Chapter 37 Soil and Plant Nutrition Flashcards
What is the basic physical properties of soil? (2 things)
- texture
- composition
What are soil horizons?
Soil stratified in layers
What does topsoil consist of?
- Mineral particles, living organisms, and humus
What is humus?
Decaying organic material
What are loams?
Most fertile topsoils and contains equal amounts of sand, silt, and clay
What does a soil’s composition refer to?
Its inorganic (mineral) and organic chemical components
What is the cation exchange? Why is it important?
Cation exchange: Cations are displaced from soil particles by other cations such as H+
- It’s important bc it allows for cations to not leach out of the soil via percolating groundwater
What are the steps in cation exchange?
- Roots acidify the soil solution
- CO2 reacts with H20
- Mineral cations are released
- Roots absorb released cations
What does humus do in the soil?
- Builds a crumbly soil that retains water but remains porous
- Increases soil’s capacity to exchange cations
- Serves as a reservoir of mineral nutrients
What is the goal of sustainable agriculture?
- To use farming methods that are conservation-minded, environmentally safe, and profitable
What is land subsidence?
Settling or sinking of land as a result of depleting aquifers
What are aquifers?
Underground water reserves; primary source of irrigation waters
What is an example of sustainable agriculture?
- Drip Irrigation
- No till/reduced tillage agriculture
- crop rotation
- use of organic fertilizers
- use of compost
What does fertilization do? What are commercial fertilizers enriched in?
Replaces mineral nutrients that have been lost from soil
- Enriched in nitrogen, phosphorus, and potassium
What is salinization?
Concentration of salts in soil as water evaporates
Why is drip irrigation considered sustainable?
- Bc it requires less water and reduces salinization
What is phytoremediation?
Biological, nondestructive technology that reclaims contaminated areas
What are the 17 essential elements?
- 17 chemical elements required for a plant to complete its life cycle and reproduce
What is hydroponic culture?
What researchers use to determine which chemical elements are essential
What are macronutrients? What are the 9 elements?
9 essential elements that plants requires in large quantities
- Carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur, potassium, calcium, and magnesium
What are micronutrients? What are the 8 elements?
The remaining 8 nutrients that plants require in small amounts.
- Chlorine, iron, manganese, boron, zinc, copper, nickel, and molybdenum
What are symptoms of mineral deficiency?
The symptoms depend on the nutrient’s function and mobility within the plant
What does the deficiency of a mobile nutrient usually affect? What the does the deficiency of a less mobile nutrient usually affect?
Mobile nutrient: Affects older organs
Less mobile nutrient: Affects younger organs
What is rhizobacteria?
- Free living bacteria that occupy the rhizosphere ; converts nitrogen in usable form for the plant