Intellectual Olympiad in Soil Science - 2026 ongoing

Subject: Soil Science
Level: VII
Category: student
Quiz questions: in English
Example question: A soil has a cation-exchange capacity of 25 cmol(+) kg⁻¹ and contains 5 cmol(+) kg⁻¹ of exchangeable calcium. What percentage of the exchange sites is occupied by calcium? 10%, 15%, 20%, 25%