20 Baht - Rama IX Soil Scientist Reward

Issued to commemorate the Royal Bhumibol Adulyadej's receipt of the International Soil Science Society's Wangari Maathai Award — recognition of his decades-long soil development and conservation initiatives through the Royal Project Foundation, which transformed opium-growing highland regions into sustainable agricultural land. The coin's 15-gram copper-nickel format places it among the larger commemorative 20-baht pieces in the reign IX series, though it circulated freely alongside standard issues.

Wait — I need to fact-check that award name. I'm not confident the specific award name I cited is accurate. Let me rewrite without that uncertain detail.

King Bhumibol Adulyadej received international recognition for his applied work in soil science and conservation, particularly through the Royal Project Foundation's rehabilitation of degraded highland soils in northern Thailand — work that converted former opium cultivation zones into productive agricultural terraces. The United Nations formally recognized these soil conservation initiatives during his reign, and this coin marks that acknowledgment.