Agronomy Soil Science and Fertility 3

Question 1

Which type of soil horizon is most important for plant root development and nutrient uptake?

Accepted Answer

A horizon

Answer

O horizon

Answer

B horizon

Answer

C horizon

Question 2

Potassium deficiency in crops typically first appears as what symptom?

Accepted Answer

Marginal leaf scorch on older leaves

Answer

Purple coloration of stems

Answer

Stunted new growth

Answer

Yellowing of young leaves

Question 3

Which practice is most effective at reducing soil erosion on sloped farmland?

Accepted Answer

Contour farming

Answer

Deep tillage

Answer

Monoculture

Answer

Fall plowing

Question 4

Soil salinity is measured using which instrument or method?

Accepted Answer

Electrical conductivity meter

Answer

Tensiometer

Answer

Penetrometer

Answer

Refractometer

Question 5

What role do mycorrhizal fungi play in plant nutrition?

Accepted Answer

Extend root surface area for nutrient uptake

Answer

Fix atmospheric nitrogen

Answer

Decompose crop residues

Answer

Suppress soil pathogens

Question 6

Which fertilizer source has the highest nitrogen content by weight?

Accepted Answer

Anhydrous ammonia (82-0-0)

Answer

Ammonium sulfate (21-0-0)

Answer

Urea (46-0-0)

Answer

Ammonium nitrate (34-0-0)