For the first five years of our soil testing, we always collected three separate soil samples for the three distinct areas in our lawn, but they were similar enough in each of the fourth and fifth years, that last year we decided to test only the front and presume that the side and back are on a similar trajectory. Accordingly, the next year we treated all areas the same, based upon the test from the front lawn. That provided good results, so we did the same thing in 2020.
Then, to explore seasonal variations in sodium levels, we advanced our spring 2021 test to the fall of 2020, to see if there would be a reduction in sodium through the summer. The measured sodium did decrease over the summer, but not as much as we hoped.
This year, we took our test earlier than ever before, mostly just because we were eager to get started!
To provide more history of our soil test results in one image, I've photoshopped the most recent 7 years into one photo. (I was having trouble easily copying in results from 2015 and 2014 due to slightly different formatting, so I gave up. There was also a lot of movement in those early years due to trying to make up for nutrient deficiencies.)
Looking at the 2022 soil test results, this seems like this may be our best test results ever. Probably just a bit of luck in sampling error, as we missed a couple macronutrient applications last year, although we had the intent of continuing to follow the 2020 plan. (See the thread for our 2020 soil test.)
Our TEC continues to climb through steady mulching of everything, including tons of oak and maple leaves. Our OM% has moved up gradually over the years due to that effort. Our phosphorus level has climbed to the "plentiful" range, which I attribute largely to the mulching of leaves and the use of Bay State Fertilizer as our primary nitrogen source, except in 2021 when we couldn't get it and thus fertilized less than usual.
The test sample was collected on April 22, 2022 from a mix of 30 core samples, each of the 1" of soil taken from between 3 inches and 4 inches depth. We were slow to actually mail in the collected sample, so we just received test results this morning.
As always, our sodium level is high -- I still suspect this is driven by road salt on our NH road even though it didn't fall as much as I hoped between our spring 2020 and fall 2020 samples. I have not yet applied gypsum to counter that, although this year, for the first time ever, we have some apparent "salt kill" right at the road edge. I speculate I should probably be making early spring gypsum applications along the road -- @Green has suggested such localized gypsum applications, saying that he has success with that approach.
I don't know enough to really comment on the micros, so I'm also looking for feedback on those, please. The boron seems to be back nearer to the 2018 value, but that makes sense as I slacked off on Boron applications in 2021 (didn't make any at all) and boron presumably leaches out of our sandy soil. I guess it really does make a difference to be making those regular apps. This is the first year I haven't seen an increase in copper. I had been attributing the steady increase in copper to the use of lots of Bay State Fertilizer, and I did apply less BSF in 2021 due to the inability to get it until the fall last year. As to the jump in the zinc level, I have no idea. I don't think I filed off shavings from a bolt into the sample...
For reference, below are the soil test related applications to the front lawn since the fall 2020 test; we didn't make any micronutrient applications due to lack of time on our part:
- 9 May 2021 - Bay State at 0.64#N/K with SOP at 2#/ksqft (1#K/ksqft)
- 10 June 2021 - Bay State at 0.40#N/K with SOP at 2#/ksqft (1#K/ksqft)
- 5 Sept 2021 - Bay State at 0.64#N/K
Thanks for your time on interpreting the test results!