Global Pathways to Low-Impact, Cost-Effective Food Security in wheat and maize production:source of data

The present study was conducted to optimize N and P fertilizer application strategies for irrigated and rainfed maize and wheat systems at the global scale. Both current production conditions and future management scenarios were considered. For this aim various forms of N and P losses (emissions) were quantified, and optimization techniques were applied to determine efficient fertilization strategies. To achieve this, several alternative nutrient management scenarios were evaluated, incorporating legume rotations and manure application two widely available, low-cost nutrient sources either individually or in combination. The scenarios included: (1) integrated use of manure (providing N and P) and legume rotation (supplying biologically fixed N) (BothML), (2) Manure application only, (3) Legume rotation only, (4) No external nutrient inputs to achieve optimization rate, and (5) Nutrient requirements based on actual yield values (Real), and (6) current fertilizer application as business as usual scenarios (BAU). Fertilizer requirements were calculated using the equations provided in the FertiliCalc model guide (http://www.uco.es/fitotecnia/fertilicalc.html), as described in the manual section of this model. A genetic algorithm (GA) was applied to determine the optimal fertilizer application rates under each scenario, using spatially explicit datasets on soil properties, climate conditions, and legume N fixation capacity. This approach enables the development of site-specific, resource-efficient fertilization strategies at the global scale.