OKSTATE SOIL 1113 EXAM 2
QUESTIONS AND ANSWERS 100% PASS
2026/2027
Chemical Properties affect - ANS - the speciation of nutrients and availability of nutrients to
plants
- the fate of pollutants in soil
- activity and survival of soil microorganisms
- choice of plants to grow
- soil physical properties
Soil pH - ANS a measure of the H+ concentration or the acidity of a soil solution (water in the
soil pores)
pH formula - ANS -log[H+]
pure water concentration - ANS H+=10^-7
meaning it has a pH of 7
circumneutral pH - ANS Near neutral pH conditions; refers to conditions when the pH of the
soil solution is between 6.5- 7.5
2026/2027 ALLRIGHTS RESERVED
1
,under acidic conditions - ANS soil has limitations in terms of supporting plant growth and the
activity of soil microorganisms
extreme basic conditions - ANS limit the ability of the soil to perform the production and
ecological regulator functions
low pH - ANS -high hydrogen ion concentration
-acidic
Guide in crop selection - ANS most edible foods grow best in slightly acidic soil from 6-6.8
pH determines what in heavy metals - ANS solubility
how to rise pH levels - ANS - apply lime
- oxides or hydroxides or carbonates of Ca (calcium) or Mg (magnesium) are added
CaO and Ca(OH)2 - ANS highly reactive and are often difficult to manage
CaCO3 - ANS not as reactive and easy to manage, cheaper and widely used
purity of the lime - ANS any impurities in the lime will reduce its ability to neutralize acidity
fineness of the lime - ANS large particles react more slowly and less completely than fine
particles
what should i do for high pH - ANS apply
- iron sulfates
- organic matter
2026/2027 ALLRIGHTS RESERVED
2
, - ammonium sulfate
How is the soil able to store soil nutrients and treat chemical contaminants - ANS clays have a
very high surface area, and their surfaces are usually charged
surface charge for montmorillonite - ANS -80 to -150
surface charge for vermiculite - ANS -100 to -200
surface charge for illite - ANS -10 to -40
the surface charge for chlorite - ANS -10 to -40
surface charge for kaolinite - ANS -1 to -15
surface charge for gibbsite - ANS 10 to -5
surface charge for goethite - ANS 20 to -5
surface charge for allophane and imogolite - ANS 20 to -150
soils almost always a have what charge - ANS negative
exchange of ions between the bulk solution and swarm is - ANS - rapid
- reversible
- stoichiometric
2026/2027 ALLRIGHTS RESERVED
3
QUESTIONS AND ANSWERS 100% PASS
2026/2027
Chemical Properties affect - ANS - the speciation of nutrients and availability of nutrients to
plants
- the fate of pollutants in soil
- activity and survival of soil microorganisms
- choice of plants to grow
- soil physical properties
Soil pH - ANS a measure of the H+ concentration or the acidity of a soil solution (water in the
soil pores)
pH formula - ANS -log[H+]
pure water concentration - ANS H+=10^-7
meaning it has a pH of 7
circumneutral pH - ANS Near neutral pH conditions; refers to conditions when the pH of the
soil solution is between 6.5- 7.5
2026/2027 ALLRIGHTS RESERVED
1
,under acidic conditions - ANS soil has limitations in terms of supporting plant growth and the
activity of soil microorganisms
extreme basic conditions - ANS limit the ability of the soil to perform the production and
ecological regulator functions
low pH - ANS -high hydrogen ion concentration
-acidic
Guide in crop selection - ANS most edible foods grow best in slightly acidic soil from 6-6.8
pH determines what in heavy metals - ANS solubility
how to rise pH levels - ANS - apply lime
- oxides or hydroxides or carbonates of Ca (calcium) or Mg (magnesium) are added
CaO and Ca(OH)2 - ANS highly reactive and are often difficult to manage
CaCO3 - ANS not as reactive and easy to manage, cheaper and widely used
purity of the lime - ANS any impurities in the lime will reduce its ability to neutralize acidity
fineness of the lime - ANS large particles react more slowly and less completely than fine
particles
what should i do for high pH - ANS apply
- iron sulfates
- organic matter
2026/2027 ALLRIGHTS RESERVED
2
, - ammonium sulfate
How is the soil able to store soil nutrients and treat chemical contaminants - ANS clays have a
very high surface area, and their surfaces are usually charged
surface charge for montmorillonite - ANS -80 to -150
surface charge for vermiculite - ANS -100 to -200
surface charge for illite - ANS -10 to -40
the surface charge for chlorite - ANS -10 to -40
surface charge for kaolinite - ANS -1 to -15
surface charge for gibbsite - ANS 10 to -5
surface charge for goethite - ANS 20 to -5
surface charge for allophane and imogolite - ANS 20 to -150
soils almost always a have what charge - ANS negative
exchange of ions between the bulk solution and swarm is - ANS - rapid
- reversible
- stoichiometric
2026/2027 ALLRIGHTS RESERVED
3
