Water-Energy-Food-Nutrient-Carbon Nexus Analysis for Agronomic Systems // Provides functions for analysing Water-Energy-Food- Nutrient-Carbon (WEFNC) nexus interactions in agricultural production systems. Includes functions for computing water use efficiency (WUE), water productivity (WP), and water footprint (WF) including green, blue, and grey components following the methodology of Hoekstra et al. (2011, ISBN:9781849712798). Includes energy budgeting tools for energy use efficiency (EUE), energy return on investment (EROI), net energy (NE), and energy productivity (EP). Computes nutrient use efficiency (NUE) metrics including agronomic efficiency (AE), physiological efficiency (PE), recovery efficiency (RE), and partial factor productivity (PFP) as defined by Dobermann (2007) https://digitalcommons.unl.edu/agronomyfacpub/316/ and Congreves et al. (2021) doi:10.3389/fpls.2021.637108. Estimates carbon footprint (CF), greenhouse gas (GHG) emissions, soil organic carbon (SOC) stocks, and global warming potential (GWP) using Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) default values (CH4 = 27, N2O = 273) as reported in Forster et al. (2021) doi:10.1017/9781009157896.009. Computes composite Water-Energy- Food-Nutrient-Carbon (WEFNC) nexus indices, trade-off correlation matrices, and generates radar and heatmap visualizations for comparing agricultural treatments. Supports conservation agriculture (CA), irrigated and rain-fed systems, and arid and semi-arid production environments. Methods follow Lal (2004) doi:10.1016/j.envint.2004.03.005 for carbon emissions from farm operations, and Hoover et al. (2023) doi:10.1016/j.scitotenv.2022.160992 for water use efficiency indicators.