Question

A gardener was working in his field. He noticed that some of his plants have yellow leaves which he has never seen before. He called his friend who was an agricultural scientist. The scientist asked him to send the soil sample to his lab. After a few days, he got the following results:

• A. The soil was deficient in Mg, Cu, Ca, K
• B. The soil was deficient in N, K, S, Mo
• C. The soil was deficient in Mn, Mg, Fe, Zn, Mo, N, K, S
• D. The soil was deficient in N, Mg, Ca, K, Mo, Se, B, Cl

Answer 1

The correct option is C The soil was deficient in Mn, Mg, Fe, Zn, Mo, N, K, S

Apart from sunglight, carbon dioxide and water, plants also require mineral nutrients for their growth and development. If the mineral requirement is not met it exhibits morphological changes called deficiency symtoms.
Yellowing of leaves is due to the loss of chlorophyll hence also called chlorosis.
Given below table containing elements and their deficiency symptoms.

Deficiency symptom	Deficient nutrient elements	Mnemonic to remember
Chlorosis: Yellowing of leaves	Mn, Mg, Fe, Zn, Mo, N, K, S	Money & Marriage (are) Irrelevant (to) Zen MoNKS where Money - Manganese (Mn) Marriage - Magnesium (Mg) Irrelevant - Iron (Fe) Zen - Zinc (Zn) MoNKS - Molybdenum (Mo), Nitrogen (N), Potassium (K), Sulphur (S)
Necrosis: Death of tissue	Mg, Cu, Ca, K	Maggie Cut Calendula (from the) Pot where Maggie - Magnesium (Mg) Cut - Copper (Cu) Calendula - Calcium (Ca) Pot - Potassium (K)
Inhibition of division of cells in the plants	Mo, P, S, N	Molly Kelly Speak Not where Molly - Molybdenum (Mo) Kelly - Potassium (K) Speak - Sulphur (S) Not - Nitrogen (N)
Delay in flowering	Mo, N, S	MoNS where Mo - Molybdenum (Mo) N - Nitrogen (N) S - Sulphur (S)

From the table we can conclude that the gardener's field was deficient in Mn, Mg, Fe, Zn, Mo, N, K, S.