Agriculture

Question 1

Yellowing of older leaves due to lack of clorophyll.

Answer 1

Chlorosis.

Question 2

What are detrimental effect of abundance of nitrogen (for corn)?

Answer 2

• dark leaves and stems
• excessive vegetative growth (at the expense of grain or fruit yield).
• ## lodging (bending and breaking)

Question 3

What is sod.

Answer 3

Torv. Organic matter that is not broken down because of lack of oxygen. Used instead of fire wood. Still in whisky production in Scotland.

Question 4

How is N requirement for a crop calculated?

Answer 4

(yield potential x C) - N in soil - N in sod) divided by fertilizer uptake efficiency = N requirement.

Question 5

Why does the yield potential for some soil types not increase by artificial drainage?

Answer 5

Because the soil type is already well drained.

Question 6

What is it called when N in soil is made available to the crop?

Answer 6

Mineralization –> Nitrification

Question 7

For how many years after plowing will sod release N?

Answer 7

3 years (the N is gradually mineralized when microorganism start working on it now that oxygen is available).

Question 8

Sod types release different quantities of N (alfaalfa, grass, mixed etc.) why?

Answer 8

Varying biological N fixation in the sod.