Manganese uptake, calcareous soils.

[JD3000]

As far as OM as a mulch layer, Im using a roughly 50/50 mix of hardwood and the leaf compost we make here. Seems like a good replication of forest floor.

How bout mixing in some pine bark fines or small chips like some blueberry growers use to help with acidity and micros?

 

[mrtree]

Also Mn limitations or deficiencies have been misdiagnosed as Fe for some time here, myself included. Lots of birches and pin oaks may look like Fe issues here but Mn is far more often the limiting nutrient. This speaks for my part of central Ohio so other places can certainly be different.

Wondering if a tissue test showing adequate micros but also high to excessive Ca and sometimes Mg can be misleading because the lime perhaps neutralizes the metals? Lime induced deficiency despite adequate Mn or Fe on the tissue test?
Dont know for sure

You are correct that Mn deficiency is often believed to be Fe defeciency. I think that tree workers are taught chlorosis equals iron. It is pretty clear that iron is much less well bound and oxidied at higher pH than Mn thus making it less likely to be the issue.

You need to know what your lab is testing for (and how). For soils some tests are total (element) while other tests may be measuring plant available element. Tissue tests are also quite tricky as they work best for expanding and new tissue rather than months old tissue. You must also know which leaves you want to test. I often see nutrient deficiency on leaves after extension but not on the old tissue, the deficiency is often lack of water movement and lack of time for accumulation.

 

[JD3000]

CLC lists it as plant available nutrient.

I cut newer and symptomatic growth for tissue testing. Generally later in summer when things look their worst, guessing summer droughts impedes uptake

 

[JD3000]

Here's one alternative I've done. Cambistat app while later soil injecting ammonium sulfate and Mn EDTA.
Excellent green-up but Im not crazy about the appearance of smaller leaves and leaf stacking. Got this job from HO who said no one had been able to correct the problem. Soil test performed to show to them what really was lacking or in excess.