{
  "schema": "irrigation-controller-v1",
  "version": "1.0.0",
  "author": "arthur-ibay",
  "date": "2026-07-17",
  "location": "Salt Lake City, UT",
  
  "theory": {
    "primary_equation": "V_required = (ET₀ × Kc × A_root) − SM_deficit",
    "runtime_equation": "T_pump = V_required ÷ Q_pump × 60",
    "units": {
      "ET₀": "mm/day",
      "Kc": "dimensionless",
      "A_root": "m²",
      "SM_deficit": "liters",
      "Q_pump": "L/min",
      "T_pump": "minutes/day"
    },
    "sources": [
      {
        "id": "Q5187947",
        "slug": "crop-coefficient",
        "description": "property of plants used in predicting evapotranspiration",
        "url": "https://4ort.xyz/entity/crop-coefficient"
      },
      {
        "id": "FAO-56",
        "title": "Crop Evapotranspiration: Guidelines for Computing Crop Requirements",
        "authors": "Allen, Pereira, Raes, Smith",
        "year": 1998,
        "publisher": "FAO Irrigation and Drainage Paper No. 56"
      }
    ]
  },

  "crop_coefficients": {
    "leafy_greens": {
      "lettuce_early": {
        "Kc": 0.95,
        "stage": "initial canopy",
        "days_after_transplant": "0-14"
      },
      "lettuce_midcanopy": {
        "Kc": 1.15,
        "stage": "peak photosynthetic",
        "days_after_transplant": "15-35",
        "peak_demand_mm_per_day": 4.2
      },
      "spinach": {
        "Kc": 1.05,
        "stage": "mature",
        "notes": "shade-intolerant, requires frequent misting"
      },
      "arugula": {
        "Kc": 0.90,
        "stage": "harvest-ready",
        "notes": "low water demand, drought-resistant"
      }
    },
    "fruiting": {
      "tomato_established": {
        "Kc": 1.10,
        "stage": "flowering onset",
        "days_after_transplant": "40-60"
      },
      "tomato_fruiting": {
        "Kc": 1.15,
        "stage": "fruit fill",
        "days_after_transplant": "61-90",
        "peak_demand_mm_per_day": 6.8
      },
      "pepper": {
        "Kc": 1.05,
        "stage": "fruit development",
        "peak_demand_mm_per_day": 5.4
      },
      "cucumber": {
        "Kc": 1.20,
        "stage": "vine maturity",
        "notes": "highest water demand of common solanaceous crops"
      }
    },
    "grains": {
      "wheat_initial": {
        "Kc": 0.40,
        "stage": "emergence to tillering"
      },
      "wheat_midseason": {
        "Kc": 1.05,
        "stage": "booting to heading",
        "peak_demand_mm_per_day": 4.8
      },
      "corn_early": {
        "Kc": 0.50,
        "stage": "seedling"
      },
      "corn_peak": {
        "Kc": 1.15,
        "stage": "silking",
        "peak_demand_mm_per_day": 7.2
      }
    }
  },

  "operational_limits": {
    "optimal_duty_cycle_minutes_per_day": 30,
    "warning_threshold_minutes_per_day": 90,
    "critical_failure_minutes_per_day": 120,
    "recommended_pulse_frequency": 4,
    "pulse_interval_hours": 6
  },

  "field_notes_wasatch": {
    "trial_date": "2026-07-10",
    "location": "Great Basin foothills, elevation 1,400m",
    "crop": "lettuce",
    "observed_ET0_july": 5.2,
    "actual_Kc_measured": 1.15,
    "pump_spec": "12 L/min diaphragm",
    "area_serviced": "50 m²",
    "computed_runtime": "11.0 minutes/day",
    "validation": "confirmed via soil probe gravimetric sampling"
  }
}