Soil Test Questions

JessieC · 2023-04-03T20:54:15+00:00

Hello Everyone, I wonder if you can help me figure out a very surprising soil test. I had one done last year, and noted that my P and K values were on the hi...

Cosey

JessieC Your tests are wildly different because you tested two different substrates. I don't think this will harm plants at all. It is higher than the average homestead topsoil but the nutrient ratios aren't wildly off. At least from where I live. The only thing that might worry me is the Boron. You can't do much about it. It's one of the rarest elements but you need Boron for Calcium to work in plants. You have a lot of calcium. 😅

I would NOT add any fertilizer in the spring, including Nitrogen. You may need to side dress or foliar feed mid summer.

An interesting and worthwhile experiment would be to do a soil test this fall after plants are done growing. It would show how much your plants fed. Also, conducting the bean or pea test as mentioned previously will help alleviate concerns.

JessieC

Cosey Interesting. And yes, I will get the tests done again! It’s fascinating to find out what’s really in there. Maybe the fact that the recent tests gave a “normal” range caused me some alarm. The VT lab just gives you an indicator like “Sufficient” or VH.
And I’ll try the pea test on all the beds. I’ve been concocting a bit in the smaller beds—they’re almost like giant containers at 6.5’ X 3.5’ and they’re tall so it’s easy to mix things in to fluff them up a bit.
Thank you!

calico20hill

THis is the first year out of 3 that the soil test has not said we had too much organic material in the soil. The original purchased garden soil must be breaking down the compost in the mix. I haven't wanted to use a mulch or even add much alfalfa meal due to that. I gave Mr isIander the job of sorting out the amendments and adding them to the beds before we top them up with new soil. With raised beds they do sink some every year.

JessieC

Well in case anyone has been on the edge of their seats, here is the new soil test 😂
I took it to the feed-n-seed place and they were very quick to turn it around. It all looks about the same, albeit with a better graphic format. I had to recalculate for the units, but almost everything is very close to my earlier test. Looks like I have nice soil with a lot of organic material.

I also took samples from a raised bed that I used last year,and those results indicate good numbers, just not such extreme numbers. The only ones in the "Medium" range are Magnesium and Boron. The soil there is a little more alkaline at 7.1, and the organic matter is 6.6%. That test might give a hint as to what I'll expect from the post-season retest that @Cosey suggested. We used soil from the same source in that bed one year ago.
Nice to have it confirmed. Soil tests are more fun than I would have expected!

MissyWeitzel

I just picked up my soil test results and the only thing recommended to add is 200 lbs of potash per acre. Does anything else stand out to any of you? The farmers at the co-op don't have a clue about dahlias specifically.

I have very sandy soil and will top dress with compost and I also mulch with shaved pine pet bedding for weed suppression, moisture retention, and it mostly breaks down in one season so it's adding some organic matter.

Teddahlia

Jessie C.'s phosphorous is at 412 and that is very, very high. Missy is at 177 and they say that is very high too. Potash and nitrogen needed for Missy's garden. Ph not on Missy's report and Jessie has perfect ph at 6.5. I love Jessie report except for the phosphorous. I wonder if if someone put down bone meal back when. In some soils you never need to add phosphorus for lawns according to Washington State people who banned phosphorus from lawn fertilizer for retail sale. High Phosphorus levels are the result of those stupid recommendations to use low nitrogen fertilizer on dahlias. I see that all the time. Dahlias many times ONLY need nitrogen and no phosphorous or potassium so who would put down low nitrogen fertilizer that only has phosphorus and potassium? Potassium is not very harmful but phosphorus is harmful in large amounts.

MissyWeitzel

Teddahlia thank you! My ph is 6.8.

Teddahlia

What is perfect pH for dahlias? I say 6.2, others say 6.3 and others 6.5. When you go below 6.0 you get slight problems. When you get into the low "fives" like 5.4 things get worse but the quick cure is generally more fertilizer as ph just inhibits absorption of fertilizer. As you go above 6.5 I have no personal experience to share except that story about the late Bill Mishler who went to the agricultural lime plant and had them fill up his pick up until it sagged. He spread that lime and he had a pH in the 7s for several years and the result was just as bad as when he had a pH of 6.0 when he started. Too much of a good thing.

Roelkem52

Teddahlia - low pH can actually make some nutrients more available, to the point of toxicity. I had some very ill looking plants, that kept testing negative for all the main viruses. So I finally sent in some leaves for a nutrient analysis. I was shocked when the results came back with greater than 500ppm manganese, when the normal range was something like 40-80. The lab suggested that I might have very acidic soil which would allow manganese to be excessively available and become toxic. So, I finally have my soil test results back and YEP - acidic soil with a pH of 5.5!! So just adding more fertilizer, would not have solved my problem at all (I realize this thread is 8 months old).

Teddahlia

Manganese is a trace element
According to the master gardener named "Farmer Google":
How do you fix high manganese in soil?

Manganese toxicity can be treated in various ways:
Application of magnesium.
Application of organic matter.
Application of lime for soils with low pH.
Prevent fluctuations in soil moisture level.
Since your soil is too acidic and you are adding lime, you should select Dolomite Lime as it adds magnesium and according to "Farmer Google" you may need some extra magnesium.
My magnesium levels were ok and I use regular lime. I have read the numbers on the regular lime that we have available and it has some magnesium in it too but not as much as dolomite lime.
PH is a balancing act where too low is bad, too high is bad and dahlias like it slightly acidic.

Teddahlia

This thread contained soils tests and proposed solutions to improve the gardens. Could those people who posted their soil tests comment on how the recommandations worked out?
We need a picture to get your attention.

MissyWeitzel

Teddahlia I got my soil test results back a couple weeks ago. Compared to last year I see improvements in micro elements and my organic matter percentage increased. My plan is to amend with potash and nitrogen granules and just continue adding organic matter via compost and leaf mulch. I'm also planning to try crab meal this year. I have fungal issues in my vegetable garden soil and there are a couple areas in my dahlia beds where I had fungal problems 2 years in a row now so I'm gonna see if just applying crab meal everywhere helps. My local hydroponics store can order me 50lb bags for a good price and I'll just use my spreader to broadcast it.

JessieC

Teddahlia Thanks for the reminder, Ted. I’ll get new soil tests soon. I had the soil with too much of everything last year. I did as suggested and did not add anything major. I did have areas where I wonder if I also had too much nitrogen. Some varieties that had thrived and bloomed the previous year gave me nothing but laughably overgrown foliage and a couple of blooms each.
In any event, the new soil tests will be informative, so I’ll get on it!
The burgundy waterlily (or is it purple, or dark red?) in your photo is stunning! And I see Margaret in the background too, if I’m not mistaken.

JessieC

Teddahlia I brought my sample over to the co-op yesterday, so I should have results next week. Thank you for the reminder!
This may belong in another thread, but I recall you saying that a time-release osmocote type fertilizer is best for grow bags. I have about a dozen of those, which are excellent for spares and pot tubers and the inevitable “I forgot I ordered this tuber!” I’ve been mixing garden soil with last year’s grow bag contents, annd I’ll add some time release fertilizer. Anyone else have suggestions for how to provide a good growing medium in a bag?
Last year we were able to put tubers in by April 15. It feels like the right time to start now. Happy planting season, everyone!

Two pictures from last year’s grow bag area.

calico20hill

We just got our soil tests back today. It says they show increasing salinity. What does one do for that? (We have two different kinds of purchased soil and test each separately each year.) Phosphorus. zinc, Iron and copper are very high. Lime presence is low. One set of beds has low lime presence....6.2 The other set of beds is not quite as low in lime and has a 6.7 ph. Magnesium and boron are very low in both sets of beds.

Would these results have anything to do with my poor tuber qualiity?

Teddahlia

Tuber production is mostly genetic. Joke: A well grown poor tuber producer will not produce more tubers but with some good care can produce bigger tubers that rot just as much. I am being a pessimist here as when a plant makes poor tubers, one has to know why. Rotting tubers,(there are some things you can do ) ;few tubers , grow more plants. Small tubers, some potassium may help. For rotting tubers digging before the rainy season helps and using fungicide may help too as rot is fungus eating tubers. You ask about fertilizer and potassium along with adequate amounts of both nitrogen and phosphorus(you have plenty), must be present to allow the increased potassium to work. Good genetics is the best answer.

calico20hill

Teddahlia Well, If I plant my surviving "Tiny Tubers" among the ones with the hardiest tubers, I wonder how many years of crossing genetics it will take to get beautiful flowers with great tubers...? Not sure I will live that long but I will see what I can do. My only idea is to learn not to over water. Oh yes, one other switch I am going to make. I have been planting my seedlings in the first row of the garden where shade arrives the earliest in the afternoon. I am going to flip that and put them at the bottom of the garden where they will get the last sun of the day. Maybe more sunlight will help them.

Teddahlia

Missy's new soil test has shown reduction in phosphorus from 177 to 121. pH the same. Boron a bit low but that is dangerous one to add.

Teddahlia

Yes, Margaret in the background. Note the flower is above the stake that is five feet above the ground and the other flowers are even higher. This one reaches 6 feet easily and has a huge main stalk. Not the tallest new waterlily however.

calico20hill

How tall IS your tallest waterlily?

Teddahlia

I believe the red 2023 seedling in Margaret's hand crossed waterlily row may be the tallest so far. A well known breeder spotted it during our garden tour and made some positive comments about it even though the flower was way above his head.
I did not measure the height but since it was a first year seedling and it was really tall, it probably will be even taller this year. It is also larger in diameter WL than most , probably 6.5 inches.

bloomhjelm

Teddahlia How big are bowls for floating waterlilies at shows? Can I use a popcorn bowl? 🙂