I had my vegetable garden soil tested by a local university extension. (If it matters, I'm in the northeast US, zone 5.)

The results indicated that the soil was deficient in nitrogen and potassium. Potassium was 78 ppm but the suggested level was 170-280. The phosphorous was high, 63 ppm and the suggested level was 30-60. The amount of nitrogen in my soil was not reported, but apparently it was found to be deficient as well.

Their recommendations were to introduce 3 lbs. of nitrogen and 4 lbs. of potassium per 1,000 square feet.

They suggested the following fertilizers:

  • 23 lbs. of dried blood for the 3 lbs. nitrogen
  • 18 lbs. of sul-po-mag for the 4 lbs. potassium

I'm happy to follow their recommendations, but am wondering if there is a single fertilizer I could apply that would achieve the same result as the blood meal and sul-po-mag. Any ideas? I'd prefer organic fertilizers where possible/appropriate.

If it matters, my soil had 4.10% organic matter (LOI-360 OM). I took the soil sample in the late fall.

1 Answer 1


Most combined fertilisers won't have the ratios of the two elements you need, and will contain other trace elements too. The best solution is to follow the recommendations you've been given, even if it means applying them separately, as you have gone to the trouble of having a soil test done and been given a 'prescription' for what's needed.

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