# Nutrient process science

TerrainLogic explicitly represents major nitrogen and phosphorus processes using published crop, soil, hydrology, erosion, fertilizer, manure, and nutrient-loss science. Formulation, transformation, placement, crop uptake and removal, residue return, biological fixation, runoff, leaching, gaseous loss, and multiyear state continuity are represented at a planning level.

Implementation and mass-conservation tests pass. Independent observational support varies by process and applicability domain; the public [Nutrient Validation: Protocol and Findings](nutrient-validation-findings.md) report provides the scored evidence, failures, limitations, and source literature.

Exact equations as assembled in TerrainLogic, production coefficients, pool/state routing, fallback behavior, detailed corrections, internal artifacts, and counterfactual implementation experiments are maintained as confidential ContourStack R&D records.