TASC Agricultural Systems flashcards
TASC Agricultural Systems · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Agricultural system
- The combination of crops, livestock, inputs, technology, and management practices used to produce food and fiber on a farm or region.
- Subsistence farming
- A system where most production feeds the farm household, with little surplus sold; typically small scale and low external input.
- Commercial farming
- A system oriented toward selling output in markets, usually with higher capital, mechanization, and purchased inputs than subsistence systems.
- Intensive agriculture
- A system that raises output per unit area through high labor, capital, fertilizer, irrigation, or multiple cropping rather than through expanding land.
- Extensive agriculture
- A system that relies on large land areas with relatively low inputs per hectare, such as rangeland grazing or dryland grain production.
- Monoculture
- Growing a single crop species over a large area or repeated seasons, which simplifies management but raises pest, disease, and soil-degradation risk.
- Crop rotation
- A planned sequence of different crops on the same field across seasons to interrupt pest cycles, diversify nutrients, and improve soil structure.
- Legume nitrogen fixation
- Symbiosis between legume roots and Rhizobium bacteria that converts atmospheric nitrogen into plant-usable ammonia, reducing fertilizer need.
- Green manure
- A cover crop grown specifically to be incorporated into soil while green, adding organic matter and nutrients before the next cash crop.
- Cover crop
- A crop grown between main crops to protect soil from erosion, suppress weeds, scavenge residual nutrients, and add organic matter.
- Liebig's law of the minimum
- The principle that crop growth is constrained by whichever essential resource is in shortest supply relative to need, not by overall abundance.
- Integrated pest management
- A decision framework combining cultural, biological, mechanical, and chemical controls, applying pesticides only when pest populations exceed economic thresholds.
- Economic threshold
- The pest population level at which the cost of control equals the value of crop loss prevented, marking the point where treatment pays.
- Soil texture
- The relative proportions of sand, silt, and clay particles in a soil, determining water retention, drainage, aeration, and workability.
- Cation exchange capacity
- A soil's capacity to hold exchangeable positively charged nutrients such as calcium, magnesium, potassium, and ammonium on clay and organic matter surfaces.
- Soil organic matter
- Decomposing plant and animal residues plus living soil organisms; it stores nutrients, holds water, and stabilizes soil aggregates.
- Nitrogen cycle
- The transformation of nitrogen among fixation, mineralization, nitrification, immobilization, denitrification, and leaching pathways that determine plant availability and losses.
- Nitrification
- Microbial conversion of ammonium to nitrite and then nitrate, a form easily leached and denitrified but readily taken up by crops.
- Denitrification
- Anaerobic microbial reduction of nitrate to nitrogen gases, causing nitrogen loss from waterlogged or compacted soils.
- Leaching
- Downward movement of soluble nutrients, especially nitrate, below the root zone with percolating water, reducing fertilizer efficiency and risking groundwater contamination.
- Eutrophication
- Nutrient enrichment of water bodies, often by phosphorus and nitrogen runoff, causing algal blooms, oxygen depletion, and aquatic habitat damage.
- Conservation tillage
- Any tillage system leaving substantial crop residue on the surface, reducing erosion and moisture loss while conserving soil organic matter.
- No-till farming
- Planting directly into undisturbed soil with no prior tillage, preserving residue cover, soil structure, and moisture but often requiring different weed management.
- Contour farming
- Plowing, planting, and cultivating across a slope's contour to slow runoff and reduce soil erosion on hilly fields.
- Terracing
- Constructing stepped level or graded ridges across slopes to shorten slope length, trap sediment, and retain water for cultivation.
- Windbreak
- A row of trees or shrubs planted to reduce wind speed, limiting wind erosion, crop damage, and moisture loss on adjacent fields.
- Irrigation efficiency
- The fraction of applied irrigation water beneficially used by the crop, with losses from evaporation, runoff, and deep percolation reducing efficiency.
- Drip irrigation
- Delivering water slowly through tubes and emitters directly to the root zone, achieving high efficiency with minimal evaporation and runoff.
- Integrated farming system
- A system linking crops, livestock, and sometimes fish or forestry so that wastes from one component become inputs for another.
- Agroforestry
- Deliberate integration of trees or shrubs with crops or livestock on the same land to diversify income and improve soil and microclimate.
- Organic farming
- A certified system restricting synthetic fertilizers and pesticides, relying on organic amendments, rotations, and biological pest control.
- Carrying capacity
- The maximum livestock population a pasture or land area can support sustainably without degrading vegetation, soil, and water resources.
- Nutrient use efficiency
- The ratio of nutrients removed in harvested crop to nutrients applied, indicating how well fertilizer inputs are converted into yield.