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Trumbull, CT 06611, USA

My soil test came back with a low Phosphrus reading. What is the recommended rate per 1000 square feet to put down of 0-40-0

Thanks, Ray

4/23/2004 6:29:21 PM

Montoursville, PA

Ray....have you discussed the why of this with your testing lab? Adding something that strong without being sure your existing is absoutely not just bound up by something else that is out of ballance could create more problems instead of helping. I think it is time to think and consider the why before taking action.

It might help if you printed out your complete test in ppms or percentages here so all angles could be considered.

4/23/2004 8:07:54 PM

Ctpumpkin@optonline.net

Phosphorus was 13PPM.

4/23/2004 8:50:31 PM

Montoursville, PA

Very interesting.

4/23/2004 9:54:30 PM

Covington, WA

Last year in my new patch the pre amendment soil test showed 2ppm of phosphorous. I applied at a rate of 5lbs per 1000 square feet. I have not gotten a test to see where my level is at this time, but I did manage to grow a series of personal bests through the season with the top one at 715 lbs. Phosphorous tends to remain in the soil without much leaching, however it can be bound up. pH is extremely important in the availability of P in the soil. I will be adding additional P this year, but at a much lower rate.

4/24/2004 2:59:16 AM

Ctpumpkin@optonline.net

Depth of till is the item. Plus we have to consider that P is expressed incorrectly on a bag of fertilizer.

If the desired level is 100 lbs of elemental P per acre foot (medium on a test result - 50PPM on an A&L report), deduct the PPM times 2 or in this case 100 (lbs desired) minus 26 (lbs here at Ray's) = 74lbs of P needed.

Convert Phosphorus in bag from P2O5 (phosphorous pentoxide) to P by multiplying by .44.

(So 40% P2o5 fertilizer contains .176lbs P per lb)

So 74 lbs needed divided by .4%P = 185 lbs/.44 = 420lbs/A/ft or 9.6 lbs per 1000 if tilled to 12".

So Ray needs to spread 10 lbs of 0-0-40 on 1000 sq ft tilled in to the top 12" to bring his Phosphate level from 26lbs per acre to the more desirable 100 lbs per acre foot.

For the record; it is very unusual to see a Phosphorus deficiency in CT.

Like Dwaine said, most soils in the Northeast have ample P. So managing soil pH is usually all we need to do to insure adequate availability of Phosphorus.

Steve

4/24/2004 8:54:59 AM

Montoursville, PA

I would do nothing and call for test evaluation or another test at the same place. I firmly believe there is knowledge missing somewhere. I would not respond to treatment for adjustment in this case untill I was absoulutely sure the test is correct...and that the level being read is not caused by some other yet undiscovered reason.

4/24/2004 9:37:12 AM