What problem does it solve? Running the APSIM Next Generation crop model correctly requires deep operational knowledge: converting global weather and soil datasets into APSIM's exact .met and layered soil formats, avoiding fatal unit traps (radiation in W/m² vs MJ/m², temperature in Kelvin, population per hectare vs per m²), assembling valid .apsimx JSON, and recovering from silent failures. This Skill externalizes that expertise so an AI agent can run, check, and validate real APSIM simulations end to end. ## Core Features & Use Cases - Deterministic pipeline tools: Five scripts cover the full workflow — convert_soil.py (HWSD/SoilGrids to APSIM soil JSON), convert_met.py (CMFD/NASA POWER/ERA5 to .met), build_apsimx.py (assemble .apsimx), run_apsim.py (execute the real .NET 8 binary), and parse_output.py (SQLite .db to CSV). - Diagnostic recovery: A preflight check verifies the binary, .NET runtime, and Python environment, and 20 symptom-to-remedy diagnostic triplets map known failure modes to fixes. - Validation conventions: dag.yaml defines headline outputs (Grain.Wt in g/m²) with obs-shape-aware metric rules, including mandatory detrending when comparing point simulations to regional yield aggregates like FAOSTAT or SPAM. - Use Case: Simulate wheat yield at a field site by converting NASA POWER weather and HWSD soil data, running APSIM with auto-sowing rules, and scoring grain yield against FAOSTAT national statistics with PBIAS and detrended correlation. ## Quick Start Run python preflight_check.py in this directory to verify the APSIM binary and environment, then ask the agent to simulate wheat yield at your site using the pipeline tools.