Land Usage (Jamaica)

Jamaica’s total land area → 10,830 km2

1997

• Agriculture including pastures 46%

• Forest 24%

• Human Settlement 4%

• Mining and Wetlands 6%

• Shrubs and woodland 20%

NOW

• Agriculture Lands 41% (Land crops 20% and land in pastures 21%)

• Forests 40% (Undisturbed 19%)

Agriculture

Agriculture is the growing of crops & the tending of livestock for subsistence, sale, or exchange.

Types of Agriculture

1. Subsistence Agriculture → The production of food to feed oneself and one’s family.

2. Industrialized Agriculture → Large scale production of crops and livestock for sale. Emphasizes high yields. Relies on the large input of energy to run machinery, irrigate crops and produce fertilizers and pesticides.

3. Sustainable Agriculture → The growing of crops and livestock in an environmentally friendly way.

Features of Subsistence / Low Input Agriculture

• Human Labor

• Slash and Burn

• Shifting Cultivation

• Fallow Periods

• Animal Manure

• Mixed Cropping

Negative Effects of Subsistence / Low Input Agriculture

• Food insecurity

• Slash and Burn Cultivation leads to:

  • Deforestation and vegetation loss

  • Shifting Cultivation as plots are abandoned after 2-5 years due to loss of soil fertility.

  • Increased fire hazards and global warming.

Green Revolution → Transformation in agricultural practices between 1940’s and 1960’s. The objective was to eradicate famine and increase food production. Shift from subsistence to industrialized agriculture.

Features of Industrialized / High Input Agriculture

• Mechanization (fossil fuel use)

• Conventional Tillage

• Monocropping

• Genetic Engineering

• Synthetic Pesticides

• Synthetic Fertilizers

• Irrigation

Mechanization and its Negative Effects

• Causes land degradation through soil compaction by heavy machinery

• Increases soil erosion

• Causes decline in soil fertility

• Erosion damage causes decreased water quality

Conventional Tillage and Its Negative Effects

In conventional tillage the soil is extensively broken up. This:

• Disrupts the soil structure

• Increases soil erosion

• Causes decline in soil fertility

• Erosion damage causes decreased water quality

Monocropping and Its Negative Effects

• Also called monoculture

• Cultivation of a single crop, usually on a large area of land

• Simplifies ecosystems reducing biodiversity

• Encourages the build up of pests thus increasing the use of pesticides

• Depletes the soil of nutrients

Pesticides

Definition → Any chemical designed to kill or inhibit the growth of an organism that people consider undesirable.

Types of Pesticides

• Synthetic or inorganic pesticides are man-made

• Organic pesticides are based on natural plant compounds such as neem.

Benefits of pesticides

• Reduced pest and disease levels results in

  • Increased production

  • Improved food quality

Negative Effects of Synthetic Pesticides

• Genetic Resistance → Fast-breeding insect species undergo natural selection and develop genetic resistance to chemical pesticides.

• Mobile → When applied pesticides may move through the soil, water or air.

• Health Impacts → Pesticides have been linked to cancers and low sperm count

• Loss of Biodiversity

  • Reduction in nutrient recycling soil organisms

  • Loss of plant genetic diversity

  • Endangerment & extinction of wildlife

• Persistent → pesticides adhere to sediment and become bioaccumulated and biomagnified

Negative Effects of Synthetic Pesticides Use

• Bioaccumulation → Increase in concentration of contaminants in the tissue of organisms

• Biomagnification → Increase in concentration of contaminants up the food chain

Fertilizers

Definition → Substances that add plant nutrients to soil and improves its ability to grow crops.

Types of Fertilizers

• Commercial Inorganic Fertilizer → Commercially prepared mixtures of plant nutrients

• Organic Fertilizer

N. B. Conventional agriculture relies on synthetic inorganic fertilizers

Negative Effects of Synthetic Fertilizer Use

• Supply only 2 or 3 of the 20+ nutrients needed by plants

• Leads to soil compaction

• Water pollution

  • Increases nitrates and phosphates in waterbodies, drinking water, food and air

  • Leads to eutrophication in the aquatic environment.

Genetic Engineering

Definition → Transfer of genetic material from one organism to another.

Benefits:

• Improve the appearance and taste of agricultural produce.

• Increase shelf life of fruits and vegetables.

• Provides genetic resistance to pest and diseases which reduces the need for application of pesticide to crops or livestock.

Negative Effects

• Genetically altered organisms might mutate and cause unforeseen effects

• Natural population balances in an ecosystem may be disturbed

• Health impacts such as allergic reactions to introduced genes in foods

Lack of GMO labeling prevents consumers from making a choice not to use GMO’s.

Irrigation

Definition → The application of water to crops.

Types of Irrigation

• Natural/Rainfall

• Flood irrigation

• Overhead/sprinkler

• Drip irrigation - most efficient water use (90%)

Flood Irrigation

Flood irrigation is wasteful of water and causes land degradation because of:

• Soil erosion

• Salinization (build up of salts in the soil)

• Waterlogging.

Land Degradation

Definition → Deterioration in the quality of land, its topsoil, vegetation, and or water resources. Usually associated with industrial agriculture and may lead to desertification.

Caused by:

• Overgrazing (animals feed too long or their numbers exceed the carrying capacity of rangeland)

• Flood irrigation

• Deforestation

• Conventional ploughing.

Desertification → Process whereby productive crop or range land turns into unproductive desert.

• Associated with industrial agriculture as well as rural poverty.

• The livelihoods of nearly one billion people in some 100 countries are threatened by desertification.

• About 25 per cent of the Earth's land, or 3.6 billion hectares, is desertified.

Sustainable Agriculture

• Crops grown in harmony with the environment

• Health of humans and livestock important

• Environment important

• Social justice important

Examples: Organic agriculture and Permaculture

Features of Sustainable Agriculture

• Companion cropping/mixed farming

• Soil conservation (preventing soil erosion)

• Alternatives to synthetic fertilizers (addition of organic matter)

• Use of alternatives to the use of synthetic pesticides

Mixed Cropping and Its Benefits

• Includes companion cropping and intercropping.

• Cultivation of more than one crop.

• Reduces the build up of pests thus reducing the use of pesticides

• Including legumes in the system adds nitrogen to the soil.

Soil Conservation Methods

• Methods used to:

  • reduce soil erosion

  • prevent depletion of soil nutrients

  • restore nutrients

• Most methods involve keeping the soil covered with vegetation

Major Methods Include:

• Conservation tillage

• Contour farming

• Terracing

• Alley cropping

• Windbreaks/ Shelterbelts

• Maintaining & restoring soil fertility

Conservation Tillage → Crop cultivation with little or no soil disturbance

• Minimum Tillage

• No-till Farming

Contour Farming → Rows planted along the contour of the land. Used mainly on gently sloping land.

Terracing → Level areas created across the contour. Used on steeper slopes.

Alley Cropping → Planting crops with rows of trees on each side or amongst trees of the forest.

Windbreaks/Shelterbelts → Row of trees planted to block wind flow.

Organic Fertilizer

Organic materials, such as animal manure, applied as a source of plant nutrients. They improve soil structure, helps to retain soil moisture and stimulate beneficial bacteria and fungi.

Three Basic Types of Organic Fertilizer

• Animal Manure

• Green Manure

• Compost

Animal Manure → Dung and urine of farm animals.

Green Manure → Freshly-cut or still-growing vegetation that is ploughed into the soil.

Compost → Partially decomposed organic plant and animal matter

• Made up of animal manure, topsoil, kitchen scraps

• Rich, natural fertilizer

Alternatives to Pesticides

Agricultural Methods:

• Tillage of land → to expose pests

• Proper timing of planting, fertilizing and irrigating

• Crop rotation

• Plant rows of hedges or trees (habitat for natural predators to pest)

Genetic Control

• Breed crops and animals resistant to pests

• Sterilize members of the pest population

Natural Enemies (Biological Control) → Predators, parasites & pathogens can be encouraged or imported to regulate pest populations.

Consideration → care should be taken to avoid biotic pollution.

Pheromones → Chemical sex attractant that may be used in traps.

Hormones → Chemical sex attractant that may be used in traps.

Quarantine → Restriction of the importation of exotic plant and animal material that might harbor pests.

Integrated Pest Management (IPM)

• Combines use of biological, cultural and chemical control

• Non-chemical controls used as far as possible; pesticides used sparingly when other methods fail

Sustainable Livestock Production

• Free Range → Livestock allowed to forage outdoors

• Integrating crop and livestock production to create closed system

• Natural remedies replace antibiotics

• Hormones avoided

Legislations

• Town and Country Planning Act 1958 → Primary law governing land use in Jamaica

• The Watersheds Protection Act, 1963 → Law governing watersheds in Jamaica

• The Forest Act 1996 → Law for the management and reservation of forests

• Country Fires Act 1955 → Aims to prevent the lighting of arbitrary fires in rural area

• The Pesticides Act 1987 → Regulates the manufacture, importation use and sale of pesticides.