Source: Michael St Maur Sheil
INTRODUCTION |
Agriculture is essentially a manipulation of ecosystems to produce or raise organic matter (crop plants or livestock) from the use of land. By employing various technologies and techniques, production can be maximised (use of fertilisers, genetic developments, irrigation, mechanisation), while other methods are used to minimise loss of crops through pests and weeds (including mechanical weeding, biological control, use of pesticides such as insecticides, fungicides, herbicides).
The purpose of agriculture has traditionally and primarily been to meet the demand for agricultural products, mainly food, but also raw materials for fibre manufacture. Although the underlying purpose of agriculture has not changed, the nature, structure and ways in which these demands have been met have all changed greatly over the last few decades, and will continue to do so.
Changes have resulted from a variety of factors. These include: patterns of consumption of agricultural products; food distribution and processing; genetic development of agricultural production and other technological developments; the progressive globalisation of agricultural markets; and the influence of national and international agricultural policies.
The failure of European agriculture to meet demand during World War 2 and shortly after, made security of food production the main objective of agricultural policy from the late 1940s. Every country in Europe has encouraged its farmers to produce more food through a variety of mechanisms, including price support, other subsidies, and support for research and development. As a result, European agriculture has been able, on the whole, to meet the needs of a population of about 680 million people in Europe ever more abundantly, and with increasing cost efficiency.
The success achieved in agricultural production has, however, entailed increased impacts on the environment, ranging from pollution of groundwater to loss of habitats for plants and animals. The natural vegetation of Europe, which once consisted predominantly of woodlands, with a relatively small number of animal and plant species (see Chapters 8 and 9), has been greatly modified as a result of agricultural activities, and many habitats as well as landscapes are reliant on extensive agriculture. During the last three decades the introduction of modern, more intensive, agricultural techniques has accelerated these changes.
European agriculture is an extremely diverse and heterogeneous economic sector in terms of the products generated, the nature and structure of production units, and the variability of potential impacts on the environment, and it is difficult to make meaningful generalisations. Nevertheless, using the available data (see Box 22A), this chapter aims to show the trends in agricultural structure and practice which have evolved to meet demands, and to indicate the associated potential impacts of agriculture on the environment.
ENVIRONMENTAL IMPACTS |
Agriculture is a human activity that, without doubt, affects the environment. However, it is important first to consider the extent to which agriculture itself is a victim of a degraded natural environment. Increased concentrations of sulphur dioxide and nitrogen dioxide in the atmosphere are harmful to plant growth. Tropospheric ozone can have a marked effect on yield, with yields diminishing as concentrations increase (UNECE, 1992) (see also Chapter 32). Increases in ultraviolet-B solar radiation may possibly inhibit the growth of certain plant crops and a whole range of organisms extending from bacteria to vertebrates (UNECE, 1992) (see Chapters 16 and 28). Air pollution can have effects on crop growth, and climate change may also have effects on some important crops grown in Europe. Chapter 27 examines the potential impacts of climate change and of increased carbon dioxide levels in the atmosphere on agriculture.
The extent and causes of the environmental impacts from agricultural practices vary significantly across Europe, particularly by farm type and by crop type. 'Industrial'-type farms, consuming large amounts of energy, raising livestock intensively and growing crops which demand high levels of fertilisers and pesticides, are commonly found in Europe. Often, on these types of productive units, farming has been carried out without due consideration for the environment. However, these intensive units are only part of the picture, and other, smaller, farms in Europe, particularly Southern Europe, bring a heterogeneity to the agricultural sector and its techniques, and therefore variations in agricultural practice, which determine the effect on the landscape and environmental media. Smaller farms where land is used intensively contribute to soil erosion, for instance, in Southern Europe. There are also many variations in the nature of the receiving environment (for example, different soil types or climatic and weather patterns) (eg, see Chapters 3 and 7). Table 22.1 summarises selected environmental impacts from agricultural practices.
Air pollution |
Agriculture contributes to a variety of emissions to the atmosphere (including, in particular, ammonia and methane). About 90 per cent of European ammonia emissions (totalling around 89 million tonnes per year) originate from livestock farming and land application of manure (Hartung, 1992; Pretty and Conway, 1988). These ammonia emissions do not only contribute to damage to terrestrial and aquatic ecosystems (with nutrients in rainwater changing nutrient-poor habitats), but also represent an economic loss of valuable nitrogen fertiliser. This problem is particularly acute in agricultural areas where animal husbandry is practised intensively (eg, in parts of Belgium, The Netherlands, Denmark), although often these countries (eg, The Netherlands and Denmark) have specific programmes for abatement of ammonia emissions from agriculture.
Livestock ruminants are also a significant source of methane emissions. In the UK, for instance, cattle and sheep accounted for about one quarter (26 per cent) of total methane emissions (4.4 Mt per year) in 1990 (WSL, 1990). In Poland, animal husbandry accounts for about 35 per cent of total methane emissions (about 2.7 Mt per year) (MEPNRF, 1991). Methane is a potent greenhouse gas, and its role is covered further in Chapters 4, 14, and 27. Acidic deposition to the soil from agriculture as a result of ammonia emissions is covered in Chapters 7 and 31.
Use of fertiliser can contribute to the greenhouse gas nitrous oxide (N2O) emissions (see Chapter 14). Denitrification by bacteria, especially in poorly drained soils, generates N2O. Pesticides drift can result in long-distance atmospheric transport of pesticides, and pesticides residues in rainwater.
Water pollution |
The main types of pollution from agricultural activities are from nitrates, pesticides, runoff of silage effluent, and slurry. Although the main source of phosphorus pollution is from sewage, agriculture, and more specifically
Lowland wetland: Poitevin marshes, France |
The use of pesticides, particularly herbicides, which are also used in non-agricultural circumstances such as on roads and railways, can lead to contamination of waterbodies and residues in drinking water supplies.
Accidental spills and leaks of materials high in organic matter (eg, slurry, silage effluent) into waterbodies can deprive aquatic organisms of oxygen and lead to serious loss of aquatic life. Non-accidental but steady releases of such materials which are also high in nutrients can lead to eutrophication. Erosion of agricultural soils and associated runoff can lead to sedimentation of waterbodies. Suspended sediments in surface waters clog waterways, increase the operating costs of water treatment facilities and silt up dams/reservoirs, reducing their flood control and/or energy producing capacity. These problems are covered in more detail in Chapters 5 and 7.
In some parts of Europe the agricultural demand for water is putting considerable strain on freshwater resources, particularly where irrigation is required. The extent of this problem is described in Chapter 33.
Soil |
Many agricultural practices, if improperly carried out, can result in a decline in soil quality. Erosion of topsoil by surface runoff of water and, to a lesser extent, wind, can be exacerbated by a number of agricultural activities. Soil compaction occurs mostly in areas with highly productive soils and heavily mechanised agriculture (see Chapter 7). The degree of compaction depends on the type of soil, soil water content, the slope of land on which machinery is used, the size of machinery, axle load (weight), the timing and frequency of passage of machinery, and agricultural practices (eg, irrigation).
Overapplication of fertilisers can alter the chemical composition of the soil. Local soil acidification may result, although this can be mitigated by adequate liming. In some circumstances acidification is enhancing the leaching of nitrates and heavy metals to groundwater (see Chapters 7 and 31). Manure, artificial fertilisers and sewage sludge used on agricultural soils all contain heavy metals and other trace elements in addition to nutrients. Sewage sludge used on agricultural soils contains far more heavy metals than artificial fertilisers. However since less sewage sludge is applied to land than artificial fertilisers it is a less important source of heavy metals. Heavy metals can accumulate in the topsoil and may lead to reduced yields by reducing growth, or to elevated levels of these elements in agricultural products, which enter the food-chain if not adequately regulated (see Chapter 7). They can also be directly ingested with soil by grazing animals.
The factors which determine potential impacts of fertilisers include: the compound used; the level of application; the soil type (including the organic matter content of the soil) to which the application is made; the season when the application is made; the intensity of farming (whether cropping or livestock); and the mitigating actions taken (for instance, liming).
Improper soil management, resulting in a net loss of nutrients and organic matter from the soil, affects 3.2 million ha of land in Europe (Oldeman et al, 1991). Loss of organic matter will result in the degradation of soil structure, and this limits root penetration, soil moisture and permeability, which in turn increases the risk of erosion and runoff and reduces the biological activity of the soil.
In Europe (including the European part of the former USSR), it has been estimated that over the total land area about 7 per cent (64 million ha) has been degraded by improper management of agricultural land, and about 5 per cent (50 million ha) has been degraded by overgrazing (Oldeman et al, 1991). The problem is particularly severe in southern Mediterranean areas such as Portugal, where more than 20 per cent of the current agricultural area is highly erodible (Gardner, 1990). This could lead to problems of desertification. In Bavaria, erosion is a problem on up to half of agricultural land (Umweltbundesamt, 1987). In Romania, soil erosion is estimated to affect about one third of arable land, and this is aggravated in some areas by large irrigation projects (IUCN, 1991). Erosion of soil can result from a combination of agricultural practices, including mechanisation, concentration, overapplication of chemicals and irrigation (see Chapter 7).
In fragile, semi-arid environments, such as in the Mediterranean areas, land degradation has increased recently for a variety of reasons and is estimated to threaten over 60 per cent of the land in Southern Europe (UNEP, 1991). The renewed pressure on land resources through migration, the changes in agriculture both in terms of what is produced (cash-crops) and the mode of production (intensive agriculture), the increased demands on water through the development of irrigation schemes, together with the impact of land degradation on flooding, groundwater recharge, salt-water intrusion and soil salinisation has in many cases been responsible for land desertification (CEC, 1994a).
Salinisation and alkalinisation can result from irrigation with improper drainage, and from use of irrigation water with saline content. Excessive levels of salt on and in the soils will seriously affect crop productivity and change the soil structure. Drainage will lower the groundwater table, thus potentially creating conflicts with demands for water resources.
Waterlogging of the soil can result from inadequate drainage and from compaction combined with heavy rainfall or overwatering, causing problems for raising crops on agricultural land.
Most soils contain heavy metals, including copper, zinc, nickel, chromium and cadmium, but these natural contents can be increased by human activities (heavy metals originating, for instance, from road traffic, industry, or waste incineration). There will also be some input of heavy metals from fertiliser (natural phosphates of sedimentary origin contain, for example, cadmium), sewage sludge, and plant protection products, especially copper in viticulture. Some crops take up heavy metals from the soil to such levels that plants may become unfit for human consumption.
Landscape, habitats and biodiversity |
Agriculture plays a significant role in the shaping of the landscape, and many natural landscapes and habitats have been moulded by agricultural use over time, such that the abandonment of agricultural activities would change considerably the appearance of the landscape. Issues of rural development are inextricably linked to agriculture and agricultural policy, and the restructuring of agriculture in Europe (under way in the EU) will lead to further decreases in the agricultural workforce, which in turn may mean less management of the land and soil. Particularly alarming are the loss of many wetlands and peatlands (see Chapter 9) and removal of hedgerows. Rural landscapes are also influenced by forestry practices, such as afforestation (see Chapter 23), tourism and recreation (Chapter 25), by development of infrastructures such as rural road networks, urban spread and industrial development. These factors have all played a role in the reduction of Europe's biodiversity, but it is likely that agricultural development has had the greatest influence (Umweltbundesamt, 1987).
The loss of natural habitats, combined with rising levels of toxic pesticide residues in the environment (which can enter the food-chain via groundwater and surface waters, the soil, the crop itself or through direct contact), has had significant effects on European wildlife and biodiversity. A further impact of pesticide use are effects on non-target species. The channelisation of streams and small waterways running through agricultural land to improve land drainage has often been associated with a decrease in aquatic biodiversity in these waterways (see Chapter 5). However, more environmentally sympathetic solutions such as multi-stage channels are now more often adopted for new works (eg, in the UK and Denmark).
Also of concern in Europe, particularly Western Europe, is loss of visual amenities by changes in the rural landscape, caused for example by removal of hedgerows, clearing of woods, the realignment of watercourses, the disappearance of meadows and riparian forest along waterways, and the abandonment of terraces, often carried out to make mechanised farming easier. Many countries have tried to protect such areas by establishing protected zones, but much of what remains is unprotected and significant changes to the countryside are still occurring. Some of the landscape, habitat and biodiversity questions are examined in more detail in Chapters 8 and 9.
THE EVOLUTION OF AGRICULTURAL PRODUCTION IN EUROPE |
There have been many changes in the nature of the production structure of agricultural systems in Europe since World War 2. These include developments in international trade and agricultural policies (see below), technological developments and greater availability and affordability of many agricultural products, and of the inputs necessary to produce them. These have each influenced the yield, labour productivity and efficiency, and have led to some significant changes in the underlying structure of European agriculture.
Decreases in agricultural employment in all parts of Europe, decreases in the number of farms in most countries, and merging of land and livestock into increasingly larger units are all elements of agricultural 'concentration'.
Greater concentration of farms, land and livestock, and specialisation in a limited range of products, have often been accompanied by an intensification in the use of land, fertilisers, pesticides, feedstuffs and energy. Together, these factors have increased the pressure on the environment caused by agricultural activities.
Highly productive 'industrialised' systems in Western Europe fall into two broad categories. Firstly, there are areas of intensive field-crop farming, dominated by large holdings concentrated in France (the Loire valley to Calais region), eastern England, eastern Denmark, northern Germany and much of The Netherlands. Secondly, there are areas of very intensive agriculture specialising in animal production (dairy products and meat) and/or fruit and vegetable farming found in the coastal and southern areas of The Netherlands, northern Belgium (Flanders), western Denmark, parts of Germany, Provence (France), along the Mediterranean coast of Spain, and central and northern Italy.
Agricultural land accounts for more than 42 per cent of the total land area in Europe, although the proportion varies between less than 10 per cent in Finland, Sweden and Norway, to 70 per cent or more in Hungary, Ireland, Ukraine and the UK. Farming has shaped, and in many ways enhanced, the landscape to which most Europeans are accustomed, and if agricultural landuse changes significantly (for instance under 'set-aside' arrangements in the EU) this could alter the landscape considerably (see Chapter 8).
The heterogeneity of European agriculture is marked by the wide diversity of the size of farm holdings. In the EU (198990, excluding East German Länder), about 8.2 million farms have been counted, of which 6 per cent are larger than 50 ha, but 60 per cent smaller than 5 ha. The average farm size in Greece was 4 ha in 198990, but 68 ha in the UK. Larger holding sizes are more efficient in terms of economic costs; fewer labour hours and less energy are required for fields unbroken by hedgerows, watercourses and other landscape features. For example, England and Wales lost around 20 per cent of hedgerows between 1947 and 1985. Figure 22.1 shows loss of biotopes between 1950 and 1970 near Groenlo, The Netherlands.
In the Eastern and Southern regions for which there are data, there is a large number of holdings of fewer than ten hectares, and in most countries in the western region the average size of holding is larger, with fewer farms. This second group includes countries like Denmark, the UK, The Netherlands, Belgium and France, where the trend over time has been an increase in average size of holding while the number of farms has been decreasing. Figure 22.2 illustrates this pattern. For instance, in France the average farm size increased from 19 ha in 1970 to 28 ha in 198990, and in the UK from 54 ha in 1970 to 68 ha in 198990.
In the Eastern region there has been a slower increase in the average size of holdings than in the countries shown in Figure 22.2. The development of agricultural structure has been heavily influenced by the policy stance of the former centrally planned economies. In East Germany, for instance, the three successive land reforms between 1945 and 1960 eradicated the dual structure of quasi-feudal properties and family farms, replacing it with an almost universal system of large-scale agricultural holdings.
The development of agricultural structure in Poland, with respect to average holding size, was different from other countries which had centrally planned economies. Farms tend to be much smaller because arrangements for land tenure (with 72 per cent of farms privately owned) were maintained under communism. The system was therefore not replaced by the industrial-type units common to a number of the countries in Central and Eastern Europe (MEPNRF, 1991).
Agricultural production and employment |
Since the 1950s, the demand for more secure, cheaper and more plentiful supplies of food in Europe has been met by significant increases in average yields and efficiency of production in terms of inputs of labour and capital. Variations across Europe reflect the heterogeneous nature of agriculture as well as differences in local climate, soil quality and available water resources. The diversity of European agriculture is also expressed in the variety of production types used in different parts of Europe.
The importance of agriculture in a country's economy can be measured by its share of GDP. For the eastern region, up until recently, this has been measured by the gross material product (GMP), which is based on material product balances. In the EU, farming makes a small and declining contribution to GDP in each country: the average was 2.8 per cent in 1991. It was lowest in Germany (1.3 per cent), the UK (1.4 per cent) and Belgium (2.1 per cent); and highest in Greece (16.1 per cent) and Ireland (8.1 per cent) (CEC, 1994b). In the Eastern region of Europe, data for the combined contribution of agriculture and forestry to GMP at current prices are available. In 1989, these sectors contributed 13 per cent to GMP in Bulgaria, 15 per cent in Poland, 16 per cent in Romania, 10 per cent in the former Czechoslovakia, and 14 per cent in Hungary (1988) (E/SB, 1991). In most of these countries, the contribution of agriculture to national product has declined since 1985 (there was no clear trend throughout the 1980s).
Figure 22.3 shows the index of agricultural production for selected countries in the different regions of Europe since 1960. The corresponding decline in agricultural employment is also shown. The gains in labour productivity in most parts of Europe are clear: fewer people are working on the land, but increases in production have nevertheless been achieved, explained mostly by higher yields from increased inputs, mechanisation and genetic development of products. The area of agricultural land used in Europe has hardly changed since 1960, and if anything it has decreased by a few per cent.
There have also been consistent gains in agricultural production and labour productivity in the Eastern region up until 1989. For cereals, an increase in production of 18 per cent was achieved during 197590. Despite these steady gains, much of the Eastern region remains a net importer of food. In fact, the gains in production and labour productivity for most countries in the Eastern region were not as significant as in other parts of Europe. Furthermore, dramatic reductions in overall agricultural production took place in some of these countries following the instabilities and changes of the late 1980s (see Figure 22.3).
In the Western region of Europe, total agricultural production has increased significantly since the 1950s. In the EU in particular, increases in production have been sustained to the extent that there is an excess supply of some products such as cereals, meats and dairy products. Wider availability of agricultural products, increased purchasing power of consumers enabling greater exercise of choice between products, and changes in consumer tastes resulted in increased supply of some products, such as red meat and dairy products. However, the same is not true for animal feed, and some EU countries import large amounts of this each year for the intensive feeding of livestock. This creates a nutrient surplus at the farm level in some countries (eg, in Northwest Europe), originating from the disposal of animal wastes, which contributes to problems of eutrophication in the freshwater and marine environment, and increased ammonia emissions to the air.
Employment in agriculture has shown a sharp decrease in all regions of Europe since 1960, but the average percentage of the total workforce in most of the Eastern region countries is still high when compared with the EU average of 6.2 per cent in 1991. For example, in East Germany it is estimated to be about 10 per cent; in Poland and Romania around one quarter of the working population is employed in agriculture and forestry combined, while in Bulgaria the proportion is about 20 per cent (E/SB, 1991). Although the average proportion employed in agriculture in the EU is low, dipping to less than 3 per cent in Belgium and the UK, in Greece it is 21.6 per cent and in Portugal 17.5 per cent (CEC, 1993).
Crop yields |
Yields, measured in tonnes of harvested crop per hectare (t/ha) of agricultural land, have improved because of a number of factors: genetic improvements in crop types, intensification and better technology. For example, total European production of cereals alone increased from 199 million tonnes in 1970 to 283 million tonnes in 1990 (ie, by 42 per cent; world production increased by 62 per cent over the same period). Against this, the area harvested for cereals in Europe declined from 72 million ha in 1970 to 66 million ha in 1990. This increase in production has therefore been derived from a reduced area of land. This is significant because it is against productivity in terms of yield (t/ha) of agricultural product from an area that the quality of the (manipulated) ecosystem needs to be assessed. If agricultural activity is modifying the ecosystem in such a way that yields cannot be maintained in the longer term, then the activity can be defined as 'unsustainable'.
In the EU, there have been considerable increases in crop yields: average wheat yields increased from 3.2 t/ha in 1975 to 4.9 t/ha in 1991. In the Eastern region (including the former USSR) average wheat yield was 3.0 t/ha in 1990. In 1990, the greatest quantities of cereals were produced by France (55 Mt) and Ukraine (48 Mt). France also had one of the highest yields (6.1 t/ha), whereas yields in Ukraine were about half these (3.6). The highest average yields for cereals are achieved in Northwestern Europe. The Netherlands has the highest yields (7 t/ha), but it is also one of the smallest producers. Belgium, the UK, Denmark and Ireland all produce average yields of about 6 t/ha.
Within the EU there are many variations in average yields. For instance, the average yield for cereals in France is 6.1 t/ha compared with 1.9 t/ha in Portugal, due to the differing crop types, soil type and climatic conditions. For durum wheat ( Triticum durum ), grown in many Mediterranean countries, the highest yields will always be lower than the best yields achieved for different wheat varieties grown in more northerly countries. Variations are partly the result of different climatic and natural conditions, but they also reflect variations in other critical factors such as the level of modernisation and use of chemical inputs.
In the Eastern region, countries with the highest yields in 1990 were the former Czechoslovakia, East Germany and Hungary. But there are also large variations in yields between countries: in 1990 the former Czechoslovakia achieved 5.2 t/ha for cereals compared with only 1.9 t/ha in the Russian Federation, 2 t/ha in Belarus and 3.6 t/ha in Ukraine (see Statistical Compendium for further details on crop yields).
The rate of increase in cereal yields has begun to level off in the Western region. Projections suggest that yields will continue to increase, but at a lower rate of up to 1 per cent per year. In the Eastern region, increases in yield are likely to rise from 1.5 per cent to about 2 per cent per year.
AGRICULTURAL PRACTICES |
The improvements in agricultural yields and productivity described above result to a great extent from the changes in agricultural practice and techniques over the last few decades in Europe. Few practices have remained unaltered by the modernisation of agriculture. Tilling, sowing and harvesting have become increasingly mechanised, and the methods of applying fertilisers and pesticides have become more sophisticated. Intensive agricultural practices, such as the shortening of traditional 3 to 4 year crop rotations, and repeated planting of the same crops year after year (which together deplete the nutrients in the soil) and irrigation, have become widespread.
This section shows trends in those agricultural practices which have the potential to cause environmental damage, and aims to highlight variations in these practices across Europe. The impacts of these practices are summarised in Table 22.1.
Many changes within the agricultural system can be summed up by 'intensification'. The result and aim of intensification has been to achieve increases in production, yields, and labour productivity in agriculture. Intensification of agricultural output is characterised by changes in a number of key factors, some of which can be readily quantified. They include: specialisation and concentration of crops and livestock; use of fertilisers and pesticides; drainage, irrigation and water abstraction; and mechanisation and physical practices (tillage and ploughing). If taken together, these factors broadly indicate that, as a whole up to the end of the 1980s, farming in Europe was becoming more intensive with most of these variables increasing consistently over recent decades in most countries. However, the overall area of agricultural land used in Europe has not seen large changes.
Intensification of farming has been particularly acute in northern EU countries, especially in The Netherlands, northern France, the southeast of the UK, Belgium, Denmark and parts of northern Germany. In the Southern, Nordic and Eastern regions it has been less intense but is nevertheless occurring. In some countries of the Eastern region, the problems of intensification are exacerbated by the inappropriate use of agricultural inputs (see fertiliser and pesticide use below).
Energy consumption in agriculture is a further factor which can illustrate the intensification of farming systems. Even though agriculture is not overall a large consumer of energy, perhaps accounting for no more than 5 per cent of total energy use, mechanisation does involve increases in energy consumption. Unfortunately, data on energy use in agriculture are rarely available, or separate from, those of other activities (for example, UNECE data combine energy use for forestry and fishing with that of agriculture). Calculations of energy efficiency within the farming sector show that some traditional subsistence farming systems use energy much more efficiently than modern, highly mechanised, farming systems (UNECE, 1992). One off-farm activity on which agriculture depends the production of nitrogenous fertilisers by industry has a high energy intensity, although this is usually considered consumption of energy by industry.
Specialisation and concentration of crops and livestock |
Specialisation encompasses a tendency to simplify the countryside in order to enlarge plots of agricultural land, with the purpose of raising just a few products (concentration); and the increased use of agricultural inputs (fertilisers, pesticides, energy). Specialisation is often regionalised, and can be characterised by a reduction in the number of 'mixed' farms which undertake a variety of agriculture. Above all, this has led to the separation of arable land and livestock farming. This has upset the nutrient cycles that were typical of traditional, integrated farming systems. Increasing amounts of fertilisers have been used to try to counteract this imbalance.
Over the last few decades, the range of products generated by European farms has reduced, and become ever more specialised. A loss of genetic potential could result if only a small number of varieties of a crop or livestock covers a large area, or if the number of varieties being used by farmers were to decline. In a specific study into wheat varieties used in UNECE countries, however, no dominant tendency was discernible over the period between 1950 and 1988; some countries increased the number of varieties they used, while others reduced them (UNECE, 1992).
Within the split between crop and livestock farming, there has also been a trend, again more pronounced in the Western region, towards a gradual intensification of livestock farming with bigger herds being grazed on less area of pasture per animal, or perhaps with animals being kept even more intensively in stalls rather than grazed on open land (see Figure 22.4). For example, in The Netherlands, concentrations of cattle and pigs averaged around 2.4 and 7 head per hectare of agricultural land respectively in 1990 (see Statistical Compendium).
Price guarantees for cereals and other crops grown for livestock feed have resulted in a shift of livestock farming from the traditional upland and grassland areas of the EU to the northwestern coastal areas of Europe. Here, because of the high internal grain price in the EU and the low import cost of so-called 'grain substitutes', livestock producers can gain a competitive edge by purchasing the same feedstuffs but at lower imported 'world' prices (von Meyer, 1989; 1993).
A consequence of this trend has been a significant increase in the quantities of excreta produced in some countries. Excreta produced can lead to increased nitrogen input to soils, and estimates of this effect for Europe are illustrated in Map 22.1. The estimates of nitrogen inputs from manure have been derived from landuse types and livestock populations at regional level in Europe. It is the excreta produced by area that is, per hectare which is important. In The Netherlands, for example, livestock excrete much more manure than the land can absorb. The average load of nitrogen from animal manure in The Netherlands has more than doubled since 1960, from 110 kg/ha per year to 241 kg/ha per year in 1988 (CBS, 1961; 1989).
A significantly higher portion of animal excreta is handled as slurry rather than straw manure in Western region countries. This has led to a rising number of pollution incidents related to inappropriate methods of storage and accidental spills of slurry into surface waters and contamination of soils and groundwater. This increases the load of nitrogen and organic matter to the soil, groundwater and surface waters (see Chapters 5 and 7).
Nitrate loads to watercourses and groundwater are also increased by seepage from inappropriately stored animal dung in fields, and field stocks of silage. In some countries (for example, Denmark), the extent of the problem has been recognised and the practice of storing manure and silage in field heaps has now been prohibited. The Netherlands is to address the problem of nitrates and organic loading to waterbodies from manure by having 'quotas' on production and storage of dung.
In some countries (eg, The Netherlands and Denmark) methods of treating excess excreta to produce energy as a source of fuel for heating (biogas) are encouraged, and ways to reduce it to more manageable volumes (eg, dehydration) for easier disposal are also being investigated.
The increased intensity of livestock rearing depends in particular on large amounts of imports of protein-rich feedstuff from non-European countries. Over one third of the world's grain is now fed to livestock. Of this, the production of pork uses more grain worldwide than any other meat industry, and the EU alone produces one fifth of the world's pork. Much of the livestock feed imported to Europe comes from the USA, Thailand, Argentina and Brazil, where there have been huge increases in the area devoted to cultivating animal feed, most of which is exported once harvested. Although, for example, more than 60 per cent of the land surface in The Netherlands is farmland, another five times as much land in other countries, mostly in the developing countries, is used for the production of fodder for Dutch livestock.
Imports of protein-rich animal feed constitute a major addition of nutrients (nitrogen and phosphorus) to the agricultural system, and contribute to the disruption of the nutrient cycle on some farms in Northwestern Europe. In this way, therefore, specialisation and concentration towards animal husbandry in specific areas can lead to mineral surpluses, which contribute to problems such as eutrophication.
Fertiliser use |
Increased use of agrochemicals, including fertilisers, pesticides and other chemicals, has been one of the most influential factors (alongside the genetic development of crop types) increasing yields from agricultural land in Europe. Practices such as short crop rotations and the use of high yield crop varieties demanding large amounts of fertilisers have contributed to nutrient imbalances on European agricultural soils.
Fertilisers can be split into two broad categories, commercial fertilisers and organic fertilisers (manure) the main elements in both being nitrogen, phosphorus and potassium. Leaching of nitrogen (as nitrates) and excess runoff of phosphorus (as phosphates) tend to occur because it is hard for the farmers to 'integrate' fully the fertiliser into the soil in just the right quantities needed and at the right time for the crop. Experiments appear to show that 10 to 60 per cent of fertiliser nitrogen is not taken up by the crop for which it was applied (UK MAFF, 1992). Direct losses of nitrogen occur when there is high rainfall soon after the fertiliser is applied, and application depends on other aspects of the weather during the months which follow. This uncertainty makes an assessment of future yield difficult and, as a result, farmers tend towards overapplication.
In some areas of Europe, agriculture is estimated to be responsible for up to 80 per cent of the nitrogen loading and 20 to 40 per cent of the phosphorus loading of surface waters (see Chapter 14). Furthermore, intensification of livestock farming has led to an animal manure (natural fertiliser) storage and disposal problem in Europe. Use of fertilisers also contributes to atmospheric emissions. For instance, fertilised soils produce 2 to 10 times as much nitrous oxide as unfertilised soils.
Average consumption of nitrogen fertiliser per hectare of agricultural land has increased in Europe (excluding the former USSR, but including Turkey) by 75 per cent between 1970 and 1989. The average consumption per hectare in 1989 was about 31 kg nitrogen/ha for Europe, including the former USSR and Turkey, but double that at 63 ­ if the former USSR is excluded.
High inputs of nitrogen fertilisers occur mainly in arable land, with the exception of the intensive grasslands of Northwestern Europe. Figure 22.5 shows the consumption of nitrogen fertilisers per ha for the different regions of Europe during 197090. Nitrogen fertiliser consumption in most countries in the Western region is higher than for most other regions. In the Western region fertiliser use rose steadily until 1970. Since then, in most countries, consumption has not increased at the same rate as before, and towards the end of the 1980s consumption of nitrogen fertiliser began to level off or even fall slightly in some countries. There are significant variations between countries in consumption per hectare of agricultural area, with less than 50 kg nitrogen/ha in, for example, Spain, Austria, Portugal and Switzerland, and below 20 kg nitrogen/ha per year in the former USSR and Iceland, to over 190 kg nitrogen/ha in The Netherlands. In The Netherlands, the total amount of nitrogen provided by artificial and natural fertilisers has been well above 200 kg nitrogen/ha per year for most of the 1980s, although since 1985 it appears to have fallen rapidly. Denmark alone accounts for over two thirds of the nitrogen leached from farmland in Scandinavia.
In the Eastern region the trend of steady increases in fertiliser use has been similar to that of the Western region. In some countries the problems of farm intensification have been exacerbated by the inefficient use of agricultural inputs.
By contrast, average application of phosphorus fertilisers in Europe has remained fairly constant over the last 20 years at just over 30 kg/ha (P2O5 unit) of agricultural land per year. In 1990 this ranged from over 50 kg phosphorus/ha in Belgium to 23 kg phosphorus/ha or less in Albania, Austria, Iceland, Romania, Sweden, Switzerland, Turkey, the UK and former Yugoslavia (Figure 22.6). In general phosphorus is strongly fixed by most soils. Only on soils with low adsorption capacity (such as sandy soils), where shallow water tables and phosphorus-demanding crops are grown (such as maize), is phosphorus released to groundwater (as in parts of The Netherlands).
Map 22.2 shows the nitrogen supply from fertiliser in agricultural soils in Europe (see also Chapters 5 and 7) estimated from fertiliser consumption and regional landuse data. (These same data form the basis of the estimates given in Chapter 5 of the risk of nitrate leaching to groundwater.) Map 22.3 shows the combined nitrogen supply to agricultural soils from fertiliser and manure (see 'livestock' above.) The highest nitrogen loads are clearly in Northwest Europe, and particularly Belgium, The Netherlands and northwestern Germany (atmospheric deposition, originating mostly from combustion of fossil fuels and volatilisation of ammonia, generally contributes about 10 to 20 kg/ha per year in most parts of Europe).
A further consideration when examining the use of fertilisers in agriculture is their contribution to air pollution. The upward trend in the production of manure and silage (Map 22.2), together with the overapplication of commercial fertilisers, has significantly increased emissions of nitrous oxide and ammonia from agriculture.
Agriculture's contribution to acidification is, however, much greater than just that deriving from deposited air pollutants. In some countries of Northwestern Europe there is a problem of potential acidification of soils and groundwater as a direct result of ammonia use as fertiliser. Ammonia fertilisers have been used on agricultural land since the 1960s when appropriate equipment became available to spread them (they are in liquid form). Even sufficient liming may not always prevent acidification: if nitrification takes place below the limed depth, then acidification continues, and in sandy areas may lead to groundwater and surface water becoming acidified (Rebsdorf et al, 1991). (See Chapters 5, 7 and 31.)
Nutrient replenishment in European agricultural soils will continue to be an important issue in the near future. However, increasing awareness among, and counselling of, farmers is likely to lead to changes in the practices of fertiliser use as rates of application are lowered and methods of application become more precise, together with alternative crop management techniques. These include: using organic agricultural practices (see Box 22B); letting fields lie fallow; periodically planting legumes to reduce excess nitrogen by fixation from the air and reducing the necessity for applying nitrogen fertilisers; ensuring vegetation cover in winter by growing wintergreen crops or 'catch crops' to provide soil cover and prevent nitrogen leaching.
However, it is difficult to determine the precise amounts to apply and types of compounds to use so as to minimise potential environmental impacts. This difficulty arises from the considerable variation in field crops, the soil type and groundwater depth, rotation profile and geomorphology. Furthermore, the expense of some of the relatively new technology required to identify at what exact time of the day and season applications should be made renders these determinations additionally complex.
Pesticide use |
Pesticides are toxic chemicals used to control or kill pests (see Chapter 17), and include herbicides, insecticides and fungicides. 'Growth regulator' is also often included in pesticides data. Use of these products has played a significant role in raising the yields of crops from European agricultural land. Heavy use of fertilisers to increase yields intensifies the risk of fungal infections in some crops. The development and widespread application of pesticides has taken place during the post-war decades, with a succession of more sophisticated and effective pesticides being introduced. More modern pesticides generally break down more quickly and have fewer unintended side-effects as they act more selectively than earlier formulations. However, there are many different pesticide products available, containing almost a 1000 types of active ingredients (see Chapter 17). This makes it difficult to deduce environmental impacts.
Data on the consumption of pesticides are far from comprehensive, making assessments of their use difficult; accurate data for many European countries are often lacking altogether. Trends are hard to discern since compounds used vary enormously, and their application depends on seasonal, climatic, crop and geomorphological factors. Consumption is usually measured in terms of the 'active ingredient' (AI), the chemical which controls or kills the pests. The amount of AI is expressed as the weight of the ingredient in individual pesticides. Formulation weight is the actual weight of the product bought in the form that it is to be used. The relationship between these two measures is not constant, and this adds to the difficulties of deriving meaningful patterns from data on pesticide use.
Apparent declining application rates may be misleading because newer generations of pesticide have high potency and require relatively lower application rates (for example, 'sulphonyl urea' or 'imidazoline' and synthetic 'pyrethroid' insecticide formulations). As with the use of fertilisers, there are considerable variations in application rates between different countries; in 1990 application rates for pesticides (per hectare of arable land and land under permanent crops) in The Netherlands were over four times what they were in West Germany, which in turn was estimated to be over five times as much pesticide per hectare as Estonia. Figure 22.7 shows pesticide consumption in some European countries for the latest year available.
Map 22.4 shows the average load of pesticides per hectare of soil under arable and permanent crops. The average used has consistently been around 20 kg/ha per year in The Netherlands. Within the average figure for usage, there is a wide variation. It is estimated that bulb-growing consumes about 120 kg/ha, mushrooms consume 112 kg/ha and greenhouse production takes 106 kg/ha. Two thirds of pesticides are consumed in arable farming, but at the much lower rate of 19 kg/ha (WWF, 1992).
Various factors are forcing much of European agriculture to rethink practices of pesticide use. The trend towards growing large monoculture crops (often repeatedly) has provided ideal conditions for pest infection and many pests have developed resistance to the pesticides employed. Awareness of the dangers of pesticide pollution in drinking waters is also developing, and it is widely recognised that herbicides can reduce biodiversity of natural flora, as more aggressive, resistant weeds take over hedgerows. Pesticides also have an impact on non-targeted wildlife, and many poisonings of animals and birds are recorded each year in European countries (see Chapter 9). Pesticides can affect species directly, through build-up in the food-chain, and also by affecting their food supplies and by changing habitats. It has been estimated that less than 0.1 per cent of the pesticides applied to crops reaches the target pests. Thus, more than 99 per cent of applied pesticides has the potential to impact non-target organisms and to become widely dispersed in the environment (Pimentel and Levitan, 1986).
Many new management approaches to pest control aim to optimise efficiency of pesticide use, and may result in reductions in amounts of active ingredient used. These often involve the integration of several pest control practices and are commonly referred to as integrated pest management (IPM). IPM is essentially a chemically based approach: monitoring pest levels on crops in order to determine the most efficient use of pesticides, while considering alternatives to chemical applications. This move towards more refined approaches, along with the development of genetically engineered pest resistant crops, the use of biological control, assessments of meteorological conditions to anticipate likely changes in pest populations, and more carefully timed application of different, lower-dose pesticides is likely to become more widespread, and may lead to reductions in pesticide use. Varied crop rotations are also an important way of reducing dependency on pesticides. On the other hand, genetic engineering is also used to make crop plants more resistant to herbicides, which may result in such plants having increased dosages.
Pesticides also find their way into the food-chain. Residues of banned compounds can be detected in food long after the compound has been banned for agricultural use in Europe. These residues can also be introduced through direct imports of food from outside Europe, or (more commonly) through imports of animal feed from outside Europe, which is then fed to European-reared livestock. However, it should be noted that it is difficult to distinguish between banned residues from this source and those persistent in the environment from application before banning. Data for Finland of DDT (and PCB) residues in pigs and cattle have been published (UNECE, 1992), which show that, despite the long-standing ban on DDT, residues of this compound are still detectable.
A few European countries have reviewed pesticide use in agriculture and horticulture, and have set specific objectives to reduce use of these chemicals; examples include Denmark, The Netherlands and Sweden.
Drainage, irrigation and water abstraction |
The purpose of drainage is to lower the groundwater table, mainly to remove excess water from clay soils and organic soils to facilitate the production of crops from agricultural land.
Irrigation in Peloponnisos, Greece |
Lowering the groundwater table leads to the oxidation and thus the loss of organic matter. It can also lead to erosion of agricultural soils and the loss of wetlands (see Chapters 5, 7 and 9). Intensive drainage is evident in many countries of Northwestern Europe, and has led to the loss of wetlands in, for example, Ireland (Baldock, 1990).
Water is abstracted for irrigation, and this can also lead to lowering of the water table. Excessive abstraction, in the same way as drainage, can in some places lead to a loss of wetlands. In some areas, particularly those subject to low rainfall combined with high average temperatures and many hours of sunshine, such as in Southeastern parts of Europe, irrigation is leading to the salinisation of significant tracts of arable land. The proportion of agricultural land irrigated (including land irrigated by controlled flooding) is about 5 per cent for Europe as a whole (including the former USSR and Turkey) but varies considerably between countries (Figure 22.8). Albania has irrigated some 38 per cent of its agricultural lands, The Netherlands 28 per cent, but in most countries in the Nordic region the percentages are much lower, due mainly to higher rainfall. In Romania, it has been estimated that, of 3.2 million ha irrigated, 200 000 are salinised (see also Chapters 7 and 33).
Mechanisation and physical practices (tillage and ploughing) |
The level of mechanisation or degree of 'capitalisation' on farms has been following a steadily upward trend over the last two decades, although there are signs that in some regions of Europe saturation has been reached or neared. Despite its benefits in increasing yields, mechanisation has clearly had some adverse environmental effects. The potential impacts of the use of heavy machinery are described in Table 22.1.
Deep ploughing exposes more soil to wind and water erosion. Crop residues can be removed (as opposed to ploughing back into the soil) by, for instance, stubble burning and stubble mulching (removing the stubble and leaving it on the soil surface). Removal of residues can lead to a serious loss of organic content in the soil, which may increase the risk of soil erosion by limiting the ability of the soil to retain humidity. Stubble burning can create a major public nuisance, and in some countries, such as Denmark and the UK (England and Wales), it has been banned, and ploughing straw back into the soil has become much more common.
Although the level of mechanisation in Central and Eastern Europe is lower than that of the West, it has increased steadily since 1970. For example, in 1970 in West Germany, there were 10.6 tractors per km2 of agricultural land. This had increased to 11.8 by 1990. The corresponding figures for East Germany were 2.4 for 1970 and 2.8 in 1990. In Poland in 1987 it was estimated that there were still approximately one million horses in use for a total of 2.8 million farm holdings. More than 1.1 million tractors were in use by 1990 (see Statistical Compendium).
It is easier and more efficient to work in large open fields when using tractors, but on some soils this can lead to soil compaction, particularly with large and heavy vehicles; and, even if it has improved the efficiency of agricultural capital, the practice of increasing field sizes has led to the loss of hedgerows, small streams, ponds and other wetland habitats (see Chapter 8).
AGRICULTURAL POLICIES |
Since World War 2, the context within which agricultural policies have been formed has varied considerably across Europe. Whatever the circumstances, however, the main objectives have been to increase farm outputs and productivity. Objectives have also included support for farmers' incomes and price stability for consumers.
In the EU, the Common Agricultural Policy has played a primary role in the formation of agricultural policy at the national level: it had the goal of ensuring self-sufficiency in Europe (Box 22C). Policies developed in EFTA countries such as Norway, Sweden and Switzerland have been strongly influenced by national concerns to ensure agricultural self-sufficiency and the protection of rural communities; most EFTA countries provide a higher level of support to agriculture than does the EU. In most Central and Eastern European countries agricultural policies have been developed within the framework of central planning, with an emphasis on 'collective' farming and its growth as a public industry, rather than a collection of private farms as in the EU.
Despite the different policy regimes, many similar measures have been adopted to achieve greater and more efficient output from agriculture. These include guaranteed prices regardless of the levels of output and demand for certain products (dairy products, cereals, beef and wine); financial support through subsidies and low-interest loans for investment in certain types of capital; high border protection (with internal prices high and unrelated to world markets); land reclamation and farm rationalisation; support for farming in marginal areas (often with serious environmental consequences); and an expansion of research services. Policies using these measures were particularly effective among the countries of Northwest Europe, where agricultural production and labour productivity have risen substantially since the 1960s (see also Figure 22.3). However, this success has led to excess supply of some products in the EU. Some of the most important effects on the environment that can be linked to agricultural policy have resulted from price support systems for agricultural products one of the main features, for example, of the CAP.
The challenge therefore is for agricultural policy to recognise that there are three different basic needs to reconcile: the production of food and agricultural products, the protection of the environment, and the maintenance of the socio-economic fabric of rural areas. Specific measures (CEC, 1993) designed to help farmers reduce impacts on the environment and to protect the rural landscape include financial compensation or assistance for:
In some countries, for example The Netherlands, Germany, Denmark and the UK, other initiatives are also being taken by national governments which aim to complement the objectives of the CAP reforms, and also those of the EC Directive (91/676/EEC) concerning the protection of waters against pollution caused by nitrates from agricultural sources. These include setting limits for the amounts of chemical inputs that can be used and the quantities of manure produced (and therefore the numbers of livestock maintained) in defined nitrate-sensitive zones (the UK) or in the whole country (The Netherlands, Germany and Denmark).
In Central and Eastern Europe the highest priorities for agriculture, as with other economic sectors, have since 1989 been to increase production, efficiency and exports, particularly to Western Europe. Many Central and Eastern countries are at the same time trying to recast policy from that of the command-led economy to more market-based systems. This brings pressures to remove subsidies to allow prices, more similar to market levels, to prevail. A further aim is to maintain or increase revenues to avoid rising agricultural unemployment. The direction of agriculture in Central and Eastern Europe will be strongly influenced by the policies followed in EU and EFTA countries; these policies will also have a wider impact on socio-economic development of rural areas in Central and Eastern European countries, where environmental concerns have not yet been integrated into agricultural policy as much as in Western Europe.
CONCLUSIONS |
European agriculture is an extremely diverse and heterogeneous economic sector in terms of the products generated, the nature and structure of production units, and the variability of potential impacts on the environment. Because of this, it is difficult to make meaningful generalisations. Nevertheless, some overall description of the main developments in European agriculture is possible from the information available.
Oilseed rape |
There is an increasing interest in various forms of low input, extensive and traditional farming systems. In the EU, Member States are now required to offer incentives to encourage such systems where they can bring environmental benefits. One such system that may be encouraged to expand as a result is 'organic' farming.