APHG 12

Chapter 12 - AGRICULTURE: HUMAN-ENVIRONMENT INTERACTION

12.1 AGRICULTURE AND THE ENVIRONMENT

Agriculture is the purposeful cultivation of plants or raising of animals to produce goods for survival.

The first crops to be harvested through agriculture were food crops, such as fruits, vegetables, and grains, the most widespread being corn (or maize), wheat, and rice. Other crops, such as oats and alfalfa, are important for feeding livestock.

Agriculture is more than growing food—though that is the primary purpose of farming and livestock-raising in many parts of the world. Fiber crops, such as cotton, are used for textile and paper products. And oil crops can be used for consumption or for industrial purposes, like with olives, corns, and soybeans which can be harvested and turned into oils used for cooking

Geographers study agriculture to understand how humans have modified the environment to sustain themselves.

The types and patterns of agricultural production and the processes that affect these patterns exist at a range of scales (regional, local, global, etc) The scale informs the geography of the sustainability of agricultural practices.

Environmental Factors (of Agriculture)

Cultivating plants or raising animals requires adaptation to environmental limitations. Sunlight, water, and nutrients are all factors that affect plant growth. Agriculture is bound to the physical environment, and four factors have a profound effect on the amount that can be grown.

Temperature is the key factor in determining the growing season—the length of the year during which plant life can grow

Generally, the greater the distance from the Equator, the shorter the growing season. At the Equator and in the tropics, the growing season can be year-round.

In constarts, areas in the subarctic cold temperatues prevent plant growth for a number of weeks or months. . In those regions, the growing season is measured in the number of frost-free days, as frost can kill plants.

Elevation also affects the growing season and what plants can be grown. Each increase of 1,000 feet above sea level means a corresponding decrease of about 3.6° F in average temperature. As a result, the higher the elevation, the shorter the growing season.

Elevation can create different cultivation opportunities in all mountainous regions, like in Central and South America, the hotter lowlands are used to grow tropical crops such as bananas and sugarcane. In the next highest zone, farmers can grow coffee, corn, and other vegetables.

Soil, a vital factor in determining the agricultural potential of a given area, it's the biologically active coating of Earth’s surface.

This layer can range from a few inches to several feet in depth. It is formed by the weathering of rock by wind, water, and other factors, which break the rock into increasingly smaller pieces over an extremely long period. It can take thousands of years to form an inch of soil.

Soil has four constituent parts: mineral particles, water, air, and organic matter like decaying plant material. The key characteristics of soil are its fertility, texture, and structure.

Topography, or Andreas land features like the slope of the land, affects the ability of soil so stay in place and retain water.

The steeper the slope, the more likely the soil will be affected by runoff. Slope can also be a factor in land productivity due to the position of the land toward or away from the sun, which affects how much of the sun’s energy the land receives.

The most favorable land for growing crops has ideal temperatures, precipitation, soils, and slope. SOme landscapes are modified for better environmental factors.

Terrace building for farming protects soil on steep slopes, while irrigation or drainage schemes influence water availability.

Adding fertilizers enhances the soil fertility of cropland. In general, it is not feasible to modify the other environmental factors—soil texture, soil depth, soil mineral content, temperature, and terrain—at large scales.

Climate

Climate differs across the globe, based on 4 key factors:

Distance from equator

Wind and ocean currents

Proximity to large body of water

Topography (shape of the land)

These components interact with one another in different ways to create different climate regions.

Distance from the equator determines temperature and daylight. The Equator and the regions near it to the north and south, called the tropics, receive direct rays from the sun year-round. Day and Night are near equal.

The northern and southern limits of these warmer regions are called the Tropic of Cancer and the Tropic of Capricorn, respectively.

North and South of the tropics contain huge dry deserts like the Sahara and Atacama. Farther north and south of these desert bands are temperate zones, with seasons.

Ocean and wind currents circulate cold or warm water and air masses over Earth’s surface. This affects patterns of temperature and precipitation.

Ocean currents that flow north and south transfer heat between lower latitudes (close to the Equator) and higher latitudes (farther from the Equator). When these currents flow away from the Equator, they bring warmth to temperate zones.

Currents flowing from a temperate zone toward the Equator carry colder water in that direction. Winds also carry air at different temperatures from one region to another. Because warmer air tends to hold more moisture and colder air tends to be drier, these wind patterns affect precipitation patterns.

Location relative to large bodies of water affects climate in two ways. First, these bodies of water warm and cool more slowly than land. As a result, most coastal areas tend to have milder climates than regions farther inland.

Second, coastal areas are cooled during the day by cool winds displaced by warmer air rising from the water. These regions are warmed at night by warm air blowing onshore as cooler night air pushes down toward the water.

Location also affects precipitation, which tends to be heavier near coastlines and lighter farther inland, with some exceptions.

Topography also has an effect, as coastal mountains have much heavier precipitation on the side facing the wind, and very light precipitation on the side away from the wind. Due to the rain shadow effect.

The combination of temperature, precipitation, wind patterns, and topography produces different

climate regions: areas that have similar climate patterns based on their latitude and their location on coasts or continental interiors.

He identified five broad climate types:

Tropical,

Dry,

temperate,

continental,

and polar

Each of these 5 can be broken down to even more specific climate types.

Tropical Climate

Areas with tropical climates all have warm temperatures year-round but vary in their amounts of precipitation.

The wet tropical climate has lots of precipitation, leading to tropical rainforests, and has heavy summer rains and dry winters. (dry season and wet season). This is a monsoon climate found in places of South and Southeast Asia and West Africa.

With some exceptions, dry climates are commonly found in continental interiors and are either arid (very dry) or semiarid (minimal precipitation). Semiarid climates receive enough precipitation to allow the growth of grasslands.

The warm temperatures of the tropics allow for year-round agriculture, which can also permit multiple harvests of crops, like rice, in a year.

Temperate Climates

Temperate Climates: climates with moderate temperatures and adequate precipitation amounts.

There are three kinds, and all three have long warm summers and short winters.

Humid Temperate climates

Found in eastern side of continents

Cold winters and year-round precipitation

Temperate rain forests

Mediterranean agriculture: consists of growing hardy trees (such as olive, fruit, and nut trees) and shrubs (like grape vines) and raising sheep and goats. These animals forage in the sparse, scrubby summer growth and maneuver around the region’s steep landscape.

Polar Climates

There are two polar climates, at the north and south pole, which are extremely cold. They have mild summers and long winters too cold for farming.

The temperatures in the ice cap climates of the Arctic and Antarctic rarely rise above freezing.

Continental Climates

Continental climates are found in the interior of continents in the Northern Hemisphere, and are characterized by distinct seasons that include cold winters and snow, as well as fall, summer, spring, etc.

The type of tropical climate limits that potential, however. Even areas with a tropical wet and dry climate may not receive sufficient precipitation in the dry months to allow crop production.

Even the plentiful precipitation of the tropical wet climate poses challenges. The heavy year-round rains allow for the flourishing growth of rain forests, but the soils in these areas tend to be poor. The main source of nutrients needed to produce crops in rain forests is plant matter.

The temperate zones, with their long growing seasons, are home to major grain-producing regions. Hardier grains like wheat, rice, corn, and more all thrive in temperate zones.

12.2 AGRICULTURAL PRACTICES

subsistence agriculture - Farming for family consumption or to sell to local markets if they meet more than end needs.

Commercial agriculture: Farmers who grow crops to sell to customers. Depends on geographic and economic factors

Intensive agriculture: a farming method that uses technology and resources to maximize crop and animal yields per unit of land.

Extensive agriculture: a farming system that uses large amounts of land and small amounts of labor and capital

Subsistence and commercial agricultural practices help define the agricultural production regions across the world.

Both subsistence and commercial agriculture are practiced at different scales known as intensive and extensive scales.

bid-rent theory explains how land value determines how a farmer will use the land—either intensively or extensively. The Bid=rent theory assumes there is one central business district.

Where land value is high, farmers will buy less land and use it intensively to produce the most agricultural yield per unit of land.

Where land has a lower value or is farther from the market, farmers will buy more land and use it less intensively, or extensively.

You will learn more about intensive and extensive agriculture later in this lesson.According to this theory, dairy and produce farmers, concerned with issues of freshness, perishability, and transportation, for example, are willing to pay higher costs—or “rent”—for land close to the market. However, farmers growing grains and cereal crops, which are easily stored and transported, will not pay as much.

The majority of consumer services are located in the center of a city because the accessibility of the location attracts these services. This central location is called the central business district (CBD). Land near the CBD is much more expensive.

With intensive agriculture , farmers expend a great deal of effort to produce as much yield as possible from an area of land. To achieve high productivity, they rely on high levels of “inputs” and energy.

What is “input” differs in region. In some, it may be fertilizers, pesticide, and growth regulators, while in others it may be additional human or animal labor, thoughtful care to soil, natural fertilizers, and more.

Regardless of the input, indecisive farming requires large amounts of energy.

Technology and energy speed up the essential steps of farming—plowing, planting, and harvesting. These inputs and expenditures of energy maximize crop yields in intensive agriculture.

INTENSIVE SUBSISTENCE AGRICULTURE

When people work the land intensively, putting forth a large amount of human labor to generate high crop yields on small plots of land to support their family and local community. - Intensive Subsistence Agriculture

The yields from intensive subsistence agriculture are affected by weather, seed quality, fertilizers and pesticides, and more.

When these disasters strike farms being used to feed a family or community, they have big effects on nutrition in community areas, leading to undernutrition or even starvation.

Fortunately, new technology is helping intensive subsistence farmers by providing weather information and data that will help them to better strategize on fertilizer use and harvest times, and by improving seed quality and farming tools.

As populations increase in intensive subsistence agriculture regions, many farmers maximize food production by modifying their local environment. Such as changing the terrain or building irrigation systems.

These practices are indicative of intensive agriculture because of their reliance on heavy labor and the high crop yields they aim to generate.

RURAL SETTLEMENT PATTERNS

Clustered settlement (also known as a nucleated settlement), in which residents live in close proximity.

Here, houses are close to one another, with social unity and common resources. Though a downside is the proximity could lead to conflict.

In dispersed settlements , houses and buildings are isolated from one another, and all the homes in a settlement are distributed over a relatively large area.

They often exist in areas with difficult terrain and physical barriers, and where resources are scarce. This promotes independence but also lacks social interactions and defense among the community.

In a linear settlement pattern, houses and buildings extend in a long line that usually follows a land feature, such as a riverfront, coast, or hill, or aligns along a transportation route.

People settle along these features because of transportation or access to water.

INTENSIVE COMMERCIAL AGRICULTURE

Some farmers in core countries engage in intensive commercial agriculture, which involves heavy investments in labor and capital and results in high yields for profit

Machine and fertilizers are used instead of human and animal labor. Most of the time the farms are near the market, but it can differ.

Regardless of the proximity to market, what all intensive commercial producers have in common is the use of intensive methods, whether these are capital- or labor-intensive, and a high yield.

The characteristics of intensive commercial agriculture can be observed in several specific types of farming including monoculture systems, plantation agriculture, market gardening, Mediterranean agriculture, and mixed crops and livestock systems.

Many people who participate in intensive commercial agriculture in the United States focus on monocropping: the cultivation of one or two crops that are rotated seasonally—commonly corn, soybeans, wheat, or cotton.

These crops are usually what the market demands and therefore can be very profitable for plantations as well as large corporate farms.

monoculture refers to the agricultural system of planting one crop or raising one type of animal annually.

Monocropping allows for specialization, simplifies cultivation, and maximizes efficiency. Farmers usually choose a crop that is conducive to the environment, to decrease inputs and increase efficiency.

However, monocropping can strip nutrients from the soil; for instance, intensive cotton production leads to soil exhaustion. One way to prevent this depletion of nutrients is through:

crop rotation: the varying of crops from year to year to allow for the restoration of valuable nutrients and the continuing productivity of the soil.

The shift to monoculture also raises the stakes for farmers. As yields go up, crop prices can decrease. Falling prices can force many farmers out of business and may encourage successful operators to purchase the land of failing farms.

Plantation agriculture involves large-scale commercial farming of one particular crop grown for markets often distant from the plantation.

Plantation agriculture usually takes place in peripheral and semi-pherial countries. Major plantation crops include cotton, tobacco, tea, coffee, sugarcane, bananas, palm oil, and rubber.

Plantation agriculture is one of the oldest forms of intensive commercial agriculture, with its roots going back to the European colonization of the Caribbean and Central and South America as well as Asia and Africa.

Tropical countries like Brazil, Jamaica, and sri-lanka continued to take advantage of their plantation culture and have become well-known for certain goods—Sri Lanka for tea, for instance. Though, this makes the former colonies rely on the production of their specialty crop.

Plantations: a large-scale commercial farm, typically located in a developing country, that specializes in producing a single cash crop like coffee, sugar cane, tobacco, or rubber

Plantations tend to be labor-intensive operations, although since many are located in peripheral countries, the cost of that labor is relatively low.

Market gardening: is farming that produces fruits, vegetables, and flowers and typically serves a specific market, or urban area, where farmers can conveniently sell to local grocery stores, restaurants, farmers’ markets, and road stands.

The practice of market gardening is driven by the perishability of the products, or their likeliness to spoil, and the demand by local consumers for fresh fruits and vegetables. Market gardens can be found in most large cities in the United States, from the Northeast to Texas to California.

The farm-to-table movement, which emphasizes fresh, locally grown ingredients, is giving a new momentum to market gardening. Still, in the winter months, most fruit and vegetables consumed in the United States are grown in Chile or Mexico.

Operators of market gardens often require greenhouses, which are high-energy, to germinate seed before the growing season.

They also need to use costly high-quality seeds and fertilizers and pesticides to ensure harvests. Some market garden operators practice organic farming, which involves using natural methods to fertilize the land and prevent pest infestations.

Truck farming, once synonymous with market gardening, now serves markets that are very distant from the farm.

Large commercial farms in Mexico and the western and southern United States, where the climate is conducive to locally growing seasonal produce in high quantity, transport specialty crops to distant markets using large-capacity refrigerated trucks.

As you have read, agriculture thrives in the Mediterranean climate of southern Europe, southwest Asia, South Africa, Australia, and California. Much of the land in these climate regions is used for this type of intensive commercial agriculture.

Another type of intensive commercial agriculture practiced frequently is:

mixed crop and livestock systems: in which both crops and livestock are raised for profit.

There are two types of mixed farming: on-farm and between-farm.

In on-farm mixed farming, the crops and livestock are raised on the same farm.

In between-farm mixing, two farmers share resources, with one growing crops and the other raising livestock.

On-farm mixing effectively combines a farm’s focus on one or two crops, such as corn and soybeans, with the raising of animals to meet the demand for high-quality meat.

Mixing provides a farmer with certain advantages: part of the crop can be fed to the livestock, and the animals’ waste can be used to fertilize the crops.

This type of farming boosts labor needs, which makes it a form of intensive commercial agriculture. The diversity of mixing also may provide some protection from a bad crop year or low market value.

EXTENSIVE SUBSISTENCE AGRICULTURE

With relatively few inputs and little investment in labor and capital, farmers who participate in extensive agriculture typically have lower outputs than farmers who employ intensive practices.

Like intensive agriculture, extensive agriculture can be practiced in subsistence agricultural regions as well as in commercial agricultural regions. Extensive agriculture is in core and peripheral countries.

Extensive subsistence agriculture is often found in regions in which intensive subsistence agriculture is not feasible because the environment is marginal—that is, too wet, too dry, or too cold—and thus, the carrying capacity (the maximum population size an environment can sustain) is low.

One type of extensive subsistence agriculture that uses relatively simple technology requiring little capital investment is shifting cultivation.

Shifting cultivation: the practice of growing crops or grazing animals on a piece of land for a year or two, then abandoning that land when the nutrients have been depleted from the soil and moving to a new piece of land where the process is repeated.

Although the size of the piece of land being used short-term is not large, shifting cultivation requires a relatively large area in which to operate over time.

Shifting Cultivation is practiced worldwide in marginal agricultural areas of the tropics, particularly in areas with high rainfall, such as in the rain forests of South America, Central and West Africa, and Southeast Asia.

Slash and Burn

Some farmers, including those in Colombia and Brazil in South America and Papua New Guinea in Oceania, use traditional subsistence farming techniques, such as slash and burn —a type of shifting cultivation—to maintain the land.

They clear the land by cutting down the trees and brush, and after the vegetation dries, burning this “slash,” resulting in a nutrient-rich ash fertilizer. The cleared land is then cultivated for several years until the soil becomes infertile.