Agriculture and Food Production Flashcards
6 cards from real Environmental Science practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Agriculture and Food Production flashcards as text
The Ogallala Aquifer, which underlies the U.S. Great Plains, is a critical concern for agriculture because:
Answer: It is being depleted by irrigation much faster than it is naturally recharged
The Ogallala is a fossil aquifer recharged over thousands of years; current irrigation withdrawals vastly exceed recharge rates, threatening the agricultural productivity of 8 Great Plains states.
Terracing as an agricultural technique on steep slopes primarily serves to:
Answer: Create level planting areas that reduce runoff velocity and soil erosion
Terraces cut horizontal steps into hillsides, converting steep, erosion-prone slopes into level or nearly level planting areas that hold water and soil.
In terms of water use efficiency, which of the following irrigation methods uses water most efficiently?
Answer: Drip (micro) irrigation
Drip irrigation delivers water directly to the root zone through emitters, minimizing evaporation and runoff; typical efficiency is 85-95% compared to 60-80% for sprinklers and 25-60% for flood irrigation.
Genetically modified (GM) crops engineered with Bt toxin produce an insecticide that:
Answer: Is derived from a naturally occurring soil bacterium and is toxic to specific insect larvae
Bt toxin is derived from Bacillus thuringiensis, a naturally occurring soil bacterium; its crystal proteins are highly selective, primarily toxic to Lepidoptera (caterpillars) or Coleoptera (beetles) larvae, not to mammals or most non-target organisms.
Salinization of agricultural soils is primarily caused by:
Answer: Irrigation with saline water or waterlogging that allows dissolved salts to accumulate as water evaporates
When irrigation water evaporates or transpires, it leaves behind dissolved salts; in waterlogged conditions without adequate drainage, salts accumulate in the root zone to toxic levels.
Agroforestry differs from conventional agriculture in that it:
Answer: Deliberately integrates trees and shrubs with crops and/or livestock to create ecological and economic benefits
Agroforestry intentionally combines perennial woody plants with crops and/or animals to exploit synergies: nitrogen fixation by tree legumes, reduced erosion, diversified income, carbon storage, and microclimate benefits.