Question
Hi, I recently came across the allexperts.com website and read several of your responses to submitted questions.  I appreciated the advise/recommendations that you had to offer; therefore, I wanted you to analyze my lawn situation and provide some tips.  However, I knew that prior to gaining your advice you would prefer for me to obtain a soil test.  Well, I did and here are my results:
Soil PH - 7.5
Organic Matter - 3.8
CEC - 18.8
K-Saturation - 2.2
Mg-Saturation - 18
Ca-Saturation - 79.7
K/Mg-Ratio - .4
Ca/Mg-Ratio - 11
Phosphurus - 35
Potassium - 193
Magnesium - 463
Calcium - 5,114

This information is like a foreign language to me, can you help interpret it???  The main question that I have is where do I go from here???  Thanks in advance for your help!!!

Answer
Thanks for your question, Chad.  I apologize for the delay in posting your answer.  This is a detailed question that I can't answer quickly, and although I've tried to figure out the most useful answer I can give you, I must point out that providing your location would allow me to be more specific about the data you've received, and/or the facility that tested your Soil (and the way they conduct those tests).  Soils are very specific to the region that built them.  I just wish I could have been quicker about this.

OK, here goes.  Have a seat.  Pour yourself a cup of coffee.  This is going to take some time.  Ready?

We'll begin with your Organic Matter... CARBON!

Soil structure is one key to a beautiful Lawn, and that begins with Organic Matter -- the Carbon-based material that microbes break down and turn into Humus.  As the Samuel Roberts Noble Foundation's Ag Consultant, Dr Eddie Funderburg, explains, 'Organic material is anything that was alive and is now in or on the Soil.  For it to become Organic Matter, it must be decomposed into Humus.  Humus is organic material that has been converted by microorganisms to a resistant state of decomposition.'

www.noble.org/Ag/Soils/OrganicMatter/Index.htm

You know what I'd like to know?  Your Soil texture -- is it Sand, Silt, Clay?  A healthy amount of Clay boosts Organic Matter content, improves Soil Structure, and grows MUCH better Grass.  Your 3.8 is an acceptable level.  I recommend 'Organic Matter Explained':

www.microsoil.com/OrganicMatter.htm

It's just as important to keep what you have when it comes to Organic Matter.  Soil structure goes out the window when you cut into the surface and dig up shovels of Soil.  That's BAD.  And if you think organic gardeners and farmers are on the right track when they rototill their plots to incorporate Soil amendments, think again.  Writes Kansas State microbiologist Charles Rice, 'No-tillage is one management practice that often preserves or increases Soil Carbon.'
 
Rice does research on Soil at Kansas State. In 2002, he posted a feature 'Storing Carbon in Soil: Why and How?' in what was then called Geotimes (now 'Earth', the official newsletter of the American Geological Institute).  One finding: 'Carbon from roots may contribute more to Soil Organic Matter formation than does Carbon from straw.'

One theory is that 'roots have a higher ratio of Carbon to Nitrogen, which would slow decomposition and encourage formation of Humus...  Carbon in Humus lasts longer.'

And because Microbes manage the transfer of Carbon, 'Differences in the Soil Microbial community can affect the ratio of Carbon converted to Carbon Dioxide vs Soil Organic Carbon.'  Fungi keep the Carbon in the Soil, he notes; Bacteria tend to aim it skyward as CO2.
 
Which brings us to some of the latest Soil secret: Charcoal.

Until recently, scientists figured Charcoal was no big deal.  You might use it to filter water or air, but in Soil it was at best a mere filler -- inert but benign.  Then some of them analyzed the highly fertile TERRA PRETA from the Amazon rainforest floor.  This jet-black material, the color of Coal, was formed hundreds of years ago by indigenous farmers who burned crop waste to the ground, over and over, season after season, collecting Carbon -- because Charcoal is 70 to 98 percent Carbon.

When researchers analyzed samples, they found specialized Bacteria thriving in the rhizosphere of native plants, producing enzymes that sent nutrients into the roots, trading it for nutrients from the plant.

So keeping Carbon underground is now a priority in some circles; the July 2008 issue of Earth magazine notes that 'supplementing Soils with Charcoal ... boosts Soil fertility by attracting Microbes, trapping moisture and helping the Soil hold nutrients.'  The Charcoal-fertilizer trend even got its own international conference this year when scientists assembled for the first International Biochar Initiative Conference in September in England; the IBI puts out its own newsletter and hosts a website:

www.biochar-international.org/images/August_2008.pdf

So you know now that although it is not N-P-K, not even a nutrient, Organic Matter is a critical component of great Soil.  Tests indicate your Soil is 3.8 percent Organic Matter.  And this is where I need to know more about where you got this tested Soil from.  Let's look at the University of Minnesota Extension website:

www.extension.umn.edu/distribution/cropsystems/DC7402.html

As they point out in their essay 'Organic Matter Management', if your Soil is 5 percent Clay, and your Organic Matter drops from 2 percent down to 1.5 percent, the 'nutrient holding capacity' decreases 14 percent.  Silty Loam Soil, 20 percent Clay, lowering OM from 4 percent to 3.5 percent loses around 4 percent of the nutrients.  They declare, 'Building Soil Organic Matter may be the most important thing you can do to enhance long-term Soil performance.'

Got that?

Next:  Phosphorus.  Since your pH is 7.5, your P is under lock and key in your Soil.  Since we've already had one chemistry lesson for the day, I'll summarize: DO NOT ADD PHOSPHORUS or ANY FERTILIZER or AMENDMENT, and this includes Organic stuff, to your Soil.  Simply lowering the pH of your Soil will gradually free up all that Phosphorus.  You have too much; if your plants (or your Grass) start to show P deficiency, it's NOT because of a shortage of P, but because the pH of your Soil must be reduced to un-lock the Phosphorus molecules that are glued to your Soil particles.  And Chad, when you amend your Soil with anything, first confirm it is not adding Phosphorus; if it is, leave it on the shelf and use something else -- or NOTHING.  Remember, Phosphorus is the middle digit in the N-P-K analysis on the bag.

Where did all this Phosphorus come from?  Thank the fertilizer companies.

Phosphorus is the big juicy Tomato grower.  The gargantuan flower builder.  The major root-builder.  Fertilizer companies make sure you know that when someone wins the Biggest Watermelon prize at the county fair, they give all the credit to the fertilizer endowed with generous quantities of Phosphorus.

Superphosphate is like Miracle Gro on steroids.  If you use it on your Lawn, expecting to support a healthy and dense root system, you'll merely trigger a shortage of several other elements as the P shoves its way past them and takes up all available spaces.  In your Soil, you should BEWARE OF THE PHOSPHORUS.

Your Potassium (K), Magnesium (Mg) and Calcium (Ca) readings are at 'saturation' levels based on your CEC levels.  This is one of my favorite Soil features, because this is a talent you find in Soil that is high in Clay.  I don't know (not to belabor the point) if you have Clay Soil, but molecules that form Clay are like little closets where you keep K, Mg, Ca.

Ideally, Clay Soil would test 175 to 250 ppm.  You have plenty; do not add more.

In alkaline Soil (yours), Calcium is the dominant cation that reacts with Phosphate.

Copper, Zinc,  Manganese and Iron -- much like Phosphorus above -- slow down very quickly in Soil with a pH of 7.5.  This does not mean your plants need MORE Cu, Z and Mn.  They're super-glued to your Soil molecules.  Lowering the pH will open the floodgates and let them all out.

How do you lower the pH in your Soil?

First, lose the Lime.  Is it possible that someone (you?) Limed the yard just listening to advice out there from companies that sell Lime?  They don't know, and they don't care, whether you need Lime or not as long as you buy it.  Up, up, up goes the pH and voila! you have alkaline Soil, and don't even know it -- and your plants are sick, and your Lawn is chlorotic, and you don't know why.

But...

Maybe you DIDN'T lime your Soil.  Maybe your Soil is Calcareous.  If you could tell me where your Soil is, I'd be able to address this.  Beyond that, I don't know where to begin with a list of all possible fixes.  In fact, without knowing where you are, I don't even know what kind of Grass you would  grow -- maybe it NEEDS alkaline Soil.  Tell me more and we know where to begin with your pH problem.

Time for lunch.

rsvp

L.I.G.