Study Notes on Agriculture and the Environment

12.1 AGRICULTURE AND THE ENVIRONMENT

  • Overview of Agriculture

    • Agriculture is a significant aspect of life worldwide, playing an essential role in food production for the global population.

    • The practices of agriculture vary based on geographical areas, cultural landscapes, and the number of people involved.

INTRODUCTION TO AGRICULTURE

  • Learning Objectives

    • PSO-1.B: Explain how major geographic concepts illustrate spatial relationships.

    • PSO-5.A: Explain the connection between physical geography and agricultural practices.

  • Definition of Agriculture

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

  • Initial Crops in Agriculture

    • Early agriculture involved harvesting food crops, primarily:

    • Fruits

    • Vegetables

    • Grains (notably corn/maize, wheat, rice)

    • Importance of other crops:

    • Oats and alfalfa for livestock feed

    • Fiber crops (e.g., cotton) for textiles and paper

    • Oil crops (e.g., olives, corn, soybeans) can be processed for cooking, lubrication, and biofuels.

  • Geographical Study of Agriculture

    • Geographers analyze agricultural practices to understand human-environment modifications essential for survival.

    • Patterns of agricultural production occur at global, regional, and local scales, guiding insights into sustainable agricultural practices and food production.

ENVIRONMENTAL FACTORS IN AGRICULTURE

  • Key Influential Factors

    • Agriculture relies heavily on adaptation to environmental limitations, specifically:

    • Climate

    • Elevation

    • Soil

    • Topography

Climate

  • Definition of Climate

    • Long-term weather patterns in a specific location (distinct from day-to-day weather).

  • Impacts of Climate on Agriculture:

    • Determines key aspects: precipitation, temperature, and length of growing seasons.

  • Growing Seasons:

    • Generally shorter distances from the Equator correlate with shorter growing seasons.

    • Tropical regions: year-round growing seasons

    • Temperate regions: growth affected by winter frost; measured in frost-free days.

Elevation

  • Higher elevations correlate with lower temperatures ( extit{approx. 3.6°F decrease per 1,000 feet increase}).

  • Results in shorter growing seasons; different crops thrive at various altitudes:

    • Tropical crops: bananas, sugarcane at low elevations

    • Vegetables, coffee at mid-elevations

    • Hardier crops (e.g., barley, potatoes) at higher elevations

    • Grazing possible at highest altitudes (grassland).

Soil

  • Soil is the biologically active layer on Earth's surface, formed through weathering rock over extensive timeframes.

  • Constituents: Mineral particles, water, air, organic matter.

  • Key Characteristics: Fertility, texture, and structure impact agricultural viability.

Topography

  • Referring to land features and slope, affecting soil retention and water management.

  • Steeper slopes increase runoff risks and may limit productivity based on sun exposure.

    • Perfect Conditions for Agriculture

  • Favorable land features include ideal temperatures, precipitation, soil quality, and optimal slopes.

  • Often, land modifications enhance these conditions, such as:

    • Terrace farming and irrigation for better water management

    • Fertilizers to boost soil fertility.

Altitudinal Zonation

  • Example in Central and South America showcasing how elevation influences agriculture.

    • Tierra Caliente (Sea Level):

      • Tropical crops (e.g., rice, bananas)

    • Tierra Templada (2,500 feet):

      • Diverse agricultural production - coffee, vegetables

    • Tierra Fría (6,000 feet):

      • Harder crops - barley, potatoes.

    • Tierra Helada (12,000 feet):

      • Grazing livestock like alpacas and llamas.

Climatic Influence on Agriculture

  • Example: In Malawi's tropical climate, tea fields minimize erosion by contour farming; terrace farming is widely used to manage soil and water loss.

CLIMATE AND AGRICULTURE

  • Factors Determining Climate

    • Four primary factors:

    • Distance from the Equator

    • Wind and ocean currents

    • Proximity to large bodies of water

    • Topography

Distance from the Equator

  • Affects daylight length and temperature. Regions near the Equator are warm year-round, while extremes create large desert zones north (e.g., Sahara) and south.

Wind and Ocean Currents

  • Crucial for regulating temperature and precipitation patterns. Examples include the Gulf Stream warming eastern North America and Europe.

Large Bodies of Water

  • Coastal areas are milder due to delayed heating/cooling of water. Precipitation levels tend to be higher near coastlines than inland.

Topography Effects

  • Coastal mountains lead to heavy precipitation on windward sides, creating rainforests, while leeward sides may remain dry. Example: Pacific Northwest of the U.S.

KÖPPEN CLIMATE CLASSIFICATIONS

  • Understanding Climate Regions

    • Developed by Vladimir Köppen, includes five major climate types:

    • Tropical

    • Dry

    • Temperate

    • Continental

    • Polar

    • Each main type can be subdivided for more specific classifications.

  • Tropical Climates

    • Consistently warm temperatures with variations in precipitation:

    • Tropical wet climates promote rainforests

    • Tropical monsoon climates notice extreme wet seasons

    • Tropical wet and dry climates yield savanna grasslands.

  • Dry Climates

    • Characterized by minimal precipitation (arid vs semiarid) that permits only specific types of vegetation.

  • Temperate Climates

    • Three key types:

    • Humid temperate: moderate temperatures and year-round precipitation

    • Marine west coast: cooler winters, ample rain (favorable for forests)

    • Mediterranean: hot, dry summers beneficial for agriculture (olives, grapes).

  • Polar Climates

    • Tundra and ice cap climates are extremely cold, limiting agricultural practices.

  • Continental Climates

    • Marked by distinct seasons, including cold winters and snow, primarily in continental interiors.

  • Agricultural Potential by Climate Type

    • Favorable conditions in tropical regions support year-round cultivation, though some areas face climatic challenges (ex: insufficient precipitation).

    • Temperate zones present ideal conditions for grain production (wheat, corn, rice) suitable for extensive agricultural practices.

Geographic Thinking Exercises

  1. Identify the four elements that make land favorable for growing crops.

  2. Describe how the agricultural practices of certain regions are influenced by the Mediterranean climate.

  3. Explain why climate similarity can occur at different latitudes.

12.2 AGRICULTURAL PRACTICES

  • Influencing Factors

    • Rural land use and agriculture depend on physical geography, resources, and cultural practices.

    • Agricultural practices can be categorized as:

    • Subsistence agriculture

    • Commercial agriculture

Subsistence Agriculture

  • Characterized by farmers growing food primarily for survival.

  • Farmers grow diverse crops/livestock for family consumption; surplus may be sold or bartered.

  • Typically involves more hand labor with fewer mechanical resources.

Commercial Agriculture

  • Farmers produce crops or livestock for profit targeting paying customers.

  • Decided by factors including farmland advantages, market demands, and agricultural practices.

  • Form of Agricultural Practice

    • Both subsistence and commercial agriculture can operate at:

    • Intensive scale

    • Extensive scale

BID-RENT THEORY

  • Theory Explanation

    • Developed by William Alonso (1964), the bid-rent theory analyzes land value determined by closeness to markets.

    • The theory posits that land users compete for desirable locations, influencing how intensively land is farmed.

  • A

    • For instance, dairy and produce farmers often pay more for land situated close to urban centers due to transport needs.

    • Grain producers pay less for ground as their products are easier to store and transport

  • Land Use Gradient

    • Central Business District (CBD) proximity typically features higher land costs, registering higher agricultural inputs while distance reduces prices.

RURAL SURVEY METHODS

  • Importance of Land Surveying

    • Land surveying shapes property boundaries that differentiate ownership and ensures clear titles.

Survey Methods Overview

  • Metes and Bounds:

    • Originated from Great Britain, uses natural features as reference points to describe property. Common in mid-Atlantic regions, leading to irregular land parcels.

  • Long-Lot Survey System:

    • Employed in French/Spanish colonies, creating long strips of land, ensuring access to waterways.

  • Township and Range System:

    • Rectangular grid system used predominantly in the U.S.

    • Government-administered, creating standardized 6x6 mile townships (36 square miles total), divided into 640-acre sections.

    • Geographic Variation

  • Different survey methods indicate the historical and cultural shifts on land use.

INTENSIVE AGRICULTURE

  • Definition and Practices

    • Intensive agriculture focuses on maximizing land yield through high effort and energy input.

    • Inputs can vary: chemical fertilizers (capital intensive) or natural methods (labor intensive).

Intensive Subsistence Agriculture

  • Heavily labor-oriented system feeding populations in semi-peripheral and peripheral regions.

  • Relies on human labor, stewardship of land, and fertilizers (animal manure) to sustain soil productivity.

  • Crop yields affected by environmental conditions, with adverse weather potentially leading to severe food scarcity.

    • Technology Role

  • Implements technological advancements for weather forecasting and cultivation practices to improve farming efficiency.

  • Wet-rice agriculture exemplifies extensive reliance on human work and careful land usage in regions like Asia.

Intensive Commercial Agriculture

  • Focuses on high-profit products intended for sale.

  • High investments for maximum yields can utilize both labor and mechanization.

  • Practices may be close to or far from markets depending on operational dynamics.

Types of Intensive Commercial Farming

  • Monoculture & Monocropping:

    • Exclusive focus on one or two crops per season to meet market demands (e.g., corn, soybeans).

  • Plantation Agriculture:

    • Large-scale cultivation of single cash crops in tropical lowlands (e.g., bananas, tea).

  • Market Gardening:

    • Producing perishables for local markets, boosted by urban demand.

  • Mixed Crop and Livestock Systems:

    • Integration of crop production with livestock raising for diversified revenue streams.

EXTENSIVE AGRICULTURE

  • Overview

    • Extensive agriculture is characterized by lower inputs and outputs, common in both subsistence and commercial systems, especially in peripheral regions.

Extensive Subsistence Agriculture

  • Predominantly found in areas unsuitable for intensive methods due to environmental constraints.

  • Examples include shifting cultivation and nomadic herding, using minimal technology and capital.

    • Shifting Cultivation:

      • Based on temporary land use before rotation to new patches due to soil nutrient depletion.

    • Slash and Burn:

      • Traditional method enhancing soil through burning vegetation, but it can lead to environmental degradation.

  • Nomadic Herding:

    • Seasonal movement of livestock in search of grazing areas, often including practices like transhumance.

Extensive Commercial Agriculture

  • Focused mainly on ranching, thriving in semi-arid grasslands with low labor intensity required.

  • Examples include cattle ranching across North America and other global regions (South America, Australia).

    • Contrast with Intensive Practices

  • Extensive ranching employs less labor than intensive farming models (CAFOs) designed for maximizing output on smaller land tracts.

GEOGRAPHIC THINKING EXERCISES

  1. Identify the environmental impacts of slash-and-burn farming techniques.

  2. Discuss why nomadic herding exemplifies extensive agriculture.