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Any advice based on these soil test results?

Posted by easychair z7 NJ (My Page) on
Tue, Aug 16, 11 at 11:28

I'm seeding a new lawn of turf type tall fescue within a month, and took several samples for the mix with the following results and recommendations from Rutgers in NJ. I'm a bit surprised by a couple of things they say like not to put down any compost and that my organic matter at 4.1% is high for silty clay loam. Does this mean I should keep adding it? I can tell you that I saw maybe only 4 worms from the 15 sites I sampled around my yard. Any advice on anything you see greatly appreciated!

pH: 6.65 Very slightly acidic

Lime Requirement Index: 7.80

Phosphorous: 94 (Optimum)
Potassium: 324 (Above Optimum)
Magnesium: 617 (Above Optimum)
Calcium: 3300 (Above Optimum)

Zinc(Zn) 6.59 (Adequate)
Copper(Cu) 1.97 (Adequate)
Manganese(Mn) 6.06 (Adequate)
Boron(B) 0.97 (Adequate)
Iron(Fe) 182.70 (High)

Soil Textural Class: Silty Clay Loam

Soluble Salts- Electrical conductivity= 0.13 mmho/cm

Organic matter by dichromate oxidation- Organic Matter= 4.1% Organic Carbon= 2.4%
High for Silty Clay Loam

"The soil pH is slightly higher than the optimum range of 6.00 to 6.60 for the growth of most Turfgrass, cool
season, but no correction is needed. Do not apply any limestone, compost, or wood ashes to the area. The pH will
decrease naturally."

"Target ratio for fertilizer product is: 1-2-1"

"The estimated nitrogen (N) need for initial establishment of this new seeding/sodding is 1 pound per 1000 square

Follow-Up Postings:

RE: Any advice based on these soil test results?

Here are pics of my mixed soil samples shaken in two jars with two different amounts of water and allowed to settle. Can you tell by the pictures what the proportions of sand, silt and clay are? I can't.

Here is a link that might be useful: Jar O'Dirt

RE: Any advice based on these soil test results?

From the photos it looks like your soil is predominately sand and some coarse silt. You can't see medium to fine silt and clay sized particles with your eye, and so it looks like these make up the uppermost layer. One problem is you really should remove all of the organics from the soil before you do this kind of test, but that's usually beyond what can be done, as it involves either burning off the organics or dissolving them in a reactive solution. The soil test indicates a silty clay loam, which simply means about 75% of the inorganic component of the soil is sand and silt. Overall, the results look good.

RE: Any advice based on these soil test results?

I am no means a soil guru, but I will give you my two cents. Your Ca:Mg ratio is on the low side, 5:1. 10:1 is a more optimal ratio. It's not a huge deal but if your soil is on the tight side this could be the reason. Gypsum can raise your calcium levels without affecting pH like calcitic lime would. You can add OM as well. 6-10% would be great. Other than that everything looks pretty good to me, but again, I am not a soil guru.

RE: Any advice based on these soil test results?

Thanks a lot, you two. I'll consider the gypsum, but I guess I don't want to increase the calcium either since it's high, right? Is there a way to lower the magnesium instead?

I don't understand why they would say not to add compost.

RE: Any advice based on these soil test results?

Don't worry about them saying it's high, it isn't detrimental at all. Obviously you aren't going to raise your calcium to 6000 to get that ratio, but adding calcium will displace some of the magnesium. Again, it's not a big deal, but it will improve your soil structure.

RE: Any advice based on these soil test results ?

Okay. Thanks.

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