What should I do with these vague soil test results?

[oldmobie]

I just did my first ever soil test; a Ferry~Morse Soil Test Kit. (I didn't pay the extorsion price shown at the link.) The results are a bit vague, but I seem to have a pH of 7 or 8, extremely low nitrogen, HIGH (off the scale) Phosphorous, and Low to Medium Potash.

How bad is that profile? Is it unusual?

I know it's easy to add nitrogen or potash, but can I do it without adding phosphorous?

I read that calcium can reduce availability of phosphorous, but the most obvious calcium source is lime, which would increase my pH, wouldn't it?

I'd appreciate any advice.

(For what it's worth, I only sampled in one spot, where I'm having trouble, and where the previous owner's washer used to discharge for years. This result may not be representative of my whole garden.)

[philagardener]

Hmmm . . . sounds like high phosphate laundry detergent may be the driver. Are you seeing yellowing of leaves? High phosphorus can interfere with the uptake of certain metals, like iron and zinc.

If you have a sense of how large the discharge area was, maybe you can avoid it or replace some soil. I'd try testing several spots to determine the extent of the problem.

[oldmobie]

May 15, 2015 20:42:19 GMT -5 philagardener said:

Hmmm . . . sounds like high phosphate laundry detergent may be the driver. Are you seeing yellowing of leaves? High phosphorus can interfere with the uptake of certain metals, like iron and zinc.

If you have a sense of how large the discharge area was, maybe you can avoid it or replace some soil. I'd try testing several spots to determine the extent of the problem.

I do have some yellowing in my tomato transplants, but they're starting to green back up.

I've always wondered if the laundry soap could have a long lasting effect. (It hasn't discharged there for around 10 years, so I'd hoped it would have leached out.)

I can grow things there, but they don't grow as well as I'd like. I don't need a miracle cure, but I want to move in the right direction and improve it from year to year.

[templeton]

Check a few other spots - if they are low in phosphate, lucky you - you might have a localized phosphate mine, right there.
T

[walnuttr]

Yup, my guess is the high pH from the caustics in the laundry, so a few years of vinegar might be useful....check with FlowerWeaver on that one. ?
Low nitrogen from micro-bugs booming with the feast of phospahte detergents....so you can possibly use bag-nitrogen such as urea or ammo-nitrate to balance that back...
Yellowing of seedlings : Maybe it's not just the soaps, it is also all the crud that comes out of the clothes.....heavy metal dyes, fluorescent additions ? give a teaspoon full of Epsom salts / magnesium sulphate, a try on a square metre ?
Might be worth looking at a dose of gypsum / calcium sulphate for the Phosphate blocking, not sure what that does to pH.

[oldmobie]

Found and applied a miracle grow time-release product. It's for tomatoes and fruit, and looking at it's analysis, phosphorous was the lowest number. The tomatoes have greened up nicely and started to grow. I probably won't do anything else until they come out. In the future, I think I'll just step up the addition of organic material produced off-site. Our methods border on "lasagna gardening" anyway. Seems to me the problem will dilute over time.

Thanks, everyone for the thought put into it.

[littleminnie]

That's funny because it is very similar to my test but mine shows pretty high K too. It is really hard to find only N fertilizer. I use manure and I read about which ones are lowest in P- cow, horse, sheep. Poultry is highest in P. The way they all connect boggles my mind. My new soil is low in N, high but not that high in P and low in K with a 5.5 ph.
The best thing to do would be a paid soil test from a lab and do it accurately by going a few inches down in several places. I use Midwest Labs because they have a lot of tests available with reasonable prices.