The underground drip that is in the oak and aspen trees, has never had a problem with root intrusion. When I planted the trees on the drip system, the possible problem of root intrusion was never brought up, nor thought of. However, after seven years, there has never been a problem. Harvey, I would think putting under ground lines in an area where there is already a tree crop would be difficult to do with out tree damage. In Denver, developers are installing drip on 1-foot centers under turf grass. The drip is laid on the soil surface, and the rolls of grass are laid directly on top. The system never waters the street, sidewalds, driveways, plus the home owner can water any time, even in the middle of the day, and during days that are windy, without evaporation loss. - Millet

Millet, as reported earlier, I haven't found any root intrusion problems either. I buried the inline drip emitters to help ease the landscape maintenance of our rental property about 7 years ago. I occassionally dug them to split using T or Y branch and never found root intrusion. My buried drip lines has pressure compensating inline emitters and remained clog free.

The idea of using underground drip in lawns, perhaps at 2" to 4" deep is something new that inspired me today. It has its definite advantages. Initially when you install the sod, you will have to water it with an overhead type that can be connected to the hose, once they are established, the underground drip will take over completely. Or to simplify things, install during the rainy season, to give time for the lawn to get established without watering, and then run the underground driplines during the drought times. There would be no mineral scale spots on cars, roses, and nearby plants, no broken pop-up heads and their frequent repairs.

Do you know how long such a system would last on lawns, given the current brands? I could experiment on various spacings, which primarily would depend on run time and flow rating of inline emitters. I know of a perfect spot to do it, and it will prevent spraying unto my apple and citrus trees. All I have to do is remove that sprinkler head, and connect a separate line for the area not reached by sprinkler head and use various configurations of underground drip.

Joe, a turf experiment is where I first read of root intrusion. Check out http://cati.csufresno.edu/CIT/rese/95/950104/index.html

By the way, how are my citrus doing that you grafted/budded for me? Are you getting my e-mails? I did surgery on an Ae Ae yesterday!

Thanks for that link Harvey. Well, turf grass has smaller roots than fruit trees and could explain why we haven't come across any intrusion yet. Are you growing grass or fruit trees?

Although it could be a potential problem with some fruit cultivars, like persimmons that have fine fibrous roots. But I don't think you'll have it with chestnuts.

Yes, some of the buds are pushing out already. I am still waiting for the clemenules to harden on the donor tree. Perhaps another week before I will graft the final item. You know, the other major factor to successful grafting is the quality of the scionwood source. It is the same with most other fruit trees like avocadoes.

My emails are sporadic. Some do not even make it into my spam folder.

Harvey, your link is interesting. I noticed the University test was in 1989, which in drip tape technology is light years ago. Joe, I am not sure what you mean by " buried my in line drip emitters". I have always (and only) used T-tape's brand. The clog free emitters are laser cut directly into the tape surface and are an integral part of the tape, not any type of an attached emitter. What you are talking about must be different. The life span of the tape under turf is probably directly proportional to the mill thickness of the tape. I purchased the thickest tape T-tape manufactured at the time, which was 20-mil. , it came with a 20 year guarantee. I think the thickest now is 15-mil. Once I used the thinnest tape they make, on a short summer crop, and had a ton of problem leaks, every day. The thin tape was a disaster. When we install our drip in the field, we raise the end of the tape above ground level. That way at the beginning of the irrigation season, we can un-cap the end, turn on the well, and flush out the lines. Then all we have to do is re-cap the end and go on about our irrigation for the year. - Millet

Joe, I've got a grass groundcover in my chestnut orchard. I'll probably plant grass in my pomegranate test plot once I have the bermuda grass, bindweed, and sedge under control. Since I don't have gophers and would like to keep it that way, I'm reluctant to plant clover, etc.

Millet (Bob), I believe root intrusion is still a concern in some crops. I read of a research project with buried lines in alfalfa that is more recent than the turf project, though the biggest problem in the alfalfa was that they had problems with a wet surface sometimes during harvest so the next phase went with lines that were buried 40 inches deep which worked out very well. I can't justify buried drip for alfalfa since my water source is so cheap and it would require a large capital investment. In addition, some spots of my open fields have a high water table and the design of such a system would be very difficult.

Harvey, around here drip irrigation for alfalfa is burried at 21-inches deep. Some of the farms around here have 30-inch rippers that they use to deep rip the ground, which then allows moisture from snow and rain to get down deep into the soil. However, ripping is always a chance. If one rips his fields and the weather turns dry for the season, then the soil is dry down deep, but if we get moisture ripping works well. - Millet