Topic 3.1a Agriculture
Topic Aims
In this topic we will address the challenge of providing food and other goods to our current world population and to nearly 9 billion people by 2050 by considering
- current food production and availability
- the pessimistic and optimistic views on whether we are capable of producing enough food for our growing population
- how food is produced, particularly the ecosystem services involved
- the impacts of agriculture on our environment.
- future prospects for increasing agricultural production including; improved breeding programs, genetic engineering, new crop types, irrigating more land, and cultivating more land
- principles of sustainable agriculture
How is Food Produced?
Historically humans have depended on three main systems to produce their food, croplands, rangelands and fisheries.
There are two major ways in which agricultural production is achieved (i.e., two types of systems) industrialised and traditional. In this course we will focus mainly on industrialised agriculture, however, we will also consider traditional agriculture, because nearly half of the worlds people rely on traditional agriculture for their livelihood and most of their food.
There are a number of other approaches to agriculture that are practiced in developed countries that provide alternatives to the conventional or industrialised approach, such as organic farming and permaculture. Although these approaches often make a valuable contribution to sustainable agriculture we will not be considering this systems specifically, although the section on sustainable farming does cover most of these principles.
Activity 3.1
Read Pages 280 – 288 in Miller & Spoolman (2012) ensuring that the following questions are answered by your summary
- What are the three major systems that have historically provided our food, what food do they provide and how?
- What must be done to ensure we can feed the projected 8.9 billion people in 2050?
- What three crops provide most of the worlds food?
- Define the styles of agriculture discussed and how they operate.
Patterns of Food Production and Nutrition
The Earth's ability to feed the increasing population is another controversial topic in environmental issues. Reasons for this include different interpretations of current patterns of food production, the impact of agriculture on the environment and the uncertain role of technology.
Activity 3.2
Read Miller & Spoolman (2012) pages 278 – 280 and answer the following questions:
- Discuss why poverty is the root cause of hunger and malnutrition rather than food shortages.
- What is food security?
- Describe the trend in world food production since 1950.
- Define undernutrition, malnutrition and overnutrition.
- About how many chronically malnourished people are there in the world?
Green Revolution
Since 1950, most of the increase in agricultural production has come from increased yields per unit area of croplands using principles of the "Green Revolution" approach.
Activity 3.3
With Reference to Miller & Spoolman (2012) pages 285 – 286 and 293 – 295 answer the following questions:
- What three steps did the green revolution involve?
- What main steps has the "Second Green Revolution" involved?
- Summarise the limitations to further expansion of the green revolution.
The high yielding varieties developed and introduced by the green revolution (GR) are known as "high responders". This means that they are capable of yielding more than traditional varieties if given optimum levels of fertilizer and water and protection from pests. However, under suboptimum conditions these varieties often produce lower yields than traditional varieties which are often more resistant to drought and local pests. This was particularly true of crop varieties developed by the original GR.
As a result GR farmers are forced into dependence on high levels of fertilizers and pesticides and often need to irrigate to obtain optimum yields. This dependence on expensive inputs can exclude peasant farmers from benefiting from the GR when it is these farmers and the people of developing nations that would benefit most from the increased food production. There is a considerable amount of foreign aid provided to make the technology of the GR available in developing countries, however, this can increase the dependence of rural areas on foreign aid.
Ecosystem Services in Agricultural Production
The major difference between different approaches to agriculture, conventional, high tech, organic, traditional farming systems etc is the extent to which they effectively utilise and maintain ecosystem services.
(a) How Much are Ecosystem Services Worth to Agriculture?
Lets consider the value of ecosystem services to agriculture. We will primarily focus on the industrialized system, as this is what is primarily in operation in Australia.
To determine how much Ecosystem Services (ESS) are worth to agriculture we have to consider value in a number of different ways:
- Value of the goods produced using these services
- Cost of replacing lost services, cost of replacing services with technological inputs
- Money ($$$$) saved by utilising "free" ESS
- Value of rural lifestyle
- Aesthetic and recreational value of rural landscapes.
Let us now consider the loss of some specific ecosystem services as an illustration of one aspect of the value of these services.
Source: Australian Natural Resources Atlas 
- Salinity (produced by the loss of trees and deep-rooted vegetation and the service they provide in stabilising water tables)
- Cost in loss of production
- Cost of rehabilitating salt damaged land
- Cost of technological fixes
- Soil Erosion (loss of vegetation and the ecosystem services that stabilise soil structure)
- Cost in loss of production
- Cost of rehabilitating salt damaged land
- There is no substitute for soil in broad acre farming
- Soil Fertility Decline (Reduction in the level of vital nutrients in the soil due to over harvesting/grazing and reduced cycling of nutrients)
- Loss of production
- Cost of fertilizers
- Energy used to produce fertilizers
- Effects of fertilizers on other organisms (e.g., soil microbes) and other parts of ecosystems (e.g., eutrophocation water ways)
- Loss of Crop Pollination (Many of our fruit, nut and some grain crops rely on insect and other animals to achieve fertilization in order to set fruit/grain)
- Lost Production (e.g., USA yields limited by lack of pollinators)
- Cost of replacing the service (hiring honey bee hives)
- Loss of Natural Pest Control (It has been said that our entire ability to successfully grow crops rests of natural biological control, because without it the potential pests would overwhelm production and only 1-2% of the potential plant eating pests ever reach pest status, largely due to the effects of natural enemies (usually other insects that eat or otherwise kill the pest) (Debach, 1991).
- Cost of pesticides
- Cost of environmental damage due to pesticides (loss of other services, loss of biodiversity etc.)
(b) Ecosystem Services Provided by Agriculture
In addition to using ecosystem services, agricultural lands offer ecosystem services.
Activity 3.4
Ecological services provided by agricultural lands include
- Help maintain water flow and soil infiltration
- Provide partial erosion protection
- Can build soil organic matter
- Store atmospheric carbon
- Can provide wildlife habitat for some species
Economic services provided by agricultural lands include
- Food crops
- Fiber crops
- Crop genetic material
- Jobs
Source Miller (2004)
- What other ecosystem services and economic services could be provided by ecologically sustainable agricultural systems?
Impacts of Agriculture on Ecosystems and Their Provision of Ecosystem Services
There are three major ways in which agricultural production systems, particularly industrialized systems, affect the provision of ecosystem services. These are:
- Conversion of ecosystems to agricultural systems that provide fewer services
- Land degradation resulting in a reduction in the amount and type of services provided
- High levels of inputs that alter the system and reduce its ability to provide ESS.
Land Degradation & Soil Erosion
Land degradation is a decrease in the ability of land to support crops, livestock or wild species in the future as a result of natural or human-induced processes.
Soil erosion is the movement of soil components, especially topsoil, from one place to another, usually by wind, flowing water or both. This natural process can be greatly accelerated by human activities that remove vegetation from the soil. There is great concerned about the widespread extent of erosion because it lowers soil fertility (decrease in agricultural productivity) and can overload waterways with nutrients (i.e. water pollution).
Activity 3.6
- Make a table listing the potential detrimental effects of agriculture on ecosystems. With reference to Figure 12.9 consider the effects of agriculture (particularly intensive agriculture) on these categories of natural capital; biodiversity, soil, air, water and human health.
| Detrimental Effects of Agriculture |
|---|
Biodiversity * Loss or degradation of habitat from clearing grasslands and forests and draining wetlands * Fish kills
Soil *Erosion *Loss of soil fertility etc |
- For each of the detrimental effects listed in Q1 identify the ecosystem service(s) affected (refer back to the table of ecosystem services in Module 1)
| Detrimental Effects of Agriculture | Ecosystem Services Affected |
|---|---|
Biodiversity * Loss or degredation of habitat from clearing grasslands and forests and draining wetlands * Fish kills etc Soil |
* This large-scale impact affects all ecosystem services to some extent *Food Production |
Future Prospects in Agriculture
There are a number of approaches that could be taken to increase food production and decrease the impact of agriculture on the environment. The major alternatives that have been suggested will be examined in this section. As you complete this section of the module think about the impact each of these approaches has on the ability of ecosystems to provide ecosystem services and we will come back to this point at the end of the section.
(a) Traditional Cross-breeding
For centuries scientists and farmers have used traditional methods of selection and cross breeding to develop genetically improved crop strains and livestock.
Activity 3.7
Read the section on crossbreeding in Miller & Spoolman (2012) pages 285-286 and answer the following questions:
- What are the three limitation of traditional crossbreeding mentioned?
- With reference to the information in this section of Miller and your own ideas or further reading make a table listing the 3 pros and 3 cons of growing more food by cross breeding.
(b) Genetic Engineering in Agriculture
Scientist have now taken the process of crossbreeding one step further and are using genetic engineering and other forms of biotechnology to develop new genetically improved strains of crops.
It is important to note that in this class we are not dealing with cloning, altering human DNA, stem cell research, genetic technology for medical procedures etc. We are strictly looking at the use of genetic engineering to produce new varieties of crops for agricultural production.
Genetic Engineering involves removing a gene from one species and inserting it into the DNA (genetic makeup) of another unrelated species to produce a beneficial genetic trait in the new genetically modified organism (GMO). Currently this technology has been applied to numerous crops to improve protection against pests (including insects, fungi and viruses), increase crop resistance to herbicides, decrease water use (i.e., increase drought resistance) and increase the nutritional value of crops. Refer to Table 3, for examples of types of genetically modified crops.
Controversy is growing over the use of genetically modified foods. GMOs are seen by advocates as a potentially sustainable way to produce higher crop yields and solve the world's food problems. However, critics are concerned about the negative environmental, human health and socio-economic effects of these so called "Frankenfoods"
| Type of Genetic Improvement | Examples of Crops |
|---|---|
Pest control |
Mainly Bt crops, which have the genes of a bacterium Bacillus thuringiensis inserted so the crop can produce toxins that deter and/or kill moth and caterpillar pests. Examples include Bt potatoes, Bt corn and Bt cotton |
Increased crop resistance to herbicides |
Crops which have herbicide resistance, meaning the crop can be sprayed for weeds without harming the crop. Examples include "round-up ready" canola, "round-up ready" soybeans |
Drought and/or salt resistance |
Using genetic techniques to enhance the water efficiency and salt resistance of crop varieties to decrease need for irrigation, expand agriculture into drier areas and rehabilitate saline soil. Still in the experimental stage |
Increased nutritional or medicinal value |
Producing food crops with higher contents of essential vitamins which can be used to vaccinate against disease. "Golden rice", vitamin A enriched rice (released). Further versions of "golden rice" also include increased iron (undergoing licensing etc). |
Nitrogen fixation |
Producing cereal crops that fix their own nitrogen, which is currently only a trait of legume plants with associated bacteria to fix N. Currently a major experimental effort. Would dramatically reduce the need for N fertilizers and produce cereals with higher protein content, alleviating a major form of malnutrition in developing countries. |
There are a number of major environmental issuses connected to this technology including risk of outcrossing with closely related wild species, risk of crop plants becoming wild and a pest themselves, control over how much land is planted to GMOs by who, and ability to ensure appropriate use and mandatory resistance management (e.g., for pest resistant crops).
Australia currently has very tight regulation of GMO use and resistance management. Whereas control and guidelines in the US and other user countries are not as tightly regulated.
Activity 3.8
Read the section on genetic engineering in Miller & Spoolman (2012) pages 293 – 294 and answer the following questions:
- Compared to traditional crossbreeding what are three major advantages of genetic engineering or gene splicing?
- List 5 concerns regarding this technology
- For further research: Using additional sources answer the following question
Activity 3.9
- What is your personal view towards GMO foods? Do you check for labelling of GMO-free or are you not concerned about this issue? Would you pay more for GMO-free food? Why?
Additional References
http://www.choice.com.au/ and follow the links through food category and archive articles to get information on GM foods
http://www.planetark.com/dailynewsstory.cfm/newsid/15727/story.htm
There are thousands of other Web sites addressing GMO crops, take a look.
Who Benefits from Genetically Modified Organisms?
One of the major criticisms against the ability of genetic engineering to solve the world's food problem is that those that require more food and more affordable food are not receiving the benefits of GMOs.
The majority of GMO crops are grown in developed countries, which do not have a problem with providing enough food for their populations, e.g., United States, Canada and some in Australia. Where genetically modified crops are used in developing countries, such as Argentina they are predominately used to produce cash crops and the seed is too expensive for local or peasant farmers to afford.
In addition to the expense of the seed, terminator genes prevent the seed produce one year from being collected and saved for use the next season. This saving of seed is an important aspect of traditional farming that reduces costs and allows the farmer to save seed from superior producing plants, thereby increasing the genetic quality of his crop. Instead farmers have to buy new seed each year.
On top of the expense of seed, GMO crops often do not perform better than traditional crop varieties unless they are provided with optimum nutrition, pest control and water. These are also expensive inputs that limit the practical use of GMOs to increase food production for local farmers in developing countries.
Other Ways to increase Agricultural Production
(a) Irrigating More Land
Irrigating a greater proportion of agricultural land is often proposed as a means of increasing agricultural production. Irrigation certainly increases the yield per hectare; about 40% of the world's food production comes from the 18% of the world's cropland that is irrigated (Miller 2005).
However, irrigated land per person has decreased. Factors contributing to this tread include;
- World population has grown faster than irrigated land
- Water is being pumped more rapidly from aquifers than it is replaced in many of the world’s food-growing areas
- Irrigation water is being used inefficiently
- Crop productivity has decreased due to irrigation salinity
- Increased urbanisation and competition for limited water with farmers
- Global warming may disrupt water supplies in some food-growing areas
- Lack of money to afford to irrigate
There are three key methods for using water more sustainably in crop production
- Increasing irrigation efficiency
- Changing to crops that require less water
- Withdrawing water from aquifers no faster than it is replaced
Please refer to the water resources module for further information on irrigation in agriculture.
(b) Cultivating More Land
Theoretically the world's cropland could be more that doubled by clearing tropical forests and irrigating arid land. However, much of this land is marginal and converting it to cropland would not be sustainable and would
- require huge amounts of expensive inputs to sustain production
- decrease soil fertility, degrade soil structure, and alter water tables
- lead to land degradation and loss of ecosystem services over time
- dramatically reduce habitat for native species.
In addition to this much of the potential agricultural land in savanna and semi arid Africa is home to 22 species of tsetse fly, which transmit a protozoan parasite that causes incurable sleeping sickness in humans and fatal diseases in livestock.
Large scale increases in irrigation in Australia and Africa would require large-scale and expensive dam projects, large inputs of fossil fuels and extensive works to prevent soil erosion, ground water contamination, salinisation and water-logging, which all reduce crop productivity. The negative environmental effects of increasing irrigation would include;
- Deplete ground water supplies
- Widespread land degradation and loss of biodiversity
- Loss of ecosystem services such as soil structure and nutrient cycling, water services of catchments affected by damming
- Decreasing agricultural profitability
- Use of marginal land
(c) Environmental Consequences of Meat Production
Activity 3.10
Briefly read over Miller & Spoolman (2012) pages 295 – 296 and answer the following questions
- Describe 6 negative consequences of meat production.
- Are there options for producting meat more sustainably?
Can the Earth Feed 9 Billion People?
Many well-respected and influential expert commentators have presented strong optimistic and pessimistic views on the ability of the Earth to provide enough food for our increasing population.
In this section we will consider the key points of each of these arguments from an agricultural and ecosystem services perspective rather than a population debate perspective (refer to the population module). It is important to note that although most of the data used to support the optimistic view in Table 1 is from Lomborg's book The Skeptical Environmentalist, this is not the only source that supports these ideas.
Activity 3.11
Open Table 1 in the attached Word document. Use Miller & Spoolman (2009) with additional references to complete the missing arguments in the following Table.
(Internal Students, please note this exercise will be discussed in the tutorial class).
Additional References
http://www.fao.org/ag/ Have a look at the articles that are listed down the centre of this page for information to support many of these points
http://www.worldwatch.org/taxonomy/term/98 Have a look at some of the press releases etc. from Worldwatch Institute for information to support many of these points
Lomborg (2001) The Skeptical Environmentalist: Measuring the Real State of the World, Cambridge University Press (available in CDU Library) http://www.lomborg.com/
Principles of Sustainable Agriculture
As discussed in the previous sections of this module the two major ways to increase agricultural production are to increase crop yields and/or increase the amount of land used to grow crops.
Activity 3.12
Read Miller & Spoolman (2012) pages 304 – 314, and answer the following questions:
- What does Miller give as the three options for reducing malnutrition and the harmful environmental effects of agriculture?
- How much cropland worldwide is currently managed organically?
- With Reference to Figure 12-35 list the components of more sustainable, organic agricultural systems
- What are some of the advantages of these types of systems?
- What are some of the compromises that will have to be made to consume sustainably produced food? (Hint: think about the effect of less effective pest control, fruit that is not waxed to improve shine, reduced transportation of produce, choice, availability, expense etc.)
- What four suggestions are given as steps that could improve the transition to sustainable agricultural production?
Review Questions
- Describe the optimistic and pessimistic arguments for whether agriculture can provide enough food for the worlds increasing population and projected 2050 populations.
Which of these arguments do you believe to be a more convincing and better supported and why?
- Read the Web-based article at http://www.affa.gov.au/
and briefly discuss the importance of GMO crops in Australian agriculture. If you can find a more up-to-date article use this instead.
- List the advantages and disadvantages of using genetically engineered plants for agricultural production.
- Discuss the role of sustainable agriculture in providing food and other resources. Include in your answer a discussion of the following points. Describe sustainable agriculture and the underlying principles of this approach to agriculture. Describe at least five of the ecosystem services involved and why they are important. What are some of the long-term benefits that could be provided by agricultural systems that are based on principles of sustainability and the maintenance of ecosystem services?
- Explain how producing more food on less land can help protect biodiversity.
- List the pros and cons of growing more food by (a) increasing crop yields through green revolutions, (b) genetically modifying crops and foods (c) getting people to switch to new types of food, (d) irrigating more cropland, (e) cultivating more land, (f) growing more food on urban lands.