The latest issue of "Fruit Gardener" magazine:

vol. 32, no. 3, May/June 2000, published by California Rare Fruit
Growers; http://www.crfg.org

has a question in their regular "Ask the Experts" column (p. 20)
in which a reader comments on the readily apparent poor health of
the date orchards in the Coachella Valley of California.

The response was that the orchards are suffering from soil compaction
and poor soil. Growers are reacting by growing nitrogen-fixing cover
crops (vetch and cowpeas) to increase soil nitrogen, and reduce
soil compaction.

PS The column does not comment on organic vs. commercial date
orchards.

Tom Billings
http://www.beyondveg.com