Floral Diversity in Organic and Modern Farming

Floral Diversity in Organic and Modern Farming Is Organic Farming better for floral diversity than modern farming? 1.0 Chapter 1 Introduction1.1 Introduction. Agriculture has had a profound impact upon biological diversity. Agricultural specialization, mechanisation and intensification leading to compaction and soil erosion, and poor farm management, have resulted in a global decline in plant, invertebrate and bird numbers in recent decades (Stoate et al., 2001). The Law of Specialization has encouraged the clearing of natural habitat for the cultivation of a few species, with biodiversity being the victim of this â€Å"trade off† between productivity and variety. This â€Å"modern† approach to agriculture was encouraged and sponsored (i.e. through the Common Agricultural Policy – CAP) by the government after the Second World War. The impact of rationing was still fresh in the minds of the UK population and a concentrated effort was made to increase agricultural output. The â€Å"baby boom† of the 1950s also added incentive to these efforts. The drive to increase agric ultural output was a great success. New fertilizers (N, P, K) and pesticides (DDT etc) were extremely successful at improving crop yields. As time went by however, evidence began to slowly emerge of environmental damage. Despite growing environmental concerns, and numerous academic studies highlighting the negative impact upon floral diversity by modern agricultural practices, the world’s population is estimated to rise to 9-10 billion by 2050, which means there will be increasing pressure on land to build new homes. Consequently, global food security is heavily dependant upon technological advances in order to avoid Malthusians scenario of poverty and famine due to â€Å"overpopulation†.   The question is whether organic farming is better for floral diversity compared with â€Å"modern† farming, but ultimately, even if evidence points to the fact that organic is more favourable than â€Å"modern methods†, the question will be will it be capable of meeting the growing demands placed on agriculture and solve environmental problems? 1.2 Early concerns Rachel Carson sounded the warning bell against the processes and practices associated with agricultural intensification in her book, Silent Spring, published in 1962. In it Carson takes a negative view on the increasing use of agricultural chemicals:    Since the mid-nineteen forties, over 200 basic chemicals have been created for use in killing insects, weeds, rodents and other organisms described in the modern vernacular as pests, and they are sold under several thousand different brand names. The sprays, dusts and aerosols are now applied almost universally to farms, gardens, forests and homes non-selective chemicals that have the power to kill every insect, the good and the bad, to still the song of birds and the leaping of fish in the streams to coat the leaves with a deadly film and to linger on in soil all this, though the intended target may be only a few weeds or insects. Can anyone believe it is possible to lay down such a barrage of poisons on the surface of the earth without making it unfit for all life? They should not be called insecticides but biocides. (Carson, 1962). Carson also talked about the detrimental use of Dichloro-diphenyl-trichloroethane (DDT). Research in the intervening years have somewhat validated her basic argument, though there were some criticisms concerning inaccuracies in her book. The Stockholm Convention is a global treaty to protect human health and the environment from persistent organic pollutants (POPs).   POPs, of which DDT is one of a so called â€Å"dirty dozen†, are chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of living organisms and are toxic to humans and wildlife.   In acting as a signatory to the Convention, the Government signalled its intention to eliminate or reduce the release of POPs into the environment. 2.0 Pollution and Biodiversity Our knowledge of the ways in which Biodiversity is essential for the survival of humans, in addition to many other species, is still evolving. From unidentified species to potentially undiscovered medicines, biodiversity is an issue of worldwide importance, providing natural resources which are essential for sustaining not only life on earth, but also economic activities. Biodiversity helps to maintain a healthy and stable environment in which businesses can operate, and its conservation is increasingly viewed by scientists, economists and businesses alike as a key part of economic stability. The growth of environmental legislation in recent times represents a governmental acknowledgement of, and response to, a strong body of scientific data establishing links between pollution and the environment. In the UK, The Royal Commission on Environmental Pollution, established in 1970, interpreted â€Å"pollution† in broad terms of the â€Å"introduction by man into the environment of substances or energy liable to cause hazards to human health, harm to living resources and ecological systems, damage to structures or amenity, or interference with legitimate uses of the environment† (Royal Commission on Environmental Pollution, 2004).   The availability of natural resources is dependant on a stable environment, which is maintained by complex interactions and processes within and between ecosystems. Any significant impacts of environmental pollution on biodiversity can impact upon our biosphere (Trevors, J.T., 2003). The costs following the loss of ecosystem services, and the resources they support, are unpredictable but likely to be considerable, therefore the management and minimisation of this risk should be of high strategic importance to any business. The Royal Commission on Environmental Pollution’s broad definition of pollution effectively means that pollution can be anything that causes damage and/or aggravation to people, wildlife, or the environment such as chemicals, noise or gases. Due to the complex nature of relationships between organisms in an ecosystem, the release of pollutants into the environment can not only kill organisms outright, but they can also change the conditions and processes occurring within a system and result in changes that can degrade entire habitats and disrupt ecological processes. These changes have the potential to cause long-term environmental change through the accumulative effects of their release. Pollutants arise from a variety of sources, such as toxic substances, accidental spills, industrial processes or illegal dumping. Not all pollutants are necessarily man-made, however, human activities often exacerbate or increase their polluting effects. For example, uranium is a naturally occurring radioactive waste that needs to be safely managed, increasing the risk of contamination and radiation that can cause lethal genetic mutations and killing living organisms. In terms of biodiversity, uranium mining often occurs in remote areas that are considered valuable for biological diversity, therefore the control of risks such as leakages into groundwater and food chains is essential. The amount of pollution in the environment is a very significant issue; pollution needs to be reduced in order to reduce its impact on biodiversity. Efforts to reduce pollution often reveal the complex nature of environmental pollution. In the UK during the 1970s and 1980s there was a growing realization that freshwater eutrophication was an increasing problem. Initial research pointed to phosphorus from industrial pollution as the main source of pollution, particularly from Sewage Treatment Works (STWs) due to a growth in phosphate-based detergents. Additional tertiary treatment at STWs failed to reduce levels of eutrophication in the long-term and it soon became clear that diffuse pollution from agriculture was, and is, the main factor resulting in continued water quality problems. The use of P fertilizer has generally exceeded agronomic requirements and led to soil P saturation. Whilst P is an essential plant nutrient, excessive concentrations are affecting the ecosystems natural coping mechanism. The result is one of â€Å"the most pressing environmental problems facing the UK today† (Environment Agency, 2005). 2.1 Ecological Impacts What are the associated ecological impacts of the post-war drive in agricultural intensification? The impact of this intensification on bird populations has been dramatic. Birds provide good indicators of environmental change as they are easily monitored, well researched, and high up in the food chain (Furness and Greenwood, 1993). Between 1970 and 1990, Fuller et al (1995) found that 24 out of 28 species had contracted in range, with a decline of abundance in 15 out of 18 species for which population change could be assessed. Of these species, seven had declined by more than 50%, declines being most pronounced amongst granivorous species (i.e., those with a substantial seed component in the diet). Similar range contractions and population declines were not found in bird communities of woodland or other widespread habitat types over the same period. In addition to fertilizer and pesticide use, practices associated with agricultural intensification also included cultivation and re-seeding of grassland, simplified crop rotations, loss of marginal habitats and increased grazing levels. All of these practices were likely to have an impact on the availability of food for nesting and feeding birds (Wilson et al, 1999). The case of the decline of grey partridge Perdix perdix L. populations in Britain however, complicates this assertion. The decline was partly attributable to poor chick survival as a consequence of the effects of herbicide-spraying of cereals on insect food supply and not necessarily a reduction in food availability (Potts, 1986). However, agricultural practices have affected arable flora in one way or another. What species have been affected? Gramineae (including wild species and stock feed crops e.g. rye grass) Many agricultural practices affect grass abundance e.g. after fertilizer application, grazing intensification, herbicide application, cutting regime and ploughing. However, Wilson et al (1999) show that some of the practices had detrimental and non-detrimental consequences, some promoting abundance of some grasses whilst reducing abundance of others. For example, Increases in cutting, grazing, tillage, fertilizer applications and herbicide usage thus cause declines in species diversity, but favour those species responsive to these conditions, including the meadow-grasses Poa, which are of particular importance in the diet of farmland birds. Polygonaceae The Polygonaceae, represented on temperate European farmland mainly by Polygonum (knotgrasses and persicarias) and Rumex (docks and sorrels), have the capacity for high seed production, making them a rich source of food for birds but invasive weeds of arable and grassland. Reviews of long-term population trends (Wilson et al., 1999) suggest that most Polygonaceae in arable areas are likely to have declined dramatically, whereas in pastures, roadsides, spoil heaps and waste ground, populations may be increasing. Chenopodiaceae This family on farmland is represented by Chenopodium (goosefoots), Atriplex (oraches) and Beta (mainly cultivated forage and sugar beets). In non-crop Chenopodiaceae, herbicide applications and grazing control populations whilst fertilization may encourage growth due to preference for high Nitrogen concentrations. Populations have declined in arable areas (Wilson et al., 1999). Caryophyllaceae The main genera taken by birds on temperate European farmland are Cerastium (mouse-ears), Silene (campions and catchflies), Stellaria (chickweeds and stitchworts) and Spergula (spurreys). With the possible exception of chickweeds, decline of Caryophyllaceae on arable land is likely to have been widespread, but in pastoral areas and other fertile, disturbed areas, not subject to intensive herbicide control, population of chickweeds and mouse-ears may be maintaining themselves or increasing (Wilson et al., 1999). Asteraceae Composites found on temperate farmland in Europe include Arctium (burdocks), Artemisia (mugworts), Carduus (thistles), Centaurea (knapweeds), Cirsium (plume-thistles), Helianthus (sunflowers), Leontodon (hawkbits), Senecio (ragworts and groundsels), Sonchus (sow-thistles), Taraxacum (dandelions) and Tussilago (coltsfoot), all of which are eaten by birds. Of these, sunflowers are oilseed crops grown mainly in warm temperate farmland, whilst the remainder are all found in the wild flora. Evidence points to declines caused by cultivation and herbicide use, and increases in response to increased grazing pressure and fertilizer use. Dandelions are adversely affected by regular ploughing, whereas modern grassland practices such as intensive grazing and inorganic fertilizer application probably favour growth. In the long term, populations of most composites are likely to be stable or declining in intensively arable areas, but in other fertile, disturbed sites, not subject to inte nsive herbicide control, populations may be increasing (Wilson et al., 1999). Brassicaceae The diet of farmland birds includes Alliaria (garlic mustards), Capsella (shepherd’s purse), Raphanus (radishes), Thlaspi (pennycresses), Brassica (includes wild and cultivated varieties of oilseeds, turnips and cabbages) and Sinapis (charlock). Overall, wild Brassicaceae have probably declined dramatically on intensive arable farmland in recent decades (Wilson et al., 1999). Fabaceae On temperate European farmland, Fabaceae are characterised by low, creeping nitrogen-fixers such as Medicago (cultivated lucerne and medicks), Trifolium (clovers and trefoils) and Vicia (vetches and beans). Better drainage and regular grazing encourage legumes, but loss of ley-based rotations has reduced the overall availability of clovers and vetches as sown crops. In the long-term, populations of wild clovers and vetches on farmland are likely to be declining due to herbicidal weed control and grassland improvement, but sown populations of certain clover species (mainly white T. repens L. and red clover T. pratense L.) will mask these declines in areas where grass-clover leys are still sown (Wilson et al., 1999). Labiatae, On farmland, Labiatae are characterised by Galeopsis (hemp-nettles), Lamium (dead-nettles) and Stachys (woundworts). Herbicide applications are detrimental to most members of the family. In the long-term, populations of dead-nettles and hemp-nettles are likely to be declining in arable areas, although dead-nettles may be increasing in other fertile, disturbed habitats (Wilson et al., 1999). Ranunculaceae, Ranunculaceae (typified by buttercups Ranunculus) are in long-term decline in both arable and pastoral farmland, probably due to a combination of herbicide control on arable land, fertilization of grasslands, and loss of pasture to cultivation (Wilson et al., 1999). Boraginaceae, On farmland, Boraginaceae are characterized by Myosotis (forget-me-nots), which are known to be sensitive to herbicide applications. There is also some evidence that populations of field forget-me-not M. arvensis (L.) Hill are in long-term decline in arable land (Wilson et al., 1999). Plantaginaceae, Violaceae, Herbicide application was the only agricultural operation recorded as having detrimental effects on Plantaginaceae (plantains) and Violaceae (violets and pansies) (Wilson et al., 1999). Urticaceae, A review by Wilson et al., (1999) found no evidence of specific impacts of agricultural practices on Urticaceae (nettles). In the long term, however, common nettle Urtica dioica L. and annual nettle U. urens L. are likely to be stable or declining in arable habitats as a result of herbicidal weed control, but are probably increasing elsewhere in disturbed, fertile habitats. Amaranthaceae Amaranthaceae (pokeweeds) are serious agricultural weeds in the Americas (Cousens and Mortimer, 1995), and increasingly so as aliens in parts of Europe. A review by Wilson et al., (1999) found no data on the effects of agricultural operations on the abundance of this family in Europe. 3.0 Analysis of Organic Farming3.1 Organic farming Organic farming has been shown to benefit some species. Recent studies in England suggest that organic systems support more broad-leaved plants than conventional systems. (e.g. Kay and Gregory, 1999). Kay and Gregory (1999) found that, out of 23 rare or declining arable plant species, 18 were more abundant on organic farms, with 13 of them being absent on conventional farms. However, if improvements were made in mechanical weed control technology in conventional farms these differences in plant abundance and species richness between the two systems could be reduced. 3.2 Organic farming a solution? When the environmental problems in agriculture came into spotlight, different forms of organic farming had been practiced in Europe for several decades. These farming methods were quickly presented as a solution for most of the problems agriculture is facing. One reason for the increase in organic agriculture in many countries in Europe today is the need to solve environmental problems. In such situations, we often tend to accept appealing solutions. Furthermore, intensive propaganda by representatives of organic farming movements has had a strong influence on public opinion, politicians, and scientists. But what is the likelihood that Organic farming can meet the requirements of agriculture and solve some of these major environmental problems? Although some environmental problems were already identified as a result of the industrialization of societies from the 19th century, the breakthrough of broad environmental consciousness, as epitomized by the Silent Spring by Rachel Carson, took place in the 1960s. New research orientations, national and multinational environmental protection agencies, and environmental interest organizations were founded. Within agriculture several organizations, sharing a prejudiced view of nature, biodynamic and organic-biological, promoted their agricultural methods as a solution to the environmental problems. One theory of organic farming, biodynamic farming, which is part of a comprehensive philosophy called anthroposophy, was presented by Steiner in 1924. Its aim was not to solve environmental problems but to introduce a form of production forces’. Biodynamic and other forms of organic agriculture exclude easily soluble inorganic fertilizers and synthetic pesticides on principle (KRAV, 1999). A comprehensive review was made by Hole et al. (2005) of the impacts on biodiversity of organic farming relative to conventional agriculture. They identified a wide range of taxa, including birds, mammals, invertebrates and arable flora, which benefit from organic management through increases in abundance and/or species richness. Also highlighted were three broad management practices (prohibition/reduced use of chemical pesticides and inorganic fertilisers; sympathetic management of non-cropped habitats; and preservation of mixed farming) that are largely intrinsic (but not exclusive) to organic farming, and that are particularly beneficial for farmland wildlife. However, most problems that occur in conventional agriculture may also be present in organic farming, such as erosion, nitrogen leaching, ammonia volatilization from animal wastes, high levels of native soil cadmium, accumulation of trace metals in soil, and subsoil compaction caused by farm machinery. Organic farming methods do not offer solutions to many of these problems. For example, the exclusion of easily soluble inorganic fertilizer does not necessarily imply less leaching or less eutrophication. On the contrary, leaching of total N from soil receiving animal manure, either composted or anaerobically stored, can be much higher than from inorganic fertilizer applied at the same N rate if measured over several years. Green manuring can also cause high nitrate leaching losses. From an environmental point of view, it does not matter whether the nutrients come from inorganic or organic sources. What matters is when, how and in what quantity plant nutrients are available to crops, i .e. if the nutrient supply is in synchrony with the demand of the crop (Myers et al., 1997). Crop quality is put forward as an important argument for organic farming. Crop quality depends on the plant nutrient status in the soil, the dynamics of nutrient release, weather conditions during growth, damage caused by pests, toxic compounds produced by the crops themselves and the adherent microflora, contamination with pesticides and pollutants, and the post-harvest treatment. Several investigations have clearly shown that the type of fertilization, contrary to the principle of organic farming, does not affect plant quality (e.g. Hansen, 1981) whereas the intensity of fertilization does. Thus, crop quality is not dependent on the principal difference between inorganic fertilization and organic manuring. Furthermore, considerable variation in crop quality can be found between farms regardless of whether they are using conventional or organic methods. This division into ‘organic’ and ‘conventional’ agriculture loses sight of the principal factors concerni ng crop quality and environmentally friendly agriculture. In contrast to conventional agriculture, organic farming without purchase of feed may result in a nutrient depletion of soils (Nolte and Werner, 1994). Through the import of feeding stuff to farms, which means a net input of nutrients, depletion is normally avoided. As the feeding stuff may be produced elsewhere with inorganic fertilizers, organic farming indirectly depends on the soil fertility of conventional farming. However, regulations about the amount of conventionally grown feeding stuff to be used in organic farming differ between countries. Side-effects caused by synthetic pesticides and drug feeding are not found in organic farming, a positive result. However, the exclusion of pesticides may result in increased concentrations of secondary plant metabolites and of mycotoxins of field fungi. Eltun (1996) reported higher concentrations of deoxynivalenol and nivalenol in grain samples from organic than from conventional farming. Furthermore, in the same experiment no pesticide residues were found in grain samples grown conventionally. Thus, the exclusion of pesticides does not necessarily mean that crop products do not contain unwanted substances. The area for housing and outdoor movement of farm animals has received more attention in organic than in conventional agriculture. This concern is positive and space requirements should be determined for all types of farming. Humans have kept livestock for millennia, resulting in the selection of animals with behaviours that differs from the wild species. The natural behavior can not be the only guideline for livestock management. It is important to keep animals in such a way that the special requirements of each species are fulfilled and destructive forms of behaviour are avoided. In order to understand today’s organic farming movement, it may be useful to know that the highly influential form of organic agriculture, biodynamic farming (Steiner, 1975), had its roots in a philosophy of life and not in the agricultural sciences. A common attitude within the organic movement is that nature and natural products are good, whereas man-made chemicals are bad, or at least not as good as natural ones. This way of thinking may also explain why man-made fertilizers and synthetic pesticides are excluded. Although there is no reason to believe that nature is only good, as exemplified in agriculture by crop failures, plant or animal diseases, and the effects of natural disasters, this romantic way of thinking is widespread. The forces of nature are fantastic and filled with still unknown secrets, but at the same time the results of natural activity may be ‘bad’. That is why natural conditions cannot be the only guideline for an ethical code about interac tions between humans and nature. We have to define an ethical code that takes into account the full truth, and it is our responsibility to do so. As indicated above, views and beliefs originating from a philosophy of life are the driving force behind organic farming. People should have free choice concerning religion or a philosophy of life and a strong ethical foundation is very important, but placing philosophical ideas above scientific thinking, especially if they contradict scientific results, leads to severe communication problems. For example, to demand the exclusion of synthetic fertilizers shifts matters of science into the field of dogma. The fundamental question, why plant nutrients should be added in organic forms or as untreated minerals only, has never been proved. 4.0 Analysis of Alternatives4.1 Alternative solutions The bottom line is that current agricultural practices are not sustainable and alternatives are needed. Plant, invertebrate and bird numbers have all declined during the last century as a result of land management practices, whilst excess levels of fertilizer inputs have led to deteriorating water quality problems (of which, groundwater contamination and eutrophication are perhaps the most significant). The cause has been the increasing intensification and specialisation of farming, with a shift from mixed farming to arable farming in the east and grassland in the west. Biodiversity has also been impacted by the planting of autumn cereals. Whilst Organic farming is being promoted as a better alternative, there is growing interest in the use of genetically modified-based agriculture. 4.2 Biotechnology and Genetically Modified Foods Biotechnology can potentially play a significant input into sustainable agricultural productivity, particularly for poor and/or small scale farmers in developing countries. Some of the benefits include development of techniques to 1) facilitate enhanced resistance to insect pests/diseases responsible for reduced yields 2) ability to tolerate drought/salinity or heavy metals. The Nuffield Council on Bioethics, concluded in 2003 that some GM crops offer real benefits to those in the developing world. Thomas (SDI, 2003) uses the example of half the cotton grown in China during 2002 being genetically modified. The GM crops produced a toxin to the cotton bollworm, a pest that can devastate crops. Yields were estimated to have increased by 10% whilst there was a 60% decrease in reported cases of humans being impacted by the toxic effects of applying pesticides without protective clothing. The report did, however, highlight a need for economi c, political and social change. Watkinson (2000), in a study on sugar beet genetically modified to tolerate broad-spectrum herbicideglyphosate, found that densities of fat hen, a common weed in sugar beet, were less than 10% of those in conventional crops. The seeds of fat hen are an important winter food resource for farmland birds. Skylarks forage preferentially in weedy fields, so therefore the impacts of GM crops critically depend on the extent to which high-density patches of weeds are affected. Argentina provides another example. The uptake of Monsanto’s round-up ready soya was phenomenal during the mid to late 90s. Some 13 million hectares were converted to GM. However, increasing dominance of larger farmers has resulted in many smaller farmers leaving their lands. Traditionally, many people were employed for weeding but increased herbicide usage has resulted in unemployment and increasing concerns surrounding the impact on human health (Branford, 2002). The benefits of using herbicide resistant crops in this context are therefore questionable. Monsanto needs to assess GM application in Argentina in order to learn from any mistakes and develop best practice guidelines for the future. Companies such as Monsanto and Syngenta appear, committed to principles of global sustainable agriculture and both have germplasm protection projects, in addition to community and environmental projects. Monsanto, in conjunction with Bayer CropScience; BASF; Dow Agrosciences; Dupont and Syngenta have established an Agricultural Biotech Council (ABC) in order to promote a reasoned and balanced debate surrounding the use of agricultural biotechnology. However, it appears more like a union to promote the benefits of agricultural biotechnology. 4.3 Biosafety During the Convention on Biodiversity (CBD) negotiations, governments were aware of the potential modern biotechnology had with regards the achievement of its 3 main aims; the conservation of biodiversity, the sustainable use of the components of biodiversity, and the fair and equitable sharing of the benefits arising from the use of genetic resources. There was, however, a proviso for adequate safety measures for the environment and human health. This proviso constitutes Article 19 of the CBD, which relates to the handling of biotechnology and the distribution of its benefits. Four paragraphs constitute Article 19 and require parties to the Convention to: 1) take appropriate measures to ensure effective participation in biotechnological research activities, especially developing countries 2) to take practical measures to promote and advance access on a fair and equitable basis 3) to consider requirements of a protocol addressing   (including advance informed agreement) and; 4) make available information about the use and safety regulations, as well as any information on the potential adverse impact of the specific organisms. Decision II/5, established an Open-ended Ad Hoc Working Group on Biosafety to develop a draft protocol on biosafety, specifically focusing on transboundary movement of any living modified organism resulting from modern biotechnology that may have adverse effects on the conservation and sustainable use of biological diversity. The details and history of this working Group, from its formation to the subsequent adoption of the Cartagena Protocol on Biosafety to the Convention on Biological Diversity on the 29 January 2000, is rather convoluted. Environmental / human health consequences and concerns arising from introduction of GM plants led to the development of regulatory regimes to assess safety. Imports of GMOs into the UK (and EC) are covered by existing Community legislation Council Directive 2001/18/EC on the deliberate release into the environment of GMOs. The Protocol is therefore most beneficial to developing countries without existing legislation on GMOs and who require information before deciding on the conservational and sustainable impact of accepting GMO imports. In the UK, further EC regulations were adopted arising from the need to address exported obligations. Such issues have led to the implementation of EC Regulation No. 1946/2003 on the transboundary movement of GMOs. 4.4 Does Sustainable Agriculture mean sustainable development? The Convention on Biosafety specifically addresses the variety of risks to rural ecosystems, particularly i