1. An Ecological Perspective (BIOL 346)
Talk Five:
Sustainable Agriculture 1 1 1

2. Sustainable Agriculture
The practice of farming using principles of ecology, the study of relationships between organisms and their environment.
It has been defined as "an integrated system of plant and animal production practices having a site-specific application that will last over the long term:
Satisfy human food and fiber needs
Enhance environmental quality and the natural resource base upon which the agricultural economy depends
Make the most efficient use of non-renewable resources and on-farm resources and integrate, where appropriate, natural biological cycles and controls
Sustain the economic viability of farm operations
Enhance the quality of life for farmers and society as a whole.

3. Sustainable agriculture integrates three main goals
Environmental health
Economic profitability
Social and economic equity.

4. Environmental health
Sustainable Agriculture refers to agricultural production that can be maintained without harming the environment.
Environmentally Sustainable Agriculture should be:
Bearable
Equitable
viable for the farmer
AND - produce the best quality food for the consumer, nurture the environment & preserve energy.

5. Economic profitability
Ecological economics is:
the interdependence of ‘human economies and natural ecosystems’.
It treats the economy and society as a subsystem of the ecosystem:
with emphasis on preserving natural capital
recognizes
That social and economic systems cannot exist independently from the environment.

6. Social and economic equity
There is a natural market premium
If successful
Equity will be recognized by the farmer as beneficial for this commitment to quality food output.
In addition farmer may get
Government favorable interest rate financial incentives and solution support.

7. Sustainable agriculture
Sustainable agriculture in the United States was addressed by the 1990 farm bill.
More recently, as consumer and retail demand for sustainable products has risen, organizations such as Food Alliance and Protected Harvest have started to provide measurement standards and certification programs for what constitutes a sustainable grown crop

8. What is Sustainable Agriculture?
Agriculture has changed dramatically, especially since the end of World War II.
Food and fiber productivity soared due to new technologies, mechanization, increased chemical use, specialization and government policies that favored maximizing production.
These changes allowed fewer farmers with reduced labor demands to produce the majority of the food and fiber in the U.S.

9. What is Sustainable Agriculture?
Has had major social and ecological impacts, which have drawn intense praise and equally intense criticism.
In fact, many regions of the world peaked in food production in the period 1980 to 1995
Are presently in decline, since desertification and critical water supplies have become limiting factors in a number of world regions.

10. What is Sustainable Agriculture?
Although these changes have had many positive effects and reduced many risks in farming, there have also been significant costs.
Prominent among these are:
Topsoil depletion,
groundwater contamination
decline of family farms,
continued neglect of the living and working conditions for farm laborers,
increasing costs of production
disintegration of economic and social conditions in rural communities.

11. What is Sustainable Agriculture?
A growing movement has emerged during the past two decades to question the role of the agricultural establishment in promoting practices that contribute to these social problems.
Today this movement for sustainable agriculture is garnering increasing support and acceptance within mainstream agriculture.
Not only does sustainable agriculture address many environmental and social concerns, but it offers innovative and economically viable opportunities for growers, laborers, consumers, policymakers and many others in the entire food system.

12. The Biosphere The atmosphere sustains life and is sustained by life.
The Gaia hypothesis
The entire planet is a living breathing organism and will protect itself – homeostasis of the whole planet!!!
The biosphere works in “cycles”
Nitrogen
Carbon
Water

13. Some greenhouse emissions related to agriculture are embedded in other sectors
fossil fuels to produce chemical fertilizers and pesticides
Processing
Packaging
Refrigeration
transport of food
land conversion from biodiverse ecosystems to giant, monoculture food plantations

14. Rodale Institute study
projects that the planet’s 3.5 billion tillable acres could sequester nearly 40 percent of current CO2 emissions if they were converted to “regenerative” organic agriculture practices
Remember:
Via photosynthesis, over 100 billion metric tons of CO2 and H2O are converted into cellulose and other plant products

15. Many studies have drawn similar conclusions.
India
organic farming research shows increases in carbon absorption by up to 55 percent (even higher when agro-forestry is added into the mix), and water holding capacity is increased by 10 percent.
California
study of 20 commercial farms found that organic fields had 28 percent more carbon in the soil than industrial farms.

16. Water cycle The resulting water vapor mixes with the atmosphere
At high altitudes where the air is cold enough it condenses to form rain and snow
Falls back to Earth.

17. Water Cycle Water evaporates from bodies of fresh water and the oceans
Much water is lost from the leaves of plants via transpiration.
Also from respiration of almost all living species

18. Water
In some areas, sufficient rainfall is available for crop growth, but many other areas require irrigation.
For irrigation systems to be sustainable they require proper management (to avoid salinization) and must not use more water from their source than is naturally replenished
taken from an article by Robert Service in Science Magazine. “Energy demands on water resources”

19. Indicators for sustainable water resource development are:
Internal renewable water resources.
This is the average annual flow of rivers and groundwater generated from endogenous precipitation.
Can be expressed in three different units:
in absolute terms (km3/yr),
a measure of the humidity of the country (mm/yr)
as a function of population (m3/person per yr).
Global renewable water resources.
sum of internal renewable water resources and incoming flow originating outside the country.
can vary with time if upstream development reduces water availability at the border.

20. Indicators for sustainable water resource development are:
Dependency ratio.
This is the proportion of the global renewable water resources originating outside the country, expressed in percentage.
It is an expression of the level to which the water resources of a country depend on neighboring countries.
Water withdrawal.
When expressed in percentage of water resources, it shows the degree of pressure on water resources.
A rough estimate shows that if water withdrawal exceeds a quarter of global renewable water resources of a country, water can be considered a limiting factor to development.
Therefore, the pressure on water resources can have a direct impact on all sectors, from agriculture to environment and fisheries.

21. The Soil The biggest ecosystem on Earth! Animals: Plants:
micro-organisms mix soils as they form burrows and pores, allowing moisture and gases to move about. In the same way, plant roots open channels in soils.
Plants:
deep taproots can penetrate many meters through the different soil layers to bring up nutrients from deeper in the profile.
fibrous roots that spread out near the soil surface have roots that are easily decomposed, adding organic matter.

22. The Soil Micro-organisms: Humans:
including fungi and bacteria, effect chemical exchanges between roots and soil and act as a reserve of nutrients.
 Humans:
impact soil formation by removing vegetation cover with erosion as the result.
Also mix the different soil layers, restarting the soil formation process as less weathered material is mixed with the more developed upper layers.

23. Soil Erosion
Fast becoming one of the worlds greatest problems. It is estimated that more than a thousand million tonnes of southern Africa's soil are eroded every year.
Experts predict that crop yields will be halved within thirty to fifty years if erosion continues at present rates.
Not unique to Africa but is occurring worldwide.
The phenomenon is being called Peak Soil as present large scale factory farming techniques are jeopardizing humanity's ability to grow food in the present and in the future.
Without efforts to improve soil management practices, the availability of arable soil will become increasingly problematic.

24. Soil Management techniques
No-till farming
soil is left intact and crop residue is left on the field.
soil layers, conserving organisms and layers in their natural state.
Keyline design 
maximizes beneficial use of water resources of a piece of land.
refers to a specific topographic feature linked to water flow
Growing wind breaks to hold the soil
Planting trees and hedges
Prevent wind from blowing away top soil

25. Soil Management techniques
Incorporating organic matter back into fields
Composting! Puts Carbon, Nitrogen, Oxygen, Water and microbes back into the soil!!! Can also add Urine –honest!!
Stop using chemical fertilizers (contain salt)
Remember Algal Blooms? Also, the salt kills natural micro-organisms in soil – contaminates water!!!!!
Protecting soil from water runoff
Careful placement of rocks and trees.
Soil Steaming
 sterilize soil with steam in open fields or greenhouses
Destroys pathogens
Destroys weeds, but dead plant material is left in soil as compost

26. Nitrogen in the environment
Present in many forms
78% of atmosphere is N2
Most of this is NOT available to living organisms
Getting N2 for the atmosphere requires breaking the triple bond between N2 gas to produce:
Ammonia (NH3)
Nitrate (NO3-)
So, N2 has to be fixed from the atmosphere so plants can use it

27. Nitrogen in the environment
This occurs naturally by:-Lightning:
8%: splits H2O: the free O and H attack N2 – forms HNO3 (nitric acid) which fall to ground with rain
Photochemical reactions:
2%: photochemical reactions between NO gas and O3 to give HNO3
Nitrogen fixation:
90%: biological – bacteria fix N2 to ammonium (NH4+)

28. Nitrogen in the environment
Once fixed in ammonium or nitrate :-
N2 enters biochemical cycle
Passes through several organic or inorganic forms before it returns to molecular nitrogen
The ammonium (NH4+) and nitrate (NO3-) ions generated via fixation are the object of fierce competition between plants and microorganisms
Plants have developed ways to get these from the soil as fast as possible

29. How do plants get their nitrogen?
Some plant species are Legumes.
Legumes seedlings germinate without any association to rhizobia
Under nitrogen limiting conditions, the plant and the bacteria seek each other out by an elaborate exchange of signals
The first stage of the association is the migration of the bacteria through the soil towards the host plant

30. How do plants get their nitrogen?
Nodule formation results a finely tuned interaction between the bacteria and the host plant
Involves the recognition of specific signals between the symbiotic bacteria and the host plant
The bacteria forms NH3 which can be used directly by the plant
The plant gives the bacteria organic nutrients.

31. Bottom line Grow crops which are best suited to local environment
Have a plentiful, and renewable local water supply
Protect the soil
Good crop management techniques

32. Good crop management techniques
Grow a variety of crops.
spreads economic risk and are less susceptible to the radical price fluctuations associated with changes in supply and demand.
Crop rotation
used to suppress weeds, pathogens and insect pests.

33. Good crop management techniques
Cover crops
stabilizing effects by holding soil and nutrients in place
conserving soil moisture with mowed or standing dead mulches, increasing the water infiltration rate and soil water holding capacity.
The use of vineyards can buffer the system against pest infestations by increasing beneficial arthropod populations and can therefore reduce the need for chemical inputs. 

34. Bottom line Low cost and effective local storage of food stuffs
Low environmental impact transport system
Local market and a steady and growing customer base.

35. So what about backyard Agricultural Sustainability?
Grow only crops which mature within the local growing season.
Only grow crops selections which will work together in such a limited space.
Think about nutrient needs.
Think about water demands.
Think about long time storage of successful crops.

36. Water barrel Free (clean) water!!!!!!! Rain barrel kit
Trash can
$40.00!!!
Set up next to garden. Fills up fast!
Melting snow will also fill it up.
Can connect many together.
Consider county, city, and state laws!

37. Composting Turning kitchen waste into natural fertilizer
Any container will work
Need air holes
Can buy bacteria cultures to add to container.
Can add worms to increase efficiently
When setting up, layer soil and kitchen waste.
Takes approx. one year to get going from scratch.

38. Wood ash
Component
Normal agar (ppm)
Ash Agar (ppm)
Arsenic
<0.1
0.1
Barium
3.3
Boron
2.2
Calcium
37.9
1409.9
Chlorine
2.1
Chromium
Cobalt
Copper
Iron
0.5
27.4
Lead
0.2
Lithium
Magnesium
11.6
107.6
Manganese
3.8
Molybdenum
Nitrogen
21.5
Phosphorus
3.6
109.4
Potassium
35.6
552.1
Sodium
83.7
90.7
Sulfur
268.3
335.8
Tin
Zinc
1.1
In addition to composting, can use wood ash from a log burning fireplace.
Ash is full of the essential nutrients required for plant growth and development.
Even contains a higher % of these nutrients than commercially available growth supplements.
Cheap, natural, and fantastic for the environment and soil health

39. Canning So, you grew hundreds of tomatoes. What to do with them?
Great preservation technique.
Allows you to store food stuffs outside of the growing season
Can use them for cooking for the rest of the year
Better than just freezing food stuffs
Can store ANYTHING by this method.
Not a new technology, just a (mostly) forgotten one, which is making a comeback.

40. Final Summary Sustainable Agriculture is:
The practice of farming using principles of ecology, the study of relationships between organisms and their environment.
refers to agricultural production that can be maintained without harming the environment.
Not only does it address many environmental and social concerns, but it:
offers innovative and economically viable opportunities for:
growers
Laborers
Consumers
policymakers.

41. The End!
Any Questions?