Final Exam Flashcards
Expressed in milliequivalents per 100 g of soil
CEC
Any element that is positively charged such as Ca2+ is called a
Cation
The ability of soil particles to absorb or adsorb and store anions
AEC
Any element that is negatively charged such as Cl is called an
Anion
Net result of the overall negative charge of the oxygen atom and the overal postive charges of the two hydrogen atoms
Polarity
Clays with 11 fixed lance type (less expanding) belong to what clay group?
Kaolinite group
This refers to the process by which soil nutrients tnents such as NO2 are washed down by water from the root zone of the plants
Leaching
The kind of acidity which is due to the hydrogen ion concentration of the soil solution
Active
The practice of covering the soil surface with matenals that can maintain an ideal soil temperature
Mulching
The most common smectite which is among the “swelling clays”
Montmorillonite
A state of subdivision of a particle in the soil such that surface properties predominate
Colloid
A type of silicate clays with two sheets held together by oxygen atom that are mutualy shared by Si and Al
Kaolinite/non-expanding
Saline soil characterized by white crust on surface and predominantly containing CaCO, is also called
White soil
Materials containing Ca or Ca and Mg compounds used mainly to neutralize soil acidity up to a desired level
Lime
Unsegmented worms in soil mostly macroscopic
Nematodes
Sificate, oxide and amorphous clays belong to this type of colloids
Inorganic soils
The process of substitution of one ion for another of similar size within crystal lattice
Isomorphous substitution
These root swelling forms due to the infection of root hairs by the Rhizobium bactena
Nodule
This bacteral species oxidizes S to form SO2
Thiobacillus
Nitrosomona Nitrosococcus. Nitrobacter and Nitrococcus belong to what group of N-Fixing Bacteria bacteria (with regards to the N cycle?
N-Fixing bacteria
Indigenous bactena are called
Authoctthonous
The process whereby cations adsorbed on the colloid are exchanged for those in the soil solution
Cation exchange
The is ability to provide essential plant nutrients in adequate amounts and proper proportions to sustain plant growth
Soil fertility
Invader bacteria are called
Allocthonous
Sorption property of sols including exchange reactions of both cations and anions
Ion sorption capacity
group of symbiotic fungi living in close association with the root system
Mycorrhizal fungi
In terms of O requirement, these group of bacteria require O, to survive
Aerobic
These are nitrogen-fixing and photosynthetic bacteria
Blue-Green Algae
The process of accumulation of chemicals at the solid-liquid interface
Adsorption
A problem sol having a low pH below 7.0
Acidic soil