Assessment of nutrient recovery, air emission and farmers’ perceptions of indigenous mound burning practice using animal and human wastes in Myanmar

Soil fertility degradation is threatening the sustainability of the global agricultural production system. Unimproved onsite sanitation systems along with inappropriate disposal of fecal sludge (FS) are predominant in the urban areas of low-income countries and rural areas all over the world. At the same time, animal waste is already used as a very common fertilizer, while the use of human waste, which has high nutrient value, is still limited. Since global issues of waste disposal and soil infertility are becoming more serious, research should be carried out to solve these problems. Hence, mound or heap burning, an indigenous agricultural practice which is currently being conducted in some remote areas in the eastern part of Myanmar and other less developed countries in Asia and Africa, was studied in this research. In traditional mound burning (MB) practice in Myanmar, dried cow dung (CD) is burnt and covered with soil to form a mound. This research was conducted (1) to study the level of nutrient recovery from the indigenous practice of MB-CD; (2) to integrate the use of FS into the indigenous practice of MB-CD; (3) to identify the environmental challenges of the practice, such as pathogens contamination and air pollution; and (4) to investigate the perceptions of farmers toward the use of FS in their farms and of the consumers toward consuming FS-fertilized crops. This study found that plant nutrients such as available nitrogen, phosphorous and potassium were increased by approximately 8, 2 and 2 times, respectively, after the 3-month maturation period in both MB experiments with both FS and CD. Moreover, there was no detection of the total coliform, Escherichia coli bacteria and Ascaris lumbricoides eggs after MB of both FS and CD. The emission factors of CO, NOx, PM2.1 and PM10 from both MB-FS and MB-CD were found to have a relatively low impact on the environment compared with other burning processes. The perceptions of farmers in the study area also revealed that most of them preferred to use the dried/treated FS in their farms, which was similar to the perceptions of consumers. This research revealed that MB could recover the nutrients from both human and animal wastes, which could then be used as fertilizers applied in agricultural fields with less environmental impact from pathogen contamination and air pollution.