I can't offer much help with the zinc but I might want to investigate the irrigation water available. Both boron and zinc can be found in high levels in water depending on source and runoff. Have you tested your water supply?

When you say you're going to add gypsum to balance out the potassium and magnesium, do you know how much to add? Did your soil test include a salt balance test?

Dan

The diligent efforts of the hippies in the domes, the successful gardeners in their homes, and the findings in the tomes find no relief from boron by adding OM to the soil. Unless there is something very new that I missed.

Dan

Sure there is. I explained a specific case above. To reitierate: despite the wish of some, excess boron in the soil is not ameliorated by the efforts of a legion of talented, knowledgeable gardeners addiing OM in a place with high boron in the water.

One must also define "adequate", as the OP's soil cannot be considered as having an inadequate OM %age, yet there is a B problem.

Dan

In mineral soils, release of boron is usually quite slow. Much of the available soil boron is held rather tightly by soil organic material. As organic matter decomposition occurs, boron is released with a portion being absorbed by plants, leached below the root zone area (especially in high rainfall/acid soil areas) or tied up (unavailable) under alkaline soil conditions.

So if I am interpreting this correctly, boron IS bound by OM but as that OM decomposes, the boron is released. It still does not indicate that adding OM will ameliorate the problem of excessive boron concentration, only perhaps delay its release and uptake.

You won't like your plants responding to B toxicity, but you are correct that Zn could be a bigger problem. What is your pH there?

Dan

This is a bit of an over-simplification......nutrient management is a rather complex subject and there are many other factors that can come into play as well - soil type, soil pH, irrigation water quality, etc. - but generally home gardeners do not need to over worry this issue. Peter's situation is somewhat unusual :-)

I've included a link to an extension service tutorial that explains nutrient deficiencies and toxicity rather well. Keep in mind that it may be addressing very regional soil conditions as a variable and recommendations may be swayed accordingly but the basic info is sound.

FWIW, both boron and zinc are naturally occurring minerals found in all soils, usually in some sort of chemical compounds or ore. Boron tends to be a rather uncommon element and is typically present in very low levels.

I remember a tupelo outside one building that was stunted and never turned a good fall color, and several perennial spp. that always looked ratty and rarely flowered.

Dan

You are kind enough to write about my excess boron, not excess moron. ;o)

Dan

Sorry buddy, you bumped and set so I had to spike. It's the law of the internet. ;P

Had I known an emoticon for bump & set, I'd have typed it.

Dan

The OM% appears within the suggested range for clay soils. What was reported for your CEC (cation exchange capacity) and specifics under Base Saturation?

Were there any specific nutrients rated as high or low?

It is interesting to compare soil test reports and the influences of regional soil differences, rainfall, etc. It is also noted that differing testing methods provide diverse results. You really need a vast knowledge of soil sciences to make heads or tails of some tests; and the lab methods.

Generally boron one of the leached trace elements. An excess would suggest that a subsoil drainage block. It is unlikely that any simple remedy will answer.

More details of the total analysis report may guide my thoughts and research.

A potential remedy is negated by your provided data. An agronomy library article "Calcium in Soil" in the 'interaction' section indicates that high soil calcium inhibits boron uptake and utilization. Your CEC calcium is above suggested percentage range range and likely (unidentified in analysis) also high. The input source increases seem less at fault unless applied in high excess or applied too often. Ground source seems most likely.

It is noted that you did not indicate toxicity symptoms in you opening post. Could it be that the analysis alone has pointed out the high zinc and boron? Perhaps the high OM% and calcium are working at limiting the B uptake.

The high CEC (21.1) is tied to higher clay component and K+ cation prominence in the available potassium level.

You may be better served in understanding the total nutrient picture by speaking with a local expert.

Thanks for broadening my appreciation of soil analysis results in different regions.

Thus it would appear that your actual pH would be 7.3. It is unlikely that a 6.8 pH would be buffer test for an increase. The high 7.3 pH would lead to an identified target pH and a recommended sulfur amendment to lower it.

Now I wish I had the soil science degree. hee hee

Was there a recommendation to change the pH?

You never said how much the zinc increased or how it was extracted (again, this is just for giggles because I guarantee you don't have a zinc toxicity problem). I'm also still wondering how boron was extracted. It should say on the data sheet what method was used or the lab can answer that question. It makes a big difference in how the data is interpreted.
Pagardner - yes, if there are symptoms showing, tissue analysis is a good way to confirm whether or not those or other elements are an issue. However, the OP hasn't mentioned any problems with plants. Without any symptoms, I wouldn't spend the money testing healthy tissue collected from plants that perform well. It's also pretty easy to get tripped up with tissue analysis. All of the reference data is based on particular tissue collected at a particle point in development. If you get the wrong tissue and compare it to the reference data, it can look like you have excesses and deficiencies that aren't really there.