Scenarios of Phosphorus Flow from Agriculture and Domestic Wastewater in Myanmar (2010–2100)

Transfer of nutrients from agriculture and wastewater to the hydrosphere attracts attention of policymakers and scientists due to an increasingly important influence on the water environment. Crop and livestock production and fisheries predominantly support the Myanmar economy. However, phosphorus (P), which is used in cultivation and is also present in domestic sewage, is a major source of biogenic pollutants and eutrophication in Myanmar. It is therefore necessary to elucidate P flows from agricultural and domestic wastewaters to formulate a series of cost-effective policies and best-management practices (BMPs). This paper describes P flows to the hydrosphere, as driven by agricultural and domestic wastewater use in Myanmar during 2010–2100. The results reveal that total P flow from farmland and livestock occurred at 55 thousand Mg/year (thousand million grams per annum) in 2010 but is expected to be 128–141 thousand Mg/year in 2100. Urban population growth is the main factor contributing to the gradual increase in P flow from domestic wastewater; however, most of the P flow is derived from agriculture, suggesting that marked reductions in fertilizer use are necessary. This research provides basic information for the appraisal of P utilization and facilitates the identification of important objectives for sustainable P management in Myanmar.