Ian Thompson

Cécile Stelzer Johnson wrote:

Rico Loma wrote:Ian, could you write more about your efforts? Color me intrigued,  this sounds like a stellar idea

Indeed it is! and if you have access to a lot of dead fish, (like from a lake where all the fishermen can clean their fish) you have it made. I found the process at this site, which gives you the recipe and proportions fish/ sugar/ lactobacillus:
https://www.ridgedalepermaculture.com/blog/making-fish-hydrolysate
It sounds relatively simple, if somewhat stinky.

Fish hydrolysate, made correctly, smells more cheesy or ketchupy than fish.  Not a great smell, but mush better than fish emulsion and potentially better than collected manure.

Rico Loma wrote:Ian, could you write more about your efforts? Color me intrigued,  this sounds like a stellar idea

Yeah, of course, is there is something specific that you would like to know? I live north central Indiana.  The largest body of water is the Wabash River with some others being the Tippecanoe River, Wildcat Creek and the Big Pine.  You fine the silver carp mostly in the Wabash and Tippecanoe rivers.  They are phyto/zoo-plankton eaters.  Grass carp are vegetation eaters.  They have become very prolific many waterways across the US due to their accidental release and compete with natives for food sources and / or foul the water with poorly digested plant material waste. Neither of these fish are omnivores or bottom feeders.  Like all fish in most waterways PFAS are becoming an issue. They are very bony, but the taste of the fish is very mild. They are just a typical "white fish". Season them up and they are tasty. Very boney though so like I said, I typically grind them twice through a meat grinder and just make fish cakes.  

Silver carp are not easy to catch because they are not going to go for most things you bait a hook with it. Bowfishing or netting is the way to go. Bow fishing is super fun.  A great hobby for spending time outdoors.  These carp species are grouped in to the "trash fish" category (a term that is misleading and misapplied to native nongame species).  You can basically take as many as you want at most waters where they exist.

I have tried at times to do a "fish rotation" through my garden, where I would save up the filleted corpses of the fish and bury them along an entire garden bed all at once. There were plenty of nutrients there but the practice took up a lot of freezer space, required a considerable time of bare soil and did not do the soil texture any favors.  A cover crop rotation is much healthier. I shot two silver carp on Saturday which came to about 3.4 kg.  I chopped up the fish put them in devoted "gross blender" and pulverized them.  Then you add you about 3 parts water per part fish and molasses and mix it all up. Molasses ratios seem to vary from 1/3 to 1 per part fish.   Stir it daily and this time of year, in about two weeks you can strain it for use.  I think it needs to pH stabilized to store with out further decomposition.  I have read dropping the pH to 3.5 with phosphoric acid is a good way to do that. All this will make about 4 gallons of concentrate which is greatly diluted and then soil / foliar applied.  Considering that 2 fish will make 4 gallons of concentrate (they are pretty big fish) and typical dilution rates are like an 1 oz per gal , this is the primary fertilizer I will need.  Considering I can spray it on cover crops, this means the cover crops will further enrich the soil (not to mention all the good they do with endomycorrhiza), fish hydrolysate is a great way to go. I will also soak my biochar (also made largely from invasive species) in dilute FH solution, making....biocharp.  It is a nice little local loop.

I bow fish silver carp out of my local waterways. Grass carp as well.  Their diets make them a little safer to eat due to less bioaccumulation.  They are boney though. I typically grind them and then make fish cakes, bones and all.

I am also starting to make fish hydrolysate out of them now.

Phil Stevens wrote:Use it to inoculate biochar by soaking. As a bonus, you lose the stench.

I plan on it. I have over 100 gallons of char to process and char.  I will still have a lot of hydrolysate to store, as well as explore the possibility of being able to sell it.

Anne Miller wrote:Is that something that can be dehydrated?  Put it into the oven about 250 degrees over ni8ght?

I believe so, but it is energy intensive and potentially very stinky.  Also, I believe the heating may not be the best thing for the amino acids in the hydrolysate.  

Anyone have an inkling of an idea of how to make fish hydrolysate shelf stable? It would probably store in the fridge for long time after a successful fermentation, but what about on-the-shelf stability? The only I have really read is that some companies, Neptune for example, acidify the hydrolysate with phosphoric acid to make shelf stable.  

Just an update.  Following recipe similar to the one posted above we have made a few batches of fish hydrolysate.  Some have turned out better than others. Key to the process is the grinding or chopping the fish to small bits.  When the ferment is going well, I would not say smells "good" but it smells way better than you'd imagine.

I manage the Foot Bridge Forest Garden as part of the GrowLocal Lafayette sharing garden network in Lafayette, IN (we are Instagram).  I manage a few fruit trees at some of the other sharing gardens but the FBFG is an actual food forest meant to serve as both a place for people to forage for food and medicinal plants and a great habitat for native insects and smaller vertebrates. I manage it, in what I would call as semi-syntropic fashion.  There are apples, pears, various brambles, hardy pecans, black walnuts, butternuts, hazel nuts, elderberry, pawpaw, persimmon, dwarf chinquapin oak, bur oak, mulberry and Ribes sp. along with a plethora native and medicinal herbaceous perennials.  Aside from being a public foraging space, I am actively stocking the place full of as many cultivars as possible.  This is to that FBFG can serve as a local repository of propagation material so that future similar projects in the future can

I will say that one of the biggest challenges is keeping the fruit from being picked until it is ripe.  As such, one of the best and most useful / popular category of plants to install in forest gardens is brambles.  It is easy to tell when they are ripe and accessible to even the shortest statured garden visitor.  There are a few trees I would avoid in most cases, apples, plums, sweet cherries, and peaches.  In our climate they are just too prone to diseases or insects or both, making them too hard to manage even remotely productively.  I have also found that it is best to use vigorous semi-dwarf and or standard root stocks and plan on pruning.  The vigorous rootstock simply result in sturdier and healthier trees.  You have to prune them harder, but it is worth it as public food forests are hard on trees.  Lastly for the purposes of longevity and long-term thinking I am ultimately going to focus on promoting the nuts, pawpaws, mulberries and persimmon trees.  These species are either native or vigorous volunteers where I am.  I literally cannot keep the mulberries out...so I just graft named varieties onto them and go with what wants to grow there.

Good morning. I have a back yard garden, the annual portion of the garden is 300 sq ft divided among 7 raised beds.  I have a bit of additional room in large containers.  Maintaining soil quality and fertility is a struggle. I would prefer to use as little exogenous, bona fide fertilizer as possible. Mulching is great, but leads to a lot of bugs and slugs. Composting is great but is mostly about soil texture and soil biology than truly maintaining fertility.  I love to use manure but being urban bound, it requires just as much time/fossil fuel/hassle or more so than "fertilizer".  I have tried a few other things such as doing a "fish rotation" where I bury invasive carp acquired through my bowfishing efforts, but that requires a significant break in the garden space usage and does no favors to the soil quality because it requires lots of digging.

As such, cover cropping is an obvious approach and there are multiple benefits (added nutrients, organic matter, enhanced soil microbiological activity, decreased off-site transport) all the stuff we know about).  It does require me to "lay fallow" a garden bed or two, at least for a period of time while the cover crop grows. This eats into my food growing space.  Also, it is known that highest modulation of the nitrogen fixers happens as the plants get larger and ready to flower.  This means I either keep the cover crop in place for a good portion of the season or do a quick rotation and not get nearly the nitrogen I could.  There seems to be a lot of "grow cover crops, they are good" info out there but a paucity of info about their most effective time:space:nutrient gain in a garden setting such as mine.  Thoughts? Suggestions? Resources?

As a side note, two things.  First, I am going to seriously take on a project of making fish hydrolysate from the aforementioned carps.  This approach might truly be the panacea I need to maintain fertility.  Good nutrient ratios and the hydrolysate is said to enhance soil microbiological activity.  Second, my municipality finally has allowed chickens to be raised in the backyard setting.  This means I can include a chickens as rotation through my garden beds to control insects under mulch and add some fertility.  How long would five chickens need to be on 40 square feet working through mulch and weeds to increase actual fertility through their self-application of manure?