fernando ribeiro

Hi Skandi,

Thanks for sharing. Your point though challenges at least one of the pillars of organic farming (at least for a large part within the permaculture movement). Specifically it raises the question of organic farming using more energy. Besides, organic farming in a large farm yields in principle lower yields, so we could say that productivity is lower regarding both lower outputs and higher inputs?

Hi Eino,

I think your thoughts are very much ontopic!

I would like to say that if you look up the invasion potential of a plant before you plant it... you can't miss much! About planting exotic species for diversifying diet i don't see anything wrong with that: I don't mind planting oranges (exotic) as they won't become invasive but I am afraid of planting bamboo (exotic) because i know it probably will take over the patch next to the water and eventually sprout on my neighbor abandoned and inaccessible land within a couple of years.

Definition of productivity: units of outputs achieved per unit of inputs. "Units" refer to energy: outputs are the calories of the yields, inputs englobe all the steps required for production, mainly energy used by machines and required to manufacture fertilizers.

Argument: organic farming is more productive than conventional farming because it uses less inputs. It is also more sustainable because our economy is based on oil, which is becoming scarce.

This argument is mentioned very often in defense of organic farming and its place in a post-peak-oil world. But how important is this as we head towards a carbon neutral economy (hopefully) by the mid of the century? If primary energy comes will be come from renewable energy sources (wind and sun), then all the tractors will be running on renewable power; the nitrogen necessary to manufacture the fertilizers will come from electrolysis done in renewable energy powered machines. Is the future greener for Big Ag?

Hi Dennis I get your point, if you have success in your plants and harvests then you are probably fixing enough nitrogen and minerals. But again that is bypassing the original question. At this point there is so much data collected in studies, I am looking after some tables that would tell me how much nitrogen one plant needs and how much other plant fixes (beside what it needs for self consumption). Because there is the risk of too much or too little nitrogen fixation...

One thing that is buried in the original article and overlooked in this comment board is the effect of the ash.

I quote the article: "The beetroots from the urine- and urine/ash–fertilized plants were found to be 10 percent and 27 percent larger by mass, respectively, than those grown in mineral fertilizer."

Anyway, great news for those that can pee directly on the plants or live close to where their plants are. Not so much for the more than half of the world population that live in cities... I agree with the article in the sense that the sewage infrastructure is not going to be revolutionized for making urine a product. We would certainly have a lot to gain with that, primarily reducing the volume of "waste" to be chemically treated and all the potable water associated with the process.

Hi all,

I am designing and implementing a food / forest / garden. Given it is a place I only go once in a while, my main aim is to optimize the design to keep it as low maintenance as possible, including the fertilization steps. I will be using mostly trees and shrubs, while keeping native ground cover (more on that later). I know that some designers suggest the use of N-fixing trees and I even opened a thread here (https://permies.com/t/165799/fixing-plants-distance); in that post was Bill Mollison's explanation on the intensity of nitrogen around a legume tree (basically, nitrogen is made available only under the tree canopy).

My question is about conflicting criteria. On the one hand I need to harvest the fruits so for practical reasons it is unreasonable to plant anything under the tree canopy, which I keep with woodchips (for discouraging weed growth and all the other good things you are aware of); on the other hand I need a lot of nitrogen for heavy fruiters which can't apparently be supplied by the other nitrogen fixer trees.
How to solve this?

I also heard about mycorrhizal fungi moving the nutrients around. This would be great as I am in the middle of an established forest so there is probably a strong network of them anyway, and the native groundcover and bushes are all nitrogen fixers. But can I really expect mycorrhizal fungi to move the nitrogen around these distances (say, 30m)?

Besides these questions, I would gladly read more about the facts and figures beyond n-fixing: how much nitrogen can be made available per species, how far does it spread, etc. Scientific papers would be more than welcome. It's just more often than not the info I found is not scientific enough: I know the principles of planting a guild with dynamic accumulators and nitrogen fixers, but how does that translate into outputs of these plants and how does that compare with my plants needs?

Thanks

Thanks for the info and inspiration, Konstantinos. I will be planting almonds soon!

Hi Eric, before posting I had read the whole thread and had understood your position; my comments were broader and concern more the idea put forward by Peter about "invasion" being a human concept, along with comments praising the fact that an invasive can be used because it is a nitrogen fixer (regardless). I just think we can't forget that in so many cases invasive species became dominant in a landscape because either they brought money along or other kind of benefit. Being a volunteer in your organization, you probably know better than me the yearly costs of fighting invasive species, and probably know more than me about biodiversity.

Without wanting to add extra noise to the thread, we should distinguish between invasive and naturalized species. Of course a huge part of what we eat comes from non-native species, but I can't stress enough how powerless we feel in Portugal and Spain about not being able to reforest native forests without huge workload after three decades of australian species take-over.

But clarifying my position about your original post: planting autumn olive where it already became so invasive is not a problem, so I would probably go for it after checking whether i could use some native or non-invasive alternatives.

Unfortunately, as noted only once in this thread (by Joshua) there is more in your area than your own parcel. Books on invasive species always mention how far normally a species can spread. Invasive species spread regardless whether humans have disturbed the landscape all around or not. I can give you example, Australian species have totally displaced many native parts of mediterranean forest, which was in part untouched before invasives arrived. These have the advantage of sprouting faster whenever there is fire, which by the way occurred before humans were around here. Then even if birds eat the autumn olive fruit, biodiversity is more than what a naked eye can see; native species evolved together with hundreds of other species (insects included) above and below the soil. Yes, native trees are taller and if we allow 200 years they would take over the forest by shading the invasives, but having the tools to fight the invasives we should do it. But beforehand, think about avoiding planting them? Just my 2 cents.

I ended up giving away the wood. I needed to do it on short notice and didn't buy the spawn on time. Maybe next time (there are more pines). It really is worth the experiment even if it is on just one pine, which comes at marginal cost. I will update the thread in that case. Thanks