Nutrient addition and uptake (group 1)
Do most tree species prefer NH4 or NO3?
NH4
What organisms break down organic matter?
Bacteria, action bacteria, and fungi.
Where does virtually all the N plants get come from?
Microbial degradation of organic matter containing N.
What is the wash off effect?
Rinsing of dry materials from plant surfaces, and exchange of nutrients directly with leaves.
Do fungi or bacteria require more N per unit of C?
Bacteria.
Name the 3 types of atmospheric deposition
Wet, dry, cloud.
What is plant litter.
Leaves or roots that have either died or separated from a plant. These can now be used as nutrients.
Which type of organic compound contains N?
Glutamate (amino acid)
What causes the threshold where immobilization slows and mineralization starts?
When all other compounds are depleted, microorganisms starve and die and the remaining consume N from them, and this process releases NH4+ into the soil for plants to use.
Name two types of non-symbiotic nitrogen fixing bacteria
Azotobacter, clostridium, cyanobacteria.
What does mycorrhizal fungi get out of its mutualistic relationship with plants?
Sugars and a reliable place to grow.
What are the six components of organic litter that can be broken down by organisms?
Glucose, glutamate, starch, cellulose, hemicellulose, and lignin.
What is one type of enzyme secreted by roots, and what is its purpose?
Phosphatases, break down soil organic matter to release phosphate.
Name some types of root architecture mentioned in the presentation.
1 named = 250 points
2 named = 500 points
3 named = 600 points
Herringbone, Intermediate, Dichotomous.
What is the order of efficiency for breaking down each type of organic compound? Which compounds break down the fastest and which are slowest?
Glucose, protein and simple sugars, cellulose, hemicellulose, lignin.