You know, I face a similar high phosphorus issue because the convention for many years in Hawaii was to fertilize with either 16-15-15 or 10-30-10 AG fertilizers. I like to blend my own and then spray it. The Lesco high nitrogen granules are probably based on urea. I do not know for sure because Lesco does not operate in Hawaii. I am working on one bermuda lawn right now where it does not respond to the normal urea based slow release granules. What it does respond to is 5 lb ammonium sulfate, 1 lb potassium nitrate, 8 oz ferrous sulfate, and 1 lb 0-60-20(phosphorus pentoxide/potassium hydroxide).
Iron makes a world of difference in the appearance of the grass. Bermuda and zoysia tend to be off color unless there is enough available iron. Iron makes a different kind of green. For me, iron in granules is more a liability than benefit. It stains sidewalks and pools. The reason why someone would even want to broadcast iron is because the grass needs it. The grass is probably needing it because the soil has iron that is unavailable to the grass. Iron sprayed on as a soluble liquid is available to the grass. It is absorbed by both the leaves and the roots in the thatch layer right above the soil itself. Another thing to look at is magnesium. In high calcium soils, it is possible for magnesium to be deficient and unavailable to the grass because the calcium competes for utilization in the grass. I draw a lot of soil tests. Cannot tell by looking what is in soil.
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Benjamin Franklin 1775
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Benjamin Franklin Poor Richard's Almanac1738