<![CDATA[Regional integration of livestock manure into inorganic fertilizer planning requires explicit accounting of crop nutrient demand, manure recoverability, nutrient retention, and plant availability. This study developed a regional nutrient budget framework for Jember Regency, Indonesia, to estimate crop nutrient demand (CND), collectable livestock manure (LM), manure-derived nutrient supply (MNS), and residual inorganic fertilizer requirement (RIFR) for nitrogen (N), phosphorus (P), and potassium (K). Regional crop and livestock data were combined with crop-specific nutrient coefficients, manure excretion rates, dry matter fractions, collection efficiencies, nutrient concentrations, retention factors, and plant-availability coefficients. The selected crops required an estimated 32,478.0 Mg N, 5,770.8 Mg P, and 26,613.6 Mg K yr⁻¹. Collectable LM was estimated at 221,268.5 Mg dry matter yr⁻¹, providing approximately 1,087.0 Mg N, 775.5 Mg P, and 2,012.2 Mg K yr⁻¹ as plant-available nutrients. Crediting these nutrients produced estimated potential reductions in inorganic fertilizer requirement of approximately 3.35% for N, 13.44% for P, and 7.56% for K. Under the enhanced manure redistribution scenario, the modeled reductions increased to approximately 5.19% for N, 20.83% for P, and 11.72% for K. Sensitivity analysis identified crop nutrient requirement coefficients and target yield as the most influential crop-side parameters, while collection efficiency and plant availability were important manure-side determinants. The framework provides a transparent and reproducible basis for nutrient-specific regional fertilizer planning; however, the estimates should be interpreted as planning values rather than field-level fertilizer recommendations, with local implementation requiring additional soil, manure, spatial, and economic information.]]>
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