Your soils pH is a bit high but given the amount of organic matter I'd not be too concerned unless you were growing blueberries or other plants that need a more acidic soil. The recomendation to add some Nitrogen is always there and is probably unnecessary given the small amount over a fairly large area. The numbers look to me to be in a good range, why did you think they were high?

They recommend adding N because N leaches out of the soil, while other minerals stick around. The reason the recommended application rate is so low is because they recommended a fertilizer that is 46% N. The usual recommendation is to add approximately 1 lb of actual N per 1000 sq ft. To get 1 lb per 1000 sq ft using 46-0-0 fertilizer, you'd need about 2.17 lbs. So the recommended application rate is actually a little high, since it works out to 1.15 lbs per 1000 sq ft.

You could probably get by with a lower application rate, or maybe a lower percentage of N so there's less danger of applying too heavily in some areas and not heavily enough in others. For example, if you bought some 21-0-0 fertilizer, you'd want to apply it at about 4.75 lbs per 1000 sq ft (I've used 21-0-0 and applied it at 5 lbs / 1000 sq ft because there is a bag that gives me that application rate, and it's easier to apply than try to figure out how much to leave in the bag and then figure out what to do with it, especially since the only time I ever apply a fertilizewr like that is in the late fall).

I agree with Kimmsr's comment on the pH. It's a little high, but the high organic content should do a really good job buffering it. Your pH is actually lower than mine, and I've only had problems with a few plants that I've tried to grow (notably a maple and a magnolia).

If you use the 21-0-0 ammonium sulfate it will provide the N and the sulphur will adjust the pH a little bit. Yes the ammendments will help to buffer it also. I use a little of this when I all a lot of shredded leaves in the winter and it works out fine.

Monday will be three weeks since I turned my two soil samples in to Calloways for the free soil analysis. I am eager to see what they have to say.
Bill P.

Thanks for the help. I'll post what happens.

Scott: how do you conclude that you have excesses? And what do the two numbers for each mineral mean? And are they ppm or lbs per acre. Only one thing is clear to me: that your calcium is out of balance with your magnesium and potash. Calcium should be 6 to 8 times the magnesium, so -- in my book -- you need to add quite a bit of calcium to knock some magnesium off the clay/humus colloid. The testers may have hesitated to recommend that, because the cheapest form of calcium is lime which would raise your already high pH. So use gypsum (calcium sulphate) because sulphates and sulphur will reduce pH. Hope this makes sense to you. And how did they know to add nitrogen when it wasn't tested? Your manure might well have provided enough. Regards, Peter.

Peter,

Good questions. I have been told that Nitrogen always needs to be added as it is unstable in the soil and therefore they don't bother to test it.

I also had a gentleman who is a soil scientist for golf courses suggest something called HI-Cal lime to adjust the calcium/ magnesium balance. I'll reprint his note on the forum for your thoughts.

Calcium sulphate seems to make sense.

I'm not sure why I'm so neurotic. The truth is that everything grows very well in my beds.

As for the units, I'll get that info and post it.

Thanks for your help.

Scott

* Posted by boxcar_grower (My Page) on
Sat, Jan 27, 07 at 8:00

Your soils do not seem that bad. All extension services use soil tests from the stone age. In my line of work, the companies use a base saturation soil test. It basically puts everything into a 100% equation. Soils cant accept some thing without driving something off.

In most soils, potassium (P) and phosphorus (K) are in rock form and is very slowly availible to plants. Even with soils of high or adequate levels still need applications of P and K for proper plant growth. K gives your plant regidity and strengthems cells walls. It is crutial in respiration of the plant. The plant adsorbs P in a "luxury consumption". Dont worry about the potassium number. Phosphorus is benefitial in root production among other things. You can over fertilize with phosphorus and get weak off green color plants. That will not occur from rock minerial in the soil however.

Calcium and magnesium and the most over looked macro mineral in the soil. I beleive calcium is just as important as nitrogen in the health of the plant. One thing that I dont like about your soil is how magnesium is just as high as calcium. The magnesium number is what is driving your pH to be in the mid 7's. I would be great to lower that number. Usually the relationship of Mg/Ca is about 1/5. My soil tests at work, my Mg runs in to 5-10% range and Ca is in the 50-60% range. How do you lower Mg you ask. Easy, add lime! Not just any kind of lime. You need a HiCal lime. All the lime stone you can get at the local home center is dolomitic lime. Very high in Mg and has calcium coarbonate as well. A HiCal lime has Low levels of Mg and is mostly comprised of Ca. You will actually lower your pH by adding lime. The more calcium will drive off the Mg (which is driving you pH)lowering your pH number. By the way pH stands for percent Hydrogen. A perfectly balanced soil will have a pH of 6.3 This is were all the macro and micro nutriens will be in propper balance. You will need a quality soil test to determine this. Now some confusion, not all 6.3 soils will be balanced. There are many variables in the soil chemistry.

As for the urea, I would not use it. I would use a quality organic balanced fertilizer. Urea is VERY HOT! etremely high in soluble salts. It volatilizes very quickly becoming a nitrate and aff into the air. You would have to apply it weekly.

One thing to remember is you are trying to feed the soil not the plants. The soil has to be corrects and the plants will take care of themselves after that.

Sources for HiCal lime? Try Agway, turfgrass managment supplier, or a local farm store. A balanced organic fertilizer would be a full organic with out synthetics added to it. A anaylasis of 5-4-5 or there abouts. I use Earthworks 5-4-5. It is available to me in my trade but you might ask your local greenhouse or nursery grower if they can get it.

Incase you were wondering, I am a superintendent of a country club and my turf is 100% reliant on soil chemestry.

www.soilfirst.com is for a organic fert source.

http://www.fedcoseeds.com/ogs/OGSorderItem.php?id=8641&listname=Rock%20Powders

That is a link to online HiCal Lime

Here is a link that might be useful: This is who I use for testing. Very good lab. If you choose to send them a sample, post the results here and I will help you read them.

With an organic matter level above 10%, I wouldn't be too concerned with adding more nitrogen to your soil unless it contains identifiable lignaceous material that needs to break down further (this can temporarily tie-up N). In this case, I would add 2 to 3 lbs. of alfalfa meal per 100 sq. ft.

Otherwise, the organic matter should supply your plants with a steady source of available nitrogen throughout the growing season.

Because all soil test labs test for readily available nutrients, and then based on the experience of the lab people postulate what is really in the soil, any lab can show different results depending on who is doing the test. Any one that comes through with a statement that says, "All extension services use soil tests from the stone age" is someone to stay away from because all the people employed in every lab in the world learned about soil testing from some Ag School that is part of the USDAs Extension Service, if not directly then the person that taught them attended one.
Nitrogen is no longer tested in labs with people that understand soil science because the availability of Nitrogen is very dependant on soil temperatures which determine soil bacterial activity. So a soil sample taken in March in Michigan will test for much less N that a soil sample from Florida taken at the same time would even though in July they could easily test for the same level whether any N was added or not, although the Florida soil might be somewhat depleted by then simply from that same bacterial activity.

Thanks for everyone's help. The question is still whether I need to do anything to these raised beds. The pH is a bit on the high side and the Ca/Mg ratio is abnormal. Should I bother to fertilize at all? or adjust the pH?

Thanks folks.

There is no need to use any "fertilizer" although I would look at ways to reduce the soils pH.