Spent grain as fertilizer ?

[Brewer3401]

Sorry if this has been already discussed.

Does spent grain have enough nitrogen to bother putting on top of hop mounds.

Good or bad idea.

Thanks

 

[mistercameron]

I put a little bit into my worm composer and they go crazy over it... but only in small amounts because it will mold pretty quick.

 

[GilaMinumBeer]

Sorry if this has been already discussed.

Does spent grain have enough nitrogen to bother putting on top of hop mounds.

Good or bad idea.

Thanks

No. It will actuall use Nitrogen already in the soil to feed the microbes for decomposition. And, it will use a LOT of Nitrogen to do it.

BUT, if used as a light top dressing it makes for a decent mulch. I say light because it will form a hard crust making it difficult for new shoots to emerge and for water to get to the soil below.

Best bet is to either mix the hulls into the soil to improve the texture or, compost them elsewhere. they can cause quite the stench if done the latter but it can also be managed if you have the time.

 

[Brewer3401]

Didn't know about depleting nitrogen - thanks.

We compost, but knowing about the stench, I'll pass on that disposal technique.

Thanks very much for the info.

I lightened up my soil with sand - drains very well, and hops are growing fast.

 

[edmanster]

I've always just put them out onto my patio to dry and then brush them into the grass.. Is this hurting my grass? I do use a good nitrogen fertilizer to turn my grass dark green quicker tho...

 

[GilaMinumBeer]

I do use a good nitrogen fertilizer to turn my grass dark green quicker tho...

At least once the yellow pool has dried.......

 

[edmanster]

At least once the yellow pool has dried.......

Lol... Got rid of the pool.. I was the only one taking care of it

 

[Julohan]

I guess i should stop dumping the spent grains on the big elm tree then.

 

[usfmikeb]

Good for composting, not good as a soil amendment.

 

[br1dge]

+1 to composting them

 

[B-Hoppy]

No. It will actuall use Nitrogen already in the soil to feed the microbes for decomposition. And, it will use a LOT of Nitrogen to do it.

I always thought the same thing but according to this article it's considered more of a nitrogen source: https://www.uaf.edu/ces/publications-db/catalog/anr/HGA-01026.pdf

Anyway, I would compost it before putting using it on your plants just to be safe. That's just me though, I like making compost. Have at it.

 

[jd3]

I use it in my worm composter, does very well.

 

[B-Hoppy]

Roger That! It's a very nice addition to any compost pile. Mine is mostly ground up leaves and then grass clippings during the growing season but whatever I have available for free gets tossed into the mix.

 

[NPK]

I have conducted research using vermicompost and animal waste compost in vegetable production. Since B-Hoppy provided a publication that gives the carbon to nitrogen ratio of the spent grain, I can give a little information as to what is going on and maybe a couple pointers.

Microbes utilize carbon for energy and nitrogen for growth (DNA). Therefore, a proper carbon to nitrogen (C:N) ratio is needed for composting. Nitrogen becomes unavailable to plants as it is absorbed by decomposers. The C:N range at which available and unavailable nitrogen tend to intersect are 20:1. Ratios lower than 20:1 net available nitrogen while ratios higher than 20:1 net a loss of nitrogen, generally speaking of course.

With C:N ratios of spent grain ranging from 12:1 to 17:1, an overall release of nitrogen can be expected. Personally, I would balance the grain out with 'brown materials' (shredded newspaper, leaves) and produce a balanced, well aerated compost to amend the soil and give the plants a little supplemental fertilizer as some of the nutrients will still be bound up by the microbes.

The publication said that little amounts of phosphorus and potassium are supplied by spent grain, at least for the first few years. Picking up some balanced fertilizer like 12-12-12, or Miracle Grow for tomatoes (18-18-21) can quickly supply the plant with nitrogen, phosphorus, and potassium.

Smells coming from compost piles are generally due to anaerobic conditions created by too much water. Fermentation reactions occur in anaerobic conditions (as we all know here) and methane gas is formed by certain microorganisms. Remember to keep your piles moist but not wet, and keep them well aerated by turning them and utilizing materials that will provide adequate air spaces.

Here are some general C:N ratios of common products:
spruce sawdust: 600:1
hardwood sawdust: 400:1
newspaper: 120:1
wheat straw: 80:1
bluegrass - fertilized: 31:1
finished household compost: 20:1
alfalfa hay: 13:1
hairy vetch cover crop: 11:1

Most of this came from The Nature and Properties of Soil, 13th Edition, by Brady and Weil (2002).

If you have any questions ask away or feel free to PM me.

 

[AHR]

Does anyone know spent grains effect the PH of the soil?

I'm thinking since the acids are soluble that most of them leach into the wort and I don't need to worry about it lowering my PH, which is good since hops prefer Alkaline soil.

 

[PapaBearJay]

Does anyone know spent grains effect the PH of the soil?



I'm thinking since the acids are soluble that most of them leach into the wort and I don't need to worry about it lowering my PH, which is good since hops prefer Alkaline soil.

That's not completely true...

Hops will grow on a variety of soil types and pH's. They tend to prefer slightly acidic soils (pH ~6.5) but will perform well in a wide range (pH 6 - 8) provided all other needs can be met.

Part of this is also variety dependent, and you're right there, as some varieties will enjoy slightly more alkaline soils (pH ~7.3+) but generally speaking as a whole this isn't the case.

As the pH changes up or down, the nutrients can become more or less available to the growing plant. Generally speaking, an alkaline soil tends to hold onto more nutrients making them unavailable, and acidic soils have them more freely available (sometimes too freely, which leads overabundance and toxicity issues).

It's all about factoring in your starting soil, and how you can modify it to provide the optimum growth!





Sent from my iPhone using Home Brew

 

[Flboy]

Delet. Just realized all I did was repeat previous reply.

 

[Flboy]

No. It will actuall use Nitrogen already in the soil to feed the microbes for decomposition. And, it will use a LOT of Nitrogen to do it.

Very true. I have been a city farmer for over 40 years. Compost first. Easy, just mix with a little soil and let the worms do their job. And as said, for mulch, very thin. Mix it into other material.

 

[AHR]

@PapaBear Jay

Thanks for the response , did not completely cover my question.
I should have said a more alkaline soil then what I have (I've conditioned myself to think of anything that is less acidic then my soil as "Alkaline" I know this is not actually true).
My current PH is around 6 (assuming nothing drastically changed over the winter), its fine but I don't want to lower it further by constantly adding spent grains if they are still acidic. I guess I could just test the the spent grains, but I used up my test kit month ago and am not planning on getting one anytime soon.

Again, Does anyone know if spent grains are acidic, or if the acids mostly leach into the wort, and if it is acidic, any suggestions on gauging how much of an effect it will have on my soil over a long period of time from dumping.

 

[BBBF]

Last fall, I put it on top of some new grass seed and the grass did better there than in the places I didn't use spent grain. Maybe the benifit of keeping them most did more good than it acting as a fertilizer.