# Algae as fertilier



## thewalnutguy (Aug 15, 2016)

I've got a 10 acre field of black walnuts I started as bare root seedlings about 30 years ago. Field is starting to look pretty nice, almost like a park. Just across the road from me is a good size pond with algae scum so thick it tempts one to try walking across it in the summer. There's a goat farm on one side of the pond, and I'm sure there's a fair amount of runoff from the property into the pond. Got me thinking that the algae could make good field dressing for my grove if I can come up with a good method to harvest it, then spread it with an old manure spreader. This assumes I can get permission from the person who owns the pond, of course. Anybody have suggestions as to harvesting and/or nutrient value of the stuff?


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## Del_ (Aug 16, 2016)

You may want to be careful of water borne diseases.


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## vanhalenps4 (Feb 6, 2017)

I don't think there will be any diseases that will affect your trees, as microbes that thrive in the water usually die when there is sufficient air and they will have to compete with the fungus and bacteria in the soil too.. However there may be some microbes that can make you sick from the goats and sitting idle. If you can oxygenate the pond for a while it might help kill any anaerobic bacteria, as they are usually the ones that cause problems. Good protection would be a must especially if you will be spreading it in a way where it can become airborne in a mist or dust... You may want to mix it with a carbon source and compost the mixture for a while to ensure any nasties are killed and also convert the nutes into a more useable form for the trees. Algae is used as a source for bio oil so there is a high oil content that may take a while to break down and may interfere with the surface ecosystem if applied right from the pond to the field. You could probably offer a "restoration service" to the owner removing the algae from the top and muck from the bottom which would be high in nutrients as well.. Then he would be able to use the pond for water


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## SeMoTony (Feb 6, 2017)

thewalnutguy said:


> I've got a 10 acre field of black walnuts I started as bare root seedlings about 30 years ago. Field is starting to look pretty nice, almost like a park. Just across the road from me is a good size pond with algae scum so thick it tempts one to try walking across it in the summer. There's a goat farm on one side of the pond, and I'm sure there's a fair amount of runoff from the property into the pond. Got me thinking that the algae could make good field dressing for my grove if I can come up with a good method to harvest it, then spread it with an old manure spreader. This assumes I can get permission from the person who owns the pond, of course. Anybody have suggestions as to harvesting and/or nutrient value of the stuff?View attachment 519783


There are over 3,000 varities of algae, from researching algae conversion into bio diesel. An answer here would not be what I would depend on. IMHO get permision now or seek forgiveness later & use water pump and screen arangement and try around a couple of the trees which are not going to be prime lumber anyway.


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## ATH (Feb 11, 2017)

Take samples of the algae and send them to a soil testing lab (call the lab first to see what they think...).

I'd just use a trash pump skimming off of the top if you can get it across the road without the hose getting run over too often (is it a busy road?)


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## Del_ (Feb 12, 2017)

disease in nursery retention ponds

https://www.google.com/search?q=disease+in+nursery+retention+ponds&ie=utf-8&oe=utf-8


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## Jason Douglas (Feb 12, 2017)

Can you compost and age the algae first?


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## sgbotsford (Jun 16, 2018)

I tried this with duckweed one year.

Mats of the stuff make fair weed barrier mulch. Works better than straw.

Collecting it: Rig your manure wagon with a removeable screen with about 1/2" mesh. Hardware cloth supported by concrete reenforcing mesh should work. 

Back your wagon to the pond edge.

Use a trash pump to skim the pond, pump the water into wagon, and let the water pour back out into the pond.

May work well if you can figure out how to support the snout of the pump hose at the corner of a 90 degree float. A couple of 2x4 studs make work well.

To help it along, make another float that you can drag across the pond to heard scum to the corral.

***

We have this as a problem in a local lake. (I am an occasional advisor on their board) Numbers:

It takes roughly 500 pounds dry weight of most algae to contain 1 pound of phosphorus. (the problem nutrient in ponds)

Algae runs 90 to 95 percent water. 

So it takes 5000 to 10000 pounds of algae to get 1 pound P.

N usually runs several times P, but the life span of N in a lake is only about 5 years, eventually being released as N2 gas, where P keeps recycling.

What may be easier to do would be to swap water with the farmer. 

Pump water from your place to his pond. Pump filtered pond water to your trees. The water will have probably a factor of 10 to 100 less nutrients in it, but it will be a lot easier to do.


***

One post mentioned disease in nursery retention ponds. Not the same. In that case the ponds are part of a complete cycle, and the disease isn't usually propagating in the pond. Bacteria tend to encyst in unvarioable conditions, fungi have spores etc. 

Some too depends on how fast the reuse cycle is. A pond with a one week retention time is far more likely to re-infect plants than one with a 1 year time. In this example, it's not a closed cycle. There is no runoff from the walnut grove into the pond.

The usual reason for nursery retention ponds is to save fertilizer -- you want to get that back at the trees/crops before some pond scum eats it, so retention times tend to be short. (Some ponds are present to reduce discharge into local streams and water table.)


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## ReidSmith (Nov 26, 2018)

It great option to use as a fetilizer, I will surely use it as a fertilizer.


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