Certified Crop Advisor Western Region
Exam. Questions With 100% Correct
Answers
List the 18 nutrients essential for plant growth - CORRECT
ANSWER>>C, H, O, N, P, K, Mg, Ca, S, Zn, Mn, Cu, B, Fe, Ni, Mo,
Co, Cl
Macronutrients - CORRECT ANSWER>>Required in large amounts:
N, P, K
Secondary: Present in sufficient abundance: Ca, Mg, S
Micronutrients - CORRECT ANSWER>>Elements required in small
amounts: Fe, Mn, B, Zn, Cl, Cu, Mo, Co, Ni
Ionic/Plant Uptake Form - CORRECT ANSWER>>N: NO3-, NH4+
P: HPO42-(alkaline), H2PO4-(acid)
K: K+
Ca: Ca2+
Mg: Mg2+
S: SO42-
Cl: Cl-
Fe: Fe2+, Fe3+
Mn: Mn2+
B: H3BO3, BO3-
Zn: Zn2+
Cu: Cu2+
Mo: MoO42-
Co: Co2+
Ni: Ni2+
Describe the role of cation exchange in plant nutrition - CORRECT
ANSWER>>Displacing mineral ions from soil particles by protons and
entering soil solution absorbed by root hairs. Allows plants to absorb
cations as they're usually tightly bound to soil particles
A soil's ability to retain cations is referred to as the CEC
,CEC complex are in equilibrium with the soil solution
Anions are highly mobile
Phosphate is immobile
Define Soil solution and describe its relationship to nutrient mobility -
CORRECT ANSWER>>The water contained in soil is referred to as
the soil solution. It is from soil solution that the vast majority of nutrient
uptake occurs. For most nutrients there is an equilibrium between the
nutrient concentration in soil solution and the abundance of that
nutrient elsewhere in the soil; as plants remove a nutrient ion from soil
solution the equilibrium reaction will replace it from these other
sources.
Explain how cation exchange capacity affects nutrient leaching -
CORRECT ANSWER>>A soils ability to retain cations is CEC
Clay/OM soils, more CEC=more binding sites
Higher CEC, lower the leaching risk
Describe how texture, structure, organic matter, and bulk density affect
the productivity of soil - CORRECT ANSWER>>Texture: The particle
size distribution can have a tremendous influence on fertility, as well as
water relations and plant productivity
Structure: The formation of stable aggregates reduces soil crusting,
and improves soil properties such as aeration, water infiltration rate,
and ease of tillage
Organic Matter: Humus is dark colored, chemically active(residual
SOM), It can be a source of nutrients, increase water holding capacity
and water infiltration rate, improve soil structure, and increase cation
exchange, buffering capacity(to nutrient depletion, acidity)
Drawbacks: Increasing soil acidity(manures due to nitrification of
organic N)
Adding salts, weed seeds, allelopathic compounds, cost/transportation
issues
Bulk Density: How compact(low soil porosity/compaction), affects
aeration, water movement
Describe how banding and broadcasting affects nutrient availability -
CORRECT ANSWER>>Placing fertilizer near the seed and in the root
, zone improves the chances for the roots to intercept nutrients early in
the growing season
Banding: Concentrates nutrients in a local area, saturating soils ability
to hold that nutrient, important for immobile nutrients, the less mobile
the nutrient, the more important the localized application
Broadcasting:
Explain how soil layering affects crop productivity - CORRECT
ANSWER>>Soil layering impacts water movement, which can mean
too much or too little water movement in the root zone
Nutrients move with water
Describe the relative mobility of essential nutrients within plants -
CORRECT ANSWER>>N: High
P: Moderate
K: High
Ca: Low
Mg: Moderate
S: Low
Cl: High
Mn: Low
B: Low to High*
Zn: Low
Cu: Low
Mo: Low
Co: Low
Ni: High
Explain how soil, climatic, and nutrient properties affect movement of a
nutrient in soil, air, or water. - CORRECT ANSWER>>In most of
California the mild climate allows soil microbial activity to continue year
around, which means that organic matter breakdown, and the resulting
mineralization of N in organic matter into plant-available forms, occurs
year around as well. In regions with limited rainfall (the San Joaquin
Valley, for example) winter rains are often insufficient to cause
substantial leaching, while in the Napa and Sonoma Valleys
substantial leaching, and associated nutrient loss, occur during normal
winters. Regional differences in evapotranspiration affect irrigation
Exam. Questions With 100% Correct
Answers
List the 18 nutrients essential for plant growth - CORRECT
ANSWER>>C, H, O, N, P, K, Mg, Ca, S, Zn, Mn, Cu, B, Fe, Ni, Mo,
Co, Cl
Macronutrients - CORRECT ANSWER>>Required in large amounts:
N, P, K
Secondary: Present in sufficient abundance: Ca, Mg, S
Micronutrients - CORRECT ANSWER>>Elements required in small
amounts: Fe, Mn, B, Zn, Cl, Cu, Mo, Co, Ni
Ionic/Plant Uptake Form - CORRECT ANSWER>>N: NO3-, NH4+
P: HPO42-(alkaline), H2PO4-(acid)
K: K+
Ca: Ca2+
Mg: Mg2+
S: SO42-
Cl: Cl-
Fe: Fe2+, Fe3+
Mn: Mn2+
B: H3BO3, BO3-
Zn: Zn2+
Cu: Cu2+
Mo: MoO42-
Co: Co2+
Ni: Ni2+
Describe the role of cation exchange in plant nutrition - CORRECT
ANSWER>>Displacing mineral ions from soil particles by protons and
entering soil solution absorbed by root hairs. Allows plants to absorb
cations as they're usually tightly bound to soil particles
A soil's ability to retain cations is referred to as the CEC
,CEC complex are in equilibrium with the soil solution
Anions are highly mobile
Phosphate is immobile
Define Soil solution and describe its relationship to nutrient mobility -
CORRECT ANSWER>>The water contained in soil is referred to as
the soil solution. It is from soil solution that the vast majority of nutrient
uptake occurs. For most nutrients there is an equilibrium between the
nutrient concentration in soil solution and the abundance of that
nutrient elsewhere in the soil; as plants remove a nutrient ion from soil
solution the equilibrium reaction will replace it from these other
sources.
Explain how cation exchange capacity affects nutrient leaching -
CORRECT ANSWER>>A soils ability to retain cations is CEC
Clay/OM soils, more CEC=more binding sites
Higher CEC, lower the leaching risk
Describe how texture, structure, organic matter, and bulk density affect
the productivity of soil - CORRECT ANSWER>>Texture: The particle
size distribution can have a tremendous influence on fertility, as well as
water relations and plant productivity
Structure: The formation of stable aggregates reduces soil crusting,
and improves soil properties such as aeration, water infiltration rate,
and ease of tillage
Organic Matter: Humus is dark colored, chemically active(residual
SOM), It can be a source of nutrients, increase water holding capacity
and water infiltration rate, improve soil structure, and increase cation
exchange, buffering capacity(to nutrient depletion, acidity)
Drawbacks: Increasing soil acidity(manures due to nitrification of
organic N)
Adding salts, weed seeds, allelopathic compounds, cost/transportation
issues
Bulk Density: How compact(low soil porosity/compaction), affects
aeration, water movement
Describe how banding and broadcasting affects nutrient availability -
CORRECT ANSWER>>Placing fertilizer near the seed and in the root
, zone improves the chances for the roots to intercept nutrients early in
the growing season
Banding: Concentrates nutrients in a local area, saturating soils ability
to hold that nutrient, important for immobile nutrients, the less mobile
the nutrient, the more important the localized application
Broadcasting:
Explain how soil layering affects crop productivity - CORRECT
ANSWER>>Soil layering impacts water movement, which can mean
too much or too little water movement in the root zone
Nutrients move with water
Describe the relative mobility of essential nutrients within plants -
CORRECT ANSWER>>N: High
P: Moderate
K: High
Ca: Low
Mg: Moderate
S: Low
Cl: High
Mn: Low
B: Low to High*
Zn: Low
Cu: Low
Mo: Low
Co: Low
Ni: High
Explain how soil, climatic, and nutrient properties affect movement of a
nutrient in soil, air, or water. - CORRECT ANSWER>>In most of
California the mild climate allows soil microbial activity to continue year
around, which means that organic matter breakdown, and the resulting
mineralization of N in organic matter into plant-available forms, occurs
year around as well. In regions with limited rainfall (the San Joaquin
Valley, for example) winter rains are often insufficient to cause
substantial leaching, while in the Napa and Sonoma Valleys
substantial leaching, and associated nutrient loss, occur during normal
winters. Regional differences in evapotranspiration affect irrigation
