conventional dry farming, Negev techniques

In conventional dry farming, once the winter rains are past, a roller is used to compact the surface and create a thin impervious layer over a moist sublayer, and or the surface is cultivated into a fine dust. Then the plants are space extra wide, and weeds are carefully controlled to insure enough water for each plant.

In the ancient Negev, hillsides were smoothed out, the rocks and vegetation (if any) removed, so that water would run into gently sloping channels and then flood over terraced level fields.

Are either of these practices "sustainable?" In the Negev, they lasted hundreds of years, until invasion, upheaval, and chaos destroyed them. So in a sense, the were "sustainable." However, was the amount of damage they did to the surrounding ecosystem too grave? Would it have eventually undermined the people's support systems?

I don't think that conventional dry farming is sustainable. Purposefully leaving vast acres of soil exposed to wind and water erosion is insane. There has to be a better way to utilize semi-arid steppes.

Runoff agriculture is most certainly sustainable. The catchment basins in the Negev are naturally barren. The only clearing done was inside micrcatchments, diamond shaped areas designed to water a single tree or shrub. The thing that was most disruptive of the ancient Negev system was flooding. The Israelis have come up with some modifications that hope to survive this threat.

Swales and keyline plowing are forms of runoff agriculture.

Agriculture is always a disruptive enterprise. All organisms alter their environment for their benefit. There is nothing inherently wrong with humans doing the same. We are capable of doing it in a more conscientious way, when conditions allow.

Referencing "Challenge of the Desert: The Negev", I was impressed at the scale they operated on. When you have catchment-production area ratios of 20-1 to 80-1 you can grow some very water intensive plants. What we're doing in the KSA, we're operating on a 2-1 ratio, and have been able to get the foundations of a silvopasture operation going on less than 3 inches of rain a year. I don't think we need to necessarily grow stone fruits and grapes the way they did in the Negev--but the baseline foundation of using a ratio of catchment to production is the only way to get things going in extremely arid areas.

Neal, those are excellent numbers. I hope you are able to entice copycats.

I stumbled upon the book, The Negev: The Challenge of a Desert, while browsing the stacks at the BYU library 36 years ago. I was fascinated by it and even investigated homesteading using runoff agriculture (the proportion of land required to be put under irrigated cultivation matched that used by the Nabateans almost exactly). Unfortunately, the rules were never going to allow it.

If you like reading about folks who scratched a livelihood out of dry, barren, but beautiful, wastelands, get a copy of Hiking, Climbing & Exploring Western Utah's Jack Watson's Ibex Country, by Michael R. Kelsey. You could consider it both inspiring and cautionary. You need to visit the area in order to fully appreciate what he accomplished.