CCA INTERNATIONAL EXAM 2025/2026 TEST BANK AND A
COMPREHENSIVE STUDY GUIDE COMPLETE ACCURATE
EXAM ACTUAL QUESTIONS WITH WELL ELABORATED
ANSWERS (VERIFIED SOLUTIONS) A NEW UPDATED
VERSION |GUARANTEED SUCCESS.
Define mineralization
Answer- Release of a nutrient when an organic material (i.e. OM,
manure, etc.) is decomposed by soil microorganisms. Conversion of a
nutrient from the organic to inorganic form.
Define immobilization
Answer- Reverse of mineralization. Nutrient is converted from inorganic
to organic form.
What is uptake antagonism between ions?
Answer- Two or more ions may compete for uptake by various
mechanisms. One ion is said to be antagonistic with regard to the uptake
of another ion.
Describe mass flow.
What nutrients is this important for?
,Answer- Nutrients move to a plant root with the water that is being
absorbed by the plant.
Important for N, Ca, and Mg.
Describe diffusion.
What nutrients is this important for?
Answer- Movement of a nutrient to a plant root due to a concentration
gradient between the soil surface and the root surface.
Important for P and K.
Describe root interception.
What nutrients is this important for?
Answer- Occurs when a root grows next to a clay or OM surface and
absorbs the nutrients. Actual uptake of a nutrient at the root surface may
be passive or active (by a carrier).
This is usually a minor way nutrients are absorbed.
Solubility of what nutrients increases in flooded soils?
Answer- Iron and manganese
,What is ammonification?
Answer- Conversion of organic N to ammonium (NH4+) by
microorganisms as they decompose an organic material. N rich materials
(C: N ratio <15-20:1) exhibit high levels of ammonification as they are
decomposed (ex. manure)
What is nitrification?
What are the two steps?
Answer- First step: Oxidation of ammonium to nitrite (NO2-) by
Nitrosamines Sp. Oxygen is required. Releases H+ decreasing ph.
Nitrification inhibitors slow this first step.
Second step: Oxidation of nitrite (NO2-) to Nitrate (NO3-) by
Nitrobacteria sp. This is fairly rapid so nitrite does not commonly
accumulate in soils. This step also requires oxygen.
What is volatilization?
What conditions favor volatilization?
Answer- - Conversion of ammonium (NH4+) to ammonia gas (NH3)
- High temp, high pH, low CEC, moist/wet soils, wind, large amounts of
surface residues
What is denitrification?
, Answer- When soil becomes saturated with water, microorganisms first
use oxygen and then, when the oxygen is depleted, they use nitrogen in
their metabolism. Products of denitrification are gaseous dinitrogen (N2)
and gaseous oxides of nitrogen that move to the atmosphere.
What is immobilization?
Answer- Nitrogen poor (C: N >20:1) organic materials (ex. wheat straw)
can cause microorganisms to remove large amounts of inorganic N from
the soil during decomposition because that N is required to build new
microbial cells. Decreases N availability. The immobilized N can be
mineralized when the microbial cells decompose.
Describe symbiotic N fixation.
Answer- Legume supplies energy to Rhizobium which uses that energy
and the enzyme, nitrogenize, to convert N2 from the atmosphere into
ammonium for the plant
Describe how phosphorus, sulfur, molybdenum, and cobalt effect
symbiotic N fixation.
Answer- P: needed to provide energy
S: important for protein synthesis
Mo: part of nitrogenize enzyme
Co: cofactor in an enzyme needed for N fixation and nodule growth
COMPREHENSIVE STUDY GUIDE COMPLETE ACCURATE
EXAM ACTUAL QUESTIONS WITH WELL ELABORATED
ANSWERS (VERIFIED SOLUTIONS) A NEW UPDATED
VERSION |GUARANTEED SUCCESS.
Define mineralization
Answer- Release of a nutrient when an organic material (i.e. OM,
manure, etc.) is decomposed by soil microorganisms. Conversion of a
nutrient from the organic to inorganic form.
Define immobilization
Answer- Reverse of mineralization. Nutrient is converted from inorganic
to organic form.
What is uptake antagonism between ions?
Answer- Two or more ions may compete for uptake by various
mechanisms. One ion is said to be antagonistic with regard to the uptake
of another ion.
Describe mass flow.
What nutrients is this important for?
,Answer- Nutrients move to a plant root with the water that is being
absorbed by the plant.
Important for N, Ca, and Mg.
Describe diffusion.
What nutrients is this important for?
Answer- Movement of a nutrient to a plant root due to a concentration
gradient between the soil surface and the root surface.
Important for P and K.
Describe root interception.
What nutrients is this important for?
Answer- Occurs when a root grows next to a clay or OM surface and
absorbs the nutrients. Actual uptake of a nutrient at the root surface may
be passive or active (by a carrier).
This is usually a minor way nutrients are absorbed.
Solubility of what nutrients increases in flooded soils?
Answer- Iron and manganese
,What is ammonification?
Answer- Conversion of organic N to ammonium (NH4+) by
microorganisms as they decompose an organic material. N rich materials
(C: N ratio <15-20:1) exhibit high levels of ammonification as they are
decomposed (ex. manure)
What is nitrification?
What are the two steps?
Answer- First step: Oxidation of ammonium to nitrite (NO2-) by
Nitrosamines Sp. Oxygen is required. Releases H+ decreasing ph.
Nitrification inhibitors slow this first step.
Second step: Oxidation of nitrite (NO2-) to Nitrate (NO3-) by
Nitrobacteria sp. This is fairly rapid so nitrite does not commonly
accumulate in soils. This step also requires oxygen.
What is volatilization?
What conditions favor volatilization?
Answer- - Conversion of ammonium (NH4+) to ammonia gas (NH3)
- High temp, high pH, low CEC, moist/wet soils, wind, large amounts of
surface residues
What is denitrification?
, Answer- When soil becomes saturated with water, microorganisms first
use oxygen and then, when the oxygen is depleted, they use nitrogen in
their metabolism. Products of denitrification are gaseous dinitrogen (N2)
and gaseous oxides of nitrogen that move to the atmosphere.
What is immobilization?
Answer- Nitrogen poor (C: N >20:1) organic materials (ex. wheat straw)
can cause microorganisms to remove large amounts of inorganic N from
the soil during decomposition because that N is required to build new
microbial cells. Decreases N availability. The immobilized N can be
mineralized when the microbial cells decompose.
Describe symbiotic N fixation.
Answer- Legume supplies energy to Rhizobium which uses that energy
and the enzyme, nitrogenize, to convert N2 from the atmosphere into
ammonium for the plant
Describe how phosphorus, sulfur, molybdenum, and cobalt effect
symbiotic N fixation.
Answer- P: needed to provide energy
S: important for protein synthesis
Mo: part of nitrogenize enzyme
Co: cofactor in an enzyme needed for N fixation and nodule growth
