A COMPARATIVE STUDY BETWEEN SUSTAINABLE (ORGANIC) & CONVENTIONAL FARMING SYSTEMS AND THEIR ECOLOGICAL IMPACTS ON THE EARTH BY DENNIS LEE WAN-CHIEN THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE DEGREE OF BACHELOR OF MULTIMEDIA (FILM & ANIMATION) (by Research) in the Faculty of Creative Multimedia MULTIMEDIA UNIVERSITY MALAYSIA October 2008 The copyright of this thesis belongs to the author under the terms of the Copyright Act 1987 as qualified by Regulation 4(1) of the Multimedia University Intellectual Property Regulations.
Due acknowledgement shall always be made of the use of any material contained in, or derived from, this thesis. © Dennis Lee Wan-Chien, 2008 All rights reserved ii DECLARATION I hereby declare that the work have been done by myself and no portion of the work contained in this thesis has been submitted in support of any application for any other degree or qualification of this or any other university or institute of learning. ____________________ Dennis Lee Wan-Chien iii ACKNOWLEDGEMENTS
I would like to thank the following people for their invaluable advice and many helpful suggestions: Dr. Ken Neo, Dr. Neo Mai and Ms. Long Yen Yen. iv DEDICATION This thesis is dedicated to my family and friends, who have been with me through the years, in times of good and bad. v ABSTRACT The conventional farming model has been the agriculture industry’s preferred method of cultivating crops since the 20th century (“Conventional Farming”, n. d. ). This model advocates the use of heavy machinery, chemicals and vast amounts of energy input.
So far, the expenses have been justified in the results as conventional farming has been extremely productive, able to furnish low cost food (Altieri and Nicholls, 2001) and has been a great help in alleviating hunger during humanity’s major population expansions (Prasad, 2005). However, questions have arisen over its environmental impact on the Earth, especially in the long term. Over-reliance on synthetic chemical fertilizers and pesticides, among other aspects of conventional farming, is having major negative impacts on public health and the environment (Pimentel, Hepperly, Hanson, Douds and Seidel, 2005).
Organic farming has emerged as a better way for farming to coexist with the Earth (Lampkin, 1999). This research focuses on comparing the rival farming systems and its overall environmental impacts on the Earth. Focus was given to the areas of energy usage, soil health and biology, water contamination and air pollution. vi TABLE OF CONTENTS COPYRIGHT PAGE DECLARATION ACKNOWLEDGEMENTS DEDICATION ABSTRACT TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES CHAPTER 1: INTRODUCTION 1. 1 1. 2 1. 3 1. 4 1. 5 1. 6 Introduction Research Questions Justification Methodology Scope Thesis Outline i iii iv v vi vii ix x 1 1 3 4 5 6 7 8 8 8 9 11 12 13 13 13 14 17 CHAPTER 2: LITERATURE REVIEW 2. 1 2. 2 2. 3 2. 4 2. 5 Introduction Conventional Agriculture Organic Agriculture Environmental Issues Summary CHAPTER 3: METHODOLOGY 3. 1 3. 2 3. 3 3. 4 Introduction Study Categories Case Study Overview Summary CHAPTER 4: DATA ANALYSIS 4. 1 Introduction 18 18 vii 4. 2 4. 3 4. 4 4. 5 4. 6 4. 7 Energy Input Soil Composition Soil Biology Water Contamination Air Pollution Summary 19 21 24 25 26 27 CHAPTER 5: DISCUSSION & CONCLUSION 5. 1 5. 2 5. 3 5. 4 5. 5 5. 6 5. Introduction Discussion Limitations Future Study Recommendations Conclusion Summary 28 28 29 32 32 33 34 35 APPENDICES REFERENCES 36 37 viii LIST OF TABLES Table 1. Energy balance in cereal crop rotation (gigajoules per hectare) in two farming systems (South-Western Slovakia; 2003 – 2005) 20 Table 2. Soil properties (milligram per kg of soil) in two farming systems (Eastern Sicily, Italy; 2002) 23 ix LIST OF FIGURES Figure 1. Average energy inputs for corn and soybeans (millions of kilocalories per hectare per year) in three farming systems (Rodale Institute Farming Systems Trial; 1991 -2000) 19
Figure 2. Percentage of soil carbon in three farming systems (Rodale Institute Farming Systems Trial; 1981, 2002) 21 Figure 3. Percentage of soil nitrogen in three farming systems (Rodale Institute Farming Systems Trial; 1981, 2002) 22 Figure 4. Greenhouse gas (GHG) emissions per hectare in two farming systems (Netherlands) 26 Figure 5. Greenhouse gas (GHG) emissions per mg of product in two farming systems (Netherlands) 26 x INTRODUCTION 1. 1 Introduction Conventional Farming At the turn of mass industrialization, agriculture saw massive change in its application and techniques of cultivation.
Various kinds of heavy machinery were invented and manufactured. There were new breakthroughs in the development of chemicals for use as fertilizers, pesticides and herbicides. The rapid rise of mechanization and use of chemical inputs increased agricultural efficiency many times over. The agricultural revolution had begun. Early in the century (“Agriculture”, n. d. ), it took one American farmer to produce food for 2. 5 people. By 1999, due to advances in agricultural technology, a single farmer could feed over 130 people. In 1945, (“Agriculture”, n. d. these developments which had largely been taking place in developed Western nations had been exported to the rest of the world via the Green Revolution. More than the pesticides and synthetic nitrogen (fertilizer) it exported, it also brought a new way to food cultivation with it: industrial or modern agriculture. In many ways, the efficiencies and cost effectiveness that this form of agriculture provided was a boon. In 2005, Prasad commented that it was great help in averting hunger because the human population more than doubled itself during the last half of the 20th century.
The Green Revolution has allowed the world to produce a surplus of food. However, questions have started to arise over its environmental impact on the Earth, especially in the longer term. In 2001, Altieri and Nicholls cited in their report that Audirac acknowledged evidence has accumulated showing that whereas the present capital and technology-intensive farming systems have been extremely productive and able to furnish low-cost food, they also bring a variety of economic, environmental and social problems. Over-reliance on synthetic chemical fertilizers 1 nd pesticides, among other aspects of conventional farming is having major negative impacts on public health and the environment (Pimentel, Hepperly, Hanson, Douds and Seidel, 2005) Organic Farming However, people have started to realize the effects of adopting industrial agriculture much earlier on. As early as the 1900s, Sir Albert Howard argued that the overuse of pesticides and synthetic fertilizers damages the long-term fertility of the soil. He was the father of modern organic agriculture. His work later went on to inspire luminaries such as Lade Eve Balfour and J. I.
Rodale who furthered the organic movement. In his report, Lampkin (1999) mentions that organic farming is being increasingly recognised by consumers, farmers, environmentalists and policy makers as a possible model for sustainability in agriculture. It is a system stressing priorities on cultivating food without the damaging and negative side effects of the conventional model. Recent scientific studies have uncovered encouraging results on the viability of organic farms where environmental and even economic factors are concerned. Currently, organic farming is steadily growing into the mainstream. 1. 2 Research Questions This research aims to find out the more environmentally sustainable method of farming between the conventional and organic model. And so, a number of smaller issues have to be answered beforehand like the effects that both systems have on the soil and environmental resources. This research also aims to provide a general set of principles for application to farms to be more ecologically conscious and efficient (in the “Recommendations” section), based on the findings. The questions are as follows: 1. How do both of these agricultural models impact the Earth?
All forms of agriculture impact the Earth in some way or another. How do both of these farming models affect the environment? 2. Which is a more ecological and environmentally efficient method of farming? In a side by side comparison of environmental measurements, which farming model does less damage to the environment? 3 1. 3 Justification In recent years, a wave of environmental awareness is sweeping the Earth. Humanity is beginning to understand the long term impacts of their actions and how whole ecosystems, numerous habitats, and even their own living environment are being threatened by their actions.
Ecological issues like global warming are gaining a foothold in the forming of public and corporate policies. Today, many agricultural scientists agree that modern agriculture is facing an environmental crisis. More and more people are having doubts on the long term sustainability of existing agricultural systems. Therefore, there is an urgent need for the agricultural industry to adopt a more ecologically sound method of farming while maintaining yields to keep world hunger at bay. If the industry continues to maintain its current method, soil and environmental degradation will continue for short term benefits.
This research will provide data and findings to support the idea of a more sustainable farming system in the hope that an environmentally safe system will be widely adopted and that the public domain will have the necessary information to lobby for such changes. 4 1. 4 Methodology Data collection and reviewing of case studies will be the main method of this research. After collating the data from the review, the pertinent facts will be published in tables and figures. In an area as wide as ecological impacts on the Earth, several categories of study need to be established.
They are: • • • • • Energy Input Soil Composition Soil Biology Water Contamination Air Pollution 5 1. 5 Scope As this study involves the review of as many case studies as possible, there is no predetermined area scope of research. However, case studies to be reviewed will generally be in the developed areas of Europe and USA. The list of case studies is as follows: 1. Environmental, Energetic & Economic Comparisons of Organic & Conventional Farming Systems 2. Comparison of Organic and Conventional Farming Systems in Terms of Energy Efficiency 3.
Comparing Energy Use and Greenhouse Gas Emissions in Organic and Conventional Farming Systems in the Netherlands 4. Comparisons of Organic and Conventional Maize and Tomato Cropping Systems from a Long-Term Experiment in California 5. Soil Fertility Comparison Among Organic and Conventional Managed Citrus Orchards in Sicily 6. Impact of Different Farming Systems on Epigeic Beneficial Arthropods and Earthworm Fauna in Arable Crops 6 1. 6 Thesis Outline Chapter 1: Introduction offers a brief history and background information of the agriculture industry and the current farming models of conventional and organic.
There is also a detailed explanation of the aims of this research and the questions it attempts to answer. This is followed by a justification of the reasons for this research and ends with a brief methodology and a note of the limitations and scope that this research is subjected to. Chapter 2: Literature Review focuses on a short history and definition of agriculture and its methods and the two main systems of conventional farming and sustainable farming. Chapter 3: Methodology offers a brief explanation of the categories of study and descriptions of the case studies involved.
Chapter 4: Data Analysis covers a detailed comparison of both systems in characteristics as well as their ecological impacts. Data will be presented in tables and graphs as well as a list of pros and cons for each system. The chapter finishes by reviewing the research questions in Chapter 1 followed by the answers to these questions as well as establishing a set of guidelines for sustainable farming. Chapter 5: Discussion & Conclusion reviews the question in Chapter 1 followed by the answers to these questions as well as establishing a set of principles/technologies for sustainable farming.
This chapter also details the limitations involved, gives recommendations for future approaches in this field of study and finally, concludes the research. 7 LITERATURE REVIEW 2. 1 Introduction Agriculture is the world’s oldest form of industry. All through history, the production of food has been a major factor in the forming of civilizations throughout the world. No state or empire can grow nor thrive without fulfilling this fundamental need of sustenance for their human capital.
Indeed, the picture of human development would have been very different if humans remained as hunter gatherers instead of delegating roles to specific segments of society to the cultivation of food. As farmers grew the capability of producing food beyond the needs of their own family, society was freed to pursue other forms of work. Before the 19th century, most food in the world was organically produced using organic manure and human and animal power (horses in the US and oxen in Asia) according to White (1970).
However, at the beginning of the industrial revolution, the face of agriculture changed to adapt to rising new methods of mechanization and later on agricultural chemistry (the use of pesticides and other chemicals). 2. 2 Conventional Agriculture The agricultural revolution spurred on by its industrial counterpart began with the invention of the horse drawn hoe and seed drill by Jethro Tull. Superphosphate fertilizer manufacturing began in England in the middle of the 19th century. The fuel-powered tractor was developed in the US in 1910 followed by the initial manufacturing of nitrogen fertilizer in Europe and the US.
In 1939, the insecticide DDT was discovered by P. Muller in Switzerland. Nitrophenols (herbicides) were developed in 1933 and later on, the development of 2, 4-D and MCPA started in the 1940s. In his commentary, Prasad (2005) mentioned that by the middle of the 20th century, the components of conventional/industrial agriculture were in widespread use in farms around the developed nations. 8 Today, industrial agriculture is a form of modern farming that refers to the industrialized production of livestock, poultry, fish, and crops. Industrial agriculture involve technoscientific, economic, and political methods.
They include innovation in agricultural machinery and farming methods, genetic technology, techniques for achieving economies of scale in production, the creation of new markets for consumption, the application of patent protection to genetic information, and global trade (“Industrial Agriculture”, n. d. ). These methods are prevalent in developed nations and increasingly more so worldwide. Due to application of industrial techniques and methodologies, crop yield of industrial farms has been more than enough to feed the growing human population over the years, as reported by Barrionuevo and Bradsher (2005) .
This is especially so during the last half of the 20th century, where the world population more than doubled itself, mostly in the developing countries. However, this is not without consequences. As conventional agriculture is inherently short term focused, people and organisations are becoming aware of the negative effects that it has on the environment (Scheierling, 1996) as well as becoming concerned of the long term viability of the industrial method (Conway and Pretty, 1991). As a reaction to these issues, organic farming was created as an alternative method. 2. Organic Agriculture The organic movement began in the 1930s and 1940s as a reaction to agriculture’s growing dependence on synthetic fertilizers. Its foundation was built by numerous individuals and movements concerned about nature conservation, pesticide use and soil conservation among others (Lampkin, 1999). As early as the 1900s, supporters of organic farming such as Sir Albert Howard argued that excessive use of pesticides and synthetic fertilizers damaged the fertility of the soil. He is widely considered to be the father of organic farming according to Heckman (2006).
Rudolf Steiner, a German philosopher, contributed to the organic movement with his biodynamic 9 agriculture. Work was also done by J. I. Rodale in the United States, Lady Eve Balfour in the United Kingdom, and many more across the world. Another component of modern agriculture, organic farming relies on crop rotation, green manure, compost, biological pest control, and mechanical cultivation to maintain soil productivity and control pests, excluding or strictly limiting the use of synthetic fertilizers and synthetic pesticides, plant growth regulators, livestock feed additives, and genetically modified rganisms (“Organic Farming” n. d. ). According to the International Federation of Organic Agriculture Movement (IFOAM), the overarching goal of organic farming is as follows: “The role of organic agriculture, whether in farming, processing, distribution, or consumption, is to sustain and enhance the health of ecosystems and organisms from the smallest in the soil to human beings. ” As of today, the organic agricultural industry is growing at a rapid pace becoming a very real alternative for food cultivation. Approximately 306,000 square kilometres (30. million hectares) worldwide are now farmed organically, representing approximately 2% of total world farmland (“Supplements to the 2007 edition of The World of Organic Agriculture”, n. d. ). In a recent study of statistics of organic agriculture (Willer, Helga, Yussefi and Minou, 2007), the biggest organic producing nations, in order, are Argentina, China and the United States. 10 2. 4 Environmental Issues Agriculture often causes ecological problems because of its environment changing nature and the eventual production of harmful by-products (“Agriculture”, n. d. ).
Some of the negative effects are: • • • • • • • • • • • • • Loss of biodiversity Surplus of nitrogen and phosphorus in rivers and lakes Detrimental effects of herbicides, fungicides, insecticides, and other biocides Conversion of natural ecosystems of all types into arable land Consolidation of diverse biomass into a few species Soil erosion Deforestation Depletion of minerals in the soil Particulate matter, including ammonia and ammonium off-gassing from animal waste contributing to air pollution Air pollution from farm equipment powered by fossil fuels Odour from agricultural waste Soil salination Water crisis
However, organic farms are perceived to have a better track record of minimizing these impacts to the environment compared to conventional farms due to their smaller ecological footprint (“Organic vs. Nonorganic: Understanding the Issues”, n. d. ). 11 2. 5 Summary Agriculture and the procurement of food crops is the prerequisite for any civilization. Over the centuries, the methods involved in agriculture have been largely similar except for improvements in tools, use of labour, plant care techniques and other small scale improvements.
However, in the 19th century, the industrial revolution initiated many new scientific breakthroughs in the field of agriculture involving mechanization and the use of agricultural chemicals. The new agricultural revolution in the developed world brought on the industrial farming system which depended on heavy inputs (chemicals and energy), large capital and vast tracts of land. Not long after, the organic farming system was created as a better alternative due to concerns that the industrial model was detrimental to the environment in the long term.
Although all agricultural models affect the environment negatively especially in the area of biodiversity, soil health, water pollution and air pollution, the organic system is perceived to be more ecologically viable. However, there are still questions as to the exact amount of improvement over the industrial system, if there is any. 12 METHODOLOGY 3. 1 Introduction This research is a compilation of data from numerous case studies conducted on the comparison between conventional and organic farms in a number of areas.
Samples from the case results presented in this report are concentrated around farming regions in Western/European nations. Data and findings from these case results will be presented in a standard format before being compiled and analysed. 3. 2 Study Categories As farms interact and affect the environment in a multitude of ways, several areas need to be picked and focused on. These categories of study are quantitatively measured using standard scientific methods. Energy Input • This area involves the measurement of fossil fuel input for the usage and upkeep of farm components like farm machinery, fertilizers, esticides and seeds, as well as labour. Soil Composition • This category involves the measurement of soil carbon and nitrogen to judge the fertility of the farm soil. Soil Biology • This area involves the measurement of beneficial microorganisms and earthworms per unit of farm soil to judge soil health. Water Contamination • This category involves the measurement of the amount of nitrate and herbicide from farms leaching into the water supply Air Pollution • This area involves the measurement of greenhouse gas emissions from farms into the atmosphere. 3 3. 3 Case Study Overview 1. Environmental, Energetic & Economic Comparisons of Organic & Conventional Farming Systems This case is a 22-year (1981-2002) study on comparing environmental, energetic and economic factors between conventional and organic farming systems. The study was conducted at the Rodale Institute FST, Kutztown, Pennsylvania, USA on 6. 1 acres of land. Soil at the study site consists of moderately well-drained Comly silt loam. The climate is sub-humid temperate at an average 12. 4°C and average rainfall is 1105 mm per year.
The experiment included three cropping systems: • • • Conventional Animal Manure and Legume-based Organic (Animal-based Organic) Legume-based Organic The main farming plots measured 18×92 m and was divided into three 6×92 m subplots for same crop comparisons in any one year. Separating the main plots were 1. 5 m grass strips to avoid contamination of soil, pesticides and fertilizers between plots. The subplots were large enough to allow the use of commercial-scale farm equipment for operations and harvesting. Each of the three cropping systems was replicated eight times.
Crop rotation was different for each system: Conventional: • • • corn, corn, soybeans, corn, soybeans corn, rye, soybeans, rye, corn silage, wheat, red clover–alfalfa hay hairy vetch, corn, rye, soybeans, winter wheat Animal-based Organic: Legume-based Organic: 14 2. Comparison of Organic and Conventional Farming Systems in Terms of Energy Efficiency This case is a 2-year (2003-2005) study on comparing energy usage between conventional and organic farming systems. The study was conducted at a maize and barley growing region in South Western Slovakia (near Piestany). Soil at the study site consists of degraded Chernozem on loess.
The climate is sub-continental with an average temperature of 9. 2°C and annual precipitation of 593 mm yearly. The experiment used a split plot arrangement in a randomized block with two replications. The harvest plot area measured 3×26 m. Crop rotation is as follows: • spring barley, pea, winter wheat, maize, spring barley, winter wheat 3. Comparing Energy Use and Greenhouse Gas Emissions in Organic and Conventional Farming Systems in the Netherlands This case is a general study on comparing energy usage and greenhouse gas emissions between conventional and organic farming systems.
The study was conducted in the Netherlands. The samples consisted of 2 pairs of farms (each pair contained a conventional and organic farm) on different soil conditions and with different crop rotations: Clay Soil • • potato, sugar beet, wheat, carrot, onion, pea leek, bean, carrot, strawberry, head lettuce, Chinese cabbage Sandy Soil 15 4. Comparisons of Organic and Conventional Maize and Tomato Cropping Systems from a Long-Term Experiment in California This case is a 11-year study on comparing soil composition and biology between conventional and organic farming systems.
The study was conducted at the LongTerm Research on Agricultural Systems project (LTRAS) at the University of California, California, USA. The experiment included 10 cropping systems using 0. 4 ha plots. Each cropping system was replicated three times. Systems differed in the amount of irrigation received (rain fed or irrigated) and in the amounts of N and organic matter applied to the soil, either as winter legume cover crops, fertilizer, or composted manure. The plots were large enough to allow for the use of commercial-scale farm equipment. 5.
Soil Fertility Comparison Among Organic and Conventional Managed Citrus Orchards in Sicily This case is a study on comparing soil fertility/composition between conventional and organic farming systems. The study was conducted on citrus orchards (Navelina and Tarocco orange) located in Eastern Sicily, Italy in a Mediterranean climate. The experiment involved 54 farms under both organic and conventional systems, where the farms were picked to obtain similar pairs (27) in similar environmental conditions. The orchard pairs were homogenous for age, cultivar and rootstock to reduce effects not linked to soil management. 6 6. Impact of Different Farming Systems on Epigeic Beneficial Arthropods and Earthworm Fauna in Arable Crops This case consists of two sections: Section 1: • A 3-year study on soil biology between conventional and organic farming systems. The study was conducted at the DOC Long Term Trial, Therwil, Switzerland. Section 2: • A 3-year study on soil biology between ICM (Integrated Crop Management) and organic farming systems. The study was conducted on 24 winter wheat fields in 12 farms in north-western Switzerland. Farms were paired according to similar environmental conditions. 3. Summary In this chapter, the various study categories concerning environmental factors were determined. The areas of study are energy input, soil composition, soil biology, water contamination and air pollution. The case studies were also reviewed and summarised on a case-by-case basis. The locations of study are in the USA and various European countries. In the next chapter, the data collected is compiled and presented in data tables and graphs. 17 DATA ANALYSIS 4. 1 Introduction Data from the numerous case studies were examined, analysed and compiled into suitable tables and graphs.
Where usage of figures and tables were unnecessary, the findings were explained in text paragraphs. The following categories were used for the meaningful classification of data concerned with environmental issues: 1. Energy Input 2. Soil Composition 3. Soil Biology 4. Water Contamination 5. Air Pollution The case studies below were examined on an individual basis and data from these reports concerning the study categories above were extracted and classified according to the categories they belong to. Code names are assigned to the case studies to simplify the data presentation process: 1.
Environmental, Energetic & Economic Comparisons of Organic & Conventional Farming Systems (C1) 2. Comparison of Organic and Conventional Farming Systems in Terms of Energy Efficiency (C2) 3. Comparing Energy Use and Greenhouse Gas Emissions in Organic and Conventional Farming Systems in the Netherlands (C3) 4. Comparisons of Organic and Conventional Maize and Tomato Cropping Systems from a Long-Term Experiment in California (C4) 5. Soil Fertility Comparison Among Organic and Conventional Managed Citrus Orchards in Sicily (C5) 6. Impact of Different Farming Systems on Epigeic Beneficial Arthropods and Earthworm Fauna in Arable Crops (C6) 8 4. 2 Energy Input Case Study: C1 6 5. 2 5 4 3 2. 3 2 1 0 Corn Organic (Animal) Organic (Legume) Soybeans Conventional 2. 3 2. 1 3. 7 3. 5 Figure 1. Average energy inputs for corn and soybeans (millions of kilocalories per hectare per year) in three farming systems (Rodale Institute Farming Systems Trial; 1991 – 2000) Total energy inputs were assessed for the 3 farming systems – organic (animal), organic (legume) and conventional. Inputs included components such as fossil fuels for farm machinery and equipment, fertilizers, herbicides and seeds. About 5. million kilocalories (kcal) of energy were expended for the cultivation of corn in the conventional system. The energy inputs for the organic animal and organic legume were 28% and 32% less compared to the conventional one (Figure 1). Fertilizers used for the conventional system were manufactured using fossil energy while nutrients for the organic systems were obtained using animal manure, legumes or both. However, in the case of soybean production, results were similar among the organic (animal), organic (legume) and conventional systems at 2. 3 million kcal, 2. 3 million kcal and 2. 1 million kcal per ha respectively (Figure 1). 9 Case Study: C2 Table 1. Energy balance in cereal crop rotation (gigajoules per hectare) in two farming systems (South-Western Slovakia; 2003 – 2005) Crop System Yields (t ha-1) Organic Conventional Organic Conventional Winter Wheat Maize for Grain Spring Barley Winter Wheat Average Organic Conventional Organic Conventional Organic Conventional Organic Conventional 4. 67 5. 77 2. 66 2. 98 4. 70 5. 45 6. 95 6. 96 4. 76 5. 96 4. 21 4. 61 Energy (GJ ha-1) Energy (GJ ha-1) 137. 7 164. 9 94. 9 97. 9 150. 5 165. 4 199. 3 213. 4 132. 0 169. 3 135. 0 140. 1 141. 6 158. 5 Energy Profit (GJ ha-1) 125. 07 148. 34 87. 50 87. 56 141. 30 145. 4 177. 99 179. 22 119. 37 152. 74 117. 80 115. 50 128. 21 138. 08 Energy Efficiency 0. 91 0. 90 0. 92 0. 89 0. 94 0. 88 0. 89 0. 84 0. 90 0. 90 0. 87 0. 82 0. 91 0. 87 Input Production 12. 63 16. 56 7. 39 10. 36 9. 20 20. 26 21. 31 34. 18 12. 63 16. 56 17. 20 24. 60 13. 39 20. 42 Spring Barley Pea Total energy inputs for the two different farming systems comprising six different crops were compiled. Inputs included direct (human labour) and indirect (fossil fuel for the operation of farm equipment and machinery) energy sources. In all crop categories, the conventional farming system is more energy demanding than the organic one.
On average, total energy needs are 55. 2% more for the conventional system versus the organic system. The crops demanding the most energy for cultivation were the ones that used farm yard manure (maize for grain and winter wheat) while pea cultivation required the least energy. In terms of energy efficiency or net energy profit (difference between energy input/delivered and energy production/gained), the highest percentage points came from the organic systems. The most major difference in energy efficiency is seen with the winter wheat crop. 20 4. 3 Soil Composition Case Study: C1 3 2. 5 2. 5 2 1. 5 1 0. 0 1981 Organic (Animal) Organic (Legume) 2002 Conventional 1. 954 2. 172 1. 841 2. 4 2 Figure 2. Percentage of soil carbon in three farming systems (Rodale Institute Farming Systems Trial; 1981, 2002) Soil carbon which corellates with soil organic matter levels, was measured in1981 and 2002 (Figure 2). In 1981, at the start of the experiment, soil carbon leves in all three systems did not show any differences: about 2. 0%. However, in 2002, soil carbon levels in the organic (animal) and organic (legume) systems showed significantly higher differences than the conventional system: 2. 5% and 2. 4% versus 2. 0% respectively. 1 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 1981 Organic (Animal) 0. 32 0. 33 0. 31 0. 35 0. 33 0. 31 2002 Organic (Legume) Conventional Figure 3. Percentage of soil nitrogen in three farming systems (Rodale Institute Farming Systems Trial; 1981, 2002) Soil nitrogen content was measured in 1981 and 2002 in the three farming systems (Figure 3). As with the soil carbon measurements, initially, soil nitrogen levels did not significantly differ between all three systems. Measurements were at approximately 0. 31%. By 2002, measurements pointed to significant increases in the organic (animal) and organic (legume) systems at 0. 5% and 0. 33% while the conventional system remained unchanged at 0. 31%. 22 Case Study: C4 After a period of 10 years, soil organic matter (carbon) levels differ significantly between the conventional and organic farming systems. Organic plots had 90 Mg of carbon per hectare (from crop residues, legume cover crops and composted manure) added over the period versus 52 Mg per hectare added for the conventional plots (from crop residues). Soil organic matter levels increased in the organic system but remained the same in the conventional one.
In the case of soil nitrogen, potentially mineralizable nitrogen (PMN) was approximately twice as abundant in the organic system (tomato phase) compared to the conventional system. Case Study: C5 Table 2. Soil properties (milligram per kg of soil) in two farming systems (Eastern Sicily, Italy; 2002) Property TOC (mg kg-1 soil) N (mg kg-1 soil) PMN (mg kg-1 soil) Conventional 10776 1083 34. 10 Organic 13322 1289 39. 0 Total organic carbon (TOC), one of the main parameters employed to determine soil fertility, were higher in the organic system (13,322 mg kg-1) compared to the conventional system (10,776 mg kg-1).
Results for the nitrogen content of soils showed similar tendencies toward the organic systems. Total soil nitrogen was measured at 1289 mg kg-1 for the organic system versus 1083 mg kg-1 for the conventional one. Potentially mineralizable nitrogen (PMN) showed an increase of 5. 10 mg kg-1 in the organic system over the conventional system. 23 4. 4 Soil Biology Case Study: C1 Soils of the Rodale Institute FST were sampled to study the impact of the organic and conventional farming systems on indigenous populations of Arbuscular Mycorrhizal (AM) fungi. AM fungi are beneficial and indigenous to most soils.
They colonize the roots of most crop plants, forming a mutual symbiosis. Results show that soils farmed with the organic systems had bigger populations of AM fungi spores and produced greater colonization of plant roots than in the conventional system. Case Study: C6 Soils at the DOC Long Term Trial in Therwil, Switzerland were sampled for content of beneficial organisms. Carabids, staphylinids and spiders were in most cases higher in activity density in the organic systems compared to the conventional ones. The communities of carabid found in organic systems were richer in species and were more evenly distributed.
Although there was close proximity between the different plots and plot size itself was small, 7 of 39 sampled species were found exclusively in the organic farming systems. Soil samples were examined and found to contain eleven earthworm species at the DOC trial. The dominant earthworm species were Nicodrilus langus, Nicodrilus noctumus, Nicodrilus caliginosus and Allolobophora rosea. Earthworm biomass, density, the occurrence of anecic, agro-ecologically important species and the number of juvenile earthworms were significantly higher in the organic farming systems than in the conventional and unfertilised systems. 4 4. 5 Water Contamination Case Study: C1 Nitrate Leaching: Concentrations of nitrogen as nitrate in leachates from the farming systems fell between 0 -28 parts per million (ppm) throughout the year. Leachate concentrations were found to be usually highest in June and July, shortly after fertilizer application in the conventional systems or in the case of the organic systems, the plowing down of animal manure and legume cover crops. Water leachate samples from the conventional system sometimes exceeded 10 ppm (the regulatory limit for nitrate concentration in drinking water). 0% of the conventional system samples were above the 10 ppm limit versus 10% and 16% of samples from the organic (animal) and organic (legume) systems. Herbicide Leaching: As the organic systems do not employ the use of herbicides, the results are taken only from the conventional systems. Four herbicides were applied in the conventional systems: atrazine (corn), pendimethalin (corn), metolachlor (corn and soybeans) and metribuzin (soybeans). Water leachate samples were collected from the conventional system from 2001 – 2003 and found to contain atrazine and metolachlor.
Metribuzin and pendimethalin were not detected. In the conventional plots where corn was planted after corn and atrazine applied two years in a row, atrazine in the leachate sometimes exceeded 3 ppb (the maximum contaminant level for drinking water). Similarly, when metolachlor was applied two years in a row in a corn after corn treatment, it peaked at 3 ppb (no maximum contaminant level yet for drinking water). 25 4. 6 Air Pollution Case Study: C3 7000 6000 5000 4000 3000 2000 1000 0 Organic (Clay) Conventional Organic (Sand) Conventional (Clay) (Sand) N2O CO2 Figure 4.
Greenhouse gas (GHG) emissions per hectare in two farming systems (Netherlands) 1200 1000 800 600 400 240 200 0 Potato Sugar Beet Peas Leek Head Lettuce Beans 200 50 75 240 180 60 50 580 470 600 980 GHG Emissions (Organic) GHG Emissions (Conventional) Figure 5. Greenhouse gas (GHG) emissions per mg of product in two farming systems (Netherlands) 26 GHG emissions per hectare on the organic clay soil (arable) and organic sand soil (vegetable) farms are lower compared to the conventional farms (Figure 4). Approximately half of the emissions content is CO2 (Carbon Dioxide) while the other half is made up of N2O (Nitrous Oxide).
N2O emissions originate from within the farm (fertilizer usage, crop residue incorporation and nitrogen fixation). On average, GHG emissions per mg of product are higher in the organic systems compared to the conventional ones. On this issue, however, there is a large difference among crops (Figure 5). For some organically grown crops, emissions are lower than the conventional ones (sugar beet, peas, beans) while being higher for others (leek, carrot, wheat). Basically, GHG emissions tend to be higher for leguminous and high nutrient requirement crops. 4. Summary In this chapter, the result from the various case studies were compiled, grouped and presented in data tables and graphs. Results were grouped according to study categories – energy input, soil composition, soil biology, water contamination and air pollution. Case studies were given code names to simplify the presentation. In the next chapter, the data collected is analyzed and discussed according to the initial research questions. 27 DISCUSSION & CONCLUSION 5. 1 Introduction This thesis is concerned with two questions which will be answered with the progression of this chapter: . How do the organic and conventional farming systems impact the environment? 2. Between the organic and conventional farming model, which is a more ecological and environmentally efficient method of farming? Through the results procured and published in Chapter 4, there are differences in results depending on the area of study and farming techniques and technologies employed in the various case studies. However, in comparison to the conventional farming system, there are definite environmental benefits attributable to the organic farming systems.
These are: • • • • • reduced and more efficient use of energy inputs improved soil organic matter higher biodiversity levels reduced leaching of chemicals into the water system lower greenhouse gas emissions (in some cases) 28 5. 2 Discussion How do the organic and conventional farming systems impact the environment? Energy Input Energy input is measured from direct and indirect fossil energy used to cultivate crops. In C1, significantly less energy from fossil fuels was used to produce corn for the organic farming system (Figure 1).
There were no major differences in energy usage for soybean cultivation. In C2, total energy needs for the conventional farming system was proven to be 55. 2% more than the organic system for similar yields of crop. These results are partly attributable to the fact that in the organic systems, synthetic fertilizers and pesticides (which require much energy to produce) were not used. Overall, the reduced use of fossil energy by the organic farming systems lessens the amount of carbon dioxide released to the atmosphere and contributes much less to global climate change.
Soil Composition Soil organic matter and mineral content is an important component of soil health and sustainable agriculture. It provides a variety of functions like improving water holding abilities in soil, increasing soil biodiversity and as an important nutrient source for crops. In C1, after 22 years of farming, soil carbon (organic matter) is significantly higher in the organic system than the conventional system. Soil carbon increased by 27. 9%, 15. 1% and 8. 6% in the organic (animal), organic (legume) and conventional systems respectively.
Similarly, soil nitrogen had risen in content levels in the organic system but remained the same in the conventional one. In C4, soil organic matter levels were reported to have risen in the organic system but stable in the conventional system. Potentially mineralizable nitrogen (PMN) in organic farm soils were twice more in content compared to the conventional system. 29 In C5, total carbon in organic soils were higher than the conventional one by 23. 6%. Soil nitrogen and PMN also showed marked increases in the organic system compared to the conventional one.
In general, the conservation of and eventual rising levels of soil carbon and nitrogen in the organic systems preserves soil health and makes it more resilient and able to handle long terms of crop cultivation. Soil Biology Organisms in the soil such as microbes, arthropods and earthworms are helpful in improving soil fertility. Earthworms and insects, especially, are known for their roles in soil health by their help in burrowing large holes in the soil that increase the percolation of water into the soil and decrease runoff. Fungi like Arbuscular Mycorrhiza (AM fungi) hold symbiotic relationships with crops.
In C1, AM fungi presence was bigger in the organic soils than in the conventional soils. In C6, carabids, staphylinids and spiders were higher in activity density in the organic systems than the conventional ones. Carabids were also found to be richer in species in the organic systems. Similarly, agriculturally useful earthworm populations were significantly higher in the organic systems. Water Contamination The leaching of agricultural fertilizers and chemicals into the water supply and underground water reservoirs is an increasing environmental problem.
Nitrate from fertilizers which leach into rivers and, eventually, the sea causes dense algae populations, which block sunlight and produce huge amounts of carbon dioxide, killing underwater life. The leaching of harmful chemicals like herbicides also causes the death of aquatic life and contaminates the water supply. In C1, nitrate leaching from the conventional systems sometimes exceeded the safe levels for drinking water (10 ppm). There was a higher frequency of water samples from the conventional systems (20%) which exceeded safe limits versus 10-16% from the organic systems.
In the conventional plots, herbicide (atrazine and metolachlor) leaching was reported to sometimes exceed 3 ppb (maximum 30 contaminant level for drinking water). The organic systems did not employ the use of herbicides. Overall, there was less environmental contamination of the water supplies from the organic systems because no commercial fertilizers, pesticides or herbicides were applied. Air Pollution The use of energy from fossil fuels in farms generates greenhouse gases (GHG), which dangerously affects climate change in the long term.
Farms which regularly expend energy directly (fossil fuel for farm machinery) or indirectly (production of fertilizers, pesticides and seeds) need to be more efficient in energy usage to regulate such gases. In C3, GHG emissions per hectare were much lower in the organic systems than the conventional systems. However, on average, GHG emissions per mg of product were actually higher in the organic systems than the conventional ones. As this was an averaged result, there were mixed results among the crops. Some caused lower emissions (sugar beet, peas, beans) while some caused higher emissions (leek, carrot, wheat).
Generally, GHG emissions from organic farms are seen to be lower but when factoring in yield levels, the organic systems tend to be higher in emissions because of lower yields. However, as stated, this usually happens only for certain crops. Between the organic and conventional farming model, which is a more ecological and environmentally efficient method of farming? Through the results and analysis of the case studies, it can be seen that the organic farming system is a more ecological and environmentally efficient method of farming.
In most cases, it also matches or produces higher yields than the conventional farming systems. 31 5. 3 Limitations In this comparison of case studies of the organic and conventional farming systems, there were several limitations which may have hindered it from becoming a more comprehensive report. • • Variety of Sites This thesis mainly focused on farming regions in the developed areas of the Western world, such as California (USA), Pennsylvania (USA), Sicily (Italy), Therwil (Switzerland) and the Netherlands with the exception of the Slovak Republic.
More countries, especially farming regions in the developing world such as South America and Asia could have been included. However, the availability of research information from these countries was limited at the time of writing. • • Amount of Cases It would make for a much stronger thesis if the number of case studies analyzed was much larger than the current number. Other than having a greater analysis of the data patterns inherent in a big number of cases, the results of the thesis would be at a much stronger standpoint. 5. Future Study In the future, this thesis may take on a more detailed study of a larger variety of agricultural systems. Although this thesis is currently concerned with the comparison of organic and conventional farming in respect to ecological factors, it will be more comprehensive to take in a bigger variety of agricultural farm types into account. For example, sustainable farming by itself is a general concept, actually consisting of diverse farm types like organic farming, biodynamic farming, do nothing farming, permaculture and no till farming. Conventional farming too can be split into industrial and intensive farming systems. 2 Studies and comparisons of such a variety of agricultural systems will turn up huge amounts of data and patterns, pointing to a suitable direction to take regarding adoption of the most suitable sustainable agricultural system for the production of food for the coming generations of humanity, while conserving the continually depleting resources of our planet. 5. 5 Recommendations Application of Organic Principles Some organic principles and technologies if applied into current conventional farming systems would be beneficial to crop production and the environment.
These are: • • • • Employing off-season cover crops Using more extended crop rotations, which act to conserve soil and water resources and reduce insect, disease and weed problems Increasing the level of soil organic matter, which helps conserve water resources and mitigates drought effect on crops Employing natural biodiversity to reduce or eliminate the use of nitrogen fertilizers, herbicides, insecticides and fungicides These principles have the potential to increase not just ecological but also the energetic and economic sustainability of all agricultural systems. 3 5. 6 Conclusion The organic and conventional farming models affect the environment in these ways: • • Energy Input Organic farming systems use significantly less fossil fuel compared to the conventional systems and subsequently, emits less carbon dioxide into the atmosphere. • • Soil Composition Soils in the organic farming systems contain higher levels of carbon and nitrogen compared to the conventional systems, providing many benefits to the overall sustainability of organic agriculture. • •
Soil Biology Organic farming systems contain higher populations of insects and earthworms than the conventional systems. Abundant creatures both above and below ground increases biodiversity, helping to improve soil conditions and plays a role in the biological control of pests and cross pollination by insects. • • Water Contamination Organic farming systems cause little to no contamination of water supplies compared to the conventional system, as no synthetic fertilizers, pesticides, herbicides and fungicides are applied. • Air Pollution Organic farming systems emit less greenhouse gases per hectare compared to the conventional system. However, the organic system performs weaker when factoring in yield amounts (GHG emission per mg of product), with the exception of some crops. 34 In this comparative study between organic and conventional farming systems and their ecological impacts on the earth, the organic farming model has been proven in many cases to be more ecologically relevant and efficient than the conventional system.
Although all agricultural systems contain negative ecological externalities, the organic farming movement is at least a first step towards the conservation of the environment and long term sustainability. 5. 7 Summary In this chapter, the data compiled from all the case studies were discussed to answer the initial research questions which were: • • “How do the organic and conventional farming systems impact the environment? ” “Between the organic and conventional farming model, which is a more ecological and environmentally efficient method of farming? Results and analysis were found to point to the organic farming systems as ultimately more ecological and environmentally efficient in the long term compared to the conventional systems. In conclusion, the organic systems were found to benefit the environment in all the areas of study, although in some categories, the benefits were less significant compared to the rest. Recommendations for the improvement of conventional systems were made. Limitations affecting this study were explained as well as plans for future study drawn out. 35 APPENDICES 36 REFERENCES 1.
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