Mackel, it's easy to figure out exactly how much you are applying. Potassium Sulfate: K2SO4 Sulfur 18.401% Potassium 44.874% 20 pounds of 16-4-8 fertilizer is 1.6 lbs of potassium per 1,000 sq feet, or 3.5 pounds of the potassium sulfate. Multiple by 1.46 to get the quantity for the whole area. (5 lbs of K2SO4 scattered over the whole area would do it - the difficulty would be getting an even distribution and no hot spots) I should add 1/2 a pound of sulfur per 1000 sq feet the 3.5 pounds of K2SO4 has .63 pounds of sulfur in it (close enough for gardens) ============ Aw heck, this is too much finicky chemistry, and if you took different samples you would probably get slightly different results from the lab. The results aren't so far off "desirable" that it's worth the bother unless your plants start showing signs of a deficiency. Add a layer of compost and call it done and see what happens.

To me it looks, feels, and (most importantly) behaves like sand (at least in terms of drainage)... but I can definitely form a ball with it and it ribbons, which is a clear indication of clay. No, I don't detect any silt or clay by feel or appearance. And like I said before, the jar test settles to a nearly homogeneous sample of sand with a very tiny layer of either silt or clay. There is no 3rd layer to tell which it is, but I think its silt and the cloudy remains in the water (after > 24 hours) is clay. So in my latest jar (graduated beaker) I have 42 mm of sand and 4 mm of probably silt and I doubt the clay layer, if I can ever even measure it, would come to a single mm. That works out to 90% sand, 9% silt and 1% clay. Fully consistent with the behavior I see with drainage and what I've always thought I had. As I said in the beginning of this thread... I'm just confused because trying to confirm that with a feel test gives me an indication of the complete opposite. It makes me wonder if there's some 4th factor... some mineral or something, that perhaps is heavy like sand (so it settles and drains) but binds the particles when wet. I have no idea really. Again, I guess it really doesn't matter. It needs compost as a first step. Then I can start over.

Driven through St. Tammany Parish many, many times. You have a very similar geography (low, flat and wet) as where I am, 50 miles south of Houston. My guess would be that you're ~ 25 feet above sea level? However, from your soil test results, your soils are about as opposite of mine as can be. Your description of your soil is very consistent with the Stough series description. It is noted as being very strongly acidic, and below about 8" indicates signs of frequent or typical anaerobic conditions, probably from the high natural water levels. You have a couple of distinct issues, one being drainage, the other being the soil test results. On drainage, given your geography and the natural soil water levels, there probably isn't much you can do to improve soil drainage via percolation directly - the underlying soil is what it is. If you pick a spot for a bed an amend it you can improve the local drainage, until the surrounding and underlying soil stops it , then your improved bed becomes the "bathtub" of sorts. You may be able to help your situation out a bit by re-evaluating the lot grading and surface water flow in high rainfall periods. For a gardening situation your better bet would be a raised bed, with enough depth that the underlying poor drainage won't be a problem. Doing that you can construct the soil in the bed to be what best suits your needs. As for your soil test, I'm curious why you chose Dr. Good Earth rather than the LSU Ag Center lab? Did the sample come from just the bed area, or is it representative of a broader view of your landscape? If the results are representative, the very low pH helps explain the low Ca and Mg levels. My thinking is focus on correcting the pH using dolomitic limestone, which should take care of both Ca and Mg, then retest. The amount is dependent upon soil type, and this is where the LSU AG Center and the local extension service can be a great help with a specific recommendation, but it will probably be something like 100 lbs per thousand square feet. With the pH corrected, the P and K levels can be supplemented via common fertilizer options, or using organic amendments. Of course if you build a raised bed, that will likely be different soil. With soil like that it would probably be worthwhile to test the soil broadly, if you haven't already done so, and working to get the pH toward ~ 6.5. For any future tests I would encourage to use the LSU labs, as they have local knowledge, can guide you on appropriate amendments and amounts to use. I would also encourage you to add the micronutrient test in the future. I suggest that because the Stough series description notes a lot of variations in both iron (Fe) and manganese (Mn) concentrations. Here is a link that might be useful: LSU AgCenter Soil Testing This post was edited by TXEB on Thu, Aug 1, 13 at 20:52

Loam is defined as a mixture of sand, silt, and loam. The soil survey classification is about topsoil, not subsoil. Sandy loam with some organic matter added is nice to work with. Pure clay subsoil is common in many parts of the country and wouldn't be a problem except, in your rainy and low-lying area, it probably stays saturated most of the year. There is absolutely nothing you can do to improve drainage but raise the bed. Don't bother digging into the clay, because doing so will not help with drainage. (Mixing some clay into the topsoil might add minerals and increase water retention, though.) If you raise the bed 8" you will have enough depth of topsoil, and the upper part of it will drain. Phosphorus is easily added as 2-3 oz of triple super phosphate (0-40-0) per square yard dug in to the upper 8-10". Potassium is easily added from the surface with routine fertilizing. Once phosphate is established, a suitable NPK ratio would be 3-1-2 or 2-1-2. Dolomite limestone as an amendment will solve three of your deficiencies: pH, calcium, and magnesium. I am surprised the testing company did not recommend a particular amount of lime, but you can use the chart above. Aim for a pH around 6.5. It's great that you got a test, because there are problems that need to be addressed, but solutions are at hand. This post was edited by michaelg on Thu, Aug 1, 13 at 15:08