Soils and fertilisers: identify the wrong statement among the following assertions.

Introduction / Context:
Fertiliser facts often mix agronomy and industrial production knowledge. This item asks you to spot the single incorrect statement, requiring understanding of plant uptake forms, soil amendments, physical quality of fertilisers, and by-product origins in heavy industry.

Given Data / Assumptions:

• Plant-available nitrogen forms are ammonium (NH4+) and nitrate (NO3−).
• Calcium sources (e.g., lime, gypsum-containing fertilisers) can ameliorate soil acidity.
• Granular fertilisers are controlled in size for flowability and lower retained moisture.
• By-product streams from coke ovens include ammonia.

Concept / Approach:
By-product ammonia from coke-oven gas is typically converted to ammonium sulphate, not ammonium nitrate. Therefore, the claim that ammonium nitrate fertiliser is a by-product of integrated steel plants is wrong. The other statements align with standard agronomic and process understanding.

Step-by-Step Solution:

Verification / Alternative check:
Steel-industry by-product fertiliser literature consistently references ammonium sulphate recovery from coke-oven gas scrubbers.

Why Other Options Are Wrong:

• (a), (b), (c), (e) are correct statements; only (d) is wrong in standard references.

Common Pitfalls:
Confusing nitrate and sulphate salts of ammonia in by-product routes; nitric acid production is not integral to coke-oven operations.

Final Answer:
Ammonium nitrate fertiliser is obtained as a by-product in integrated steel plants with by-product coke ovens.