Soil Water Flashcards
(18 cards)
Why do plants need water?
To inflate their cells, to dissolve chemicals, to transport minerals upwards, to translocate sugars away from the leaves, to replace water lost through transpiration, to take part in reactions such as photosynthesis
What is porosity?
Total number of pores in a soil
What is permeability?
How easily air and water can travel through the soil connections
What are the macropores?
Large pores ( more than 60 microns)
What are the mesopores?
Medium pores (0.2 to 60 microns)
What are the micropores?
Tiny pores (less than 0.2 microns)
What is saturation point?
When all the pore spaces are filled with water
What is gravitational water?
The water that will drain from the soil due to gravity
What is field capacity?
The ideal amount of water in the soil for plants and happens when the macropores are air filled and the micro and mesopores are water filled
What is plant available water?
The water held in mesopores that plants can take up
What is permanent wilting point?
When all the water has been removed from the macro and mesopores due to drainage, plant uptake and evaporation from the soil surface
What is unavailable water?
The water in micropores that is unavailable to plants
What is soil moisture defecit?
The water required by rain/irrigation to raise the soil back to field capacity
What is capillary action?
The movement of a liquid along the surface of a solid caused by the attraction of molecules of the liquid to the molecules of the liquid to the molecules of the solid
What is the water table?
The point where the saturated soil meets the unsaturated soil. There can be a summer water table and a winter water table
How can water content and availability be optimised in clays?
Ensuring good structure is achieved and maintained. Avoiding compaction. Adding OM especially bulky OM like manures. Adding grit
How can water content be optimised in sands?
Ensuring good structure is achieved and maintained. Adding OM especially humus
