The Great Irrigation Debate (Not exactly) - Robert Kourik and John Kempf - July 21, 2014
Here is the archive of this show:
Robert Kourik is edible landscaper and author of books on Drip Irrigation, Roots Demystified, and Designing and Maintaining Your Edible Landscape Naturally.
John Kempf is founder and CEO of Advancing Eco Agriculture which provides education on what makes plants reach their full potential, and provides plant nutrients.
The show turned out less a debate and more an in-depth discussion of making soil that supports plant immunity from pests and disease, for which water is a key essential element. It was agreed that fairly frequent (daily) irrigation makes sense, though for trees John Kempf thought less often made sense. I would say consider frequent watering when the tree is growing feeder roots: the several weeks after petal fall and again after buds are set for next year (in CA, late April-Late May and August) and less often in other times. One of the more novel (to the hosts) ideas was that of the 4-level plant health pyramid
of plant health and where various diseases and insect pests cannot get beyond. The first level, complex carbohydrates, will resist soil-borne pathogens like verticillium wilt, phytopthera to some extent. Aphid and whitefly and a number of soft-bodied pests (at the infestation level) indicate lack of proteins (second level not reached) that can be corrected with things like soft rock phosphate, oystershell lime, gypsum; and for trace minerals, Azomite, kelp meal, or greensand (or in some cases specific trace minerals if indicated by a soil test). Beetles are harder to repel and require not just lipids (level 3) where air-borne pathogens are stopped (mildews) but also Plant Secondary Metabolites (like essential oils). To acheive level 3 and level 4, the soil biology is key.