up the P

my last soil analysis came back showing very little phosphorous . . just wondering if there is a way to make phosphorous more water soluable. i was thinking of making a tea... aereating some aged chicken manure and applying it as a soil drench. Is this feasable? anyone else have a "quick" fix ??


Paul Townsend
Orcas Island Wa

Phosphorus can be manipulated into a more plant usable form through co-composting, that is, adding it to the compost heap during its creation. Organic acids in the heap help make this happen. It also means you can spread more things at once. I would add that adding rock phosphate or colloidal rock to the orchard directly may also be a good idea, since you also want some nutrients out there to release slowly. Steamed bone meal may be a quicker source also, with the added benefit of nitrogen. Manure and urine soaked animal bedding will also contain usable forms of phosphorus.

Walden Heights Nursery & Orchard
Zone 3 in Vermont

Thanks Todd
I understand it takes a while for the phosphorus to become usable.I have been applying bone meal for years along with cover cropping and tilling , plus now i have spread alder chips throughout the orchard and introduced oyster mushroom mycillium to the chips. It all sounds like a good recipe for healthy soil ,but like i said the last soil test came back with a P difficiency .Maybe i just need to be patient ? last year was the first year that i started using EM .. trying to follow Micheals' magical perscription with the neem kelp and fish oil , comfery, nettles and horestail teas.
the soil here is clay for sure .
thanks again for input.

Paul Townsend

Hi Paul,

Here in NY I have been told by extension folks that woody plants like apples have such good mycorrhizal associations that they get all the P they need, even when soil tests show low levels. In fact, I have heard it said that in NY, there has never been a case in which apple trees in natural soil responded to P additions.

So, maybe you should do a tissue test this summer before you decide to add P.

Brian Caldwell

Hemlock Grove Farm
Zone 5 in New York

I second Brian's recommendations. Michorrizal fungi not only can make formerly unavailable P ready for plant uptake, but can access this phosphorus directly from the leaf litter/mold. Thus a soil sample which by design does not allow organic matter in the top inch or so in its sample, it would not show up. Since your sample is low, presumably the parent material in your area is low in P, so you may still have to add it in some form. Foliar feeding is most likely going to be your most effective short term answer, to carry you over until the soil ammendments kick in. Foliar feeding can help, but it is my understanding that there is not sufficient information that nutrients are transported well through the entire plant system, that many may remain in the immediate area of absorption.

This is a good example of how this idea of approximating a self sustaining forest like ecosystem will aid us. The acidic fungal realm can help us save some effort and dough. The acidity furthermore will keep P more available simply through the pH factor (high pH can lead to unavailable phosphorus). To complicate matters, low pH can be even worse through Al and Fe bonding.

Tissue tests are king really. UMass tests go for 25 for one including N, and 18 non N- which includes all the big players including P. Compare that with 20 bucks per bag of rock phosphate (50#) and we all can quickly misfertilize and waste money.

This is a great sort of subject, because it applies to all the nutrients out there. This is the time for those soil science majors out there to chime in and really tell us all what's what.



Edited 1 time(s). Last edit at 02/15/2015 09:50PM by Todd Parlo.

Use humates to chelate the P from rock phos, of which one application can last 5 to 10 years or more. Raw leonardite if you need the acidity: pH 4 (much better than sulpur for acidification). Better is the hydroxides extracted water soluble form used on soil( 12 lbs. / A = the activity of 20 tons/A or inch of compost) and also foliarly. I prefer the brand Tera Vita made on Russian patents and having 30+ years of research behind it. Go to www.teravita.com to read 24 pages on this research; 16 different modes of action in plants and soils. I think it is also a very strong stimulant for soil mycorrhizza that harvest P. Use a foliar product with phosphoric acid to get it in instantly "Fruit Mix" by Lancaster Ag Products based on Carey Ream's work, (www.lancasterag.com), though not "organic" is based on the plant biology. Bio assays may not indicate needed P levels very well as it is needed in much larger quantities as the catylist that drives all photosynthesis in the form of adionese triphosphate(sp), but doesn't become part of the cell structure; and thus is often the limiting factor nutrientwise.

BioRational Resource
SE PA
zone6b-now7a

Phosphorus, a much needed macronutrient in plant health, is yet another resource mismanaged in modern agriculture. Traditionally, farm and even municipal wastes were returned to the growing lands to be recycled into the ecological chain. Present in respectable amounts in bones and urine, and lesser amounts in most plant residues, farmers utilized the P in an economical way.

Currently most agricultural systems worldwide rely on geological deposits of phosphate rock, most now on the African continent. The mining is often damaging to the environment, without accounting for transportation.
Some facts:

Closed loop traditional systems recycled phosphorus nearly 50 times.
Nearly 90% of phosphorus worldwide is used in agriculture.
Geographical deposits of phosphorus are finite. (Actual figures are a point of debate currently).

Some things to do:

Since overuse is a common practice on farms and in gardens, get a soil test to determine levels. Also, since P is most usable to plants within a fairly narrow pH range, 6.5 to 6.8, strive for this level. Although soil microbes and good organic matter levels are helpful, P can more readily be obtained in a mineralized form for plant uptake. Too low a pH and it is tied up with iron or aluminum, higher pH and it is tied up with calcium. Since soils are often not at this level, it stands to reason that there may be a banking of P in the soil through bonding in a less soluble form (immobilized). Simple pH adjustments may make existing forms available for uptake.

As with other nutrients, it is about balance and understanding of the system. For those who are interested in nutrient dense farming and other popular approaches, they are only effective if you get the numbers and conditions right. Dumping any resource on the land in hopes that it will help can also be mismanagement. When nutrient are in excess, they may either be unavailable for uptake, or worse, available (mineralized) and thus prone to leaching (which in the case of P, leads to pollution and issues like algal blooms ). Re-cycling phosphorus containing farm and family waste products can provide a free source of P. As with all farm inputs, it is uneconomical to misuse them.

There is a current "Peak Phosphorus" debate going on for those interested.

Walden Heights Nursery & Orchard
Zone 3 in Vermont