Working in salt

Irrigate a hot soil and the water evaporates; what was dissolved in it does not. Salt concentrates in the rooting zone, and each season it concentrates further. At Al Jouf in northern Saudi Arabia the water arrives clean from the Jordanian mountains and picks up its salt on the way, passing beneath a desert that was once sea bed.

Zander humus works against this in a way that is physiologically documented rather than merely asserted. Its cation exchange capacity of 200–300 meq/100 g gives it an enormous appetite for ions; it holds water at around 200% of its own volume; and it enables greater calcium uptake, which protects plant cell membranes from salt damage.

The practical consequence, from the Al Jouf olive trial: trees standing in soil roughly six times more saline than the conventionally farmed control matched that control's growth by the end of the season. In a trial with Al Ain Municipality, one of the 300 trees planted stood at close to 22,000 ppm salinity.

Studies in Russia and Ukraine show the buffering holds for at least nine years — long enough to get a plantation established, which is the whole battle.