AP Environmental Science Unit 5 Study Guide

Green Revolution

Shifts towards industrial scale farming via mechanization, synthetic fertilization, pesticide use, irrigation, and increased crop varieties.

Benefits of Green Revolution

Increased yields, decreased world hunger, increased world’s carrying capacity, lower production costs, increased profits for farmers, short term productivity rise.

Drawbacks of Green Revolution

Destroys nutrients, causes excess fertilizer runoff, releases particulate matter, requires high water and energy, leads to soil erosion and pest vulnerability.

Mechanization in Agriculture

Increased yields and profits but leads to greenhouse gas emissions and soil compaction, which decreases water holding capacity.

Synthetic Fertilizers

Increases yield by adding key nutrients directly to the soil, but can cause eutrophication and carbon dioxide emissions during production.

Pesticides

Chemicals that increase crop yields but can wash off crops, harming non-target species and contaminating local ecosystems.

High-Yield Variety Crops

Hybrid or genetically modified crops designed to produce higher yields and may include additional nutrients.

GMOs

Genetically modified organisms that tend to have higher yields and pest resistance but can lead to loss of biodiversity.

Monocropping

Growing only one species of crop, which increases efficiency and application of pesticides, but decreases biodiversity.

Tilling

The agricultural practice of breaking up soil to facilitate planting, which may lead to loss of nutrients and increase air pollution.

Slash and Burn

An agricultural method involving cutting vegetation and burning it to clear land and return nutrients to the soil.

Leaching

The process by which excess nutrients are carried away from the soil into groundwater or surface waters.

Irrigation Efficiency Ranking

Ordered from least to most efficient: Furrow, Flood, Spray, and Drip irrigation.

Waterlogging in Soils

Occurs when overwatering saturates the soil, preventing oxygen from reaching roots and resulting in stunted growth or crop death.

Soil Salinization

The accumulation of salt in soil over time, often due to irrigation, which can lead to dehydration and toxicity for crops.

Aquifers

Underground water reservoirs that can be depleted through excessive agricultural water use.

Saltwater Intrusion

The process by which saltwater contaminates freshwater aquifers due to lowered water table pressures.

Broad Spectrum Pesticides

Powerful pesticides that target entire groups of organisms, affecting non-target species and ecosystems.

The Pesticide Treadmill

Cycle of pesticide application leading to resistant pests, necessitating stronger pesticides and perpetuating resistance.

Concentrated Animal Feeding Operations (CAFOs)

Facilities where animals are confined and fed antibiotics, raising efficiency but raising ethical and environmental concerns.

Free-Range Grazing

An agricultural method where animals graze in open pastures, potentially leading to overgrazing and soil erosion.

Integrated Pest Management (IPM)

A holistic approach to pest control that minimizes environmental disruption through a combination of pest management methods.

Sustainable Agricultural Practices

Methods like contour plowing, cover crops, and crop rotation aimed at reducing erosion, enhancing soil health, and increasing biodiversity.

Nitrogen Fixation by Legumes

The process whereby nitrogen-fixing bacteria on the roots of legumes convert atmospheric nitrogen into forms usable by plants.

Crop Rotation

An agricultural practice of alternating different crops in a sequence to improve soil health and prevent pest buildup.

Green Manure Cover Crops

Plants grown primarily to be plowed back into the soil to enrich it with nutrients.

Contour Plowing

Plowing along the contours of the land to reduce soil erosion and improve water retention.