Nutrient stocks, flows and balances for the Bolivian agri-food system: Can recycling human excreta close the nutrient circularity gap?

Analysis of the current state nutrient stocks, flows, and balances a territory is necessary to inform strategies that can transition agri-food sector circular economy model. In this study, we quantified nitrogen phosphorus budgets for Bolivian system at national regional scales by way agro-ecological zoning. We performed calculate indicators sufficiency (extent deficit/surplus) circularity (proportion nutrients recirculated). also evaluated potential renewable stocks (human excreta livestock manure) meet deficits in system. Our results showed there are apparent 32 kt N 8 P cannot be accounted using available data. estimate real required bring yields 45 crops grown Bolivia parity with those neighbouring countries 110 33 P. About 44% 74% currently recirculated system, major inputs being biological fixation, manure, crop residues. However, recycling likely decrease future because strategy address increase domestic production synthetic fertilisers. analysis shows sufficient stock already human (39 5 P) cover 100% deficit 64% deficit. The low-altitude zone Chiquitania-Pantanal alone accounts 65% cultivation 80% demand country. Here, export-oriented like soybean sorghum grown, but less than 25% recirculated. contrast, surpluses 41 34 zones Valleys Altiplano where traditional agriculture practiced, majority food local consumption. Overall, find excreta, combined transfer surpluses, could an effective reduce overall