Difficult soil.. prep?

[bobm]

Rick F. what you have is known as "hard pan" . On our 20 acre ranch outside of Fresno, the hard pan is situated from on the soil surface ranging down to 5 feet down. It can be as thick as an inch to 12++ inches thick. The San Juaquine Valley was a high desert before water canals were brought in for irrigation. The first orchards were planted in the 1950s, but they had to drill 1-2 in holes in the soils down to about 4 feet down, drop sticks of dynamite down the tree row lines and set the dynamite off to break up the hard pan, then level the dirt back in and plant the orchard trees. Now, on my ranch, I hired 3 D9s to rip the soil down to 3 feet, then level the land with a land plane , then planted pastures. I have 2 acres of land cut off the rest of the property by a creek for our house site, so I had a bob cat drill 3 side by side holes down to 42 inches which were through the hard pan to sandy soil benieth that depth. However, there was an area where I had to use a wrecking bar and a shovel to dig down to 5 feet to get through it. I then planted 100 Redwood trees ( now 30-40 feet tall and doing well ) as well as several types of fruit trees. I also installed 4" sewer line pipe down to 42"( sewer line pipe is 10 feet long , so cut into 3 pieces ) depth into the holes before I back filled, then installed an underground drip system to all of the trees with the drip emitters at the top of the sewer line pipes. This forces the trees to grow their roots far down to get water moisture as well as a better and deeper root anchor system. I hope that this helps you .

 

[catjac1975]

Rick F. what you have is known as "hard pan" . On our 20 acre ranch outside of Fresno, the hard pan is situated from on the soil surface ranging down to 5 feet down. It can be as thick as an inch to 12++ inches thick. The San Juaquine Valley was a high desert before water canals were brought in for irrigation. The first orchards were planted in the 1950s, but they had to drill 1-2 in holes in the soils down to about 4 feet down, drop sticks of dynamite down the tree row lines and set the dynamite off to break up the hard pan, then level the dirt back in and plant the orchard trees. Now, on my ranch, I hired 3 D9s to rip the soil down to 3 feet, then level the land with a land plane , then planted pastures. I have 2 acres of land cut off the rest of the property by a creek for our house site, so I had a bob cat drill 3 side by side holes down to 42 inches which were through the hard pan to sandy soil benieth that depth. However, there was an area where I had to use a wrecking bar and a shovel to dig down to 5 feet to get through it. I then planted 100 Redwood trees ( now 30-40 feet tall and doing well ) as well as several types of fruit trees. I also installed 4" sewer line pipe down to 42"( sewer line pipe is 10 feet long , so cut into 3 pieces ) depth into the holes before I back filled, then installed an underground drip system to all of the trees with the drip emitters at the top of the sewer line pipes. This forces the trees to grow their roots far down to get water moisture as well as a better and deeper root anchor system. I hope that this helps you .

Wow that is dedication. So, does the hard pan break up and get mixed with the sandy soil? Or is it removed?

 

[RickF]

Thanks.. I dug some pretty deep holes in the aforementioned raised planter and didn't seem to find any caliche at least beyond about 2' down and drainage seemed vastly better. We'll see.. I'll have to do some toying around in the first holes I dug.. As long as I dont sleep walk outside and fall in them...

 

[RickF]

Ok.. So it's been almost a year since I started this thread. We've had a good amount of rain this winter so far (5.6") considering I'm in the high desert on the edge of Los Angeles county. Anyway, I never bothered to fill in these two holes -- they were left open for all these months. Yesterday I was out cleaning sycamore leaves up in the backyard and noticed there were NO puddles in these holes when I was expecting to see some. Sure, they had lots of old leaves and other stuff that was blown in over the months. However, today I went out with the breaker bar and pointed shovel and cleaned out the old stuff and got down to the hardpan/caliche layer. I took out the breaker bar and started whacking it pretty well with the pointy end and I noticed after a bit that it appeared that the bar was sinking down further than I expected. So, I started extracting more dirt and using the breaker bar more and this is the result :

I'm not sure exactly how thick the hardpan/caliche was but I'd guess a good 6" perhaps? The sides are easy-peasy to excavate now -- I will NOT be putting any of the old dirt/hardpan back in the hole -- it's going to the dump. I will try my best to widen the hole to perhaps double what it is now (it's probably about 18" wide now I'd guess... I will NOT be putting any apples in -- I ended up planting them elsewhere. I'll have to find something that will be happy out here..

 

[RickF]

I should state that I might opt to build a cinder block planter around these holes to raise the trees off the ground a bit -- or perhaps I'll just do something seasonal for now till I know what I want to do with these guys.. thoughts would be, obviously, greatly appreciated!

 

[flowerbug]

if you're going to plant more hardy and drought tolerant trees you shouldn't have to mound anything (and i wouldn't in an arid climate anyways).

what are you going to plant?

 

[RickF]

I don't know yet.. I think the two holes are about 5-6' apart and if I can make an oblong planter encompassing the two holes and put veggies in the middle -- but I'd love to have the planter to a height of perhaps 3'.. Perhaps the first year I'll opt to not have any trees but to just have seasonal plants. I was poking around on the Arizona Native Seed Search and found some stuff on there that I'd like to try out as in large part Arizona ought to be similar in climate to where I live (aside from the monsoon season anyway).

 

[ducks4you]

Have you contacted your local extension office for help? THEY would know better than we would what is possible to grow there.

 

[RickF]

I may have to see what extensions are around here.. I know in general I can grow pretty much whatever can be grown in Arizona in large part -- but have to be careful for cold stuff as we do get down to the mid 20's here in the winter. I do know enough now that blackberries while they can live here, its not their fave place and they tend to get bugs chomping on them a lot.. Not worth it..

 

[RickF]

On a side note, we got a LOT of rain last night and I had dug some of my holes out a bit more a few days ago.. This is what I found this AM -- obviously the drainage rates are different between these two holes that are about 5-6 feet apart. If you have any ideas on what the scum is on top of the first pic I'd love to know as it's not the first time I've seen it. Both holes are about the same depth -- the 2nd pic is perhaps about 6" shallower -- but the first image is dug to a depth of 36".. The water level is perhaps about 4-5" from the top of the hole. I had started to dig out the outline of the planter which is why you see various levels.