This photo taken on March 18, 2026 shows farmers Siriporn and Amnat Taidee, who have previously treated their rice fields with microbial solution Soil Digest, in Chiang Rai province. Rice farmers Siriporn and Amnat Taidee used to burn their paddy fields between plantings -- a common method of clearing crop residue partly blamed for toxic smog that blankets much of Thailand every spring. (Photo by Lillian SUWANRUMPHA / AFP via Getty Images) / To go with 'THAILAND-POLLUTION-ENVIRONMENT-AGRICULTURE-SCIENCE,FOCUS' by Chayanit ITTHIPONGMAETEE and Sally JENSEN