I have soil tests done once in a while where I think the ground is not supporting good growth. After 22 years in one block and 12 years in another, the soil tests have come to show a steady state in nutrient and other soil properties.

On some of our landscaping or maintenance accounts, we have samples tested from time to time, all taken about the same time of the year for comparison's sake.

It's hard to justify the expense of a soil test for a home garden, unless there is a problem growing a particular crop. I test around our blueberry shrubs once a year, for pH, because our native soil has pH = 7.6, and blueberries do best at pH = 4.5. I do not test for N, P, and K, however. We have a compost pile, and our garden plot is amended with compost every spring. There have been disease issues, like blight on the tomato leaves, and insects that bore into the squash vines. But we are not seeing sign of poor plant nutrition here.

So say if a soil test shows you are missing a nutrient. What
do you do? You noticed the area was lower growth, so say you never get a soil test, what would you do differently? Do you directly apply something with the missing nutrient the soil test shows?

I top dress my jalapeno rows through the season if I see they are getting yellow. I use composted leaves and composted horse manure, and till in the previous crop.

As I posted the previous poster was posting as well :)

So my last post above was a response to marshall.

--

now to respond to eric.

eric,

i see you are saying the same thing as marshall. If you notice something wrong, then you go about taking care of it, makes sense.

This post was edited by TheMasterGardener1 on Mon, Jan 6, 14 at 21:57

The property where we farm is 7 of 12 acres with at least 11 soil types because the two valleys and slopes have distinct geologies and the remaining grounds were graded. So soils types range for old blow sand over clayey stony river terraces through to black clayey Diablo soil series derived from Monterrey shale. Four of these soil types are distinct enough to be tested seperately and to be managed differently.

I've learned to read hunger signs in plants. In my orchard business I rely of leaf or petiole testing for nutrient deficiencies. For annual crops, I read the state of the old standing crop before prepping the bed. If the bed carried, say cabbage a heavy feeder, I would double the compost application and knife in bands of complete fertilizer. If the finish crop is a light feeder to be followed by a light feeder, we might just add compost. With annual, if you see hunger signs your are already in trouble. Plants do respond quickly to soluable N and to some extent micros but not much to P and K as a sidedress, at least in "organic" forms. Conventional growers could side dress with triple phosphate and get quick response.

I do test every couple of years, just to see wassup. I use manure, so I like to keep a watch on soluble salts to see if I need to skip manure some years. Plus, my native soil is 5.4 ph, so I need to know when/if I need lime.
Cost:
county extension service (in WV), free.
If I want slightly more info (like OM, or a baseline for heavy metals): U of Mass, $10.00

It's also like getting a grade on how well you're building your soil. Yay! I got an A+ in phosphorus! I think that's the other reason I test-- feedback.

This post was edited by elisa_Z5 on Mon, Jan 6, 14 at 22:34

"So say if a soil test shows you are missing a nutrient. What
do you do? You noticed the area was lower growth, so say you never get a soil test, what would you do differently? Do you directly apply something with the missing nutrient the soil test shows?"

Soil test normally just measure the soluble, plant available nutrients. So your soil test could show that you are deficient in soluble nutrients. But here is the kicker, soluble nutrients are only a fraction(around 1%) of the nutrients found in soil, the majority is locked immobile in mineral form. So you could have a soil test conducted, and your test results show you are deficient in various nutrients. However, these nutrients are already in your soil, just no in soluble form. The secret is getting these nutrients in plant available form. The soil food web break down these minerals and nutrients and make them available to the plant. Sand, silt, and clay formed from thousands of thousands of years of rocks and matter decomposing and breaking down into what we know today is soil. Think about all the rocks and matter that break down in those thousands of years. Look at our feet of soil we have to grow on. It takes hundreds of years just to make one inch of that soil. Once you understand that, it's easy to see that our soil(sand,silt,clay) is full of minerals.

The key to unlocking these locked nutrients in the soil is the organisms breaking down this matter, and then the predators eating those organisms and excreting the nutrients from that organism. That's a very simplistic view of the soil food web, theres much more to it.

If I received results from a soil test showing I am deficient in plant available boron, calcium, and copper, for example, I would then go about figuring a way to add the missing organisms in my soil food web. You could do this in various inoculates, composts, compost teas,etc.

Now if you don't get the life, the organisms that your soil needs, you will not have a means of turning the locked nutrients that your soil already has plenty of into plant available nutrients. So what do you do, how do you get nutrients to the plants? That's when synthetic fertilizers come into play. But, why in the world would you pay good money for synthetic nutrients when your soil already has those nutrients?

pH is quite important to availability. Different forms of different compounds of nutrients/toxins are more/less available depending upon pH. Fixation can occur at high and low pHs...there tends to be a "sweet spot" where it's most available depending on the dominate form in the soil.

Soil, and the chemicals/elements/etc in it, can have radically different profiles in soil chemistry depending on pH even when starting with the exact same makeup of components.

This post was edited by nc-crn on Tue, Jan 7, 14 at 2:42

As I have stated here numerous times, as well as urged others, I have had soil tests done many times. The initial soil test showed the soil pH was 5.7 and that P and K were low and that Ca and Mg were out of balance and from the simple soil tests I post here (some think too frequently) I knew the soil organic matter was too low.
We opted to work on increasing the level of OM and after 3 years retested the soil to find the soil pH was 6.8, P and K were optimal and Ca and Mg were closer to balance, and the soil OM was 6 percent, the soil held moisture better, earthworms and other, visible, members of the Soil Food
Web were present, the soil held together better, and the putrid odor was gone and was replaced with that of good, rich earth. Soil tests, done periodically, since indicate the soil pH has stabilized at 7.2 and P and K are now at high optimal and in balance, and Ca and Mg are in balance.
I have fewer insect pest and plant disease problems to contend with, and have not had BER in tomatoes in years.
Could I have had the same results without those soil tests? Probably, but I would not have known that I was going in the right direction.

When I started to develop this farm site 23 years ago, the OM% was 0.5. I don't recall now the rest of the soil test other than the CEC and various N measurements were very low and Boron very high. Green manuring (two cycles) barely raised the OM count; thus my move to compost most of the waste coming off the rest of the landscape, to compost horse manure from adjacent horse facilities, and to start adding quality compost to the beds. We stopped adding composted manures in 1997.

The latest OM levels were in the 5.0-5.5% range, and holding steady now for 7 years.

"If I received results from a soil test showing I am deficient in plant available boron, calcium, and copper, for example, I would then go about figuring a way to add the missing organisms in my soil food web. You could do this in various inoculates, composts, compost teas,etc."

Probably in most regions this is true - bumping up the activity in the soil web will break loose nutrients from the "locked up" sources.

However, be careful assuming it is always true. There are regions where a mineral is simply absent and no amount of locally-grown OM will provide it.

"However, be careful assuming it is always true. There are regions where a mineral is simply absent and no amount of locally-grown OM will provide it."

Thanks Brown! I just wanted to bring up the fact that the majority of fertilizers and nutrients don't need to be applied to the soil like we do today, it is costly on the farmer and the environment. We don't need to be trapped thinking we need a magic chemical to grow plants.

After all, what portion of soils are actually truly depleted?

A lot of priceless info. I am reading all of your posts now. Will respond in detail when I have a bit more time.

Thanks everyone!

"After all, what portion of soils are actually truly depleted?"

Well, in fact some very sizable regions are. The one I am familiar with is peninsular florida. B is not measurable there in soil tests, nor is Mn and some other traces. Even some of the macros are very low - not merely deficient.

A lot of priceless info. I am reading all of your posts now. Will respond in detail when I have a bit more time.
Thanks everyone!

You are welcome Mastergardener! It's my passion to inform people, especially you, the way you support synthetic fertilizers,etc. I hope, now, you can understand why most of these synthetic fertilizers are unnecessary.

I do a soil test every other year at least. Production was so great in 2013 that I skipped doing one in fall and will this year. As for what to do with the info, well that all depends. Our university has expensive tests and so I just do OM%, NPK, ph and one other thing each time. Last time I checked cal and mag. Then it all depends what the test shows as to what is done. The test will recommend a fertilizer type which is not how I deal with it.

Because I have sandy, high ph soil, high in P&K, I make sure to use N only fertilizer and spread lots of sulfur. My OM is never high enough so I use tons of compost and manure. The OM is creeping up in each test. We have had low rainfall for a couple years which worsened the ph.

As for chemical fertilizers vs. adding OM, well the fertilizers in general work great but just for a short time. I like to call them crack. The after effects are very sad. I have a neighbor beginning to garden and is just growing right in the sand. They obviously use a chemical fertilizer like Miracle Gro so the garden looks great for the first half of the year and then in the second half it is atrocious! The plants have withdrawal and the soil is no better off. It is all about the soil!!!

I am constantly fighting high pH. Soil tests range from 7.5 ro 7.9. pH of irrigation water is close tyo 7.10 during this drougtht (and 7.2 to 7.8 during wetter years. Even our compost pH finishes out over 7.2. We use some gypsum for the sulfur and the calcium for those crops that have higher needs (e.g. brassicas and solanaceae). We also use it with alliums along with steamed bone meal and a bit of sulpomag mined fertilizer.

It seems the more om in my soil, the better. I see some do battle ph, even with high om, so I must have good soil.

I read all yours posts and liked that you took the time to add it.Thanks again everyone.

Our soil and water tend to have high boron levels. Having high organic percentage naturally buffers and sequester boron and avoid boron damage to plants.

I have my soil tested every four years; generally speaking changes are too gradual for significant alterations to be noticed in any shorter time. The 2013 test presented me with two object lessons. First, organic matter is 9%, good. But how it got there was by over-application of compost, with the result that both potash and phosphate are too high. I would have been better off just using winter cover crops and leaf mold. Excesses are far harder to correct than deficiencies.

Second, trace minerals are good, except that zinc and boron are very excessive. The reason is that I gave myself a scare because I hadn't been concerned with traces, so I over-applied rock dust and sea minerals. So the benefit of regular soil tests, in my case, is that it showed up the results of my foolishness. I take some consolation in the belief, possibly unwarranted, that forty years of strictly organic practice have buffered the soil and thus mitigate the excesses insofar as high organic matter levels signify high soil microbes counts, and I have never used fertilizers or pesticides. All guesswork of course, but I do usually get high BRIX readings, so we're not off the rails yet. Regards, Peter.