Soil testing

[MontyJ]

Who else has their soil tested at a lab? I don't see many posts on soil testing and interpreting the results here on TEG. I even did a search and found very few. For a community this size, there is an extraordinary amount of knowledge available. I dare say that many of you are some of the best gardeners I have ever had the privilege of meeting so to speak. I used to grow competitively, primarily giant pumpkins, tomatoes and cabbage. During that time I spent countless hours studying the soil, and still spend a lot of time studying it. I believe the success of a garden all starts with the soil. There is no more critical factor (unless your into hydroponics of course). So...

I was reading through some old posts and came across this one:

http://www.theeasygarden.com/forum/viewtopic.php?pid=235437#p235437

It's the soil test results received by Obsessed back in 2009. I read the replies, most of which were pretty good, but one thing struck me. There was one number listed that completely blew my mind. What astounded me more was that nobody mentioned it. That single number could be a typo, but I don't think so. Can anyone identify the number that concerns me? And why?

 

[digitS']

Excessive copper? I'm going to be relying on you MontyJ.

I don't remember that we once had the soil tested when I was a kid on the farm.

In the greenhouse, the "soil guy" did plant tissue testing and based his recommendations for fertilizer injection on both soil and plants. We relied completely on that outside expert.

Steve

 

[Carol Dee]

I have a question. Might be no problem, but.... DH burned 3 freshly cut trees right in the middle of the large garden. He plans to till the ash in. He has not done a soil test. Will all that ash be too much?

 

[MontyJ]

Easy answer first...

Carol, it will probably be fine. Depending on the size of the area, spread the ash and till it in. Without knowing the amount of ash and lacking a soil sample and garden area, that's about all I can tell you. I doubt it will hurt anything though. At most it might raise the pH some which isn't a big problem unless your soil is naturally alkaline.

Steve, look at the Zinc level. It's 61.30ppm! That level is so toxic that no plant could grow. That tells me the soil sample was contaminated, probably by using a zinc coated spade to take the sample with. Either that, or part of the sample came from an area very close to a chain link fence, or was mixed in a galvanized container. I would normally expect to see zinc levels well below 10ppm. At 61ppm iron would probably be completely locked out and unavailable to plants. The sample had to be contaminated, which brings into question the validity of the entire sample results.

Someone also mentioned high sodium and reducing the epsome salts to correct it. Epsome salts accounts for the high Magnesium and Sulphur numbers, but not the sodium. Epsome salts is Magnesium Sulphate. I would think that the Sodium is also a contaminate, probably from the container used to collect or mix the sample in. Perhaps Obsessed used the same container at the beach in La, or perhaps had a grain of ice melter salt in it? Remember, these measurements are taken in ppm or parts per million. To put it in perspective, take 1,000,000 grains of sugar and replace 10 grains of that sugar with 10 grains of salt. That is 10 parts per million. The slightest contamination can ruin an entire soil test.

 

[MontyJ]

Excessive copper?

In the greenhouse, the "soil guy" did plant tissue testing and based his recommendations for fertilizer injection on both soil and plants. We relied completely on that outside expert.

Steve

Tissue testing is the ultimate way to determine the health of both soil and plants. It's more expensive than soil testing, but the results are far more accurate.

 

[Smiles Jr.]

Wood ash typically is acidic. This may not be a bad thing if your soil can handle it or if it is too alkaline. An acid soil is normally made more alkaline by mixing lime into the soil. The big question is HOW MUCH. This is where a good soil sample should be taken and analyzed. The results will provide all kinds of information as well as recommendations. As you know, some plants like acid soil and some like alkaline soil.

I usually send in soil samples every other year or whenever I till new ground for planting.

 

[MontyJ]

Actually, wood ash is typically alkaline. It will raise the pH of most soils.

 

[Ridgerunner]

When I had mine tested a few years back when I first moved here, I got the container it was to go in before I took the sample. I didn't have to worry about the container being contaminated but you make a real good point about the shovel maybe being contaminated.

I had to tell them what crop I planned to grow in it. There was one category that fit a general garden reasonably well. And they wanted samples from three different areas. It was all mixed together for testing but by taking different samples I should have gotten a better average for the conditions.

I not only got an analysis back, I got specific recommendations as to how much lime I needed to add to get the pH down as well as other things to add. To be honest, I didn't look at the analysis as much as I did the recommendations.

I should get another test done but I'm not sure what it would tell me. I've added more compost in certain areas, provided different nutrients depending on what grew where, burned my scrap wood and added those ashes to certain areas, turned in different types and amounts of mulch. I have an idea I could get some pretty different results depending on here I took the sample. Thats part of my reluctance in taking another sample. Im not sure how much I could trust the results as being truly representative.

Editted to add: I do have a pH meter so that part is covered.

 

[HunkieDorie23]

Actually, wood ash is typically alkaline. It will raise the pH of most soils.

Yes it is alkaline but I know that wood ash is best added to carrot beds in the fall. I added some to a garlic bed once, they didn't appreciate it at all. Not all garden soil is created equal for every plant. Look at what you are going to do with that area and then amend them to suit the plant.

 

[majorcatfish]

will be turning some virgin soil this year so yes will be sending off same to the co op extension from there as well as the garden it's been a couple years, will be interesting to what it says

here's a basic chart on how to change your ph