I. Introduction
This unit is on food. Food is one of our most important human needs. Not only does life depend on it, but the quality of the food we eat effects the quality of our lives. The purpose of this unit is to help us become better food consumers. The method for doing so is to develop our understanding of food issues by working with and discussing information in four areas: the world food situation, food production, food storage and transportation, and becoming better food consumers.
The world food situation section looks at some of the significant differences between developed and developing countries, what world food security means, and some aspects of hunger and malnutrition.
The food production section aims primarily at developing a sense of how a plant grows, that the carbon, nitrogen and water processes cycle and the energy process flows primarily to earth and away from it. Soil condition, fertilizers, pesticides, erosion, seeds, water and energy are important agricultural issues.
The part on food storage and transportation stresses that grains are the world’s most important food because they are easy to store and transport, can be grown with relatively little labor, have a high yield for work involved, and have high nutritional value. Wheat, rice and corn are the most important of the grains and together they provide the basic food for most of the world. This section further states that perishable foods have a variety of storage and transportation needs and that almost all U.S. domestic foods both dry and perishable are transported by truck.
The part on becoming better consumers considers two approaches, the U.S. Department of Agriculture’s (USDA’s) seven nutritional guidelines and an international approach, in trying to find suitable guidelines for food selection, preparation and consumption. As consumers, whatever we buy we encourage the production of that item. Each food item we buy has nutritional, environmental, and political effects.
II. The World Food Situation
i. Developed and Developing Countries: Science andTechnology.
In the world today we have developed countries such as those in North America, Europe, Japan, Oceanic and USSR, and developing countries such as those in Africa, Asia, and Latin America. One of the major differences between the two groups is that the developed nations have a high level of science and technology.
Science can be defined as the systematized arrangement of facts about the physical world as they are currently understood. Technology can be defined as the sum of the ways a group uses knowledge from the sciences and arts to provide for their material needs. The combined use of a high level of scientific and technological knowledge has a profound effect on the daily lives of people; this is illustrated in the following table that compares developed and developing countries.
The Gap Between Developed and Developing Countries
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Comparing
|
Developing
|
Developed
|
|
countries
|
countries
|
Per capita GNP, $
|
500
|
5,500
|
Number of people
Deaths per
Life Expectancy
Grams of Protein per
day per person
|
54
|
97
|
Literacy, %
|
43
|
97
|
2. World Food Security.\
World food security means the assurance of adequate daily food consumption at the national, village and family level even in years of bad harvest. To accomplish this would require that each country become as food sufficient as possible and that we maintain a food reserve of 17 to 18 percent of the total annual world consumption.
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This reserve would help keep
This is what we want, world food security; what we have is a large number of people who are hungry and malnourished.
3. Hunger and Malnutrition.
How extensive is the problem of hunger and malnutrition? There are about 5 billion people on Earth, more than 1 billion people are chronically hungry and 35,000 people die each day from hunger. That is 24 of us 18 of whom are children die from hunger each minute.
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What do we mean by hunger? Hunger is an urgent need or desire for food. It can exist as chronic undernutrition, malnutrition, malabsorptive hunger, seasonal hunger and famine.
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What do we mean by malnutrition? Malnutrition is any faulty or insufficient dietary condition. Specifically, it is a condition resulting when an individual’s diet has a relative deficiency or relative excess of specific nutrients vital to good health.
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There are many reasons for malnutrition, personal difficulties in metabolism, lack of knowledge as to adequate food selection, inadequate preparation and consumption patterns, a shortage of food and lack of means to obtain food.
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4. Why We Have Hunger and Malnutrition.
Personal difficulty in metabolism is a medical problem possibly caused by hereditary or disease factors. Lack of knowledge as to adequate food selection and inadequate preparation and consumption patterns are educational problems and the target of this unit, Shortage of food and lack of means to obtain it are political issues.
5. The Hunger Project and The World Food Council,
The Hunger Project
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, and international organization of over 3 million people who are committed to ending hunger by the year 2000, state that we have more than enough food to feed all the people on earth.
If all the food produced on earth each year were divided equally among all the people of the earth, every person would receive about 2.3 kilograms (five pounds) of food per day more than three times the minimum amount needed to support life. The grain alone would provide everyone with the equivalent of two loaves of bread a day. The food
currently
raised each year is more than enough to adequately feed the 6.1 billion people anticipated by the year 2000.
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The World Food Council
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of the United Nations, the organization that monitors food problems and acts as a political catalyst by providing a forum for discussion of policy and proposals, states that several delegations believe that hunger and malnutrition are due to international financial and trade crisis and an inequitable economic order.
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III. Food Production
Understanding how food is produced will help us to better understand the nutritional as well as the environmental and political aspects of food. To talk about food production means to talk about growing plants. All our food comes from plants, or animals that eat plants, or animals that eat animals that eat plants.
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Some work is being done in aquaculture, but our main food supply comes from land products and that is the focus here.
1. How a plant grows.
As a plant grows it takes water and nutrients from the soil, takes carbon dioxide from the air and uses the sun’s energy to chemically combine these ingredients to make the carbohydrates (sugar and starch), protein and fat molecules in its structure. During this process, called photosynthesis, oxygen is released into the air. The process of how a plant grows is represented by the following illustration.
(figure available in print format)
The carbon in the carbon dioxide that plants take in from the air becomes part of the chemical structure of the plant’s carbohydrate, protein and fat molecules. When animals eat plant food, some of it is used as energy and some is stored. As animals use food energy in their living activities, they breath out carbon in the form of carbon dioxide, thus it is returning to the air. The animals breathe in oxygen and breathe out carbon dioxide.
Plants take in carbon dioxide and breathe out oxygen. Carbon dioxide is also continually being released into the air from decaying waste of plants and animals. This process is called the carbon cycle and is represented by the following illustration.
(figure available in print format)
The energy that the plant receives from the sun does the work of photosynthesis. The result of photosynthesis is that energy is stored in the plant material and can be recovered by burning plants such as wood or using plant food for animal energy.
Energy does not cycle like carbon, it primarily flows to earth and back out into the atmosphere. Solar energy arrives on earth in the form of visible light or ultra violet rays. Three of the things that could happen to solar energy as it comes to earth are: it could hit a pavement and be reflected back into the atmosphere as infrared rays, be absorbed by a plant and cause photosynthesis, or strike water and provide the heat for water evaporation. Most energy eventually flows away from earth in the form of heat: it does not cycle. Examples of energy flow are illustrated below.
(figure available in print format)
2. Land.
A plant needs land in which to grow. Three major land concerns are maintenance of active soil, use of fertilizers and pesticides, and control of erosion.
a.
Soil
. Active soil is essential for growing good food. A clear description of what soil is as follows.
The soil is an ever changing natural body that covers a large portion of the earth’s land surface. It teems with life. One gram of soil may contain several billion bacteria. Also found in the soil are roots of higher plants, algae, small mammals (e.g., squirrels, gophers, woodchucks, mice, moles), worms, insects, snails and many more.
A soil in one place may differ from a soil in another place. And a soil in an area will change with the passage of time.
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All soil, regardless of the place or time, consists of these four major components: mineral particles (sand, silt, and clay), organic matter (partially decayed plant and animal waste), water and air. When a soil contains the proper proportion of these four components, it can supply plants with many of their life sustaining requirements.
Soil composition is complex; this can be seen by the two tables below. The first table lists the nutrients most plants need to grow, and therefore good soil needs to have most of these. The second table illustrates what some farmers consider to be the composition of a good growing soil.
Nutrients Essential for the Growth and Development of Most Plants
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Nutrients needed
|
Nutrients needed in
|
in substantial amounts
|
much smaller amounts
|
Carbon
|
Iron
|
Oxygen
|
Boron
|
Hydrogen
|
Copper
|
Nitrogen
|
Zinc
|
Phosphorous
|
Molybdenum
|
Potassium
|
Manganese
|
Sulfur
|
Chlorine
|
Magnesium
Calcium
Composition of Good Growing Soil
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Component
|
Percentage of soil by Volume
|
mineral particles
|
45%
|
organic matter
|
5%
|
water
|
25%
|
air
|
25%
|
b.
Fertilizers and pesticides
. As plants grow they take the sixteen nutrients they need from the soil. Once plants are grown and harvested, the nutrients they took are gone from the soil forever, If nutrients are not restored to the soil, it will become depleted and no longer have the nutrients needed to produce food crops. There are two basic methods to replacing lost nutrients, organic and inorganic methods,
The organic method uses organic fertilizers, a balance of plants and animals, and legume rotation. Organic fertilizers are made from the decomposition of plant and animal wastes. A balance of plants and animals refer to the use of a field first for crops and then for grazing animals. This type of rotation allows the soil to rest and become enriched by incorporating the animal manure.
Legume rotation replaces nitrogen in the soil. Nitrogen is the most difficult of the nutrients to replace. Though it is found in abundance in the air, most plants cannot use nitrogen in that form. Legume plants, however, can. In legume rotation s field is planted alternately with legume and non-legume plants. Legumes include such plants as beans, peas, alfalfa, and clover. Non-legumes include grain crops, fruits, vegetables, and other plants. Legumes take nitrogen from the air and deposit it through their roots into the soil as a water soluble compound. The non-legume plants are able to use the water soluble form. Thus legumes put nitrogen into the soil; non-legumes take it from the soil. Further, as plant and animal waste decomposes, nitrogen is again released into the air. This entire process is called the nitrogen cycle and it is illustrated below.
(figure available in print format)
The inorganic method of replacing nutrients in the soil uses chemically produced compounds called inorganic fertilizers. Currently most U.S. farmers use inorganic fertilizers.
The proponents of organic fertilizers believe that (1) using the natural nutrients of organic matter from plant and animal waste and some crops grown for that purpose (green manure) produces richer soil and healthier plants and (2) this method requires significantly less fuel energy. Opponents of organic fertilizers say it (1) requires too much labor and (2) doesn’t produce as much food.
Proponents of inorganic fertilizers hold that it (1) is easier to apply, (2) produces high crop-yields, and (3) helps to produce low cost food. Critics of inorganic fertilizers say (1) they take a lot of fuel energy to produce and (2) cause contamination of drinking wells and lakes.
Opponents of organic farming, a method that uses organic fertilizers and alternatives to pesticides and herbicides (see below), believe that it is not practical. Some farms, however, do well using organic farming methods. One study done on organic farming results showed that organic farms used about 1/3 as much energy and the farmers enjoyed essentially the same income as the inorganic farmers.
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Pesticides and herbicides are chemical compounds used to protect crops from insects, disease or weeds. Their use is more controversial than the use of fertilizers. On the positive side they protect crops from insects, disease and weeds thus allowing for greater production of food. On the negative side they are poisons that can seep into the land and contaminate drinking wells and lakes, get into the leaves, roots and fruit of plants and then into the bodies of people who eat them. They also kill off useful insects, and the continual use of pesticides have caused some insects to develop immunity to them so that more and more pesticide is needed to do the job.
There are traditional and new developing methods of dealing with pests that do not require pesticides and herbicides. Some of these are as follows: growing healthy plants in healthy soil, one organically fertilized, makes it more resistant to pests and disease; planting a variety of crops instead of only one kind prevents an entire wipeout should a blight strike one type of crop; planting various combinations of plants that have a protective effect on each other in that one plant has a repelling effect on a pest that would otherwise go after one of the plants planted with it; and finally, using sophisticated biological technologies involving predator releases, microbial disease, biodegradable botanical sprays, resistant varieties, and mechanical and pheromone traps.
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To use such methods takes more skill and work than spraying a field with poison. However, it takes time to learn these skills, labor is expensive, and farmers must deal with the economic realities.
c.
Erosion
. The last land issue to be covered is erosion. It is not enough to develop and maintain active soil, you also have to protect it from being washed or blown away. About 5 billion tons of top soil, approximately 12 tons per acre, are lost annually from U.S. croplands. About three-quarters of the erosion is from water and one quarter from wind.
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Just as the top soil is being continually eroded away, it is also continually being formed. The problem is that the rate it is being formed is about 1.5 tons per acre per year and the rate it’s being eroded is 12 tons per acre per year.
The conservation of topsoil is a major problem. Erosion is almost nonexistent in well-covered woodland, slow in land covered with trees and grass, and fast in fields that are cropped each year and not covered. Some of the factors that determine the severity of soil erosion are soil type, soil depth, slope of the land, length of slope, amount of organic matter present, cultivation practices, crops grown, rotation schedule, and duration and intensity of wind or rainfall. Worldwide soil erosion is worse than in the U.S. In developing countries it is estimated at twice as much.
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3. Seeds.
There are different kinds of seeds for each species of plant. Each kind of seeds had different qualities like some will do well in a moist climate but not in a dry one, or Certain seeds will produce plants that are resistant to specific insects. Throughout the world continual research is being done to try to find seeds that best meet the needs of each area.
4. Water.
In addition to seeds, soil and fertilizers, plants need water. The earth has a lot of water that flows and cycles about it. The amount of water on earth is constant. We do not get more and we do not lose it. The water cycle basically goes as follows: Heat from the sun’s energy evaporates water from oceans and other surfaces; the moisture gathers in the atmosphere forming clouds. As the clouds become saturated, they drop the moisture in the form of rain or snow. As the rain or snow falls to earth any number of things could happen to it including being absorbed by the soil, running off the land into streams, or penetrating the soil to become part of an underground water flow. Eventually it will find its way into a stream, evaporate it once gain. The cycle will continue to repeat. The following illustration represents the water (hydrologic) cycle.
(figure available in print format)
Some land receives an abundance of water, but other land must be irrigated to make it arable. Throughout the history of agriculture and throughout the world today, farmers are trying to find improved ways of watering crops. As an example of the amount of land needing irrigation, in the U.S. in 1984 there were 175,134,000 acres of cropland planted and 44,731 acres had to be irrigated.
5. Energy.
Along with land, fertilizers, seeds and water, plants need energy to help them grow. The most important source of energy is the sun’s energy mentioned above. But labor and fuel energy are also significant.
Different agricultural methods require vastly different amounts and types of energy. For instance, traditional dryland Asian rice culture uses about one calorie of energy (in the form of human labor) to produce about twenty calories of rice. Modern U.S. corn production requires about one calorie (mostly in the form of tractor fuel, fertilizer and heat for drying) to produce one calorie of corn. At the high extreme, feedlot beef production and modern deep sea fishing require from ten to twenty calories of energy to yield one calorie of food.
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Energy used to produce food usually does not stop with growing it. Most foods are processed, transported, and stored before we get them. The following table shows the percentage breakdown of the energy required to produce a 1-kilogram loaf of white bread and deliver it to a retail store in the United Kingdom. It is interesting to notice that slightly less than one-fifth (19.4%) of the energy used to produce the loaf of bread was used in the actual production of wheat. Slightly over four-fifths (80.6%) of the energy required was not related to farm cost of growing the basic food, wheat, but primarily for processing (57%), packaging (10.3%) and transportation (9,8%). The retail store used 3.4% of the energy.
Energy Needed to Produce and Deliver a 1 Kg Loaf of Bread
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Growing Wheat
|
19..4%
|
Confection
|
64.3%
|
tractors, etc.
|
5.3%
|
direct fuel and power
|
30.2%
|
fertilizers
|
11.1%
|
other items
|
17.3%
|
drying, spraying
|
3.0%
|
packaging
|
9.0%
|
|
|
transport
|
7.8%
|
Milling Wheat
|
12.9%
|
Retail Stores
|
3.4%
|
direct fuel and power
|
7.4%
|
retail stores
|
3.4%
|
other
|
2.1%
|
packaging (1.3%) and