Do I need to increase the copper and iron levels in my soil?
Question:
Last year I had a soil test done through the University of Maine Cooperative Extension. The copper and iron levels were a bit low (copper=0.10/ iron-2.7). Do I need to increase these levels? How would I do that? I’ve read that the soil pH level affects uptake of these micronutrients. My soil pH is 6.5 – 7.0.
Answer:
Your soil report should have included recommendations for raising the iron and copper, if it was warranted. Your pH range is great for uptake of the nutrients for most vegetable and home landscape plants, unless you have acid-loving species planted. If you haven’t noticed deterioration of your plants and/or harvests, and iron and copper are the only low figures, I would simply continue to add garden compost or well-composted manure to the soil each year (1/2-1″ is all you need) and your levels should normalize over time. Copper in particular can be tricky to amend, with copper toxicity a concern.
If you are having problems with growth and suspect soil fertility, we can take a look at some photos and see if the iron and/or copper are at fault (though serious problems with deficiencies of those micronutrients are relatively rare). Otherwise, I wouldn’t stress too much.