W8.2, Micronutrient nutrition

Question 1

Cobalt (Co) is an essential micronutrient.

Answer 1

False. It’s not essential for plants, but it is essential for animals and other organisms.

e. g. Rhizobia require Co to complete N fixation.
e. g. Some rumen bacteria require Co to produce vitamin B12

Question 2

Micronutrients are named so because they’re less important than macronutrients (though still essential).

Answer 2

False.

They’re so named because they’re required in lower quantities.

Question 3

Molybdenum (Mo) deficient pastures are legume-dominant.

Answer 3

False. Legumes require Mo as a cofactor for N fixation, so Mo deficient pastures are grass-dominant.

Question 4

Why is it worth knowing the history of micronutrient application for a crop?

Answer 4

Because most have a long residual effect and should last for 5-15 years or so.

Question 5

True or false?

Increasing SOM (e.g. by retaining residues) is a good long-term strategy for minimising micronutrient deficiencies.

Answer 5

True.