A process simulation-based framework for resource, food, and ecology trade-off by optimizing irrigation and N management

Improving food production and resource utilization efficiency and mitigating the functional degradation of agroecosystems are major challenges worldwide. However, few studies have reconciled the conflicts among resources, food, and ecology (RFE) in agricultural production. This study develops a water-carbon-nitrogen process simulation-based framework for RFE trade-off by coupling the agro-hydrological model, i.e., AHC (Agro-Hydrological & chemical and Crop systems simulator) with the ecosystem service value (ESV) assessment method and decision-making method, i.e., VIKOR (VlseKriterijuska Optimizacija I Komoromisno Resenje). The framework is capable of (1) quantifying farmland ESVs; (2) reconciling conflicts among resource utilization, food production and ecosystem development by optimizing farmland irrigation and nitrogen (N) application strategies (FINS). The framework was used to analyze the FINS, and then to obtain the compromise decision focusing on a lower negative ESV and the maximizing group utility decision focusing on a higher yield and positive ESV for spring wheat farmland in Northwest China. Results indicated that under the local FINS, i.e., 450 mm irrigation and 340 kg ha(-1) N application, the total ESV generated by spring wheat farmland per season was [4.76, 4.87] x 10(4) CNY ha(-1). Among these ESVs, every 1 CNY ha(-1) positive ESV generation was accompanied by approximately 0.11 CNY ha(-1) negative ESV. Compared with the local FINS, the compromise decision, i.e., the FINS with 210 mm irrigation and 200 kg ha(-1)N application, significantly reduced negative ESV but caused slight losses in yield and positive ESV, while the maximizing group utility decision, i.e., the FINS with 210 mm irrigation and 260 kg ha(-1)N application, increased yield and positive ESV but resulted in a small negative ESV mitigation. Moreover, both FINSs could save irrigation water and N fertilizer resources, and improve water and N productivity to various degrees. This framework has excellent performance in reconciling conflicts among RFE systems and generating coordinated solutions and has potential to achieve sustainable development goals in agricultural RFE systems.