# Phosphorous application



## mooch91 (May 5, 2019)

A Penn State soil test showed my soil deficient in phosphorous (26 ppm) and a slightly high pH (7.2). Their recommendation was to apply 2 lb/1000 sq ft of phosphate over the course of this season. I believe I had read the recommendation to apply no more than 1.0 lb/1000 sq ft phosphate in a single application.

I picked up some 11-52-0 MAP (monoammonium phosphate) yesterday, which will give me the phosphate plus lower the pH a little. If I apply all that I bought, I will be putting down about 1 lb/1000 sq ft of phosphate and about 0.2/1000 sq ft of nitrogen. Being from ammonia, the nitrogen will be fast release.

I had already been planning to put down a little bit of nitrogen each month through the growing season, including the summer months, especially since we've had nothing but constant rain which is depleting it readily.

Will the 1 lb/1000 sq ft phosphate application rate be an issue for late June? Should I cut the rate in half and save the other half for a later application? I'm just not sure if phosphate has the same potential as nitrogen for either burning or promoting disease and other issues during the warmer months.

Thanks!


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## g-man (Jun 15, 2017)

The nitrogen is fairly low. I apply MAP at 2lb/ksqft and will likely apply some today.


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## mooch91 (May 5, 2019)

g-man said:


> The nitrogen is fairly low. I apply MAP at 2lb/ksqft and will likely apply some today.


That was the rate I bought for and initially intended. That would be about a pound of phosphate per 1000.

So that high of a rate of phosphate should not be an issue during the warmer months? The nitrogen is the greater concern?


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## mooch91 (May 5, 2019)

Caution thrown to the wind... 2 lb/1000 MAP is down!


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## Ridgerunner (May 16, 2017)

The one pound of an amendment (K2O,, P2O5, etc.) is just a convenient rule of thumb. It's just an arbitrary guideline with a over abundance of caution. Even so, you haven't exceeded the rec as 2#/M of 11-52-0 is just slightly more than a pound of P2O5.


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