Hello,
I have a tree and I want to sense the soil moisture from the surface up to 1 meter depth. I found this here:
soil-moisture-sensor
but it does not go up to 1 meter depth. Any solutions?
Also, how do I measure the Evapotranspiration of the tree? Can you help me?
Thank you...
Dig a hole, place sensor with long enough wire inside, fill back up.
Before doing so, find a sensor that will last longer than the few days, maybe weeks, this one lasts. There are capacitive soil moisture sensors out there (no electrolyses on those), some are even waterproofed (you'd never think that would come in handy when doing soil moisture measurements!).
I had to look up the meaning... never heard of the word... but some methods for measuring evapotranspiration can be found on Wikipedia.
Here's a link to the Van der lee vineyard blog.
The owner of the vineyard developed a system to control irrigation there which led to him set up a company to market the tech he developed. One of the components is a moisture sensor which lets him get readings at various depths which look easy to make yourself.
I am searching on google many hours now, but I got more confused.
This guy here:
evapotranspiration
talks about scintillometer.
Can I use scintillometer for measuring Evapotranspiration of the tree? Because I see articles about scintillometer and gamma cosmic rays...
cosmic rays
Thank you..
Someone who has experience and can help me?
Thank you...
If I use multiple soil moisture sensors the one under the other inside the soil of the tree, I should get the soil moisture to the the range surface (0 meters) to 1 meter depth as I need, right?
Also for evapotranspiration, if I use multiple humidity sensors (ex. DHT11) from surface up to peak of the tree, I believe I could measure something about that right?
It used to be called trans-evaporation if you're talking about water vapor leaving leaves.
Find a light bandwidth that water vapor will absorb and there's an LED that puts it out and see what differences you can detect using spectral absorption.
I guess it's not enough to measure sap transported up and divide by leaf area?
GoForSmoke:
It used to be called trans-evaporation if you're talking about water vapor leaving leaves.
Find a light bandwidth that water vapor will absorb and there's an LED that puts it out and see what differences you can detect using spectral absorption.
I guess it's not enough to measure sap transported up and divide by leaf area?
What you suggest reminds me something like a LIDAR?
Here it says:
LIDAR
Raman LIDAR
Raman scattering is the theory of light scattering by molecules, where the wavelength is changed by the scattering. The change in wavelength depends on the temperature of the air and the type of molecule from which the scattering takes place. At Capel Dewi near Aberystwyth, Mid-Wales, a Raman scatter lidar is used to measure water vapour concentration and air temperature.
can this work with what I want to do?
It's a different principle. It might work better.
alex5678:
...how do I measure the Evapotranspiration of the tree?
This is something that I have never seen on this list before.
It would seem to me that the weather will have a much greater impact on the readings.
someone washing their car nearby will effect the humidity in the air and that would be registered on any device sensitive enough to measure the moisture leaving the tree.
If you were to take a plot of land around the tree and sink cassons to prevent roots from getting water from any other source
then make an identical area of land, with the same soil.
then water them both with equal amounts of water
then monitor soil moisture
you could find that the tree will take more water from the soil than the control plot.
the difference would be the water the tree uses.
of course you could just use a plot of land without a tree and get an idea of the difference.
Or you read humidity just over leaves vs humidity 1 meter away and the car wash humidity becomes baseline.
I have found this paper here:
Raman LIDAR
who use a Raman LIDAR for their experiments. I suppose it is expensive machine. Is there a way to construct a Raman LIDAR using non-expensive equipment, laser, phototransistor etc, as happens with most hobbyist construction/DIY? What theory should I follow?
GoForSmoke:
Or you read humidity just over leaves vs humidity 1 meter away and the car wash humidity becomes baseline.
read humidity in 6 places around the perimeter of the tree
read humidity in 3 places inside, near the trunk.
use wind direction.
the more data, the more opportunity to know what is happening.
most science uses lots and lots and lots of sensors, then figures that some few things can represent the whole.
This guy here:
sensor
says:
A scintillometer seems doable as diy. For an area like a tree, I'd start with a laser diode ( i dont know which frequency, but as a complete guess id try infrared, possibly red, and stay away from green and blue), the other end would be either a phototransistor or a photocell. A low noise (probably high gain) amplifier and a quality anolog to digital converter (maybe a 24 bit sound card, probably a pi zero attached not an arduine or esp)
Can this be done with Arduino somehow? I am googling it also...
Thank you...
What do current humidity sensors do?
As the poster in that link correctly stated: it's speculative.
I'm not really sure what they had in mind but doesn't sound like a possible Arduino project. It appears they want to sample at high rates for lots of data and then do some serious maths.
dave-in-nj:
read humidity in 6 places around the perimeter of the tree
read humidity in 3 places inside, near the trunk.
use wind direction.
the more data, the more opportunity to know what is happening.
most science uses lots and lots and lots of sensors, then figures that some few things can represent the whole.
Hello, how wind direction could help?
Also in #13 dave-in-nj suggests a number of humidity sensors. I have installed 2 DHT11 to measure the humidity. How I decide what is the best number of humidity sensors that I should install in order to measure evapotranspiration. Is there a formula for this? An equation?
Thank you