and replacement of corals (Cloern, 2001). When driven to a far extent, nutrient enrichment of coastal stratified waters* can cause anaerobic conditions or low-oxygen conditions and result in significant bottom fauna mortality and losses of fish resources.

Generally, fresh waters (lakes, reservoirs, rivers) in temperate regions are phosphorus (P) limited, whereas nitrogen (N) is considered to be the primary limiting element in marine systems. This is however an oversimplification; it was early suggested that both N and P are important nutrients in estuaries and this has been confirmed with observations of P limitation during spring and N limitation during summer in coastal-near environments, such as the Gulf of Riga (Latvia), Roskilde Fjord (Denmark), Bay of Brest (France) and Delaware Bay (USA). Also, present understanding of the relative importance of N and P is strongly biased by the predominance of studies at temperate latitudes, since tropical marine systems seem to be more frequently P-limited (Cloern, 2001).

Increased human disturbance of the nitrogen and phosphorus cycle during the 20th century is the main cause for the eutrophication problem. Nitrogen fluxes in rivers in Europe and the US have increased significantly; movements of total dissolved N into most temperate-zone rivers in the North Atlantic Basin may have increased by as much as two to twenty-fold since pre-industrial times (Howarth et al., 1996). The highest N increases have been found in rivers in the North Sea region. Phosphorus loading to estuarine systems has increased two- to six-fold since 1900. When examined as a whole, existing nutrient records show a rapid change in the fertility of coastal ecosystems over the last half of the 20th century (Cloern, 2001).

Emissions of nitrogen to water from agriculture occur predominantly as nitrate leaching from the soils, but in severe cases it can also be in the form of discharged effluents from manure waste storages. The magnitude of soil leaching is determined by farming systems, type of soils and climate. High livestock density and crop rotations dominated by annual crops with high fertilising intensity and short growing season (e.g. potatoes) are examples of farming systems that are characterised by relatively high nitrate leaching, as opposed to crop rotations with a high degree of perennial crops, such as grasslands. Climate conditions with rainy and mild winters increase risks for leaching, and lighter sandy soils generally have higher nitrate leaching as compared to heavier clay soils.

During the transport of leached N in rivers, there are transformation processes leading to some of the emitted nitrate being removed by plant uptake and denitrification; these processes are referred to as ‘nitrogen retention’. In Sweden, current average retention of nitrogen lost from arable land has been estimated at approximately 40% (Arheimer et al., 1997). In other words, 40% of the leached N from arable land is disarmed in rivers and lakes mainly through the denitrification process transforming the nitrate into environmentally harmless nitrogen (N2), and 60% reaches surrounding seas and water via river mouths as reactive N and is thereby potentially environmentally harmful. During the second half of the 19th century and first half of 20th century, lakes and wetlands were extensively drained to gain more arable land in many European countries and this has affected the net losses of N to surrounding seas since the landscape has lost some of its capacity to neutralize the emitted reactive nitrate and transform it into inert N2. The rise in N concentration in rivers has often been connected to the increased input of fertiliser N. Studies show that there are also other mechanisms, notably draining of lakes and wetlands, which can be as important as the input of fertiliser N in affecting net losses to the surrounding seas from arable land (Hoffman et al., 2000).

Since the 1980s there has been an increasingly efficient removal of P by sewage wastewater systems in the developed world and this has resulted in agriculture’s contribution of diffuse P losses to aquatic environments becoming relatively more important to the eutrophication problem. Phosphorus is lost from arable land by soil erosion, surface runoff and leaching. One problem of today is that many agricultural soils have accumulated phosphorus in excess. In the first half of the 20th century it was seen as economically justifiable to add extra phosphorous when applying fertilisers in order to increase the soil P-content. But the adding of more phosphorus than crops remove and, moreover, application of farmyard manure that is often rich in P, has resulted in high accumulations of phosphorus in many soils. In Denmark, P-accumulation was 1400 kg ha− 1 during the 20th century (Damgaard Poulsen and Holten Rubaek, 2005); in Sweden, soil-P accumulation between from ~1950 to 2000 was around 700 kg ha− 1 as a nation average, and in regions with high animal density around 1000 kg ha− 1 (Andersson et al., 1998). The structural movement towards geographic concentration of livestock production has affected P accumulation in soils in regions with high animal density and this is bound to increase the risk of phosphorus losses to aquatic ecosystems.

1.2.2 Terrestrial eutrophication

Terrestrial eutrophication includes the effects of excess nutrients on plant functioning and species composition in natural or semi-natural terrestrial ecosystems. Under uninfluenced conditions, vegetation in natural ecosystems is mainly controlled by the limited availability of nitrogen. Atmospheric N deposition caused by human activities leads to increased loads of nitrogen and, from this, follows changes in structures and functions in N-limited ecosystems. For example, there is an increased competition from nitrogen adapted species at the expense of less adapted species and an altered tolerance towards diseases, drought, frost, etc. Based on measurements of precipitation in remote areas, annual wet deposition of inorganic N in unpolluted regions is estimated to be in the range 0.1 –...

Produkt-Details

• Erscheint lt. Verlag: 30.9.2010
• Sprache: englisch
• Themenwelt: Technik ► Lebensmitteltechnologie
• Themenwelt: Technik ► Umwelttechnik / Biotechnologie
• ISBN-10: 0-85709-022-4 / 0857090224
• ISBN-13: 978-0-85709-022-5 / 9780857090225