AP®︎ Human Geography: Topic 5.5 Flashcards

Mid-twentieth-century diffusion of high-yield seeds, chemical inputs, irrigation, and mechanized farming, especially in developing countries; it increased food production but created environmental costs and unequal social benefits

Selectively bred seeds, especially wheat and rice, that produce more grain per unit of land when supplied with sufficient fertilizer, water, and pest control

Commercial fertilizers, pesticides, and herbicides used to increase plant growth and limit crop losses, but capable of contaminating soil and water

Use of tractors, pumps, threshers, harvesters, and other machinery to farm faster and with less labor, requiring capital and potentially displacing workers

Harvesting two or more crops from the same field in one year, increasing total annual output from the land

Increasing output primarily by producing more from each unit of existing farmland rather than by expanding cultivated area

Pumping water from an aquifer faster than natural processes replenish it, lowering water tables and threatening future irrigation

Buildup of salts left behind by evaporating irrigation water, eventually inhibiting plant growth and reducing yields

Saturation of soil caused by excess irrigation or a raised water table, leaving too little oxygen for healthy root growth

Excess fertilizer nutrients cause rapid algae growth whose decomposition removes dissolved oxygen and can kill aquatic organisms

Repeated chemical use favors resistant pests or weeds, making the chemicals less effective and encouraging heavier or different applications

Decline in soil quality through intensive cultivation, erosion, machinery compaction, loss of organic matter, or reduced biological activity

Loss of agrobiodiversity as a few uniform high-yield crops replace numerous locally adapted varieties

Higher yields on existing farmland can reduce pressure to convert forests, wetlands, or grasslands into cropland, though protection is not guaranteed

Controlled provision of dependable water to crops, enabling high-yield varieties and multiple cropping but potentially causing groundwater depletion, salinization, and waterlogging

Reliable physical and economic access to sufficient food; increased national food production alone does not guarantee it