Anyone interested in growing plants should watch this video.
It's amazing what these organisms can do!
Let me know how you liked the video, lets discuss.
Here is a link that might be useful: Soil Food Web
Or download and read the Soil Biology Primer written by Dr. Ingham and others, or do both.
Here is a link that might be useful: Soil Biology Primer
And then discuss?
I couldn't quite make it through the video (time constraints) but a really fascinating book about this is Teaming With Microbes. Definitely makes you feel like Conan the Destroyer when/if you dig in the garden!
Since I try not to dig, I have noticed that keeping a layer of mulch is important to keep soil from being compacted by weather.
Did I hear Dr. Ingram say/imply that manure was not good for soil biology?
I thought she was referring to the tilling in of manure -- so, the tilling, not the manure. Unless I missed something since I didn't finish the video.
Quoting Dr. Ingham: "...When you only till once and that's it, you don't have any impact on soil fertility. Its when you start to add manures onto that soil surfaces and the manures can come with a high amount of salt, now you have a second negative impact. You may have more than one or two negative impacts and now we watch fertility start going down the hill."
I went back and took word-for-word what she said and it is now obvious that she views manures as a dangerous because they can have a significant concentration of salt. This suggests a potential problem with fresh manures as opposed to long term composted manures since rain tends to wash the free salt away.
The question I must now ask is which manures have the higher salts? My current preference is horse manure but I never thought to ask about salt before I saw this video.
The next question is does it really matter in Florida? Drainage is never a problem since we have a few inches of topsoil then several feet of builder's sand and limestone.
I saw adding horse manure as an easy way to get organic matter to build my soil. Is this a potential problem?
False alarm. From this link it seems I don't have anything to worry about because;
1. Horse manure tends to have a lower salt content (though significant) than most other manures.
2. I use it as the bottom layer of my beds. I never plant directly into it. The top layers are worm casting, peat moss, sand.
3. It sits for at least a month before I use it.
4. Florida is REALLY well drained.
Here is a link that might be useful: USE OF MANURES AS SOIL AMENDMENTS
A salt is a compound created by the reaction of an acid and a base. A salt may, or may not, be something undesirable. Whether a salt might be good, bad, or indifferent depends on which salt you are referring to.
Here is a link that might be useful: salt
Sodium chloride salt is an issue with some pig manures depending on the farm/animal management and how much (and how many years in a row vs rainfall) you're applying.
For most other animals the NaCl addition is pretty much negligible.
It used to be an issue with horses, but the past 10-20 years the amount of NaCl amended feed given to horses has severely lessened with better knowledge that many horses were being given too much. Many stables will use a feed not amended with salt and use a salt lick (or the other way around) whereas in the past they were getting dosed all the time with everything but the water they drank.
actually, it is more important to be extremely careful with tilling in florida sand than most anyplace, because it takes a long time for microbes to get established. To achieve anything like the web that typically exists in heavier soils in cooler climates requires adding some minerals to the sand and then keeping the ground covered with thick layers of mulch.
Deal with weeds by hand-pulling.
Yes, I can understand why. This Florida "soil" drains easy but it also dries out fast which would hinder the formation of bacteria/fungi colonies. I have even begun to cut up large limbs from my tree pruning into 6-12" chunks and place them deep into beds/new tree planting holes then add 6-12" of amended soil, compost, worm castings, peat moss atop. It beats having it hauled away to waste and as it slowly rots it should act as a water store for the plants to get through dry periods.
By accident, I seem to be addressing some of those "tilling-in-Florida-sand" issues. The fresh worm castings I add to the top layers of my new plantings should add beneficial soil bacteria/fungi to the growing medium (I grow my own castings). I do add a thick layer of mulch 'round new tree plantings and atop new beds to control weeds and retain water.
Please keep me posted over the next year or two, I'll be quite interested to know how hugelkuture beds perform in florida sand.
I musta read this "hugelkuture " idea a while back and it stuck in my head. Never knew its formal name till you mentioned it! Thanks! I never dreamed it was such an elaborate concept. http://www.richsoil.com/hugelkultur/
Please answer a question that has been nagging me for sometime: Given the law of conservation of energy/matter can neither be created nor destroyed, how do the straight tilless farming people overcome the loss of organic matter each harvest?
Because we westerners abhor "nightsoil", are we doomed to produce our food in an ultimately non-sustainable way? Are we doomed to either add chemical amendments or organic matter (from non-sustainable sources) back into our soil to replace the mass of our harvests? Is there something I am missing?
Watching that video of Dr. Ingram, I found her confidence and her "yeah, we got this!" attitude very attractive. It is as if she had unlocked the secret solution to the formula that Derrick Jensen said could not be solved. He said no agriculture is ultimately sustainable. And, that the last sustainable age of man was the stone age. A truly gloomy analysis. However, I have never been able to shake the feeling that he's right.
Tilless agriculture people seem to suggest that the soil can be built up over time and improved by not tilling and crop rotation while we harvest year after year. How is this possible? What is the mechanism??
There is no way to keep 100% of what you put into a soil in any method of soil management.
Between what is lost to the atmosphere (majority of loss) and leaching (smaller losses), management will never come close to 100% retention without it being buried/sequestered so deeply it's practically useless to agriculture.
Organic matter and volatile nutrients "disappear" over time by their very nature...both chemistry and forces acting upon them breaking them down.
Losses of 20-75% to the environment + leeching vs what the soil sequesters or plants uptake isn't uncommon depending on what's applied, time of application, crop, and environment.
That said, even with systems promoting losses they still add more than what was initially there and build up over time. No till farmland over the past 15+ years has really done wonders in huge chunks of intensely farmed fields...and there's been a whole lot of it the past 15+ years to draw studies on. You don't get to keep it all, but you keep a little more incrementally which makes a difference as the years/seasons add up.
It gets a little more difficult/different in some areas, like the arid South-West where it's a battle to keep organic matter around even in the most conservative of systems.
This post was edited by nc-crn on Sat, Jan 4, 14 at 23:05
"...even with systems promoting losses they still add more than what was initially there and build up over time....You don't get to keep it all, but you keep a little more incrementally which makes a difference as the years/seasons add up. "
So there is a net gain in topsoil organic matter. Are there any measurements taken that you know of that can quantify this gain? This still means (unfortunately) that there must be constant, period subsidy additions of organic matter to keep this incremental buildup going.
However, there does not seem to be consensus as to whether this buildup is even real:
Baker et al. (2007) Tillage and soil carbon sequestration "What do we really know?. Journal of Agriculture, Ecosystems & Environment. Volume 118, Issues 1-4;
"It is widely believed that soil disturbance by tillage was a primary cause of the historical loss of soil organic carbon (SOC) in North America, and that substantial SOC sequestration can be accomplished by changing from conventional plowing to less intensive methods known as conservation tillage. This is based on experiments where changes in carbon storage have been estimated through soil sampling of tillage trials. However, sampling protocol may have biased the results. In essentially all cases where conservation tillage was found to sequester C, soils were only sampled to a depth of 30 cm or less, even though crop roots often extend much deeper. In the few studies where sampling extended deeper than 30 cm, conservation tillage has shown no consistent accrual of SOC, instead showing a difference in the distribution of SOC, with higher concentrations near the surface in conservation tillage and higher concentrations in deeper layers under conventional tillage. These contrasting results may be due to tillage-induced differences in thermal and physical conditions that affect root growth and distribution. Long-term, continuous gas exchange measurements have also been unable to detect C gain due to reduced tillage. Though there are other good reasons to use conservation tillage, evidence that it promotes C sequestration is not compelling."
So, no till may be less wasteful, more profitable and less damaging to the environment but it is really not sustainable.
...I'm crestfallen.... :-(
Soil Organic Carbon, or Matter, was lost not necessarily because of plowing but because it was not replaced. Soil Organic Matter is what the Soil Food Web feeds on and they digest it converting the nutrients that SOM contains into things the plants can use and in that process it "disappears", The SOM needs to be replaced regularly and that is why Ma Nature produced a variety of plants that contribute material to the soil.
This is becoming an interesting thread.
Of course the loss of historical SOM (or SOC as per the linked article) is due to first clearing trees and shrubs and then frequent plowing, or simply plowing grasslands. The fact that it was not replaced simply reflects the fact that it is not possible to "replace" in a short time SOM that took centuries to build up. We are talking big scale here, not gardens where one can simply keep up with the loss by composting yard-clippings.
What NC is saying about the reality of loss of inputs seems right on to me. However, the difference between 20% loss and 70% is really huge and impactive and we obviously need to shoot for the former.
Bouk, be advised that florida sand is one of the more difficult places on the continent to attempt an increase in SOC. It ends naturally to be between 1 and 2%, and is highly resistant to change due to the very high losses in both direction that NC mentioned: warm air year-round makes very high atmospheric losses and the super-drained sand makes high losses to leaching. Both can be reduced with deep mulch and never bare the sand if possible.
I think that one of the better tools that some big farmers are using now is cover crops. These crops tend to crowd out winter annuals [weeds] and leave a more weed free surface in the spring. They also sequester nitrogen, bring up minerals from deeper levels, they make organic matter for the soil, and help against erosion in fall, winter, and spring. One problem with such a useful cover crop as tillage radishes is the difficulty of establishing a stand early enough in late summer or fall [after a cash crop] to do enough good. I can get good results in the portions of my gardens that are cleared early enough, but farms are different.
I read on AgTalk where farmers from Minnesota and the Dakotas say they need 'black dirt' exposed in the spring to get enough heat and drying in the soil to plant corn or soybeans early enough to be practicable. Some may say, "Well, don't plant corn. Plant more peas and dried [like soup] beans." Yeah, but you can only sell so many of those.
They'd sell a heck of a lot more food legumes if people ate a lot less meat products, as back in the day.
As we traveled, last December, to southeast Ohio and passed by many large farms we passed in Michigan, Indiana, and Ohio, that during the growing season have acres of corn or soybeans I noticed that very few had any cover or green manure crops growing. Most all of the fields I saw were barren with maybe some corn stubble partially tilled in although a few did have some green growth. Photos I have seen of large tracts that grow grains tell me that very few plant cover or green manure crops.
I'm sure that the quite large cost for cover crop seed is a disincentive. Growing grain is a very low-margin business, typically, right? The cost of seed and the extra passes to sow and till it in would likely eliminate the profit. I think at large scale one either improves land or makes money, but not both.
"Most all of the fields I saw were barren with maybe some corn stubble partially tilled in although a few did have some green growth. "
You are correct, here in Ohio, at least where I'm from, few plant cover crops. Most till in the organic matter in the fall, and leave their fields bare all winter. As pnbrown says, it is an additional investment, that brings little if any profit.
I rarely see even small home gardeners planting cover crops..
Every few years I grow cover crops on a third of my vegetable ground during the winter months and till them in early Spring. I tried no till but was plagued with snail, slugs, and rodents. If I waited too long to till in the cover crops, I induced early insect pests to move into nearby croplands. Since we rarely spray for pests, I look to migrating lady beetles to clue me as to optimum time to take down the cover.
My soils tend to stay cool for much of the year and so for a long time fungal associations tend to dominate. Once soil temps hit the mid 60s, bacterial dominance comes to release lots of gaseous and soluable N and other products. We try to time our transplanting of early summer crops to soil temperature.
Talking about cover crops/green manures, and are they worth planting? I found a great video of several farmers adopting a no-till cover crop system, each one of those farmers seen great benefit. At the end of the video the farmers were talking about a 10% increase in corn and a hundred pound increase in Cotten..
Here is a link that might be useful: Cover crops, are they worth it?
I always see a great response following a green manure cropping cycle. My problem is not having enough ground in production to recoup the lost income from crop sales off covercropped ground. If the results were "a wash", that would be okay, but the resulting higher yields are never enough to recoup the lost income for me. We crop year-round, and do fallow specific beds or sections at any time of the year to rest the ground or to break a pest cycle.
I'm in your same boat my friend. I could invest $30 in a 56 lb bag of rye, which i used to, but I got the thinking, is this really sustainable? I can not grow the rye, why should I be dependent on a store. Besides, the rye delayed planting..
What does one do, if they can't grow cover crops? Would thick leaf mulch on the soil be enough to protect it from the cold, erosion,etc? What is tbe next best alternate to cover crops? Who knows, maybe thick leaf mulch is better, in some cases?
One big reason that more cover crops are not grown on Midwestern farm fields is the time frame to establish the cover crops. Yes, rye can be sown in October, but then it has the additional onus of having to kill it off before planting a spring crop. Tillage radishes need to be planted by September 10 to really flourish. I know this by experience. A few have tried aerial seeding in the fall. In fact it was done across the road from me, but it was entirely too late in the standing corn.
If one is trying to add organic material (and thus added nutrients) to the soil, grasses create more biomass below ground, upwards of 80% if unmowed. Winter killing of covercrops is sometimes spotty even in cold climates but our covercrops flourish in our warm winters.
Some crops, such as broccoli, seem unaffected by weed competition once the plants have sized up, the crop being very deeply rooted. There is then an opportunity to undersow a groundcover.
That's the trouble I've had with cover crops -- even oats don't reliably winter-kill. Though if I'd sowed any I'd have good luck this year -- minus 21 tonight, with wind chills of minus 45.
I mulch with hay, and last years soil test, with borings taken from the most barren looking places (no hay residue) showed 8.5% organic matter.
I planted some rye once. It has to be mown and tilled up in spring [to be organic minded]......not my idea of fun if a very large area.
I find the radishes work very well here. They winter kill easily. I can plant them after the first 6 plantings of sweet corn. I chop and shred the corn stalks in place. Also they work in well after spring broccoli and peas. Also they work well on any unused plots if sown July 1st or later.
Lowenfels and Lewis ,who wrote Teaming With Microbes, a Gardener's Guide to the Soil Food Web, say that vegetable gardens need compost and/or mulch that is bacterially dominated (because vegetable plants prefer their nitrogen in nitrate form), and that trees and shrubs need mulch that is fungally dominated (because they prefer their nitrogen in ammonium form). From this, I had gathered that spreading leaves on a veggie garden would not be approved of by these authors because the leaves encourage a flush of fungi where you want more bacteria than fungi. But I often read on the garden web about people using fall leaves in the garden, so it seems to work.
What do you folks think about the whole bacteria/fungi -- greens vs dry leaves issue?
Elisa, my experience over a lot of years of experimenting with minimal-till and a lot of brown matter kept on the surface of the soil - light soil - says that such systems run very low on N and bacterial action. High-fertility crops struggle and low-fertility ones like root crops do pretty well, also legumes generally do well.
For the non-lugume fruiting crops there doesn't seem to be an alternative to incorporating some high-octane fertilizer, whether compost, manure, or synthetic.
I make over 100 tons of compost a year; all through a thermic phase to kill off weed seeds and pathogens but finishing up as fungal-rich compost. Spreading and lightly tilling in these composts seem to support vigorous annual plant growth. Much of fungal material is disrupted by the screening and later handling, so become the feed for soil microorganisms.
I used to worry about the issue of bacterial versus fungal but found that the fungal-rich compost tended to break down in the soil slower and over a longer time so that the plants did not receive a spike of nutrients and than much less before the end of the cropping cycle.
That is a good point.. I mix my leaves with grass clippings and various other green plant material.. Like composting on top the soil. You could also promote bacteria domination by adding bacteria dominated compost, compost tea, etc.
All in all, I believe that if you have a complete thriving food web in the soil, your pretty good at that point.. Organic matter buffers everything to some degree.. Plus, the plant will promote it's own partial environment.
Hmmm . . . I've been figuring that the hay I use to mulch has been a "green," encouraging bacterial growth. But the "is hay a green or a brown" question seems to have different answers. This is definitely not alfalfa hay -- it's just good old west virginia what ever is growing hay. And if it is old by the time I put it on, then maybe I'm actually mulching w/ brown.
I'm thinking this because my veggie results are similar to what you describe above, Pat.
I like to read what farmers are posting about farming methods like full tillage, strip tillage, and no-till. See, I grew up on the farm and am surrounded by farms for miles.
Every style can give you reasons why their tillage or lack of same works for them. Like Steve Solomon [I believe it was] remarked, "He made the mistake of assuming what worked for him there would work elsewhere."
"Every style can give you reasons why their tillage or lack of same works for them. Like Steve Solomon [I believe it was] remarked, "He made the mistake of assuming what worked for him there would work elsewhere.""
I hear ya.. There are different food webs for different environments. Regardless of what organisms make up the food web, the food web is key to soil health. If you are directing that quote to me, which i'm assuming, it's important to note that you do do different practices in different environments. i'm not saying that you do the exact same thing for every garden.. It does matter.. Do you want fungal domination, bacterial, anerobic, aerobic? It all depends.. What I do, might not be advised in other regions. But there is one thing that stays constant, every garden should have a healthy food web.
Every garden or farm has a less than "healthy" food web system and is affected by biotic and abiotic soil changes over time and changing weather conditions also come into play. Tillage and even cultivation raises hell with food web systems. The goal is to establish resiliency in the system, meaning having enough food, air and moisture for the microorganisms.
The food web system under orchard trees is of course different than those under cultivation of annual crops and is often "healthier" than on adjacent cultivated ground.
This post was edited by marshallz10 on Tue, Jan 7, 14 at 20:01
Wow, Marshall, 100 tons per year. I guess you all have a front-end loader on site.
Elisa, yeah, it really shows up in a heavy feeder like potato or tomato, say. Both of those do pretty good with plenty of compost, and even more with composted manure, but try to work them into a minimal-till low-input system and you find out where the term "small potatoes" came from.
No, just 3-4 guys. We are careful on making and turning the windrows.
So the feedstock is mostly from off-site?
Nope, off the 12 acres (we rarely till under the remnant farm crop.) Plus a quarter from other landscaping and maintenance jobs. The chip tree material for mulching (and some for composting) comes from a couple of tree services I trust.) We have a small chipper/shredder to reduce branches to compostable materials.
I probably should add that this 100 tons is projected from the average of 1 cu yard of compost weighs about 1.5 tons dry and closer to 2 tons wet. We make over 80 cu yards of compost a year from an estimated 1000 cu yards of organic waste. I forgot to mention we also compost the prep wastes from the food services, another source of green waste.
We use about 65 yards of compost on our farm beds and the remainder under our fruit trees and roses.
So mostly grasses/grain straw? Cut and gathered how?
No, nearly all of the is high carbon material. We do generate some grass clippings and straw/hay in season, but nearly all the "greens" come off the farm. We grow an ave. 3.2 crops/yr/bed, so lots of culled materials
I make high fungal compost, sifting out the coarse OM at the end. The woody stuff is passed through the shredder and receives quite a beating, leaving lots of surface area for microbes to do their work.
My system takes approximately 3 months of active composting (weekly turning and watering for 4--6 weeks, additional turns and watering as needed for another 6-8 weeks. If possible, I store combined piles of near-finished compost for up to 6 months when internal temperature fall consistently to 100F.
The sifted coarse material is used to innoculate new compost piles.
So marshall, are you then spreading and always tilling the compost in, or do you sometimes just spread?
In the orchard, we spread under the drip line and add any needed fertilizer then mulch with woody chips. The annuals cropping is treated differently
I practice a modified French Intensive culture with perennial beds mostly worked by hand but every year or so we will double dig with broad fork and then add compost and till it in, no more than 4-6 inches deep. If by hand, then we use potato hooks (4-pronged) to roughly incorporate the compost (and any needed fertilizers), then regrade to 3.5-5.0-foot wide beds. I figure we add about 25 tons/acre in spring and a maybe half that in fall. Hard to tell because mostly we work over one bed at a time, these averaging about 75-125-feet long.
Im curious, what fertilizer do you use?
So the majority of the feedstock is in fact from the food crop beds, rather than purpose-grown, I take it.
Pat, when I was opening new ground, badly compacted and mix of roadbase and fill, I grew mixes of deep and shallow-rooting annuals and perennials, including cardoon, Those were mowed and raked a number of times over two years and added to compost operation. Followed up with a season of green manuring over winter months, mowed twice, and tilled in roughly in spring. We followed up with transplanting winter squash to get a crop and to suppress weeds. Turned out to be wonderful ground for the most part.
Elisa, mostly my soils in this subtropical climate run short of Nitrogen and sometimes sulfur with plentifiul P and K and most micros from the compost. If I need an acid-inducing fertilizer, I use organic cotton seed meal. For root crops I add Hoof and Horn and/or steamed bonemeal. For general ground prep, we use prilled OMRI acccepted 9-3-7 in colder soils and 4-4-4 in warm soils. I just purchased a hundred pounds of 10-3-0. derived from organic feather meal. I side dress with blood meal (prilled) for quick nitrogen. I have used fish meal but too much bother with wildlife digging in the beds.
I don't believe in using just one or two kinds of fertilizer, even organic because no bagged fertilizer is complete.
All transplants are watered in using fish/kelp emulsion to reduce transplant shock. We often growout a crop without supplemental fertilizing.
I've been market farming this way for over 20 years.
This post was edited by marshallz10 on Thu, Jan 9, 14 at 22:32
Thinking about your list above of high-N sources reminds me that vegan gardening is difficult unless one has easy and free access to seaweed.
The Nearings probably investigated sustainable vegan food-production more than any. When they were in VT they used turf primarily as compost feedstock; at the ME seashore of course they used seaweed.
Marshall, thank you so much for taking the time to give all this information. Next, please send pictures! ;)
I keep imagining you at Green Gulch, but you must be further south, right?
Yes, thanks Marshall, very informative.
Elisa, the market gardens and orchards are a quarter of a mile from the Pacific near Carpinteria, Cal.
I see from Google that there are coastal orchards just north of Oxnard.
Lots of different kinds of orchards in Ventura and Santa Barbara Counties, lots of citrus north and west of Oxnard and lots of Avocado west of those.
Marshall,, Looking from Google satelite there are a patch work of mostly orchards between 101 and 'the hills'. I saw a large nursery along Casitas Pass Road in Street View....sure different from where I live.
Most of the bottomland in ag in Carpinteria Valley is ornamental plant nurseries or in greenhouse production, not just flowers and ornamentals but also hydroponic vegetable, like butter lettuce and tomatoes. I'm on the far west side of those, nestled among horse facilities and patches of orchards remaining from a few decades ago.
Marshall, It's quite interesting when taking a closer look. Do you need to irrigate?
Yes, at the farm I've recorded 0.95 inches of rainfall since July! Last rainy season we received about 40% of normal, down around 9 inches for the year. Normally we don't need to irrigate from late November to April. We've had 4 small rains since mid Oct., none penetrating more than 7 inches.
Drought! Actually Extreme Drought.
I originally posted this question a few weeks back; "Because we westerners abhor "nightsoil", are we doomed to produce our food in an ultimately non-sustainable way? Are we doomed to either add chemical amendments or organic matter (from non-sustainable sources) back into our soil to replace the mass of our harvests? Is there something I am missing? "
After speaking with Michael Madfis our local permaculture expert, he said the permaculture solution to this loss is "for every acre/hectare/sq yard under annual cultivation, you need to have 4 acre/hectare/sq yard units under perennial cultivation to produce the extra organic matter used to replace the losses from the annual plot."
My guess is that in practice this is a "rule of thumb" whose ratio may need to be altered up or down depending on the nutrient aggressiveness of the annuals harvest.
I agree with Madfis, more or less, depending on climate/soil; another way to look at it is there is x amount of produce that can be taken from x amount of land sustainably.
On the sustainable question, I have always assumed that what comes out must go back, otherwise the soil is slowly but constantly losing its fertility. So I tend to agree with the need-for-night-soil proposition. Can X-I really equal 1? What am I missing? Regards, Peter.
Carbon can go out, at a rate somewhat less than its extraction from the air via photosynthesis, right? In a very well-managed and live system, atmospheric N can be gained and so less than that amount can go out. Other elements go out bound to those molecules, which can only be replaced by chemical and organic breakdown of rock particles (sans fertilizer)? In a very live system such breakdown might be more rapid than otherwise.
Yes, pn. There is a tremendous volume of minerals locked up in the subsoil and below that.....almost limitless in a way. Nitrogen is something to be renewed constantly. Carbon is abundant in the air and soil.
The 'trick' is to have that soil synergy to release the lockbox of nutrients. A lot of that comes from increased organic matter. For many of us it is easier to assist nature by importing some minerals.
I guess my quest isn't totally to be self supporting as in many ways I am dependent for my very life and breath on God and need others in many areas. How self sustainable is that?
This post was edited by wayne_5 on Thu, Feb 6, 14 at 21:34
Every way, I reckon.
In my somewhat simple view a sustainable practice is one that still produces great results after 10,000 years of use. I choose 10,000 years because that's how old agriculture is, and we hope that it might last more than another 10,000 years. In that context, nitrogen isn't a problem because we have legumes, both natural and cultivars. But phosphorus and boron , to pick two examples of 'mining' minerals , are -- because their only source is the earth, and we lose some into streams, rivers, and therefore the ocean every year, where it's difficult to recover. Presently, too much phosphorus is the problem, especially on dairy farms. As a result we aren't recycling enough animal and human urine, for example, so it's lost to the sea. Keep this up for 10,000 years, and there's a huge problem. So sustainability has to be thought of as retuning everything to the soil that's been taken out of it. And that's where using night-soil isn't eccentricity but necessity. The alternative result is Mesopotamia. Regards, Peter.
Peter, I generally agree.
Of course, like with the early river-valley agrarian civilizations of the middle-east, our large scale systems will fail within a few more centuries at most, and we will return to a much more sustainable de-centralized agriculture.
It seems as if a lot of people here would rely on nightsoil as a sustanable fertilizer, anendment, whatever. "Nightsoil" has a negative connotation of dirt, filth, sewage, just plain unsanitary. Today, we know how to properly compost,. So the finished product has no odor, nor pathogens. I would not consider that night soil. Instead, you can get a very clean product from composting properly. "nightsoil" could be a little misleading..
". In that context, nitrogen isn't a problem because we have legumes, both natural and cultivars. But phosphorus and boron , to pick two examples of 'mining' minerals , are -- because their only source is the earth, and we lose some into streams, rivers, and therefore the ocean every year, where it's difficult to recover."
It might be difficult to recover isolated minerals that leached off the earth for whatever reason. But, is the leached nutrients/minerals lost? I highly doubt they are lost, gone forwever. Instead, I invision these minerals/nutrients being constantly recycled by organisms, etc. In fact, I dont see how they will ever not be recycled?
Now, say that phosphorus leached put of the soil into a nearby river, to a lake/ocean. The phosphourus is being recycled by organisms, so now you have more phosphorus in the ocean, and less in the soil. Essentially, the ocean is robbing the soil of nutrients. So is the nutrients still in the soil, no. Is the nutrients lost forever, not sustanable what so ever, i highly doubt that. There might be a problem getting the excess nutrients from the ocean back into the soil, but nontheless the nutrients are still there being recycled by organisms in a sustanable manor, no?
I'm glad to see this topic still being discussed! I thought it would've went to page two by now..
NN, check out Walter's book about sea-energy growing.
I glimpes over the book reviews on amazon briefly, it seemed really interesting, ill check it out. What is it about, extracting minerals/nutrients from the ocean?
Yes, exactly that. In some cases, growing plants in daily soakings of sea water.
It's an idea that has been around a long time, with many anecdotal success stories. For example, reports of increased crop vigor in following years after a major storms soak fields with salt water near coasts are very common.
It's amazing what we intuitively know...
I was aware of the concept for some time... I live on top of Lake Erie, I always contemplate about harvesting algae/ seaweed from the lake in hopes it would be rich with minerals/nutrients like the ocean... Some say the work outweighs the benefit, some are worried about pollutants, or even salts.. How much difference, in terms of nutrients/minerals, are in a lake vs the ocean? Can you efficiently harvest "stuff" from the lake to nourish your garden, like Walter talks about from the ocean? I been interesting about this very topic for some time.. I would gaze the horizon, taking in the beautiful sunset reflecting off the lake, while cleaning my fishing hook of the seaweed and other debris from the lake. I always ask myself, can I use this gook on my hook to fertilize my garden. I pay big money for kelp here, if i could use a local source, that would be ideal.