calcular el PH de suelo

def ph_calc(soil_type, calcium_level):
  if soil_type == 'clay':
    if calcium_level < 1000:
      return 5.5
    elif calcium_level < 3000:
      return 6.5
    else:
      return 7.5
  elif soil_type == 'loam':
    return 6.5
  elif soil_type == 'sand':
    return 7.0
  else:
    return 'invalid soil type'
    
ph_calc('clay', 2500)