Topic: Going underground.

[dj1111s]

I will soon be ordering the leaf wetness sensor along with the wireless soil temp and moisture station.  I'm sure there are many previous posts on this topic but what I'm after is the latest greatest up to date recommendations for the depths of the sensors.  I'm not a farmer or gardener so I'm not really doing this for me but rather to help others that could use the data.  Ok, I will find it fascinating to see what the sensors report over the seasons/years.    And yes more importantly it will help feed the obsession. 

I have found websites that give advice on depths but they don't all agree.  And some are very specific for different types of farming.  And one source that was mentioned recently on this forum shows depths for only 3 sensors, not 4.

My soil is pure red clay starting at no deeper than 12".  I've been thinking of depths for the 4 sensors at 6", 12", 24" and 36".

Thanks, Dan

[Skywatch]

6, 12, and 24 inches sound good. That's about where I have mine. As you've probably read before the moisture and temperature probes need to be sited together when buried. As far as leaf wetness sensors I think it varies from user to user. I have my leaf wetness sensor installed 3' above the ground on a 1/2" PVC pipe in the veggy garden.

Davis recommends installing in the planting area between plants but not sheltered.

[Aardvark]

I have mine at 4,12,18,36 inch depth.    It gives me a better idea of soil saturation and temperature. This winter I was able to see how deeply the ground was frozen.  and then I am able to take that data and  get a decent plot over time as to the conditions.  I think it gives one a good picture of the soil conditions.  http://www.desmoinesweather.org/RainGraphs/soil_history.htm

[SLOweather]

In another thread I posted these links:

http://waterquality.montana.edu/docs/irrigation/deep_roots.shtml

http://waterquality.montana.edu/docs/irrigation/shallow_roots.shtml

They have tables for several soil types, and recommended burying depths. The table then tell you how much water is available in the soil in inches.

FWIW, somewhere here on WxForum I also posted my method of using Class 315 PVC glued to the sensor, with the temp probe inside the pipe and cales run up the pipe, so that the probe can be easily inserted in a hole in the ground made with auger or driven rod.

[kcidwx]

We start out at every 3" then go every 6". Just depends on the number of probes.

[dj1111s]

Thank you for all the great and "confirming" advice.  The next thing to think about is location.  I have a very "varying" yard as far as terrain, shade and sun exposure.  There are spots that stay green all summer and some that dry up the instant we have a bit of a drought going.  I also need to think of sun light for the solar panel.  The ideal spot would be in the same location as my ISS but it is on the high end of a slope.  Judging by the greenness of the grass throughout the summer it is not a spot that gets dry particularly fast.  Another good spot would be to the east of this, where it gets full sun from about 7 in the morning 'til 7 at night.  But it is an area that typically gets very dry by August.  There are other spots that get good sunlight but they are far from the house and in areas where neighbors outdoor recreation can spill over onto our property.  How did you guys spot the location for your sensors?

Dan.

[moehoward4]

Just remember....the cable lengths on the temp and moisture probes are only 15 feet. You can use the 7817 temp sensor, just cut the end off(plug end!!) and twist the red and black together, then the green and yellow together ( tin them) and insert the pairs into the station. It makes no difference which pair goes into each slot. I used this method for a couple of years ( I had 2 7817's kicking around ) with no problems. Just a suggestion.....

[smorris]

For something completely different, I've got two sets of sensors buried in the lawn at 2" and 4", and a third set of sensors buried at 10" in my vegetable garden.

We have very sandy soil, so my garden boxes are raised 10" filled with a very rich mix of soil. (see image on the web site linked in my sig.) I can "watch" the moisture move through the soil and know when it is drying out.

The two sets of sensors in the lawn let me know the condition of my turf. But that's not why they are at those specific depths. A local meteorologist contacted me and asked about my soil station. I originally had just one set of each sensors when I was doing a review for Davis, and after purchasing the unit, I added two temp and moisture sensors. So when he wrote, I hadn't buried the addition ones yet, and wasn't sure how deep I was going to place them. He suggested the 2" and 4" depths until I decided how I wanted to use them. These depths are what meteorologists use in early winter to help in their estimation of when the first snow accumulations will occur.

So I've just left them at those depths, since they are useful for turf health in the summer and to him in the winter.

Steve

[SLOweather]

Just remember....the cable lengths on the temp and moisture probes are only 15 feet.

However, according to the Wireless Leaf & Soil Moisture/Temperature Station Installation Manual, the soil moisture probes can be extended up to 1000' using 18 ga wire, and the temp probes up to 800' with 24 ga wire, or 1200' with 22 ga wire.

[wxtech]

I wanted the top sensor to measure surface soil temperature.  So I buried it at 2" with just enough soil to block the direct sun.  The entire area was covered with mulch to prevent grass covering the area.  The bottom sensor was buried as deep as my post hole digger would reach.  I was searching for a depth to measure where the temperature wouldn't vary daily.
The sensors are a few inches long, so they need to be buried horizontally.   I tied the sensor cables to a long wooden stick so that the sensors could be better managed (accurate depth) as I was burying them.  The sensors were then laid at right angles from the stick.  A note on the stick above ground is a notice what is buried there.  18/8 lawn sprinkler wire makes good extension burial wire.
Soil temperature was reported on my weather web site for several years and I never received a single comment about soil temperature. 

[Breezy]

My Davis Leaf and Soil Moisture/Temperature station assembly has been built and has undergone indoor testing for the past 2 months. It is currently attached to the back deck. Hopefully the frost will be out of the ground by April 25th when the burial date is planned with a soil page publishing date set for May 1st. My sensors will be placed at depths of 4", 12", 24" and 36". I've included a few pictures of the station assembly.

The best to all from Hessville, NY, USA ...

Jeff

[Breezy]

It's buried and up and running. The soil page can be seen at http://indiantrailweather.com/wxsoil2.php

Jeff

[Skywatch]

Looking good. Looks like a solid setup.

[dj1111s]

Thanks again for all the great advice and examples.  I just received my soil moisture, temp and leaf wetness station on Thursday.  Excellent and fast service again from Ryan.

I really like Breezy's all in one setup.  Would make installation a "Breeze" .  My problem is my soil is pure clay starting at 10 to 12 inches deep.  Digging is a big pain and considering for future maintenance I have to think about digging them up/pulling them out.  There is no such thing as carefully digging in hard clay to find the sensors.  Slamming the post hole digger into the ground to try to get it to penetrate as deep as possible is the typical method.  I'm looking at using the methods in the Davis instructions for the 2 deeper sensors using a metal pole to poke slightly oversized holes for the sensors instead of digging.  I'll mix a slurry of clay to pour in the holes before inserting the sensors to eliminate air pockets that would otherwise take time to fill in.  The 2 shallower sensors should end up in topsoil.

[dj1111s]

Well I finally got my soil/leaf station and all its sensors installed.  OMG what a pain dealing with the clay to bury them.  But they are all sending data now.  I was really impressed with the fact that just after setting my console to receive from the station, and verified all the sensors were working, I went to WU and the new data was there also.  Really cool when everything cooperates.

One question.  When I look at the data in Weatherlink, where it's now showing the "extra sensors", it's also reporting leaf temperature.  In Weatherlink setup I don't have those selections checked.  http://www.weatherlink.com/user/ptlycly/index.php?view=summary&headers=1