Energetics of Agroecosystems
Level 12: Guiding QuestionWhat will be the next energy that will take the place of petroleum?
Energy is the lifeblood of ecosystems and of the biosphere as a whole. At the most fundamental level, what ecosystems do is capture and transform energy.
Energy is constantly flowing through ecosystems in one direction. It enters as solar energy and is converted by photosynthesizing organisms (plants and algae) into potential energy, which is stored in the chemical bonds of organic molecules, or biomass. Whenever this potential energy is harvested by organisms to do work (e.g., grow, move, reproduce), much of it is transformed into heat energy that is no longer available for further work or transformation—it is lost from the ecosystem. Agriculture, in essence, is the human manipulation of the capture and flow of energy in ecosystems. Humans use agroecosystems to convert solar energy into particular forms of biomass—forms that can be used as food, feed, fiber, and fuel. |
All agroecosystems—from the simple, localized plantings and harvests of the earliest agriculture to the intensively altered agroecosystems of today—require an input of energy from their human stewards in addition to that provided by the sun. This input is necessary in part because of the heavy removal of energy from agroecosystems in the form of harvested material. But it is also necessary because an agroecosystem must to some extent deviate from, and be in opposition to, natural processes. Humans must intervene in a variety of ways—manage noncrop plants and herbivores, irrigate, cultivate soil, and so on—and doing so requires work. (Gliessman 253) Gliessman, Stephen R.. Agroecology: The Ecology of Sustainable Food Systems, Third Edition, 3rd Edition. CRC Press, 41974. VitalBook file. |
Promoting Diversity in an Agrosystem: Your thoughts
Notice the words that you used to express your thoughts on increasing diversity in agrosystems
Positioning, Precisely, GPS, Prevent, Practices, Soil, Cover, Native, Differently
Positioning, Precisely, GPS, Prevent, Practices, Soil, Cover, Native, Differently
Level 12 Investigation: Biofuels from Fermentation
The Challenge
What does ethanol production look like when grain is fermented without the addition of enzymes?
If we add enzymes, will there be much of a change in the ethanol production? In this activity we will be measuring the percent of ethanol gas in the air above a mash sample with and without the addition of enzymes. |
A fuel is any material that can be burned for heat or power. A biofule is a fuel derived from biomass such as platnt matter. Biofuels are usually alcohols such as ethanol, a product of the fermentation of sucrose in plas crops such as corn. Automibiles use gasoline for fuel. Gasoline is a product of oil and when burned contributes to an increase in carbon dioxide in the atmosphere. Ethanol can be addedto gasoline to reduce the amount of carbon dioxide emitted as a result of combustion.
When grains sprout, they produce enzymes such as amylase which break the large starch molecules in the seed into smaller units sucrose. The sprouted grains with the enzymes and sucrose are dried and made into mash. If yeast is added to this enzyme renriched mash in a deoxygenated environment, the yeast will begin to ferment the mach.Ethanol is a byproduct of this fermentation. Most grains, along with other plant products such as sawdust, soybeans and switch grass, can be fermented to produce ethanol. |
BioFuels from Fermentation: Lab Procedures
To complete the lab please filling out "Biofuels from Fermentation" form below.
Pics from our Knaggs Ranch Field Trip
Level 12 Videos: Sustainability Matters
Use the videos to help you explain agroecology concepts in your website.
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Level 12 Elaborate: Making a WebsiteThe document on the right is a rubric that outlines what you will be evaluated on our final. The basic concept here is to show the instructor what you have learned in "Sustainable Agriculture". You should answer the following questions; what is your definition for "sustainable agriculuture, what are the major "best practices" in sustainability in a agrosystem, what are the components in agroecology, how do "best practices" sustain ecosystems, do biotic and abiotic factors support sustainability, what are basic monitoring practics we have seen used? Remember you are to use the website to convince the instructor that you have learned the best practices that are used in the "real world" situations. Use videos, pictures examples of your work, maps, data you have collected, drawings and anything that will educate people about what is "Sustainable Agriculture " and why it is benefical to our local community. Use your notes, watch the videos I have included to help you remember what we have learned.
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Level 12 Review
Examples of Student Websites
Level 12 Summary: Unit Test
Use the question below to help you with explaining the concept of sustainability.