My soil test (UMASS Amherst) came back deficient in Copper, along with the recommendation to mix a small (I forget now what exact) amount of copper sulfate with fertilizer before applying fertilizer the usual way. I mixed it with Milorganite, and the difference in garden recovery was quite striking.

FWIW, I also had a Boron deficiency.

Interesting. Kimmsr is right that compost will boost your micronutrients over time.

But to answer your question, the amount of water doesn't really matter, it's the amount of copper sulfate that matters. Figure out what you want to spray it with and use an amount of water that is enough to cover the entire area but not so much that you're spraying for hours to get it done. 3360 sq ft is a pretty large area. I wonder if it wouldn't be easiest just to use a watering can, dilute the stuff into a fairly large amount of water (10-20 gal) and just walk around sprinkling. It's soluble enough that it will move around in the soil somewhat when it rains, so you don't have to be fussy about covering every single inch with a precise amount. Or, you could use a sprayer and probably do it more evenly, but you'd need a large one to cover that area.

Potassium sulfate is also water soluble, although you could get K from a fertilizer with a high last number so you don't have to use K2SO4 necessarily. If your pH is low, consider wood ash - very high in K. Anyway if you use the salt, it's soluble and could be sprayed along with the copper sulfate. They also make fine wettable sulfur powder that is suitable for suspending in water for spraying. I have no idea what to use for boron, maybe boric acid powder, it's cheap if you buy it in a can labeled 'roach powder.' Or borax (sodium borate, aka 20 Mule Team Borax cleaning product). Whatever you use, just make sure there are no undesirable ingredients and that it's water soluble for spraying.

Thank you for all your replies and great advice and experience. The main reason I was asking on the forum was that Monday morning was the day that we planned to fertilize the garden and the Soil Test company is closed until Monday and it is in a different time zone, so we would lose precious time waiting for their answer (they did call back Monday afternoon)

Kimmq: yes, compost has micronutrients but it also has phosphorus and other nutrients in it and we don't want to add those to the soil as their readings are just right.

josko021: I am hoping for a great burst of abundance with our soil amending also! I did what you did, I mixed the copper with all the other powders and just hand-sprinkled it onto the beds (with gloves and mask, of course).

toxcrusadr: I didn't end up using water to amend the beds. I did use the fine wettable sulfur, but i sprinkled it on the beds mixed with the rest of the amendments. And as you said, I used 20 Mule team Borax. Our water source is a far way and uphill from our garden and I didn't want to lug water. Thanks again!

random question. How do get the zone information beside your username? I would like to do that also. I am zone 7b - Georgia

Just go up to YOUR HOUZZ, click on the drop down that says EDIT PROFILE, and just retype your user name to include anything you want.

Just one caveat. "and we don't want to add those to the soil as their readings are just right." Micromanaging (literally!) such stuff is a huge waste of time and energy. Have faith that adding OM of pretty much any sort "buffers" soil chemistry to a forgiving state. Soil test companies are much pickier than plants.

"Our water source is a far way and uphill from our garden and I didn't want to lug water". That is going to be more of an issue for your garden than a slight copper deficiency. Will you be able to get some sort of watering system set up?

One of the concerns I have found over the years is that gardeners will limit the amount of organic material put into the soil out of concern that the nutrients would become too much. But the nutrients, we have found, will be in balance. Adequate amounts of organic matter in soil is necessary for good healthy plant growth.

kimmq is kimmsr

A general rule of thumb is that you can add 1/2"-1" of compost per year to an active garden for maintenance.

I probably shouldn't revive, but I will. My OM runs over 10% annually. To keep my micronutrients where I want them I needed to add about 4oz per 1000 sqft. of copper which had dropped to 0.7. So, I grab an empty coffee can and mix sand and copper sulfate crystals together and then spread like feeding the chickens. Till in and done.

Yea, compost can only add what it contains... if its short on copper then it will have to be added, etc. I too (also have 10% organic matter confirmed by soil testing) am short on copper and boron as well as manganese and sulfur... and twice as much potassium as my target. So I've applied micronized sulfur powder (the wettable kind as in a foliar fungicidal spray) put it in a watering can with water and sprinkled the soil... (it is just elemental sulfur with a wetting agent so nobody panic). Did the same with the boric acid and manganese sulfate and copper sulfate (though I do have both a 15% copper chelate and a manganese chelate on hand, I figured I needed the sulfate to pull out some excess potassium anyway). According to my research, it seems copper doesn't move too far in the soil so I did a 6" till to work it all in. The garden performed well last year but now I'm expecting even greater things from the garden for this year...

You sound almost identical to what I had to do this year. Do you use borax to boost boron levels? I want to get my potassium up though. I like it when it is around 600-800ppm. No one around here is carrying SOP so I picked up a bag of MOP. I'll be adding about 10oz of Manganese Sulfate too. Good Luck!

We actually use Borax for the laundry (I know, I know but we are old folks and stuck in the old ways) so there's a box of it sitting on the shelf down in the laundry room... however I also knew I had 5-lbs of Boric acid in the garage (we use for pest control) and since I don't really need the added sodium in my garden (who does, right?) I chose to use the boric acid rather than Borax. I had to look it up on the internet to find the boron content of Boric acid (17.5%) and from there did the math. It easily dissolves in water.

Hey my potassium is at 937-lbs/ac which puts me at well over 7% and that bothers me... I'd rather be down around 3-4% (below 600 -lbs/ac anyway).

EDIT: just noticed I signed up under my other account (long story there) but I'm the same guy that posted above you... hope you're not confused.

>>my potassium is at 937-lbs/ac which puts me at well over 7%

I'm probably missing something obvious here but...7% of what?

Hello,

I'm no soil expert, but excess potassium ties up other nutrients like calcium, magnesium. So, balance becomes a key ingredient in managing your soil. 5% to 7% are industry accepted standards for cation saturation or potassium. However, there are competitive growers who regularly keep soi levels in the 1000-1400ppm for potassium and make up for deficiencies with foliar nutrients.

tox... I don't how much you know about the "art" of balancing minerals, but it starts with getting a soil analysis. As part of that analysis there is something called CEC (or TEC or TCEC, its all the same really) Cation Exchange Capacity, which basically states the quantity of available sites for cations to attach to on humus and clay particles... sort of the storage capacity for cations in the soil. When attempting to balance the minerals in the soil, we talk in terms of the percentage of those available sites that are taken up by each element (just the cations). There is great debate in some circles about what that ideal ratio of cations should be. What I was referring to was that many believe potassium should occupy between 3-5% of those available sites, however my soil with a CEC of over 16 equates to about 7.5% potassium. Though more exchangeable potassium (to a point) will grow bigger produce what does grow is biased away from protein and favors more carbohydrates. I used sulfates to try and knock off the "excess" potassium and hopefully they get replaced with some copper and manganese ions and the balance with calcium (its the reason I also added gypsum). There's a little more to my soil analysis story that involves a 7.2 pH I'm also not too happy with but I'll leave the details out about how I've dealt with that.

monomersemail_1, are you growing commercially? What's the crop(s)? The thing about the application of advanced soil science is how it translates to real world results. Most here are small, residential gardeners. Let's say a person wants to grow a few pepper plants. A 3% difference between what constitutes 'ideal', and what is present, means that you may get a better total yield of what? 1/2 a pepper?

So, shoot for the ideal if you wish, but please understand that the headaches of achieving ideals is completely unnecessary for most. It makes for interesting reading fodder, and for looking to theory, but even then... soil is such a complex and diverse media that there is absolutely nothing yet 'written in stone' - so to speak. One person is growing in sand in the desert; another is growing in clay in the wilds of wherever; and yet another is growing in a completely soilless medium indoors under light. AND... what 'percentages' of minerals/nutrients a certain crop may thrive under, may be completely different for another crop. These ideals are so widely drawn that they are only strictly applicable in theory. They are by no means something that MUST be achieved for a successful garden to thrive.

If, however, you wish to lower the percentages of something in soil, you may consider growing and harvesting crops which feed more heavily on that particular mineral/nutrient.

Grow a few potatoes... and guess what... next year you'll be lamenting that you don't have ENOUGH potassium.

rgreen... I can appreciate what you are saying and agree that the theory of balancing minerals in the soil is not an exact science (thus I used quotes around the term "art" in my posting)... yes, there are so many variables to consider that trying to put too fine an edge on what the perfect "balance" ratio is to target can be fraught with issues involving goals and practicality.

There are many who don't hold to the theory of placing such a great importance on balancing of minerals but rather chase the biology end of gardening. Obviously both biology and mineral sciences are interconnected and one cannot be entirely separated from the other but who's to say which is the best approach to gardening/farming?

I figure those of us who favor getting a soil analysis in the first place must, on some level, have an ideal target in mind for the mineral balance of our soil otherwise what was the point of getting the analysis, right? However it seems there are many of us who don't agree on exactly what that target ratio should be. Oh, there are obvious limits on what is deficient and what's toxic because of interactions between various minerals and pH must be included in that discussion... but when one tries to nail it down any finer than those obvious limits that's where the discussions begin. There seems to be about as many suggested mineral balance ratios targeted as there are would-be soil analysts out there. Each one has their own reasoning based as least somewhat on known principles of soil science and then drawn to a logical set of conclusions as to why they are favoring their particular target ratio for soil minerals. For me that's where the fun begins... this is all somewhat new to me (only been playing around with it for two years now) The attraction for me is the chemistry and the mathematics and trying to understand how this works and then applying it to my own garden soil and observing the results. To be able to discuss it with other like-minded gardeners just adds to the interest in this hobby... So thanks for the input and insights.

As you've probably already knew, I'm no commercial farmer, just a hobby gardener like the rest of the posters here. I'm currently subscribing to the notion that nutrient density in vegetable gardening is tied to balancing of mineral ratios in the soil. I'm still working on zeroing in on my targeted ratios... that takes time just like anything else in gardening. Once I'm there I'm assuming my pH and soil biology will fall inline (not that they are really far out of wack but again I have an ideal in mind). I feel like I'm just one more season and one more soil analysis away from achieving this ideal. Then the next step would be finding out what it takes to maintain this balance from year to year... I'm hoping it pretty much takes care of itself with only minor inputs once I do this enough times and get familiar with my soil over time.

I think it would be interesting for you, a hobbyist, to also have a control group. Many of the experiments that establish 'ideals' are geared towards those who are growing commercially (for one thing, they are the ones who can afford to fund such testing.) If you had a control, you could see if your efforts made a difference, AND... just how appreciative a difference can be made on a small scale. If it were possible to show that a 'regular' person gardening in their back yard can apply such knowledge in a meaningful, and relatively 'simple' way, you may have more than just a hobby, but a book deal! :-)

Thanks for pointing out that % saturation is what you were talking about. I'm very familiar with the concept, maybe I just missed where it was posted earlier in the thread. Usually people talk more in terms of ppm than saturation so I didn't recognize it when I saw it.

tox... the thing about just using ppm is that doesn't really take TEC into account... when the whole focus is about attaining a balance ratio target for the cations then percentages makes more sense and ppm is used to figure out how much of what to add. Of course not everyone "believes" in the targeting of ratios approach, which is probably why ppm is adequate to describe deficiencies and toxicities.

Yes, I get that.