Can crushed rapeseed be used instead of rapeseed meal as fertilizer?

[proninyaroslav]

Hi. Traditionally, the Japanese use rapeseed meal as fertilizer. This is a non-waste production, they extract oil from seeds and use the resulting meal as fertilizer. But I wondered: is it possible to use simply crushed rapeseed seeds that have not been pressed for oil? Does the presence of oil affect the fertilizer quality, does it become dangerous for plants? Or vice versa, a large amount of oil in crushed seeds improves the fertilizer quality?

 

[sorce]

Reckon meal is a smaller particle than crushed.
Smaller able to decompose and have NpK value.
Perhaps the oil suppresses the decomp.

Sorce

 

[Wires_Guy_wires]

Oil requires entirely different microbes to break it down compared to 'cake'. Oil is hydrophobic and without the oil removed, other bacteria and fungi will have a hard time reaching the seed to break down. The oil-munching microbes tend to be pathogenic of nature; they eat live seeds, live roots and infect seeds and seedlings.
Now in a normal garden setting I'd say there's pathogens all around and it shouldn't do much harm to use crushed seeds. In a containerized setting, I'd not recommend using the stuff without removing the oil first.
If you look up BHO extractions used in cannabis, I think you could use the same technique to extract the oil from your seed by washing it with butane. You might have to freeze and thaw the crushed seeds a few times to get the cells to release all the oil. The butane will evaporate, so it wouldn't harm the plant later on. But.. Is it worth the hassle and the danger? I believe not. Pressing the seed would be possible too, if you're good with a welder, a diy press can be made in an hour.

 

[proninyaroslav]

Oil is hydrophobic and without the oil removed, other bacteria and fungi will have a hard time reaching the seed to break down. The oil-munching microbes tend to be pathogenic of nature; they eat live seeds, live roots and infect seeds and seedlings.

Oh, this is a very important point, thanks. I have several bags of rapeseed that I don’t need and I asked myself this question: why not use it as a bonsai fertilizer without oil extraction (after crushing it).

 

[Wires_Guy_wires]

Oh, this is a very important point, thanks. I have several bags of rapeseed that I don’t need and I asked myself this question: why not use it as a bonsai fertilizer without oil extraction (after crushing it).

You can always ferment it (google search bokashi), then use it as a compost or compost tea. No need to waste the stuff! With a good fermentation starter culture, there should be no pathogens alive after a few days/weeks. Fermentation inside pots is harder to do, because there's a lot of air in the air (yeah, I know what I said ;-) ).

 

[proninyaroslav]

You can always ferment it (google search bokashi)

In this case, I don't need to do oil extraction, since there are a lot more bacteria and they can cope on their own?

 

[Wires_Guy_wires]

They can, but it's not going to smell very nice. Since most oils and fatty acids tend to break down into something smelly, if they even break down at all.. But it's worth a shot nonetheless I think. If the Japanese were able to turn human waste into soy-sauce-smelling compost tea through fermentation for 1500 years, I assume that rapeseed could go through the same process. The worst that could happen is that you end up with foul smelling compost with a gunky layer at the bottom. The best that could happen is that you have a couple pounds of highly concentrated nutrients.

Here's some creative reasoning for another option: The seeds use that oil to grow and protect themselves, so why not germinate them in water, scoop them out, let them dry and die? They'll grow for a day or two, maybe three, use up most of the oils, and then you blend them to a cake/paste or whatever. Or you could ferment them after those few days.

 

[proninyaroslav]

Thanks for the ideas. I think the best option is to extract the oil using a homemade jack construction. The ideal oil extract in this case, I think, is not important.

 

[meushi]

Digging up an old thread...
You want rapeseed meal, but there are two types:
-fat meal (press extraction only, about 8% oil remaining)
-fully extracted meal (press extraction, followed by solvent extraction of the leftovers, about 1% oil remaining)

Most of the rapeseed meal you'll commercially find will be the fully extracted meal.

Maruta Tamahi from Joy Agris is pre-fermented fat meal. You mix the meal with water until you get a pancake batter-like consistency, you cover and let it ferment a few weeks. Shape it into a sausage of the thickness you want and chop it into 1" sections or use a carp boilies maker to speed up the process.

Knowing a farmer making his own rapeseed feed or pressing your own rapeseed are pretty much the only ways to get fat meal.