Bio 2106: Environmental Biology
Lab 2: Food Production and World Hunger
Lab Requires: Calorie counter book/ library or Internet access
Time to Compete: 1 week
Many of us may have had grandparents or parents who were raised on a farm, or a ranch. Most individuals in this country however, no longer raise their own food. We run to the grocery store for a weeks worth of shopping, or eat out at a restaurant, or drive through a fast food chain. While the ultra modern method of obtaining food saves our time, and our personal energy, it completely distorts our perception of amount of land and energy it takes to produce an apple, or a quart of milk, or a steak. Here is an example. Every day, most Americans eat a tremendous amount of meat. Most do not realize that a dietary chart defines a single portion of meat as equal in size to a pack of playing cards. Not only do we eat more meat than we need, we eat more meat than is considered healthy in a balance diet. More over, most of us do not recognize that the same amount of land it takes to raise one cow in one year- (and a single cow is then be eaten by one person) could support 22 people, if it was farmed in grains or other plant material.
The objective of this lab is to allow you to see the link between the food that you eat and the amount of land it takes to grow the food. Moreover, you will calculate the amount of fossil fuels it takes to grow and harvest, ship and prepare your food.
PART A:
1. Recording Your Diet
In this first part of the lab, you need to select a three-day period during which you will record your diet. You will need to make a careful and complete list of all the types, and quantities of food that you eat. Please choose a three-day period that represents your typical diet- it will give you the most accurate information! Obtain a calorie counter book to calculate your daily caloric intake of each kind of food. Calorie counting book can be obtained at the grocery store (usually the checkout stand), at the library or via the web. Note that calorie-counting books are often confusing in that they express values in terms of calories (with a lower case c.). This is incorrect: values are actually measures in large calories or kilocalories- (k cal.)
Take an average value for each of the days. For example if you have 200 kcal or potatoes on day 1, 400 kcal of potatoes on day 2, and 400 kcal of potatoes on day 3, the average would be 1000 kcal/3days = 333kcal. If you have 500 kcal of cheese but you ate cheese once, you would write down 500 kcal of cheese. Now multiply your average by 365 days to calculate your annual consumption by food type. Record these numbers in the appropriate column in table A (see next page).
2. Land Use and Your Diet
The amount of food it takes to raise a given type of food will vary significantly depending upon the type of food. Legumes, such as soybeans and peas are less demanding upon the land since they fix their own nitrogen. Other foods such as beef and pork take more energy, since cows and pigs cannot use easily turn plant energy into muscle. Almost 90% of the energy stored in plants gets lost when animals graze the land. The values from some of the more basic food types in a modern American diet are given in the table on the following page. To complete Table A, divide your annual consumption of a given food by its yield.
TABLE A
Food Item |
Your Total Annual Consumption |
Yield of Crop (kcal/m/yr.) |
Area of land required to support you (consumption/yield) |
Bread |
650 |
||
Wheat cereal |
810 |
||
Rice or rice cereal |
1250 |
||
Corn cereal |
1600 |
||
Soybeans |
2500 |
||
Citrus fruits |
1000 |
||
Frozen Juice |
400 |
||
Apples |
1500 |
||
Pear, peaches |
900 |
||
Potatoes |
1600 |
||
Carrots |
800 |
||
Other vegetables |
200 |
||
Cane (white) sugar |
3500 |
||
Soft drinks |
3500 |
||
Peanut butter |
900 |
||
Vegetable oil or margarine (butter) |
300 |
||
Milk |
400 |
||
Cheese |
40 |
||
Eggs |
200 |
||
Chicken |
200 |
||
Pork |
200 |
||
Beef |
130 |
||
Fish |
2 |
||
TOTAL (in square meters) = ___________
Convert your answer in terms of hectares and acres,
1) Taking the number of square meters and divide by 10,000 giving you the hectares
= Hectares
2) Convert from hectares to acres by multiplying by 2. 47
= Acres
PART B. Fossil Fuel and you Diet.
Introduction
In another lab on fossil fuels and personal consumption, you recorded how much energy you use to heat you home or play your stereo, or run you refrigerator. What you did not include is all the amount of energy it takes to get the food that you consume from the farm to your freezer. If you grow your own food, you simply step out the back door. But what if you ate a frozen cheese pizza? If the cow lives in Michigan and the wheat was grown in Iowa, there is a lot of energy spent processing and shipping and delivering the food to your supermarket. Then you have to drive to the store and pick it up (or have the pizza person drive and deliver it to your house!). Thus to accurately represent the real energy used to grow food, you need to calculate these not –so- hidden costs.
A. Energy consumed before you by the food:
1. Energy used in agriculture production on the farm for production of fertilizers and pesticides (if non organic), for the manufacturing of machinery to harvest the food
2. Energy used in processing and packaging the food
3. Energy used in transportation
B. Energy consumption in the home
1) Fuel used to drive to the market
2) Energy used in refrigeration
3) Energy used in cooking
You will try to estimate each of these categories. Not that there are a lot of assumptions and averages out in to make this calculation. The data given on the following table are only estimates. But the point of the exercise will not be lost in that you can appreciate the amount of energy that goes into preparing you dinner. The following paragraph will provide you with the information needed to complete Table B below.
A. Energy consumed before you buy the food.
1. Agricultural production: The energy used to produce crops varies a lot. These numbers have already been provided for you in Table B.
2. Processing: Fruits, potatoes and other vegetables and raw grains are essentially sold as is. There is not a lot of processing that goes on, so their processing energy is 0. Simple processing, such as baking bread, slaughtering and packaging meat making cheese and freezing canning foods use approximately. 3kcal of energy per kcal of food. Highly processed convenience foods, such as fast foods and gas stations, use about twice that amount, or 6kcal of energy per kcal of food.
3. Transportation: the national average is about 2kcal of energy per 1kcal of food
The first column is your annual consumption in kcal/year that was calculated in Table A. The second column, the agricultural production, is given for you. You need to estimate the processing energies (column 3) and then add up all the subsidies (columns 2, 3, and 4) and place this number in column 5. . Multiple this value (column 5) times the annual consumption (column 1) to get the annual energy for each food type ((column 6). Finally add all the individual annual energies together to derive your total fossil fuel subsidy before you buy the food.
TABLE B: Fossil Fuel Subsidies before you buy the Food
Food Item |
Your annual consumption |
Agricultural Subsidies |
Processing |
Transportation |
Total subsidies |
Annual energy |
Bread |
1 |
2 |
||||
Wheat cereal |
1 |
2 |
||||
Rice or rice cereal |
2 |
2 |
||||
Corn (any) |
1 |
2 |
||||
Soybean |
1 |
2 |
||||
Citrus fruits |
4 |
2 |
||||
Frozen Juice |
4 |
2 |
||||
Apples |
1 |
2 |
||||
Pear, peaches |
1 |
2 |
||||
Potatoes |
1 |
2 |
||||
Carrots |
1 |
|||||
Other vegetable |
3 |
2 |
||||
Cane (white) sugar |
1 |
2 |
||||
Soft drinks |
1 |
2 |
||||
Peanut butter |
1 |
2 |
||||
Vegetable oil or margarine (butter) |
1 |
2 |
||||
Milk |
2.5 |
2 |
||||
Cheese |
2.5 |
2 |
||||
Eggs |
6 |
2 |
||||
Chicken |
10 |
2 |
||||
Pork |
10 |
2 |
||||
Beef |
12 |
2 |
||||
Fish |
10 |
2 |
||||
Total Fossil Fuel subsidy for your annual consumption = __________
Part B. Energy Consumption in the Home:
1. Transportation: To calculate the kcal of energy you spend to get your food, fill in the following equation.
___ trips to the store X miles round trip X 52 weeks/year
per week distance = _____ gal/yr.
_________________________________________________
____ miles per gallon for your car
Now multiply the total gallons per year times 32,000kcal/gal to convert your answer to kcal per year.
2. Refrigeration: On average, a single-door manual defrost refrigerator uses 600 kilowatt hours/ year (abbreviated kWh/year). Maytags, which are very efficient, used about 500 kWh/year. A large 20cu. ft double door automatic defrost refrigerator uses 1800 kWh/year. Determine which category your refrigerator best compares with and estimate your energy consumption. In kWh/year.
Multiply this answer by 860kcal/kWh to convert your answer into kcal/year.
3. Cooking: a) from the previous lab on personal energy consumption, record the number of minutes you use your oven or stove per week. b) if you know the wattage, you can calculate the kcal per year. On average, an electric stove uses 12500 watts. For example, if you use your stove 10 hours a week, that would equal 125 kWh/hr
___ min/wk X 52wk/year X ____ kWh/min X kcal/kWh = _____ kcal year
4. Final Energy Calculation
a. Add the total annual energy requirements for food purchase, storage and preparation (Part B.
b. Add the fossil fuel subsidies for food production, processing and transportation (Part A).
c. Your total energy cost in feeding yourself for 1 year = ________ kcal/year