Soil Flashcards
What is soil fertility?
The ability for soil to sustain plant growth
Describe water content for fertile soil
Good drainage to prevent water logging but allows enough retention for soil biota to survive.
Describe Soluble Material for fertile soil
Fertile soils have macronutrients like nitrogen and phosphorus as well as micronutrients like copper or iron. Toxic ions are adsorbed so they cannot be mobilised and taken into plants
Describe Air Content in fertile soil
Aerated soil allow aerobic processes to take place, which usually increase fertility
Describe Dead Organic Matter in fertile soil
Dead organic matter helps water retention and provides food for soil biota and nutrients for plants.
Describe pH in fertile soil
Usually in the range of 5.5-7.0, avoiding acidic conditions that can damage membranes and alkaline conditions that can deny nutrients
Describe soil biota in fertile soil
- Detritivores break up dead organic matter and increase nutrients
- Decomposers release enzymes that break down organic matter
- Several bacteria types interact with nitrogen
- Mycorrhizal fungi aid nutrient uptake of plants
What is the soil triangle?
Coolest thing in env sci
What type of soil has the largest particles?
Sand
What type of soil has the smallest particles?
Clay
What is a loam?
Soils with a fairly equal mix of clay, sand and silt that have an ideal mix of properties for agriculture
What are peds? What are the two types?
A ped is soil particles held together by roots, soil biota or other factors.
Crumb peds are small and round and have good drainage and aeration.
Platy peds are large and flat and have bad drainage and aeration.
How does soil depth affect fertility?
Deeper soils are more stable in water content and allow good root anchorage.
How can ploughing affect soil fertility?
Increases the air content of the soil
How can we affect soil nutrient levels?
- Fertilisers
- Supporting natural processes
- Erosion
- Biomass removal
- Inhibiting natural processes
What benefits does Irrigation have for soil fertility?
increases water content allowing plants to keep their stomata open to do gaseous exchange during normally dry periods
What can cause soil compaction?
Heavy machinery and livestock
What are the two types of erosion?
Wind and water
What conditions can increase risk of wind erosion?
Dry climate and high-clay soil reducing particle cohesion.
What issues can wind erosion cause?
Reduces soil levels in area, increases soil level elsewhere and can cover plants
What are the 3 types of water erosion?
- Rain splash
- Runoff
- Slumping
Why does Rain Splash erosion take longer?
Each drop of rain only causes loose soil particles to move slightly, so even downhill movement takes time
What condition allows for Runoff erosion?
When soil has reached it maximum infiltration capacity
How does slumping erosion work?
When soil on slopes becomes wet its mass and lubrication increases leading to it making large downward movements
