Solved by verified expert:For this assignment you will provide two responses to the following Papers. Each response should be150 words each :Discuss what Sustainable Agriculture will need to “look like” ( compare and contrast with current Industrialized Ag.) in the face of exponential population growth and how it will vary depending on whether it occurs in a Developed (1st World) vs Developing (3rd World) Countries. The two Papers are attached Refer the two paper:s (loaded under “Assignments” on BB)Agriculture Land Use, Royal BC Museum, for ideas on this discussionAgricultural Practices as Barriers to Sustainabilityhttps://bboc.vvc.edu/bbcswebdav/pid-2001083-dt-con…
ag_land_use_royal_bc_museum__1_.docx
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Agricultural Land-Use
3.1 Introduction
The beginning of agriculture dates back to a period in human history almost ten to twelve thousand years
ago. At this time, humans in several different regions of the world began domesticating several wild
species of plants and animals. Some of the first crops to be domesticated were the ancestors of today’s
modern grains. By continuously replanting only the largest and healthiest of these plants over the centuries,
these once wild plants were selectively adapted to local growing conditions. As a result of this selective
breeding, present day strains of rice, wheat, and other grains are far more productive than their acient
relatives.
Table 3.1: Original source region for various modern crops grown in abundance today.
Source Region
Crop Domesticated
Palestine, Syria
Wheat and Barley
Middle East
Mediterranean Basin
Southwest Asia
Central Asia
India and Southeast Asia
Mexico and Central America
South America
Barley, Rye, Oats, Flax, Alfalfa, Plum and Carrot
Pea, Lentil and Bean
Millet, Soybean, Radish, Tea, Peach, Apricot, Orange and Lemon
Spinach, Onion, Garlic, Almond, Pear and Apple
Rice, Cotton, Sugar Cane and Banana
Corn, New World Cotton, Sisal and Peppers
Tomato, Potato, Peanut and Pineapple
The rise of agriculture also brought about cultural and societial changes to the early human population. In
hunter gatherer societies nearly everyone was involved in the collection of food. However, early
agriculture required a smaller proportion of human society to produce food for the rest, allowing the people
not involved in farming to pursue other cultural endeavors. Early agriculture also allowed once nomadic
people to established themselves in one location.
Early agriculture was primarily subsistence in nature. Farmers generally only grew enough food to feed the
themselves and their extended families. The invention of the plow approximately 7000 years ago changed
this practice. With the development of the plow, food supplies and human population sizes could increase
by simply cultivating more land. As a result of the greater food supplied and increased population growth,
human communities began organizing in villages, towns, cities, and nation states. While the development
of the plow had a positive influence on the development of humankind, its influence on nature and the
environment was generally negative. Massive land clearing, for the purpose of growing more food,
destroyed and degraded the habitats of many types of wildlife.
In the 19th and 20th centuries, humankind realized that the growing human population was running short of
new sources of land for cultivation. A new technology had to be developed to expand food resources
without requiring more land for cultivation. Since 1950, sharp increases in agricultural productivity have
come from what is commonly called the green revolution. The green revolution increased yields by
planting monocultures of hybrid crop varieties and by the application of large amounts of inorganic
fertilizer, irrigation water, and pesticides. Between 1950-1970, this approach resulted in dramatic increases
in crop yields mainly in more developed countries(MDCs ). After 1967, a variant of this 1st green
revolution was transmitted to many less developed countries(LDCs) through MDC sponsored
development projects. This 2nd green revolution involved the cultivation of new high yield, fast-growing
dwarf varieties of rice and wheat, specially bred for tropical and subtropical climates. However, achieving
high yields with these new crops still required large inputs of fertilizers, water and pesticides. For many
LDCs, these inputs are impractical because of their high cost.
Increasing agricultural productivity through green revolution technologies relies heavily on the use of fossil
fuels for running machinery and producing fertilizers. Today, it now takes about 1.2 barrels of oil to
produce a single ton of grain in more developed countries. This is some seven times greater than from
1950. Thus, industrial agriculture has become addicted to oil, using about 8 % of world oil output. Many
LDCs do not have the finances to buy the oil needed to run an industrialized agricultural system.
Future increases in production are predicted to come from genetic engineering and other forms of
biotechnology. In the next 20 to 40 years, scientists hope to breed high yield plant strains that have greater
resistance to insects and disease, thrive on less fertilizer, make their own nitrogen fertilizer like legumes, do
well in slightly salty soils, and make more efficient use of solar energy during photosynthesis. A good
example of the products that can be created from this type of research is triticale. Triticale is a new cereal
grain produced by cross breeding wheat and rye. Triticale can flourish under a variety of conditions
including poor soils, and cold and hot climates.
Some analysts, however, point to several factors will limited the spread and long-term success of the green
revolutions. Thus, future increases in agricultural productivity may be limited by:
•
•
•
•
The availability of fertilzers and water. New crops required huge amounts of fertilizers and water.
Biological limitations. Plants have been far less responsive to genetic engineering than animals.
Climate and soil limitations. Areas without enough rainfall or irrigation water or with poor soils
cannot benefit from new varieties.
Environmental degradation. Without careful land use and environmental controls, degradation of
water and soil can limit the long-term ecological and economic sustainability of the green
revolutions.
In the last few decades, many nations have also turned to the oceans to supply some of their food resources.
Using various harvesting techniques, about 40 different species of marine organisms are caught for human
and livestock consumption. Of these forty species, Cod, Herring, Jack, Mackerel, and Tuna account for
over 60 % of the commercial fish harvested. From 1950 to 1990, the world catch of fish has increased by
about 400 %. Because of this drastic increase, the numbers of some species of fish have declined
substantially due to overfishing. In Canada, overfishing of North Atlantic Cod has caused the government
to take extreme actions to stop the destruction of this fishery.
Another technique humans use to supplement their food resource from the sea, is fish farming or
aquaculture . Fish farming involves cultivating aquatic species in a controlled environment. Usually the
controlled environment is a floating cage, a pond or lake, or a fenced-in area of lake or ocean. In 1990,
aquaculture supplied the world with 15 % of its seafood. Of this 15 %, three-fourths of it comes from
LDCs. Fish farming does create some ecological problems. For example, the development of shrimp
farming in Southeast Asia is responsible for the clearing of millions of hectares of mangrove swamps.
Mangrove swamps are the home to several thousand different species of plants, birds, reptiles, amphibians,
fish, insects, and mammals.
3.2 Global Food Resources
Of the 350,000 species of plants cataloged by science only about one hundred crops are primarily used to
feed the citizens of the world. About 15 plants and 8 animal species supply 90 % of our food. Wheat, rice,
corn and potato are the primary crops that provide us with the bulk of the starch we consume. Other
important crops, in order of production, include: barley, sweet potato, cassava, grape, soybean, oats,
sorghum, sugarcane, millet, banana, tomato, sugar beet, rye, orange, coconut, cottonseed, apple, yam,
peanut, watermelon, cabbage, onion, bean, pea, sunflower seed, and mango. Fruits and vegetables are
valuable components of a healthy diet because they provide high levels of vitamins, oils, minerals, proteins
and fiber.
Other foods consumed include fish, meat and animal products such as milk, eggs, and cheese. For most of
the people on this planet meat and animal products, like milk, are too expensive to consume. As a result, 80
% of the meat and milk produced is consumed by only 20 % of the world’s population. The raising of
livestock on the Earth’s land surface is creating some important environmental problems. Pasture and open
range now occupies 24 % of the Earth’s terrestrial surface and supports more than 3 billion domestic
grazing animals. Over grazing by these animals is causing desertification, chemical and physical soil
degradation, accelerated erosion, and plant biodiversity reductions.
Table 3.2 describes the countries with the largest areas in production of crops. The table also supplies
information on amount of cropland per capita (1991), average percentage of land being irrigated (1989-91),
average amount of fertilizer applied in kilograms per hectare (1989-91), average production of cereals
(1990-92), and average cereal yield in kilograms per hectare (1990-92). The total amount of arable land
worldwide is about 1,441 million hectares. The Russian Federation, which contains about 2.7 % of the
Earth’s inhabitants, currently cultivates about 213 million hectares or about 15 % of the world’s cropland.
Most of this production is sold to other countries or is used to feed livestock. The most efficient farmers are
found in China. With 22 % of the world’s population, the Chinese have to make do with only 6.7 % of the
Earth’s arable cropland. Yet, their population is well fed because intensive subsistence farming techniques
produce yields equivalent to those produced in countries practicing industrialized farming. However,
intensive subsistence agriculture requires large inputs of human labor, irrigation and fertilization in order to
achieve these yields.
Most of the cereal production in the United States, Canada, Russian Federation and Australia is not used to
feed humans directly. Most of this food is used to feed livestock which are used for dairy products, eggs or
slaughtered for meat. This process of creating food is highly inefficient. As discussed earlier in this course,
the efficiency of animals to assimilate food energy is less than 10 %. In fact, it takes about 16 kilograms of
grain and soybeans to produce 1 kilogram of edible beef.
Table 3.2 : Top Fifteen Countries in Terms of Land Under Crop Cultivation.
Statistics Also Describing: Cropland Per Capita in Hectares (1991); Average Percent
Land Irrigated (1989-91); Average Annual Fertilizer Used in Kg Per Hectare (198991); Average Cereal Production in 1000s of Metric Tons (1990-1992); and Cereal
Yield Per Hectare in Kilograms (1990-92). ( Source : Food and Agriculture
Organization of the United Nations and the United Nations Population Division.)
Cropland
000s of Hectares
(1991)
Cropland
Per Capita
in Hectares (1991)
Average Percent
Land Irrigated
(1989-91)
Average Annual
Fertilizer Used
in Kg Per Hectare
(1989-91)
Average C
Production
of Metric
(1990-19
212,800
1.44
3%
52
100,22
197,300
11.79
1%
3
23,21
187,776
0.74
10 %
99
315,48
169,700
0.20
27 %
73
196,17
96,554
0.08
49 %
284
399,92
61,350
0.40
4%
54
37,81
46,877
2.70
4%
26
22,21
45,930
1.70
2%
46
52,85
35,610
9.71
3%
7
571
34,629
0.67
8%
126
39,99
32,335
0.29
3%
12
13,11
27,689
0.48
9%
65
30,12
27,200
0.83
6%
6
21,97
26,100
1.27
16 %
41
1,985
24,720
0.29
21 %
69
24,66
3.3 Industrial Agriculture and the Environment
As previously mentioned, modern day agriculture has been responsible for dramatically increasing the food
supply. However, many of the practices used by industrial farmers can cause damage to nature or can be
extremely limited by normal variablity in the environment.
3.3.1 Erosion and Soil Degradation
Recent increases in the human population have placed a great strain on the world’s soil systems. More that
5.5 billion people are now using about 10 % of the land area of the Earth to raise crops and livestock. When
used for such purposes, soils can suffer various types of degradation that can ultimately reduce their ability
to produce food resources. Erosion is the number one factor degrading soils globally. Erosion is a process
where wind and water facilitate the movement of top soil from one place to another. Water erosion is more
detrimental to soils globally both by the volume of soil removed and area of land influenced. Soils are
normally protected from erosion by the above- and below-ground parts of plants. Above-ground parts of
plants, like stems and leaves, reduce the potential of wind and water to erode soils by acting as barriers to
these mediums. Plants can also reduce erosion by binding and anchoring soil particles to roots.
Agriculture increases the risk of erosion through its disturbance of vegetation by way of land-use
conversion, tilling or overgrazing. Many farmers prepare land by tilling or ploughing their fields to produce
a smooth planting surface devoid or vegetation. This process, however, creates a soil surface that is very
vulnerable to erosion. In Canada and the United States, some farmers have been using a technique known
as conservation tillage or zero tillage to reduce the erosion problem. This technique uses special
machinery and herbicides to plant crops with minimal disturbance to the soil surface.
The following agricultural practices lead to accelerated soil erosion:
•
•
Overgrazing of animals (where more animals are raised than the forage can sustain).
Trampling and eating diminishes the number of species grown in a particular forage area,
and without adequate vegetative cover the land becomes more susceptible to both wind
and rain erosion. Further when animals are grazed in riparian areas (areas next to
streams) , the trampling near the stream banks causes erosion and stream sedimentation.
Planting of a monoculture. This practice can lead to erosion for several reasons. First, a
monoculture is harvested all at one time, which leaves the entire field bare and the natural
rainfall is not retained by the soil and flows rapidly over the surface rather than into the
•
•
•
•
ground. Secondly, if a disease or pests invade the area, the entire crop is usually wiped
out and again leaving the bare soil susceptible to the elements.
Row cropping. This agricultural practice is common with monocultures but can also be
found in polycultures. This technique exposes the soil between each row of crops which
is then vulnerable to erosion.
Tilling or plowing. This is one of the oldest agricultural practices, it involves mixing up
the nutrients within the soil, loosening the soil particles, incorporating oxygen and getting
rid of weeds, however, it also increases the likelihood of erosion because it disturbs the
natural surface and protective vegetation.
Crop removal. The continuous removal of crops does not only increase the soil
susceptibility to erosion due to exposure but it also increases it because the organic matter
in the soil is depleted. Organic matter has the ability to absorb a lot of rainwater and
without it, erosion is increased because water doesn’t soak into the soil.
Development of new land. This is a problem particularly in the least developed countries.
Rising populations are forcing people onto marginal lands to grow crops. Hillsides are
not developed properly, and are very vulnerable to erosion when water passes over them.
Many of these practices have resulted in degraded land across the globe. Slight degradation refers to land
where yield potential has been reduced by 10 %, 10-50 % yield potential reduction is referred to as
moderate degradation and severely degraded is land that has lost more than 50 % of its potential yield.
Problems of soil ersion can be stopped, and certain techniques can lead to soil enhancement and rebuilding.
The techniques commonly used are:
1. Plowing style. The way in which a field is plowed can have a substantial effect on the amount of erosion
that occurs. The following techniques are commonly used to reduce ersions:
a) Contour farming. This method involves tilling the field at right angles to the slope of the land. The
ridges that are created act like a dam to hold the water while it soaks into the soil rather than running down
the slope taking the soil with it. Contour farming has the ability to reduce erosion by up to 50%.
b) Terracing. This is another way of preparing the fields for planting and is usually used on much steeper
slopes, by leveling off areas on the slope to prevent the flow of water down it. There are disadvantages to
terracing however, in that the terraces themselves can be easily eroded and they generally require a lot of
maintenance and repair.
2. Timing. The time which a field is tilled can have a major effect on the amount of erosion that takes place
during the year. If a field is plowed in the fall, erosion can take place all winter long, however if ground
cover remains until spring, there isn’t as much time for the erosion to take place.
3. No-till Cultivation. Specialized machinery is available that can loosen the soil, plant seeds and take care
of weed control all at once with minimum disturbance to the soil. Since all of these aspects are taken care
of at one time there is less time for erosion to occur. There is a trade off though, weed and insect
populations can increase which compete or destroy crops because they are not continuously being removed.
4. Farming Method. There are several ways in which a field can be cultivated in order to avoid erosion:
a) Strip Farming. This involves planting crops in widely spaced rows but filling in the spaces with another
crop to ensure complete ground cover. The ground is completely covered so it retards water flow so that it
soaks into the soil consequently reducing erosion problems.
b) Polyvarietal cultivation (where the soil is planted with several varieties of the same crop). As harvest
times vary for the different varieties of the crop, results in protection from erosion because the entire field
is not exposed all at once.
c) Trees act to protect against the mechanical damage and drying effects of the wind.
5. Adding Organic Matter. The addition of organic matter to the soil is important and can be achieved by
plowing in crop residues or an entire crop grown specifically to be plowed into the ground (green manure).
Microbes in the soil decompose the organic matter and produce polysaccharides which are sticky and act to
glue soil particles together and help it to resist erosion.
Even though there are many, simple, methods for reducing erosion many farmers choose not to use them
because short-term costs of implementing these practices outweigh the short-term benefits. For example, it
is more expensive in terms of time and machinery required for a farmer to plant several crops on the same
piece of land than it is to plant one single crop variety.
3.3.2 Fertilizer Use and Abuse
All plants require a certain quantity of nutrients to support growth. Macronutrients are nutrients which a
plant requires in large quantities (such as carbon, oxygen, nitrogen and phosphorus). Micronutrients are
also essential for plant growth but are required in much smaller doses, nutrients include iron, copper,
manganese and zinc. Some of the macro and micronutrients are readily available from the environment
such as carbon, hydrogen and oxygen. Others, such as nitrogen, have to be converted into a usable form for
plants. Even though the atmosphere is approximately 78 % nitrogen, none of this can be used by plants
directly, instead it has to be converted to such products as nitrate by the bacteria that live on roots and in
the soils. The replacement of nutrients to the soil is very important because once a crop is harv ested the
nutrients that it used for growth are permanently lost from the soil. If the same crop is grown repeatedly on
the same field (as is done in conventional agriculture) many of the micronutrients are depleted such as
boron, zinc and manganese. Other macronutrients, such as n …
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