PH Probes

[tdawgcj7]

I'm considering purchasing a Soil PH meter and wonder if anyone has had any luck with these types of devices. I have done soil tests in the past and added lime, but want to see where my PH is now.
Thank you for your input.

Justin

 

[SwampCat]

I had one of the inexpensive probes - maybe $15/$18. It showed a pH of 7.5. I had a low end chemical soil test kit - it showed a pH of 7.5. NRCS soil test showed a pH of 7.5. Consistent all across the board.

 

[finahol]

The biggest issue I have found with the probes is that the soil must be moist and that it takes a minute or 3 for it to stabilize. Otherwise i have found mine to be quite accurate. Mine is digital, I believe Rapitest is the brand. Beware, the probe is a bit fragile. Friends that borrow it have had to replace it a few times whem punching it into rocks a bit too over zealously.

 

[tdawgcj7]

got my probe and tested in my new plot where my rape is just starting to come up.

 

[Bill]

That’s interesting..
I always thought they were like snake oil so I never tried one.

 

[yoderjac]

That’s interesting..
I always thought they were like snake oil so I never tried one.

It is not that they don't work, it is that they are not very practical. They work great in the RM containers I uses to grow trees. The problem is that pH can vary quite a bit. When we take soil samples, we take them in many spots in the field and mix the soil and at root depth. Many folks don't do sufficient sampling. A soil test is measuring the average (for everything they measure).

One would need to do something similar with a pH meter, walking through the field taking samples at multiple spots and multiple depths to get an average. I think the correct way is to do what the lab does and mix the samples and apply water that you know is neutral and then test the solution with the meter. There is also more that goes into a lime recommendation from a reputable lab. In addition to your soil type and your crop, they will ask about when it was previously limed and how much. With my soils, they tell me to apply no more than 3 tons/ac in one application and then wait 6 months and apply the rest.

So, I think a pH meter is fine for giving your confidence that your lime application is moving the pH in the right direction, but it is not a substitute for proper sampling and a recommendation from a good lab.

Thanks,

Jack

 

[tdawgcj7]

That’s interesting..
I always thought they were like snake oil so I never tried one.

It is not that they don't work, it is that they are not very practical. They work great in the RM containers I uses to grow trees. The problem is that pH can vary quite a bit. When we take soil samples, we take them in many spots in the field and mix the soil and at root depth. Many folks don't do sufficient sampling. A soil test is measuring the average (for everything they measure).

One would need to do something similar with a pH meter, walking through the field taking samples at multiple spots and multiple depths to get an average. I think the correct way is to do what the lab does and mix the samples and apply water that you know is neutral and then test the solution with the meter. There is also more that goes into a lime recommendation from a reputable lab. In addition to your soil type and your crop, they will ask about when it was previously limed and how much. With my soils, they tell me to apply no more than 3 tons/ac in one application and then wait 6 months and apply the rest.

So, I think a pH meter is fine for giving your confidence that your lime application is moving the pH in the right direction, but it is not a substitute for proper sampling and a recommendation from a good lab.

Thanks,

Jack

Thank you for the input.

 

[TreeDaddy]

I use one for checking moisture in containers growing chestnuts

Getting the "water thing" right with chestnuts seems to be a learned skill that is as much art(?feel) as science

bill