PDA

View Full Version : Soil Testing Lab


lawnstudent
06-08-2002, 10:23 AM
Any recommendations or advise on setting up a professional soil testing lab? What pH meter would you rcommend? What about a spectrometer? I've done soil testing, but how do they test tissue samples for N, P & K? Thanks for your input.

jim

tremor
06-08-2002, 10:52 AM
Jim,

We use CLC Labs in Westerville, OH. I've checked them against both State Ag Coop Soil/Tissue labs as well as another commercial lab. They're great. I can call Chuck next week & ask him for his thoughts on this.

For now check this out. I can't vouch for any kit that costs this little. To outfit a state of the art commercial lab would cost many tens of thousands of dollars even if you had an appropriate area to do so.

When I submit leaves or clipping to the lab, they have me air dry the sample for 24 hours, then wrap it loosely in dry newspaper, & next day ups the sample to them. The costs are huge. To be able to get good accuary here at the house would be great.

http://www.acornnaturalists.com/p290.htm

Steve

lawnstudent
06-08-2002, 01:59 PM
Steve,

I can understand that tissue testing is not feasable out of a home lab, but are you saying that a quality bench pH meter will not give you accuracy? A quality bench pH meter is not that expensive. K can be tested using ammonium acetate and a spectrometer. Is this not an acurate process? P testing is a little more complicated, but again a spectrometer is used to read the transmission of the sample. Is this also not accurate? I agree that a spectrometer is not cheap, but they are not that expense either. I am not a fan of kits that use color charts. You lose way too much accuracy interpreting a color chart.

jim

tremor
06-10-2002, 07:29 AM
Jim,

How much is a spectrometer? Who's selling them?

The color charts are pretty much what I was referring to. I had one that was moderatley effective. But we eventually stopped useing it. We resorted to the services of a commercial lab. I liked the professional look of the printed results with the acompanying interpretation. But I suppose anyone who's a little computer savvy could build a decent shell in Excel.
It's gathering the other data (besides macro & micro nutrients) like CEC & such that becomes so time consuming outside the commercial lab. Accuracy is also a concern of mine.
Have you found a reasonable kit that can be used at the home or office?

Steve

lawnstudent
06-10-2002, 02:08 PM
Steve,

there is a time and place for a complete soil analysis. My thought was to focus on the three big items: pH, Phosphorus & Potassium. Other than Iron, I seldom see secondary macronutreint or micronutrient problems. Focusing on the big three allows me to establish a basic fert program for all my accounts.

In my soil science class we used a spectrometer to perform P & K measurements. Our professor indicated that this spectrometer was in the $1000.00 price range. I am looking at spectrometers and will report on details of my findings. Also, labs upgrade equipment and there may be a good market of used equipment. I am looking into that as well.

jim

tremor
06-15-2002, 07:27 AM
Jim,

This came up again yesterday at one of my stops.

My customer owns a garden center & would like to do Ph, Buffer Ph, P, & K. Have you decided yet on how you'll be doing this?

Steve

lawnstudent
06-15-2002, 04:21 PM
Originally posted by tremor
Jim,

This came up again yesterday at one of my stops.

My customer owns a garden center & would like to do Ph, Buffer Ph, P, & K. Have you decided yet on how you'll be doing this?

Steve

steve,

I've been on vacation the last week. I will continue my reasearch starting next week. I will keep you posted of my progress. As far as pH testing goes, a good bench pH meter can be bought for around $250.00. This would include a two or three pH buffer calibration setting.

P & K will need a spectrometer. I think the big labs use an ICP Spectrometer. These can be quite expensive at $50,000.00 or more, but I know that there are spectrometers out there that can do a quality job in the $1,000 range.

The extractent reagent used in these big ICP Spectrometers is something called "Mehlich-3". The advantage of this reagent is that all macro and micronurtients can be tested in one operation with an ICP Spectrometer (with the exception of sulfur). The smaller non-ICP spectrometers do not give you this much automation.

jim