What do I do to add phosphorous to my lawn?

Asked May 3, 2017, 1:30 PM EDT

Unusual as it is in our area, our soil test indicates a deficiency of phosphorous in our soil (index level 15 in Delaware soil test) where I am currently trying to transition to an organic maintenance program for our tall fescue lawn. The recommendation from the lab was triple super phosphate, but we wanted to avoid chemical fertilizers. The catch 22 is that my husband also does not want to use meat industry byproducts (bone meal, feather meal, manure) and so the best solution i can find was Sunleaves Madagascan Bat Guano (0-13-0). However, I'm now concerned that the Guano may have too much calcium, and we already have an excess of calcium in the soil, according to our soil test. How do I find out about the calcium content of the Guano? And if it's not a good solution, can you suggest an alternative?
(side note: our pH is 6.7, just about right)

Montgomery County Maryland

1 Response

Thank you for your question. The pH you have is in the proper range for lawn establishment. A commercial starter fertilizer for lawns would add the phosphorus you need, but since you prefer to avoid chemical fertilizers, the bat guano can be an option. We do not have any solid research about the effectiveness of using bat guano for lawns. Also, it can get expensive to use bat guano if you are working with a large area. If you do use it, don't be too concerned about too much calcium. Higher calcium would not be a major concern. Your pH is good and the phosphorus correction is the main nutrient you'll want to address for good turf establishment.