permaculture

[jedd <jedd@progsoc.org>]

 Hi Antonio,

 ] unfortunately I have not yet planned what roostocks I might/should, 
 ] use nor which ones available locally.

 As much as you can, ignore the limitations of local availability, and
 keep reminding yourself of the planned longevity of this orchard
 (ie. a few months effort or delay is worth the bother).

 An orchard where you're irrigating on zones, and those zones may
 be interspersed throughout the area, rather than strictly adjacent to
 each other, as it were .. might lend itself to fruit salad or
 multi-graft trees.  This spreads out the benefit of irrigation over
 the year, and was something I was considering to ease the problems
 of having to individually tailor water requirements per tree.

 To clarify - rather than have a number of early, mid and late
 ripening trees of the same type - have grafts of each of the several
 varieties on each of the trees.  Effectively all species crop at the
 same time, and that time is quite lengthy because the varieties
 are cropping sequentially.

 Obviously this involves more maintenance work, particularly early
 on, and an extra dimension to the planning phase as you work out
 comparable varieties (in terms of vigour, mostly) that can politely
 share a root system.

 In addition to potentially simplifying your irrigation, you have
 added benefits from reduction in alternating years (grapefruits,
 and some other citrus have this tendency), less impact from any
 seasonal variances on overall productivity, and if you decide you
 really don't like one particular variety .. you just cut that type
 off all the trees, rather than having to pull out several trees.

 ] Soil has 4-5% slope, we are talking about duplex clay soil 

 I'm guessing you're doing earthworks (diversion drains, swales,
 terraces, whatever) prior to planting?

 ] We have 575mm average rainfall each year, with summer temperatures
 ] reaching easily 40-45º C (southern Spain) zone 10 and mild winters.

 Very similar profile to me - though we get into 9b here (inland from
 Sydney, Australia) and slightly warmer summer temperatures.

 ] main rainfall happens during fall (October through genuary) although there 
are
 ] wet spells untill may. Main dry months are June through september.

 Stick with seasons!  (Easier for us southerners to deal with :)

 ] In some spots the acuifer is quite shallow (1,2m)

 What do the locals say about the history of this .. ie, is it moving,
 does it sometimes disappear, is the quality of the water changing?

 Also some trees really dislike having perennially wet feet.

 ] ... and a huge peccan, where I think the
 ] acuifer is closest to the surface.

 Pecans typically spend their first few years sending down a huge
 taproot until they find groundwater, and then start to grow top-side
 (IOW, I doubt that it'd care if the aquifer was several metres deep).

 ] I'd like to plant, figs (of course), peach, plums, nectarines,

 Note that many pome and stone fruits have chill requirements, so
 you'd need to be careful with your selection of varieties .. and maybe
 consider specific locations for certain ones (frost pockets for the
 varieties needing the most chill).  Have you worked out how
 many hours of chill you get there?  If you're zone 10, mild winters,
 it might really limit your choices.  If you're preparing for the
 continued increase in average temperatures in your part of the
 world, it'll be even more limiting.

 With walnuts - their roots exude a substance (juglione?) that can
 hinder neighbouring plants' growth - in some cases quite severely,
 tomatoes, from memory, are particularly susceptible.  This effect
 can extend for 50 metres, and can out-last the life of the tree by
 some years.  I believe black walnut (J. nigra) is especially bad
 in this regard.

 ] pistacho, (maybe wallnuts and hazelnuts), jujube,
 ] cherries, apricots, avogados, almonds, kaki, mulberries, and
 ] any other drought tolerants species that I can come across.

 With your climate and your apparent passion .. you may want to
 consider some of the Eugenias - E. brasiliensis (Grumichama),
 and E. uniflora (Surinam Cherry) - the latter can be a bit invasive,
 works well as a hedge, etc.  Grumichama and jaboticaba and many
 of the other sub-tropical fruits that grow well in zone 10 and above
 could be worth some experimentation.  You may find that although
 they tend to be thirstier plants, once established (and with their
 feet in the ground water) they require little effort to maintain.

 Jedd.