Design of a drip system
in a pecan orchard
I am designing a drip system for a pecan orchard (50 acres). I do not
know where to start. Does anyone know of a good reference that would serve as a primer. I
really would like to have something that had the hydraulics of the system explained. Thank
Try the url, www.aces.edu/department/irrig/
There are a dozen or so extension circulars on microirrigation design and specific crop
systems under the heading "MICRO-IRRIGATION HANDBOOK". This has a southern
flavor but you may find it helpful.
Ted W. Tyson
Try NMSU pecan handbook available at http://www.cahe.nmsu.edu/pubs/_h/welcome.html
Dear Wesley, Give me a call at 1-800-527-4935 and I will discuss the drip
irrigation projects we have done on Pecans in both the US and Mexico.
Wesley, Rainbird's Landscape Irrigation Design Manual has a pretty good
introduction to pipe hydraulics (turbulent flow) with elevation and so forth, but it is
oriented toward residential and commercial landscapes and sprinklers. If the basic
hydraulics of turbulent pipe flow is what you need that would be a good start - and it is
probably free (or maybe around $5.00 US) at your local Rainbird supplier. I am sure Toro
has something similar. Years ago Hardie Irrigation (now owned by Toro) had a Micro-
irrigation design manual that had some good info - "barb" losses of punch-in
emitters, various sizes of polyethylene pipe and friction losses, and so forth.
Not sure if it available now. I will bet that Charles Burt may have
something out like this - as a publication, perhaps, or a book (http://www.itrc.org). I seem to remember something like
this - it may have been something Freddie Lamm and that excellent group at Kansas State
have done also. Check their websites for more (http:/www.oznet.ksu.edu/irrigate
Go to your local NRCS office they have design manuals for drip
hydraulics. Most of the suppliers like Rainbird and Netafim not only have design manuals
but computer programs also. The Irrigation Training and Research Center puts out several.
Just choose your poison
Wesley and other Trickle-L people,
I meant to reply to your earlier message, Wesley, regarding pecan
irrigation system design, but put it off until I could put my hands on some old pecan
irrigation papers I had written while I was in Texas. These might be able to help you in
terms of pecan irrigation design & system hydraulics. Here are some key concepts: *
because if is a tree crop, pecan water use has been reported both on a land area basis and
a per-tree basis.
On a land acre basis, water use will be close to what alfalfa is during
June-August. It is a tree that is fairly slow to leaf out, so early-season use will be
less then alfalfa. While the trees are young they only use a proportion of the water that
full-canopy trees do.
Once about 60% of the orchard floor is shaded at solar noon, full use has
been reached. Water use on a per tree basis has mudded the water since orchards are
planted at a wide range of densities (25 to 50 per acre is common), and will eventually
get thinned down to about 10 or 15 per acre.
This confusion is one of the reasons that so many of the pecan orchards in
arid areas were so poorly designed. * the papers that I have on design are:
1) Irrigation system design for pecans
2) Retrofitting micro-sprinklers into an existing drip irrigation system
for pecans in the arid West
3) Managing pecan orchards with limited water supplies
4) Design procedures for a drip irrigation system for pecans using drip
tape/tubing None of these papers are in electronic format and must be sent by mail. If you
are interested in getting copies I'll be glad to mail them to you. Please respond
privately (not on Trickle-L) with your name, address, etc. Finally, in my opinion there is
no better way to irrigate pecans then with SDI and I would encourage this.