Question

Which among the following fertilizers is least likely to affect the Soil pH?

[A] Urea 
[B] Rock Phosphate 
[C] Ammonia 
[D] Muriate of potash

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Answer 1

D [ Muriate of potash ]

Notes:

In comparison to N and P, the K fertilizers are least likely to affect the soil pH. Also note that among N, P and K, Nitrogen is the main nutrient affecting soil pH. Nitrogen fertilizers can make soil more acidic as well as more alkaline.

Answer 2

Among the following fertilizers, the Muriate of potash is least likely to affect the soil pH. (Option d)

• Muriate of potash is a K-fertilizer or a fertilizer containing potassium.
• Urea, rock phosphate, and ammonia are fertilizers containing nitrogen and phosphorous, or they are N- and P- fertilizers.
• Among the important N-, P-, K-fertilizers, it is nitrogen and phosphorous that makes the soil acidic and alkaline.
• Potassium fertilizers do not change the pH much.
• Also, the presence of chlorides in these fertilizers prevents nitrification within the soil.