New Swale construction

I live on a moderately forested south-facing ponderosa stand and I'm trying to establish a food forest on the east side of the land.  Friday I brought in a Bobcat to do some dirt work and put in a 50' long swale, going down to the very shallow bedrock.  The area has about 6" of top soil, 12" of fractured decomposing granite and immature soils, then solid granite.  Frankly, how anything grows here is a miracle.  In the end we achieved a 12-18" rounded mound on the back side which I've covered with 3-4" of BOSS compost (local nursery mix of sheep, cow, and horse manure along with finer undigested material (mostly straw and some wood material). 

We removed three 14-20" ponderosas to clear the area which are now uphill but accessible.  While most of the tree material over 3" diameter will go to firewood for next winter, I'm planning on chipping the rest.  My question is should I use this wood and needle mulch (mostly smaller branches with needles) over my swale or am I risking making the soil too acidic for the plum, paw-paw, apple, raspberries, blackberries and blueberries that I'll be planting in the area?  Obviously the blueberries will love it the acidity, but I'm concerned about the needles making it too acidic for the trees.


Clearing the site


Constructing the swale


Scraping bedrock


Shaping the swale


Adding compost

you have a tractor. use that to make hugelkutur beds out of that wood.

hubert cumberdale wrote:
you have a tractor. use that to make hugelkutur beds out of that wood.

I have no heavy equipment.  The bobcat was a friend's and cost me $300 for the day for this and some other projects.  I have some other hugelkultur beds I'm working on, but that's not what I'm asking about in this thread. 

i myself dont know about the acidity levels and such.  but im impressed with the soil. it may be shallow but whats there sure looks good.  i like the pics.

Try this site:
http://yourorganicgardeningblog.com/let-nature-care-for-your-garden-with-pine-needles/

This one too:

http://tomclothier.hort.net/page24.html

Our apple, cherry, pear, and black currants seem to be doing fine so far, planted right next to huglekulture mounds comprised of conifers, and the ground having hosted conifers for what was probably eons.  They haven't been there long yet, but no adverse reactions so far.

Paul's recent podcast with Helen Atthowe discusses the effect of pine needles on the soil. 

http://www.richsoil.com/permaculture/143-podcast-012-helen-atthow-soil-conifers-fukuoka/

The pine needles will have very little effect on your pH, but the bark/wood may.  Most attempts to alter pH have short term effects (a few seasons at best).  The finer that you can shred the wood chips, the quicker their effect will diminish.  Once they have decomposed, your soil will revert back to the pH it was before their addition.

Endurance
It would seem like an awful waste if you did not use all those needles
and chipped brances, since the topsoil is so shallow there.
I have been using pine needles that our neighbors sweep up and want to burn !
Much of it has broken down and the soil is none the worse for it.
If you put in trees later will you try to make holes in that bedrock?
Is the swale above the area you will develop for the FF?

Thanks everyone for the input.  I hadn't listened to the recent soil podcast, but I had seen a recent post by Paul in TSP regarding the toxicity of pine trees.  After listening to the first part of the podcast today on my drive in to work and checking out a few of the links (thanks Kurt), I think I'm going to take advantage of the county's free aged mulch and chip up my branches and needles for future use.  It seems like planting new, young trees and shrubs and surrounding them with new needles and pines is likely to have an alleoplathic response.  By letting my mulch age a few months before using it, I should be able to avoid this and I can always use more mulch in the future.

Thanks for the feedback.  I'm planning on mixing in the compost I brought in, testing the soil's pH, and going from there.  If it's below 6, I'll likely amend with some wood ash, as I have plenty available.  Given that much of the soil is essentially sand (decomposing granite), any organic material will be welcome.  I have a few trees and 100 strawberry plants arriving this week, so I have too many priorities and not enough time.  Deer fence, irrigation (for the first year), mixing in the compost, bringing in mulch, planting the trees and ground cover... I'm in for a busy week!

@ Jen:  I have about 18" of topsoil at the height of the swale and below that is fractured granite (DG).  The ponderosas have found a way to carve out an existence and with the aid of the swale and some first year TLC, I suspect I'll have moderate success my first year.  In the long run, I plan on terracing 3-4 levels to my property line.  The average slope on the property is 10%, but it's as flat as 4% in some areas and up to 12% in other areas.  Eventually there will be more terraces and more swales, but this is year one with a 3 acres.  Right now my focus is getting one swale started with a dozen or so trees, shrubs, ground cover, and some grape and kiwi vines and putting in a small veggie garden before spring is over.  After that's established, I'll have time to focus on more construction.