|A simple chicken composter|
Wednesday, May 18, 2016
Okay, first of all, let me say that I despise that phrase. The concept that people who are missing some facts that you have, fail to see their impact, or just don't care are somehow either asleep, bleating sheep, or both, is just insulting and really, really condescending. However, "I feel I may have some information that would be worth considering and perhaps incorporating into your cognitive model" lacks the same punch.
So what idea do I think is worth incorporating into your cognitive model? Let me start with the ideas that I believe to be mistaken. There are actually two opposite opinions that I want to cover here:
1) Nature alone cannot feed our population.
Hunter-gatherer societies cannot sustain large populations, even in a pristine wilderness. There just isn’t enough food available out there to go around. To compensate, we invented agriculture. But eventually that wasn’t good enough so we invented fertilizers and huge equipment. But we know that soon even that won’t be enough. We need to find ever better ways. Nature brings pests and diseases, so everywhere we see a hazard, we cut out nature. Hydroponics and large scale urban vertical farming are great examples. One book on vertical farming stated that urban vertical farms would be sealed with air locks, positive pressure would be applied to the whole building, and workers would have to change their clothes upon arriving, all to make sure no pests got in.
The problem with this thinking is that nature has developed some really amazing tools to work with, but most of them really only function properly as a part of a functional ecosystem. You can’t build that ecosystem if you are too busy excluding most of it or poisoning it into submission.
2) We should give up technology and move back to nature.
This opinion is the counter-point to fallacy #1. These people see the damage done by industrial farming and the wholesale destruction of natural systems and want to toss the whole thing and move back to nature. The idea is that the only way to fix the problems caused by modern life is to throw them out, go off the grid and build a regenerating farm using natural systems.
The problem with this is that just because a technology is being used incorrectly or inappropriately doesn’t mean it is inherently bad. Sure, some parts are bad. I think we could do without glyphosate entirely. But we have some really amazing tools at our disposal that could be a wonderful part of the solution.
So what new thought should be incorporated into people’s cognitive model?
The natural world has developed a whole host of tools that perform a spectrum of functions. It is only through understanding of those tools and their interactions to each other that we can truly solve the problems facing us today. Modern technology can be used in conjunction with natural functions to accelerate the functionality of the whole system.
In essence, by combining human technology and understanding of natural processes we can sort of hack nature to create something better than both, but that is still regenerative. Compost is a perfect example. You will never, in nature, find a well-aerated pile of decomposing organic matter of precisely the right mixture of high-nitrogen and high-carbon material. However, someone figured out that if you create such a thing, the process generates heat and supercharges the soil creation process. It is a combination of natural and human processes to create something that works better than either.
But compost is just the beginning. With a deep understanding of a wide variety of organisms and how they work, combined with some serious systems thinking, a whole new technology could be devised. We could use those natural processes and recombine them into regenerative solutions that solve problems, provide a greater quantity of local, nutritious food. In the process, we surround ourselves with life and bring nature back into our cities, living side-by-side with the people.
This blog is called Mad Bioneer. The –neer is a take-off from engineer, and to that end I like to gear the content here towards practical solutions. And I am not looking win-win here. I am at the least looking for win-win-win. Just how many different functions can we really fit into the solving of one problem? Let’s take a look at an example problem and see what we can come up with.
Problem: Food Waste
Description: Food waste is a huge problem in America. We leave it on our plates in restaurants, we let it go bad in the refrigerator, we let it expire in our cupboards. When thrown out, it rots and smells bad. It attracts vermin, from rats to insects, that in turn spread disease and become a nuisance.
I read a book on vertical farming recently and the author tackles this issue. His suggestion is to burn the food waste to provide energy to power vertical farms. I can’t imagine the energy density is all that great on food waste, and burning it just turns it into greenhouse gas without any side benefits at all. I think we can do better.
The immediate thought is to compost it. It would have to be mixed with lots of brown matter, but in most cities, that can be provided from yard waste. In the process, great soil is produced in large quantities. Win-win. Not good enough.
The bacteria consuming the food don’t give any other functions other than producing soil. Chickens would be a great addition. Scrap the addition of brown matter and feed the scraps to chickens. Chickens are omnivores. They prefer bugs, but will take food scraps and can eat just about anything we eat. They will gobble up leftover food, and leave behind some high nitrogen packets. In the process they produce eggs and meat. Win-win-win. Still not good enough.
If you dump a huge pile of food waste in a bin where chickens can get to it, it will start to rot. While chickens are omnivores, they aren’t scavengers. We need something else to do the bulk of the processing while it rots. Give the chickens one to two days with the pile of food waste, then move them to the next pile. Now we bring in black soldier flies. Black soldier fly larvae (BSFL) are voracious consumers of rotting food waste and thrive on high protein waste that is a little rich for earthworms. In the process, given the right container, they self-harvest and provide an easy, high-quality, high-protein food source. We have fed our chickens already. Let’s use this step for something else.
The BSFL could be fed to tilapia in an aquaponics or similar setup. The protein from the food waste becomes fish food. They process it into meat and their waste products go to fertilize plants in the other part of the system. So now you are producing meat and vegetables off of the waste reclamation process and you haven’t even gotten soil yet.
Unfortunately, BSFL don’t make very good compost. So they would just take up the early part of the process. They pick out the rich foods and the rotting foods and begin the process of breaking them down. But they don’t need to be left in forever. At this point, you add that brown material from your municipal yard waste collection to get the mixture right and add worms. This step will probably take the longest. But when the product is mostly complete, you can add the chickens back in and let them gobble up the worms and any other bugs in the system.
By carefully choosing the vermin we introduce to the system (chickens, BSFL, tilapia, and worms rather than rats and cockroaches), we are able to control the benefits the process confers. Sure, it takes longer, but look at all the production that is gained and value that is added.
Problem #2: Yard Waste – tree trimmings
Problem Description: Tree trimmings are a constant part of suburban life. We like our trees and we like them neat. But sent to the landfill, the organic material rots slowly in a low oxygen environment, producing methane and taking up space.
Some municipalities are now chipping the woody waste and composting it to produce soil. While this is a better solution, it still doesn’t add enough value. How about if we chip those branches up and pasteurize them. Then we can grow gourmet mushrooms on them, like shiitake and oyster mushrooms. While the mushrooms will do the hard part of the decomposing process, they won’t quite finish it off. Worms do a really great job of turning finished mushroom blocks into soil. The worms could then go to feed chickens. So now you have produced mushrooms, eggs, and meat from the process as well as healthy compost to add to soil.
These are just ways to handle resources destined for decomposition. The same thought process can be applied to a variety of problems, including food production itself. All it takes is some deeper understanding of the organisms and processes involved and some systems-level thinking. Let’s get on this.
Monday, May 2, 2016
The soils came to be called terra preta soils and have been the subject of much study. Due to the high concentration of pottery sherds, bones, charcoal, and other indicators of human life, it was obvious that the soils were made by a previous civilization. But it was initially unclear why the soils retained such a high degree of fertility, with fertility possibly even increasing over time instead of degrading as would be expected. It turned out that the cause was the concentration of charcoal in the soil that was doing it.
The study of this soil led to the discovery of biochar, a form of charcoal produced by pyrolysis, creating the charcoal at high temperatures and in a relatively low oxygen environment. The physical and chemical structure of biochar acts a lot like the carbon commonly used in water and air filters. It is extremely porous, leading to a high surface area, one that is really good at cation exchange. For the lay person, that means it bonds with a wide variety of compounds, holding them in place. In a carbon filter, this means it bonds with soluble lead, arsenic, and chlorine, things you want removed from the water so it is safe to drink. In soil, this capability is more applicable to nitrogen, phosphorus, and potassium. Biochar in soil can hold on to the very nutrients that plants need to survive and thrive.
The benefits don't stop there, though. Because of biochar's porosity, it is also very good at retaining water. Interestingly, the open structure of biochar seems to be an ideal support for microbial life. Beneficial bacteria and fungi thrive in the environment created by biochar. The nutrients bound to the biochar are easily accessible to the microorganisms crawling all over the surface, where they can become a part of the life cycle of the soil, eventually to end up in plants.
So what does it mean for food production? Biochar has a huge potential in agriculture. One of the great frustrations of modern agriculture is that soil fertility is falling. To combat that, soils are heavily treated with synthetic fertilizers. Those fertilizers wash away readily in the rain, meaning that more need to be added. But it also causes a problem downstream. All that fertilizer in the water causes an algae bloom. That algae bloom is followed by the algae dying. As the algae in the water column starts to rot, it steals oxygen from the water, killing fish, crustaceans, and anything else, creating a dead zone. The annual dead zone on the Gulf of Mexico reached 6400 square miles in 2015. All that fertilizer used to make that dead zone was purchased by farmers, each one hoping that that fertilizer would go to their plants.
So what if something could be added to the soil that helped all that fertilizer stay in place? What if that amendment also increased water retention, thereby increasing drought tolerance? What if it also increased beneficial microbial activity, the very activity that supports plant growth? And where does it come from? We really like having trees in our cities, and we like them to be well trimmed. Those trimmings typically head for the landfill. What if we diverted that waste product instead and made our soils better? That biochar could be added to farmland, and just like in the Amazon Basin, that fertility could be realized for hundreds of years. Biochar can take hundreds or even thousands of years to degrade in a natural environment, and it improves the soil that whole time.
But what about more modern, higher tech growing methods? Could biochar be used as media for hydroponics or aquaponics? I have seen a lot of discussion of the possibility online, but very little actual data on whether it works or not. I think that an analysis of what biochar does and how it would apply to hydroponics and aquaponics might be in order.
Again, biochar absorbs nutrients and holds on to them. It will do this with huge amounts of nutrients. Now, biological activity can access those nutrients (remember the "exchange" part of cation exchange) and help feed them to the plants. But that means two things for aquaponics and hydroponics. The first is that the biochar is going to absorb a LOT of nutrients until it is filled up. In land-based agriculture, the biochar is typically "charged" or pre-filled with nutrients before being added to the soil. In hydro- and aquaponics, that doesn't necessarily have to happen, but the grower needs to know that the biochar will take its fill before the plants can get it, and that process can take some time, perhaps weeks or months.
The second thing to recognize is that it is the biological activity that exchanges all those cations. Fungi is particularly active in that process, but bacteria are also important. Without that living system, the biochar will just act as a nutrient sink that will have to be filled before a regular nutrient profile can be maintained.
Biochar in a properly alive media would have a stabilizing force on the nutrient load of the media. Once it is full, the bacteria and fungi can access it if nutrients drop too low and it will absorb when nutrient loads are too high. Adding it while a tank is cycling might help lessen the stress on the fish, but the grower might want to refrain from adding plants until the nitrate level starts to climb, indicating that the biochar filter is full. Also, adding it as a supplement to the media rather than as a media in itself would be a good idea, perhaps 20% or less.
As for me, I do aquaponics with soil. The soil I create is a vibrant, living community that holds its own nutrients pretty well and should have no trouble accessing nutrients held in the biochar. I am working on expanding and creating new aquaponics beds and will be trying biochar as a supplement to the soil in the system, probably at around 20% of total volume. I will report back on how that worked when I have more information.