Deck 15: Micronutrients and Other Trace Elements

Question 1

Plant symptoms such as aborted fruits, dead terminal buds, and misshapen new leaves suggest a deficiency of which micronutrient?

A)B
B)Cu
C)Zn
D)Fe
E)Mn

Answer 1

A

Question 2

Which micronutrient element is found in the greatest quantity in most soils?

A)B
B)Cu
C)Fe
D)Mn
E)Zn

Answer 2

C

Question 3

Which of the following micronutrients becomes more available for plant uptake as soil pH is increased from pH 6 to pH 8?

A)manganese
B)iron
C)zinc
D)boron
E)none of the above

Answer 3

E

Question 4

Which micronutrient is particularly critical for legume plants because of its place in the nitrogenase enzyme that allows Rhizobia-infected legumes to utilize atmospheric nitrogen?

A)B
B)Mo
C)Cu
D)Mn
E)Zn

Question 5

Simply spraying a solution to coat the seeds before planting often provides enough of which micronutrient to meet the needs of the crop?

A)B
B)Mo
C)Cu
D)Mn
E)Zn

Question 6

Which method of application generally would require the greatest amount of iron to alleviate an iron deficiency in an orange grove?

A)application of iron chelate to the soil in localized pockets
B)application of iron chelate to soil evenly with thorough mixing
C)foliar spray of iron chelate
D)application of iron sulfate to soil in localized pockets
E)application of iron sulfate to soil evenly with thorough mixing

Question 7

Molybdenum deficiency is most likely to occur under which of the following soil conditions?

A)soil with pH 6.3 and subject to frequent flooding
B)well drained calcareous soil with pH 8.1
C)well drained humid region loamy sand with pH 5.0
D)muck soil (Saprist) with pH 5.5
E)poorly drained calcareous soil with pH 7.6

Question 8

Which of the following micronutrients is least commonly found to be deficient in plants?

A)manganese
B)iron
C)copper
D)boron
E)chlorine

Question 9

Iron deficiency is most likely to occur under which of the following soil conditions?

A)soil with pH 4.3 and subject to frequent flooding
B)leached humid region sandy soil limed to pH 8.0
C)well drained humid region loamy sand (Spodosol) with pH 5.0
D)muck soil (Saprist) with pH 5.5
E)silt loam Mollisol with pH 7.5

Question 10

Which of the following nutrient elements is usually present in the soil solution as a simple cation?

A)B
B)Zn
C)Cl
D)Mo
E)all of the above

Question 11

Plants that are efficient at taking iron up from a calcareous soil are known to employ which of the following methods?

A)lower pH of their rhizosphere
B)produce reducing agents that reduce Fe³⁺ to Fe²⁺ in the rhizosphere.
C)produce organic compounds that can form stable chelates with iron.
D)all of the above
E)none of the above

Question 12

Which of the following nutrient elements is usually present in the soil solution as an undissociated acid?

A)B
B)Cu
C)Zn
D)Fe
E)Mo

Question 13

Applying 10 kg/ha of which of the following nutrients would most likely cause toxicity to plants?

A)manganese
B)iron
C)copper
D)boron
E)chlorine

Question 14

Molybdenum toxicity is most likely to occur under which soil conditions?

A)soil with pH 4.3 and subject to frequent flooding
B)well drained calcareous soil with pH 8.0
C)excessively well drained humid region loamy sand with pH 5.0
D)muck soil (Saprist) with pH 5.5
E)poorly drained calcareous soil with pH 8.0

Question 15

The availability of which of the following micronutrients is commonly affected by soil redox potential?

A)manganese
B)zinc
C)cobalt
D)boron
E)all of the above

Question 16

In an alkaline soil, much of the iron in most iron chelates is rapidly replaced in the chelate complex by which other metallic nutrient?

A)Ca
B)Zn
C)Mn
D)Cu
E)K

Question 17

Plant symptoms such as interveinal chlorosis on new leaves suggest a deficiency of which micronutrient?

A)Zn
B)Fe
C)Mn
D)all of the above
E)none of the above

Question 18

Copper deficiency is most likely to occur under which of the following soil conditions?

A)soil with pH 4.3 and subject to frequent flooding
B)well drained loamy sand Ultisol with pH 6.1
C)silt loam soil with pH 7.0
D)muck soil (Saprist) with pH 5.5
E)poorly drained calcareous soil with pH 7.6

Question 19

Manganese toxicity is most likely to be a problem under which soil conditions?

A)clay loam Ultisol, pH 4.3, subject to frequent flooding
B)well drained calcareous soil, pH 8.1
C)well drained humid region loamy sand, pH 5.0
D)muck soil (Saprist) with pH 5.5
E)poorly drained calcareous soil with pH 7.6

Question 20

When soil pH is between 4.5 and 5.5, which micronutrient most commonly causes plant toxicity?

A)Zn
B)Cu
C)Fe
D)Mn
E)Mo

Question 21

Mycorrhizae help plants avoid toxicities of zinc, copper, and other micronutrients by decreasing the uptake of these elements from soil into the plant shoot.

Question 22

Mycorrhizae help plants overcome deficiencies of zinc, copper, and other micronutrients by increasing the plant uptake of these elements from soil.

Question 23

Where the available supply of iron and zinc are low, deficiency of these elements can often be overcome by larger than normal applications of phosphorus fertilizer.

Question 24

Molybdenum occurs in the soil solution as a complex anion similar to that formed by phosphorus.

Question 25

When organic amendments such as animal or green manures are added to soils, micronutrient availability generally is enhanced by the production of natural chelating agents.

Question 26

Micronutrient deficiencies are more likely to occur where inorganic chemical fertilizers, rather than organic manures, have been used to stimulate vigorous plant growth.

Question 27

Most micronutrients play essential roles in plant metabolism as enzyme activators.

Question 28

In the future, as food production is increased in countries around the world, micronutrient deficiencies are likely to become less of a problem than they are today.

Question 29

Because many chelating agents are naturally occurring, a kilogram of zinc generally costs less in the form of zinc-chelate than in the form of zinc sulfate.

Question 30

Plants generally convert oxidized iron to its reduced form by means of organic reducing agents before the iron is taken up or utilized by the plant.

Question 31

Boron is commonly deficient in acid soils because chemical reactions under acid conditions make it less available for plant uptake .

Question 32

A soluble iron chelate with a very high stability constant will be less effective as a fertilizer material than one with a lower stability constant.

Question 33

It is common for some plants growing on a particular soil to suffer from a micronutrient deficiency while other plants growing on the same soil are well supplied with the nutrient in question.

Question 34

Roots of monocotyledonous plant (e.g.grasses) have been shown to take in the entire organo-metallic complex when utilizing chelated sources of micronutrients such as iron.

Question 35

Histosols (organic soils) are typically well supplied with nitrogen and phosphorus but deficient in most micronutrients.

Question 36

Application of FeSO₄ or ZnSO₄ to many soils is much less effective than the addition of the same amount of micronutrient in the form of a chelate.

Question 37

Dicot plants are thought to remove chelated micronutrients from their organic ligands before taking metallic cations into their roots.

Question 38

Once a micronutrient ion is introduced into the soil as a chelate, it will remain in that form until taken up by a plant or a microorganism.

Question 39

Azaleas, pin oaks and other acid-soil loving forest plants have evolved very efficient mechanisms for extracting iron from soils.

Question 40

The data in the following Table suggest the occurrence of a positive synergism between two nutrients.

Question 41

Interveinal yellowing of the oldest leaves on a plant is a symptom that suggest a deficiency of Mn or Fe.

Question 42

Dolomitic limestone is a good material to fertilize acid soils with both for both Ca and Mg.