1. The water system would have to be metered so that the same amount of pressure was available at the top as at the bottom or you would end up with almost no water at the top – “low pressure,” and too much water at the bottom, known as “high pressure.”

2. Porosity of the soil would/could be an issue. A soil aggregate test could help determine this.

3. Organic irrigation management would mean an overhead sprinkler system. Then it would not matter in which order, or about porosity, because under an organic system the available water would be held in the compost/duff layer.

4. Leafy green annual vegetables with short root systems (lettuce, beans, peas) need more frequent watering than deep rooted, perennial and tuberous plants.

5. I think light, soil and air circulation (in that order) are far more important than irrigation as some crops take longer and others only grow during the rainy cool seasons. On extreme slopes erosion control can be an issue and thus terracing is a consideration.