A journey into hybrid solar power

         Welcome Back! Last week we talked about one of my favorite forms of food production, aquaponics, and we talked about why it won't revolutionize our waning agriculture industry. Specifically we covered the root cause of the ills of agriculture, many industries for that matter, and how globally we suffer from a cultural mentality that must dramatically change in order to revolutionize or change our food production and distribution systems in a positive and meaningful way.

         This week we are going to talk about hybrid photovoltaic/thermal (PV/T) power and some of the applications of these systems. Specifically I am centering this article around the EarthShip inspired greenhouse I am building this year and how I intend on using hybrid PV/T power to heat and cool the greenhouse for a year round tropical environment. I will briefly cover PV and thermal panels and how they work, along with some of their drawbacks and how hybridizing them can turn some of those drawbacks into net positives. My intent with the real world design example is to provide a more practical application explanation of theory based off of a design that I have experience and knowledge of instead of a theory alone explanation. As well, it gives you a bit of a look into my goals, my nerdy passions, my mind and life.

My intro and adventure with solar energy. 

         I became interested in solar, wind, geothermal, and bio-fuel power somewhere around age 19 or 20 and like anything I develop an interest in, I researched and read every article, book, and company I could find. I don't remember what or who in particular got me started, only that I became an overnight fanatic of all clean, renewable, and non-conventional forms of energy and I have been ever since. After some research I realized our energy industry, like so many others, is teetering on the cliff of oblivion just waiting for the right factor to send it over the edge. This is probably where my passion for Environmental Science and Sociology began. I thought it was ridiculous that we rely so heavily on centralized power from pollution generating, exceedingly hard to extract, and finite fossil fuels like coal and natural gas when there are billions of acres of rooftops worldwide that could act as a decentralized solar electrical infrastructure. I found it mind blowingly stupid of our nation to ignore the possibilities of feed in tariffs for solar, small scale wind, and geothermal when countries like the UK, Germany, and Spain were prime examples for successful implementation of such systems. Also considering the latitude of Germany and the UK make them poor candidates for mass implementation of solar energy production as compared to the solar resources and latitude of the US, how could they be beating the pants off of us in an industry we by all means should be a world leader in.

         While I still hold the same beliefs and convictions, my decade of experience and education since then has allowed me to recognize that entrenched ideologies, corporate law, and the bureaucratic process make initiatives like feed in tariffs, decentralized energy production, and switching to renewables exceedingly difficult to accomplish on any meaningful scale. At least with food production we have farmers markets to help in the whole decentralizing process, whereas energy production is a far way off from allowing the individual to capitalize on and stake their claim to a small part of the industry. However, even with food production, we face many obstacles from our legislature and ingrained cultural beliefs. The tide does seem to be changing for energy production however, the price per watt of solar energy has dropped significantly over the past decade. I remember when it was almost $2.50 per watt and now the price hovers around $1.35 per watt and may be below $1.00 per watt by 2020. This in combination with more investment into increased efficiency of solar and more home owners installing solar on their homes, is laying the groundwork for decentralized energy production and a significant decrease in our dependence on fossil fuels. Just not fast enough by carbon emission and sustainability standards.

So how does Solar PV work and how will I use it?

         Photovoltaic or electricity producing solar panels are generally made of silicon wafers (solar cells) that have been chemically treated to have a positive or negative charge, a process called doping, and they operate off the principle of the photoelectric effect. there are other types of non-silicon solar cells, however they are special application for things like satellites in space or low energy metallic plates and you are not likely to see them in any home or commercial scale electricity production. The basic design is a negative and a positive charged cell are sandwiched together with the negative cell being the one that faces the sun and the space between the two cells is called the P/N (or positive/negative) junction. Again there are variations on this, this is just the most common. As a light photon strikes the negative cell, it frees an electron which then travels to the positive cell and as it crosses the P/N junction it generates an electrical charge. Think of the negative cell as the emitter in the video and the positive cell as the collector in the video. The tiny silver bars you see inside solar cells are a collection grid for the free floating electrons to travel down and be harvested for use in generating electricity. Usually a cell can produce between .5 to 1.5 volts, so it takes quite a few to produce any significant energy. Hence why a rooftop array may only provide half a homes needs, depending on the roof size and home electricity consumption. On the flip side of that coin, with responsible energy usage and a well situated and large enough rooftop, one home could provide enough power for four or five. I know with my houses roof space resource and home energy usage of 500-600Kw/month, we could provide energy for just shy of three homes with comparable usage.

Great visual of how a solar cell works, and the link gives a good explanation of how solar yard lights work. Just think of a panel or array as a very large scale version of the yard light.

          For the greenhouse system, I plan on utilizing solar PV to run all of the electrical components in the greenhouse and aquaponics. This includes lights (both regular lights for working at night and seasonal florescent grow lights for starting sprouts under 24 hour light), water and air pumps, fans, the system controller, a battery bank, and anything else that may pop up over time. All the excess electricity will be used by my family in the house and will offset our already low energy usage and bill. Considering the electrical usage of an average aquaponics system (20-30 watts for a single bilge pump, 20 watts for an air pump, maybe a 1Kw heater (though it'd be more efficient to insulate and heat the room and let the water act as a thermal battery), then extrapolating for my planned system size (not likely using heaters) and adding in several 50 to 60 watt canister fans or air moving fans, I believe I'd be using no more than 400Kw per month. And that's with a rather liberal usage of electricity. The 2100w PV system in my initial design will be more than the greenhouse will need.

PV drawbacks and how I intend on addressing them.

         Like anything, solar PV has a few drawbacks. The most significant being that they only work when the sun is out and they are not being shaded. So if you have no other form of energy, as in the grid or a generator, you need battery backup or you will go without electricity at night and on cloudy days. The sunlight part is obvious enough given solar panels harvest sunlight to make electricity, so how does this shading thing work? Well, because of the way the panels operate, if even one cell is more than 40% shaded, it will not produce any energy and will draw down the energy production of the rest of the panel possibly damaging the cell or the whole panel. Likewise, if a solar array is connected to a single inverter, like most are, then a single panel being only 25% shaded will be enough to drop the entire array output by 50% or more. Now think about things like snow, dust, airborne soot particulate, and the like. This is in addition to the shadow arcs of trees, chimneys, pipes, swamp coolers (Ive been asked "whats that" many times before, it's a dry climate form of energy efficient air conditioning), etc... that may shade a panel in part or full for part of the day. Personally I believe that micro-inverters should be used for the grand majority of home and business arrays because any shading on one panel will only affect the performance of that one panel and not of the array. The cost is about 10% to 20% higher than a single inverter system, however added electrical output and lower line losses will pay back the additional cost in a couple of years. Commercial arrays are another story, one where single inverters are a more economically driven factor due to the sheer size of the array making micro inverters cost prohibitive while the sites themselves are almost guaranteed to have no trees or buildings shading them.

         For my system, I plan on using micro-inverters however I have many other factors to consider. In front of the greenhouse I plan on planting a polyculture centered around taproot and heartroot habit mulberry, persimmon, and chestnut trees to keep the water table low in this low part of my yard, stabilize the soil in that area, and shade the south face of the greenhouse in high summer when it would be subject to extremely high temperatures. As an added benefit I get pretty trees with delicious and healthy fruits and my ducks get a woodland meadow habitat when it's all completed. The average temperature at my location for the past eight years has been between 95 and 105 degrees Fahrenheit from roughly June to August and anthropogenic climate destabilization seems to be making those numbers climb. In those conditions, even with good ventilation, the greenhouse may overheat. In winter when the sun is low in the sky and the trees are bare, the glazing should get almost maximum insolation (large tree branches on espalier will block some sunlight, its unavoidable) while the earthen walls, roof, and floor will insulate the interior from the cold. The espalier trees could be problematic for the solar panels if not maintained at the proper height for shading the greenhouse but not the panels. As well, I plan on having a backup battery bank in addition to running the proper cabling to tie the greenhouse to my home and therefore the grid. When considering that the greenhouse will have live fish largely dependent on constant water flow and aeration, I'd rather have the grid as my primary backup and the batteries as a secondary than try to go grid free and have my system go down for whatever reason while I'm not home.

East facing cutaway of my initial plan showing solar panel location at the highest point of the 15 foot tall greenhouse and the general location of the expected mature size espalier trees. Ive still not settled on a design for the aquaponics system, the system depicted is just to see what I do and don't like.

North facing view of greenhouse showing eight solar panels, expected to be 250 watts each for an array size of 2350 watts. For the cost, I might run five panels at 285 watts for a 1710 watt system, still more than I'd need.

Heat, a solar PV killer and waste byproduct or untapped resource?

         Another factor is heat, heat is the enemy of solar PV panels. As an industry standard panels are rated at 25 degrees Celsius (77F) and for every degree above 25C, the electrical output drops by .4% to .5%. This doesn't sound like much until we consider that rooftop PV panels operate at roughly 55C-75C (130F-167F). Do the math, .4x25 to 50 = 10% to 20%, and .5x25 to 50 = 12.5% to 25%. That's anywhere from  10% to 25% reduction in electrical output, or for my estimated 2100 watt system (2.1Kw) those percentages mean it is only an 1890w (1.89Kw) to 1575w (1.57Kw) system before calculating shading, DC/AC conversion, load and line losses, or any other variables. Ouch!

         Where does the heat come from? Only the visible light spectrum is utilized in solar energy production. Infrared light passes right through the panels as if they didn't exist, and ultraviolet light is primarily converted into heat energy and only partly into electrical energy. This has to do with the voltage and amperage potentials of the different light spectra and their photon energy. Infrared light, though the most abundant, produces such little energy that the resources for collection are not justifiable. While ultraviolet light, though the highest in energy potential, has the lowest working potential and is harder to effectively harness.  The excess heat energy from the ultraviolet photons pools behind the panel while the infrared light is absorbed by the roof and panel backing material and slowly radiates back out as more heat. Another factor of heat with solar PV is that heat degrades the silicon cells and shortens their effective lifespan. So it's well worth the effort and costs to cool the panels, however cooling fans and the sort consume roughly equal the amount of energy they save in reducing temperatures thus making them only marginally beneficial. This is where hybridizing with solar thermal comes into play as it only adds roughly 25% to the cost of the panel and harnesses 2x to 4x more energy than a PV panel alone.

SolarWall example of how hybrid solar PV/T systems work. I intend on modifying this to meet my needs and putting my own unique spin on it to avoid any patent infringment.

Solar thermal and how I intend on using it.

         For the sake of simplicity, were going to focus on home scale air heating and will only touch on water heating. We will not be discussing electricity producing thermal systems or commercial concentrator systems. Those are fascinating topics for another article on another day. 

         Solar thermal collectors are very simple and don't have as much to them as solar PV, unless were talking about concentrator arrays and computer controlled or evacuated tube water heating. The panels rely on infrared light and as a result are not affected by cloudy days, moderate shade, or the like. They however do require daylight to work, that is to say they don't work very well at night. Though there are several designs from many manufacturers, my favorite designs are the DIY home built ones for both air and water heating. What I like the most about solar thermal is you can build your own for low to no cost using new or salvaged components. Though you can build your own PV panels, for the cost and carbon footprint in doing so you are better off buying them wholesale from a reputable manufacture. Really the only downsides thermal panels have are they don't work at night, as mentioned above, and in summer air units need to have their heat load dumped to avoid internal damage. For water heat, cold climates are problematic in that systems can freeze and suffer internal damage from expanding ice in the pipes and hot climates or summer heat can damage a system that does not have a large enough reservoir to dissipate its heat load. However there are many options to avoid damage while running the systems in extreme temperatures and climates.

          I intend on keeping the greenhouse a tropical environment year round, which in Colorado zone 5a is no small task. However Ive seen it done with a barn converted into a greenhouse in Colorado zone 4b and it's exposed on four sides plus the roof, my greenhouse will be earth bermed and have a living roof, leaving only the south glazing and the east entry door exposed. With all that thermal mass, not including the water in the aquaponics system as thermal batteries, I believe I can do it and keep the system for the most part passive. I plan on drawing the excess heat away from the PV panels with a home built thermal hybrid air system that will pump the excess heat into the ground below the greenhouse and into the ambient air in the greenhouse in winter. In summer the panels will draw cool air from a shaded area on the north side of the greenhouse through the ground below the greenhouse and through the panels which will evacuate out the roof of the greenhouse. I believe this will all be possible by thrermosiphon action alone, however I plan on using high velocity canister fans to increase airflow in the greenhouse in general, so combining them with the panels will stack functions. I contemplated using thermal water to heat the fish stock tanks in winter, however that would require somewhere to dump the heat load in summer when the greenhouse would be too hot to need water heating. With the earthen insulation and under floor air heating, there should be more than enough heat to warm the water in the stock tanks during the day while the water and thermal mass of the floor will heat the greenhouse at night.

 

The initial schematic with view of preliminary ducting concept for HVAC. This version has been modified for more accurate portrayal of the attached shed housing the chicken and duck coops, and rabbit hutch.

         Hopefully you are already seeing the benefits of combining solar PV with solar thermal. Not only would the thermal component capture the lost infrared light that passes through the PV portion, it also collects the excess heat and removes it from behind the PV panel helping keep the whole system cooler thus increasing electrical output and overall energy extraction. Using no extra space, the hybrid panels turn a waste product into a resource. This is stacking functions in true permaculture fashion. Whats more is this not just an ideal, its a reality already being utilized commercially.

         If this has piqued your interest and you want to learn more or maybe want to design and build your own system for whatever your purposes may be, I recommend checking out BuildItSolar.com and OtherPower.com. What I like most about them is that of all the text books and online resources Ive read, these websites have given me the best information for practical application of that amassed knowledge. You will find all kinds of projects where others have experimented, tinkered, designed, and built all kinds of different and innovative renewable energy systems.

         Ive not settled on a topic for next week, though I'm thinking seed starting since Ive got some already going and many more scheduled for the next month. If you have any suggestions, definitely send them my way. This diversion from my normal daily topics of conversation has been really fun and refreshing, I'm thinking I might do one of these more technology geared or non-Environment and Society geared articles per month to mix it up a bit. In any event, have a wonderful week and look for ways to make the world we inhabit a better place.

Why aquaponics is not a revolution in agriculture

         Welcome back! Last week we talked about water and drought, some of the problems we face, and most importantly, some easy solutions we can all implement to help regenerate local and regional water cycles. I go so far as to say with enough effort the world over, we can positively affect the world's water, carbon, and climatic cycles while reversing climate destabilization. If we can destabilize the whole planet, then we can repair the damage and reverse course, it's not too late to take meaningful action.

         This week, in response to an article I read and questions from friends, I want to get into dealing a dose of reality about aquaponics, or rather our global westernized mentality and how aquaponics, though revolutionary in itself, is not a revolution in thought and will not revolutionize agriculture. Only a systemic change in how we think about, interact with, and treat the world around us will accomplish that. Lets start with a basic description of what aquaponics is, how it's revolutionary in food production, and some of its applications. From there I will be able to describe how aquaponics fails to address mentality. I will end on the changes in mentality and actions that must happen before any agricultural revolution can take place.

My Experience

         You already know my story and progression with outdoor conventional and organic soil farming. I've also grown vegetables indoors for three years. I grew organically in soil and with both synthetic and organic hydroponics using deep water culture (DWC), nutrient film technique (NFT), and aeroponics. I've found that with a lot of labor input and energy, indoor soil can be competitive in both yield and growth rate with hydroponics, however that extra input mitigates those benefits as compared to the labor involved in hydroponics. On the flip side, I've never had a great tasting crop of anything come out of my hydroponics systems, they weren't bad they just weren't any better than what you get at the grocery. My soil systems, whether indoor or outdoor, have always produced phenomenally flavorful foods.

         I've seen and may attempt a hybrid system with cloth bags that are sub irrigated with what looks like an NFT setup, however I've stopped and do not recommend indoor growing of anything because of the resources consumed and the carbon footprint in powering the lights necessary for good crop yields. I do make exception for seed starting under florescent light to guarantee a long enough season for some crops , however the mercury vapor in florescent bulbs is a dangerous poison and the spent bulbs need to be taken to a reputable recycler for disposal. If I do build a setup to try the hybrid system, it'll have to be outdoors and seasonal only or, possibly year round in my greenhouse if it proves to be highly productive with low labor and few inputs. I'm concerned about how the soil media could affect my aquaponics nutrient levels and pH, I've read wood chips make a great hydroponics media and from experience growing outdoors in wood chip piles, I totally agree. However the varying chemicals in the wood could be toxic to the fish in an aquaponics system, this is where some of my concern for soil bags in aquaponics comes from. As well, I have concerns about mineral salinization of the soil since the bags promote growth and massive roots by means of evaporative capillary action. Time and experimentation will tell, now to the the bulk of the article.

 Aquaponics in a nutshell

         Aquaponics is the net positive combination of fish farming (aquaculture) and hydroponics, two very resource intensive and environmentally damaging forms of food production. Aquaculture produces high amounts of concentrated fish waste that needs to be disposed of regularly. If the aquaculture system is set up in natural bodies of water, the wastes pollute the local watershed and kill off most of the native species while contributing to large algae blooms. If the aquaculture system is in a sealed system, the wastes must be removed regularly, which requires more labor or mechanical input. The systems are poorly regulated and more often than not the wastes wind up in local watersheds or going down the drain, which overloads water treatment and increases the use of toxic chemicals for denaturing nitrogen and phosphorus and increases resource consumption while damaging local ecosystems. Some of the wastes end up in landfills, contributing to methane greenhouse gas production and not being used for beneficial agricultural uses while a very small percentage ends up being used as fertilizers for the home garden or industrial agricultural uses. All in all its horrible system that causes more damage than benefit. Aquaculture is short sighted and has far reaching implications that endanger the stability of ecosystems, dramatically affect climate, and contribute to lowering planetary habitability for all species including humans. Frankly it should be illegal in open water and strict regulations implemented for sealed and dry land fish farms.

Aquaculture illustration

         Hydroponics is growing plants, namely but not limited to vegetables and leafy greens in a water and nutrient solution, with or without an aggregate media. With hydroponics, you get significantly more root contact with nutrients, and significantly better yields than soil alone. As well, by comparison hydroponics requires significantly less maintenance and labor than gardening or farming in soil. I'm an advocate for deep organic soil, and though some soil techniques can compete with hydroponics, the scales are heavily weighted in favor of hydroponics for yield and speed of production. In addition, the recirculating water guarantees that about 1/10th of the water is used in hydroponics than in conventional gardening or farming, though drip irrigation gets soil gardening really close to being competitive with hydroponics on water usage.

Nice example of an easy to make diy NFT hydroponics system

         So where is the downside to hydroponics? Hydroponics is capital intensive and relies on chemical (organic or synthetic) inputs for its nutrient source and if you trace the products back to their source you'll find the deferred costs in fuel used, generated pollution, resources consumed, and ecological damage in the manufacturing and distribution of organic and synthetic chemical nutrients far outweighs the benefits of increased yields. To carry this further, synthetic nutrients noticeably taint the flavor the foods at best, and at worst remain in the foods and are toxic to human health and the environment. Organic nutrients, though generally not harmful to human health or the local ecosystem (in highly concentrated doses they can be however), tend to foul up hydroponic systems because they promote system colonization by beneficial bacteria that make the nutrients more readily available to the plants. This then creates considerably more labor and higher costs, mitigating the maintenance and labor benefits of hydroponics while producing a concentrated and potentially toxic waste product similar to the fish wastes in aquaculture.

         So if both systems are so bad in practice, how would combining them be any better? Simply put, aquaponics uses the fish wastes as the organic nutrient source for plant growth thus making use of an otherwise concentrated toxic sludge waste while closing the manufacturing and distribution loop of the nutrient source for hydroponics. In aquaponics, a healthy and vibrant biological community is necessary for proper nitrification of the fish wastes, thus reducing maintenance and labor by creating a need for bacterial communities that would be problematic in hydroponic systems. Aquaponics is an almost closed loop system with few inputs and low capital requirements, however the inputs must be considered in order to gain a complete picture of both the benefits and drawbacks to aquaponics.

  Illustration of simple aquaponics system and the nitrogen cycle

         One input and potential drawback is feed. Though you can produce supplementary feed on site such as duckweed in the aquaponics system or compost worms, meal worms, crickets, and black soldier fly larvae from food scraps, the reality is you will need to bring in feed from an outside source and must consider the carbon and ecological footprint (deferred costs) of that feed source. Another drawback is that aquaponics systems tend to run deficient in iron and can run deficient in potassium and other nutrients, thus requiring outside inputs and consideration of the deferred environmental costs of those inputs.

         As well, Aquaponics produces a small amount of potentially toxic or polluting undissolved waste solids that need to be purged from the system. However, the amount is small enough that they can be diluted and used as a nutrient rich and biologically active soil additive for home garden soils. Commercial producers should consider packaging and resale as a concentrated soil amending garden product. As well a bumper crop of prawns or crayfish can be used as biological water filters that eat a considerable amount of the solid wastes and convert them into more soluble nutrient forms. All things considered, aquaponics is a revolutionary shift in thought for both aquaculture and hydroponics with a net positive output as compared to its inputs.

          Aquaponics has both home and commercial scale applications on more of a continuum than a dividing line. That is, home scale systems can be a supplemental food source thus lowering living expenses and environmental impact per individual, or they can be large enough to produce all home food needs and a modest side income. Commercial systems can be small farm to mega plantation in size and scale. I believe every home and commercial rooftop (warehouses, office buildings, grocery stores, etc...) should house aquaponics outdoors or in greenhouses while mega farms should not exist as they are allergic to biodiversity and flexibility by design. This is a logical viewpoint for sustainable solutions to part of our food production system. However that's the ideal, what looks good on paper, not necessarily representative of western thought, industry practice, or general reality.

         Home scale production is a possibility for the majority of urban and suburban houses everywhere. As aquaponics becomes more mainstream and industry standards more prevalent, I believe this part of 'the ideal' could become reality. Year round rooftop greenhouse production of food is being proven by several companies in Canada and the U.S., and seems to be gaining momentum as the millennial generation is demanding more local and ethically run businesses. However, intensive decentralized production across urban environments is less likely due to varying degrees of bureaucracy and regulation in just these two countries alone. Bummer!

 Image: Great IBC aquaponics setup I plan on mimicing for my setup

You can download the IBC of Aquaponics from Backyard Aquaponics here.

The Backyard Aquaponics homepage is here. 

The revolution

         So now we have a quick snapshot of what aquaponics is, where it came from, and its applications. I've let my bias slip, I love aquaponics and I think it's a phenomenal low tech way of producing lots of healthy food in a small space with a low to neutral environmental impact. So how could it fail to revolutionize our waning agriculture industry? This is where were going to shift gears and take a look at our cultural mentality and industry practices when it comes to technology in food production and how they prevent any revolution from taking place. Were going to take a look into the history of our thought process and what it will take to revolutionize the way we approach food production and the world.

         Throughout the history of agriculture, reaching all the way back to the first seeds sewn in ancient Mesopotamia, population growth has always outpaced food production in agricultural societies. Check out David Mongomery and Jared Diamond for an in depth look into this subject. It basically breaks down to more food production or better technology allowing for higher yields will lead to population increases and not to greater food abundance. The addiction then begins when societies choose to either innovate new technologies or move to more fertile lands, causing the whole cycle of overtaxing land resources and population outpacing production to start over. It's a positive feedback loop that will always end in failure to thrive and demand new resources or technologies. This is not a natural state of being however, this is a mentality and thought process that negates critical thought about itself and fails to recognize the need to change thought and action in order to fix the problems it caused. It's a form of collective mental illness, insanity. As Albert Einstein put it, Insanity - doing the same thing over and over again and expecting different results.

         Enter scene: aquaponics, a revolutionary technology that has serious potential for producing more food with significantly lower inputs than current systems. Just like plowing was a technological revolution, and synthesized atmospheric nitrogen, and mined organic and mineral phosphorus, and deeper plowing, and mechanization, and so on. I hope you're getting the point, technological advancements have come to the rescue time and again while the prevailing beliefs in infinite resources and uncontrolled over-consumption have not been addressed. As we've covered, aquaponics is not without its downsides and not without its inputs. Simply replacing current technology with another without consideration to things like exponential population growth; resource depletion; linear lines of production, distribution, consumption, and waste; and so on, will only serve to perpetuate the systems and problems as they exist today. We have to be careful not to mistake the revolution in technology for a revolution thought, they are no synonymous.

         This all runs deep in the cultural mentality of Western societies and we are on the cusp of environmental and societal collapse worldwide. Change has to come by necessity, either revolution or collapse and natural systems don't care which. This is not to say we are destined for collapse or that our mentality about the world and everything in it is the sole cause, only that the path we are on as dictated by our collective mentality is headed in that general direction. However, there are many other factors that could exacerbate or mitigate this. One possibility is Bill Mollison's permaculture as an ethic and a life governing philosophy. We must think of everything as a cyclical system, every waste as a production for something else; every resource consumed has to be reusable or replaceable; in order to maintain planetary homeostasis (the ability to support life, including our species), we have to actively keep the world's systems in balance. It's a naturalist fallacy of logic to argue that natural systems innately balance themselves when disturbed, therefore non-action would be the best action. As a species we have cognitively separated ourselves from those natural systems and have actively damaged, destroyed, and destabilized them. The responsibility then falls to us, not the damaged natural systems, to repair and balance out what we have done.

         As much as I love aquaponics, it is not and will not be a revolution in agriculture because the revolution has to come in the form of the philosophy we keep and actions we take. Don't take my word for it, look at the world around you and question if it sustainable long term and what effect we are having on everything we touch. The science and research has been there for nearly a century now and the time for hiding behind our own cognitive dissonance is over. The time to take positive and meaningful action is now, really it was 40 to 50 years ago however there's never a better time for anything than the present.

         I've been talking a lot about environmental conditions, both here and in my daily activities. They're very important and have immense consequences for our futures no matter what course of action we take. However I want to get off this broken record train for a while. With that in mind, next week I want to switch things up and talk about solar power, specifically hybrid PV/T systems, as I plan on running my greenhouse aquaponics system on solar power and heating/cooling the greenhouse itself with passive systems or very low input from active systems like fans. I've been considering several setups and options, and this is where I think I'll settle myself when that time comes this winter to next summer. Have a wonderful week and look for ways to take daily action to improve the world we inhabit.


        

Water

         Welcome back! Last week we talked about ways anyone and everyone can and must build soils, whether at home, on the farm, or even on the patio. This week in light of drought across the world as a result anthropogenic climate destabilization, and in following a two part blog on soil and soil health, were going to talk about water, drought, and what it means for us, along with ways to manage water more effectively. We'll start off with natural systems like water and drought cycles, transition to unnatural cycles caused by human activity and the problems we face, then move on to things we can do to increase water in the soil and actively recharge aquifers.

         Some would argue that water shortage is more important than soil health and preservation, I argue that it's of equal importance, they both exist within the same interconnected cyclical system. Where one fails, the other is sure to follow. That is without adequate water, soil dies and without deep healthy soils, less water can be stored in the ground and cycled in local ecosystems. When we hear about the drought in California, which is really an analog for drought in the entire Western US; the drought in Sao Paulo, which is an analog for drought across most of Brazil; or drought in Asia, Australia, and Europe, we're being told a story about the water cycle and drought cycles, both natural an unnatural. Drought cycles across the world, generally speaking, are natural. This does not mean they aren't dangerous or bad for us, simply that they are part of normal planetary cycles. When we disrupt the water cycle, as in the case of deforestation and soil degradation in Brazil and the Midwestern U.S., intensive irrigation in California, mega-cities preventing local evapotranspiration the world over and so on, we create artificial and prolonged droughts that lead to desertification. Likewise, we prolong and intensify natural drought cycles which also leads to desertification.

The Water Cycle.

Image Credit: http://www.hydrologicdata.com/water-cycle.html

          The forests and grasslands are the major pumps of the water cycle and at any one time trap up to 3/4 of the worlds liquid fresh water. Likewise, at any given point in time only 3% of the worlds water is fresh water and most of that is in the form of glacial ice. So when we clear cut forests or convert fragile prairies and grasslands to seasonal monoculture agricultural land, we lessen or destroy the infiltration, percolation, groundwater movement, plant uptake, and land based evapotranspiration aspects of the water cycle. Thus we leave runoff and surface flow as the primary form of land based water movement. This makes water availability seasonally fleeting and becomes a positive feedback loop that perpetuates and exacerbates drought conditions. In California, and much of the Southwestern U.S. this is what we've done, think back to last week where we talked about the importance of mulch and living ground cover for protecting soils.

         For example, much of the desert of the Southwestern U.S. was once fragile prairie and grassland with marginal pine and juniper forests. The prairies were burned and used for growing cotton for sheeting planes in WWI and have never been replanted, no attempt at ecological repair has been made. Likewise, the pine and juniper forests that once covered most  of the Colorado Plateau were clear cut over about a 700 year period by the native inhabitants who lived there from roughly CE 500 to 1200. Have you ever been to Chaco Canyon? It's one of my favorite places in the entire world and one of the few places in this world that speaks to directly to my soul. What I find amazing is just 1500 years ago Chaco and the surrounding area were mostly covered in forests and could sustain moderate agriculture, where today there are no forests and only marginal scrub in and around the canyon. Imagine how much more stable and moist the Colorado Plateau and surrounding areas would be if we made the effort to repair and replant all the forests and grassland prairies. Imagine how productive and useful the area would be, even if only for wildlife and a small or low density human population, we could build a biodiversity powerhouse out of an extremely damaged ecosystem.

Chaco canyon and most of the Southwest went from looking like this,

Utah portion of Colorado Plateau forest landscape.

Photo Credit: http://4cornershikesbridges.blogspot.com/2008/10/cathedral-arch-and-angel-arch.html

and this,

Arizona grassland similar to what most of the prairies of the Southwest U.S. once looked like.

Photo credit: https://arizonahighways.wordpress.com/2012/09/07/friday-fotos-arizona-boasts-some-very-pretty-grasslands/

to looking like this.

Chaco Canyon from above Pueblo Bonito facing The North Road. This is during a wet season, much greener than I've ever seen it there.

Photo Credit: http://theslideprojector.com/art9/art9lecturepresentations/art9lecture19.html

          History is filled with examples of societies that destroyed their local ecosystems, depleted their water resources, desertified their lands, expanded their population too fast, and ultimately collapsed. California and Sao Paulo are no exception; our modern and seemingly infallible societies are no exception. Within a month or two Sao Paulo is expected to run out of water and as agriculture fails, water rations become scarce and the choice between life and death more pressing, either more expensive and ecologically damaging and short sighted measures that undermine long term sustainability like ocean desalinization will be implemented, or emigration driven collapse will follow.

         By this time next year, California is expected to run out of water and will be wholly reliant on fossil water, which takes thousands to millions of years to replace. At best we can expect another 50 years of fossil water before there is none left, its an emergency savings account that were spending without making new deposits. Meanwhile the land above ground is becoming ever more desertified, agriculture in the central valley is beginning to fail, we are pumping so much water that its contributing to sea level rise and salinization of aquifers, and the only plan for repairing this won't come into full effect for almost 30 years. The scariest part is a sizable portion of the U.S. food supply comes from California.

         The entire Western U.S. is following closely behind California's trend and collapse is eminent. This pattern is being mirrored worldwide. Global ecological and societal collapse are what we are faced with, and instead of being on regionally localized levels like the Roman Empire, the Maya, the Anasazi, the Norse and so on, were facing collapse on a global scale for the first time ever. All of this is due to the rapid destabilization of climates in relation to global warming, and the mismanagement and abuse of water resources and soil.

         However, permaculture and holistic farming offer several low tech and easy to implement ways of capturing and using water for both ecological repair and food production. This is not a matter of modernity vs. primitive living, this is about taking responsibility for ourselves, living sustainably, and creating abundance for all lifeforms on this planet, not just our species. We can do this by thinking ecologically; using wastes as a resource for something else, stacking functions, and being mindful that there are consequences for every action we take.

         Nutrients and sunlight aside, one of the best ways to guarantee fast and vigorous plant growth is to have plenty of available water in the root zone. With this in mind, a logical answer is to increase the water being made available to the plants in the form of irrigation. However artificial irrigation can and usually does lead or contribute to soil salinization, water reserve depletion, and erosion. I argue that to increase available water we need more reservoirs of water, however not open air bodies of water that contribute more to water shortage problems than they help to prevent. To be clear I don't argue against them either, they do serve purposes and fill vital functions. The reservoirs I argue for are ground water storage systems, usually swales and their variations and high soil organic matter content. The last two weeks we talked a lot about soil health and moisture holding capacity, so I'll only mention here in brief that deep soils rich in organic matter are a great way to hold and keep the water that falls on your site.

Enter: the swale.

 Lost of good swale information at Temperate Climate Permaculture.

http://tcpermaculture.blogspot.com/2011/06/permaculture-projects-swales.html 

         A swale is basically a ditch dug level on contour to the land with the removed soil bermed up on the downhill side. The basic Idea here is to slow or stop any water flowing downhill and force it to percolate into the ground and travel underground instead of over the landscape. This creates a well watered root zone around and downhill from the swale, and once established usually only needs seasonal rainfall to remain hydrated. As well, the water slowly percolates down to and recharges aquifers. That is to say, swales by design actively help recharge aquifers by directing water into the ground and by reducing our dependence on fossil water. Another benefit is the downhill berm increases the plantable area and creates distinct microclimates on its top, sides, and base.

         A rain garden is a depression meant to slow and collect water at a certain point, allowing it to settle and percolate into the soil much in the same way as with swales. The main difference is rain gardens aren't necessarily ditches, on contour, or uniformly shaped. They can be put pretty much anywhere the site calls for and in a myriad of shapes and depths. Because of these benefits, swales and rain gardens are a staple in permaculture and ecological land management design. Check out the folks at Midwest Permaculture, they have created some of the best home integrated rain gardens Ive seen.

         Two important drawbacks that are not often mentioned about swales are downhill soil salinization if the water table is too high, and mudslides on steep slopes (which ironically happen to be where swales are most beneficial). The way to handle both of these problems is to plant water loving tap rooted and heart rooted trees (such as boxelder, mulberry, chestnut, persimmon, and the dreaded silver maple) and shrubs on the downhill side of the berm, and on top of the berm in the case of really steep slopes. A thick, fibrous community of roots is vitally important for holding soil in place in any situation, especially on sloped land. Water loving trees like boxelder are great for keeping the water table created by the swale low enough that evaporation driven salinization does not become an issue. On really steep slopes the obnoxious silver maple turns all of its otherwise negative aspects (it has a monstrous heart root system and is a water pig) into a powerhouse of soil holding and stabilizing benefits, especially if coppiced regularly to add mulch to the surrounding area. Recall in the soil posts how heavy mulching with dead organic matter or thick living mulches mitigates evaporation while promoting soil stability and health.

         A slight modification that I love and recommend is to build a Hugelkultur mound as the downhill berm. Though I think the word itself is made up, as Ive not found any etymology for it prior to Sep Holzer, it means wood mound agriculture. The basic principle is as the wood breaks down it absorbes water, becoming a drought resistant sponge, and slowly releases its nutrient load over the course of its life. When well built they can last from 20 to 100 years before needing rebuilt and even then what you'll remove is thick healthy humus that can be spread anywhere you need high quality organic matter to amend the soil. Like anything, hugelkultur is not all positives. There are two major drawbacks to hugel mounds, nutrient lockup and water lockup, both problematic for the first two to five years depending on local climate and materials used. Wood can hold up to ten times its own dry weight in water and as it starts breaking down, it absorbs all the water around it until fully saturated. Depending on local rainfall or water avaiability, this can take quite a while. Though once saturated, a hugel is almost drought proof. Because wood has a high carbon to nitrogen ration, it also locks up all of the available nitrogen in the surrounding soil until the composting process starts and biological activity begins breaking down the wood.

         Personally I can't stand the thought of wasting potable water to flush nitrogen and phosphorus rich urine down the drain to be then treated with chemicals that are very harmful to the environment, while simultaneously paying lots of money for petroleum based nitrogen and resource intensive mined phosphorus. It's your choice to make, however I use urine to fertilize hugels for the first couple years and have never had a problem with nutrient lockup while gardening on them. Though I do warn that if you do use this method of free fertilizer, any medications you may be taking will end up in your hugel and thus your crops.

 

 Hugelkultur explained.

 http://www.permaculture.co.uk/articles/many-benefits-hugelkultur

Swale with hugelkultur berm, design adapted by Midwest Permaculture. 

 http://midwestpermaculture.com/2012/07/hugelkultured-swale-with-linear-food-forest/

          The process that I have come up with and works for me is as follows. Keep in mind I have modified and adapted my process from those of others and you should modify it to fit your need and your specific site, there is no one size fits all when building hugelkultur mounds. 

1. Dig a shallow contoured ditch where you want the berm to be.
2. Fill it with enough logs for the above ground portion to equal about 1/3 of the expected final mass of the berm. This is somewhat standardized, you dont want more than 35% of your mound mass to be wood.
3. Pile the removed soil on top of the logs and level it out.
4. Cover with six to nine inches of wood chips inoculated with king stropharia mushroom mycelium, cover this with cardboard, and let it colonize for a year.
5. The following year dig your swale uphill of the berm and pile the soil on top of the berm.
6. Cover with about three inches of well aged compost, then mulch with wood chips again. As the king stropharia mycelium colonizes the wood, it will begin sending mushrooms up through the roughly six inches of soil and mulch.
7. At this point you're ready to plant out the berm and as long as you feed the mycelium a good mulch every year, you'll continue to collect mushrooms for a decade or more. 

This a longer and more involved process, it usually takes me three years to build a 4' high by 4' wide hugel, however it also helps ensure proper establishment of a healthy fungal community that increases water holding capacity, provides an additional yield, adds to the site biodiversity, and has been documented to increase vegetable yields.

         Though systems like drip irrigation, sub irrigated raised beds, and olla irrigation have serious water saving potential, they're not exactly within the scope of this post. They are techniques for conserving water use, while what this article is describing are methods for keeping the water that arrives naturally. The only caveat to this is when rain barrels are used to collect roof runoff and then are the only source of water for the irrigation systems. However keep in mind that water is then diverted away from swales, rain gardens, and hugel mounds. As well rain barrels are subject to local laws and regulations where swales and rain gardens are not. Where I live in Colorado residential rain collection is illegal though not well enforced, while swales, rain gardens, and hugels are merely landscape decoration.

         This post has run a bit longer than I had planned, however the point I want to drive home is that water availability is paramount to the continuation of our daily lives. I like to look at available fresh water like personal finances, its not about how much money you make or how much water you get, its about how much you keep. Here in Colorado, I get about 14 inches of water on average and I keep most of it in my soil and in my plants. In parts of the southwest they get maybe 10 inches per year and I have seen many lush gardens that center around keeping all the water they get. At the same time, many tropical and subtropical areas of the world get over 30 inches of rain per year and keep almost none of it. So think of these water capturing and storage methods I've covered in brief as investments that collect and store your water, increase water availability, and make more efficient and better use of it as time goes on. Next week I'm going to talk about aquaponics, however with a twist. Ive read a few articles recently that hail aquaponics as the revolution in agriculture that will save the world, I'm going to counter that argument with a reality check. I love aquaponics, however sensationalizing a new technology or process is a recipe for disaster. Have a great week and tune in to find out more.

Soil Buiding 101

          Welcome back. Last week we talked a bit about the importance of soil, soil health, and how soil relates to climate stability, climate change, and water availability. We touched on some of the implications of soil degradation for societies worldwide, however focusing more on the U.S. as this where I live and know the most about. This week I want to cover ways of actively building soil while making the case that anybody, regardless of income, has the resources available to build healthy, biologically active, and highly productive soils. I argue that soil stewardship is more than an ability of all, it is the responsibility and obligation of all citizens of planet Earth. So lets take what we discussed last week and put it all together, lets cover some ways of actively building soil and using biological processes to speed up soil building to a few years or decades as opposed to the millennia of natural processes alone.

          To start with, Mulch, Mulch, Mulch. Mulch is the soils best friend. It creates a barrier that prevents evaporation of moisture from the soil, protects the soil from the harsh sun and wind, prevents soil compaction, insulates the soil, acts as a slow release fertilizer, creates a wonderful habitat for soil biology, and substantially builds organic matter directly on site. Earthworms will move mulch into the root zone in the form castings rich in nutrients and beneficial bacteria while red wigglers, pill bugs, and millipedes will break mulch materials down at varying surface levels. Disease has a harder time spreading through mulched soil, with noted exceptions, while beneficial fungi will run rampant. This is because biologically diverse ecosystems provide fewer vectors for disease and parasites while providing habitat for a wide variety of predatory species.

          From my own experience bringing in some fifty cubic yards of mulched wood and just under one hundred cubic yards of unmulched leaves, the biological activity on site absolutely exploded in just a few weeks and this was over the winter. Though I will caution that when bringing in so much raw organic matter from many sites, mine came from several locations near my house, you do increase the probability of introducing an unwanted disease or pathogen. For example, with the wood mulch came an aggressive mold that is no danger to my veggies or tree crops, however because of its tenacity I've had a very difficult time establishing the fungi species I want in that same wood mulch because they come in pure culture and the mold is already well established. This is a gamble you make when urban freesourcing raw materials, arborist companies wont do business with you if you pick and choose. If they bring it for free, then it's as is. I find the gamble worth the benefit of increased organic matter however, especially when with patience I can acclimate more aggressive fungi like oyster mushroom or king stropharia to out compete the mold for niche dominance and then transition to establishing more finicky mushroom species.

Making leaf mulch with the lawnmower in the driveway.

          Second to and in combination with mulching, if you already have a garden or are farming stop tilling your soil. At first this may seem counter intuitive, after all plowing or rototilling loosens compacted soil, allows for better root and water penetration, and increases yields. However this is short lived because the complex network of fungi, bacteria, protozoa, nematodes (tiny worms), and so on is delicate and easily disturbed or destroyed. This is also a false sense of security because it fails to address the real issue, depleted soil health and fertility. This is a lesson I learned the hard way. After several years of deep tilling to increase my yields, I effectively killed off most of my soil organisms, desertified my entire yard, and invited disease into my once backyard oasis. The only way I was able to grow anything at that point was by using synthetic fertilizers to replace what the soil biology did naturally. I replaced a free and low input, high output biological system with an expensive and high input, medium output synthetic system. A complex soil community is what gives healthy soil its loose and friable texture and nutrient holding capacity, without which my clay dominated soil was easily compacted, depleted of nutrients, and rendered useless.

          There are two primary, though not exclusive, solutions for no till systems. The first is to dedicate beds to intensively growing crops that never have heavy machinery or anything else that could compact the soil on them and to deliberately plant where you intend each plant to grow. This is more labor intensive and most appropriate for a home scale garden or urban farm, however by preserving and promoting biological activity and healthy soil structure while actively managing pests and disease as they appear, you hedge the labor costs with having no fertilizer or machinery costs. The second is more appropriate for commercial scale farming, though can be and is used for home gardening. This is a no till system with mixed species seasonal cover crops. Normally most farm fields are left bare for half the year or more, which leaves fields exposed to dessication, oxidation, an erosion from intense winter sun and winds, exposed to freezing winter temperatures that damage or destroy soil organism communities among many other negative impacts. Likewise, the already discussed effects tilling has on soil organisms. The idea behind cover cropping is to grow your own mulch on site with the added benefits of keeping the soil covered with a protective layer throughout the winter and spring, collecting sunlight and carbon while locking up valuable nitrogen and phosphorus, and feeding a mixed diet to the soil biology while dramatically increasing soil organic matter content. Annual crops are then seeded into the residues of the cover crops and benefit from the slow release of nutrients as the cover crop residues decompose.

Typical no till cover crop system with annual crop directly seeded in residues.

Photo credit and info: http://precisionagricultu.re/tag/no-till/

          The perfect companion to mixed species cover cropping is Allan Savory's intensive grazing concept, aka mob grazing. The idea here is again to mimic natural biological systems. Conventional grazing practices say to turn your livestock out on the whole acreage of your pasture, however this leads to uneven grazing due to preference, overgrazing, uneven distribution of manure, lowered productivity, and generally poor soil and pasture health. With intensive grazing, the entire pasture is separated on average into half acre paddocks where the livestock are cycled through two half acres per day. One half acre in the in the morning and the second in the evening. However there are many variations on this and you should look into what will work best for your site. The goal with paddocks is to graze the entire half acre paddock to no more than 50% and not graze it again for at minimum 60 days. In turn the entire paddock is well manured and not overgrazed while allowing ample time for the pasture crops to recover before being grazed again. This dramatically increases pasture productivity, soil organic matter, and animal health. Even better, you can have mixed species herds to increase the diversity in manure type and animal contributed soil biology while more effectively grazing different pasture crops. With a well planned out system, you could even rotate annual crops in for more diverse streams of income. I wonder if I could do this with my chickens on such a small scale as a 1/5 acre lot, hmmm.

Intensive/paddock grazing example.

Photo credit and more info: http://transterraform.com/permaculture-strategies-intensive-rotational-grazing/

Simple example of Allan Savory's concept.

Photo credit and more info: http://permaculturenews.org/2010/05/07/holistic-management-herbivores-hats-and-hope/

 

          And of course, no soil article is complete without discussing compost. I believe no home should be without a composting system of some sort. From a simple compost pile; to vermicomposting (worm composting); to deep bedding in the chicken coop; to all the crazy tumblers, bins, and barrels, there is a composting system for you. The best part is you're using a resource that otherwise would go to the landfill to become contaminated and unrecoverable while adding to methane emissions. Composting is as easy as putting your green and brown kitchen scraps in a pile and letting it rot over winter. As well, composting and especially vermicompost is by far one of the best ways to increase biological activity in the soil. My favorite form of composting is anaerobic digestion because you get the carbon rich humus out of it with the added benefit of capturing methane for later use. With digestion you double the productivity of the composting process with no extra inputs and because of how anaerobic bacteria work you can safely compost human, dog, and cat manure as well. However the initial cost and land needed are limiting factors for digestive composting, as such on the home scale I recommend sticking with tower style vermicomposting or standard composting bins.

          Currently, I fill my chicken run with deep bedding of kitchen scraps and wood mulch and I keep a giant hot pile of composting wood mulch, horse manure, kitchen scraps, brewery waste, and coffee grounds. All of these things are freesourced from my local area. Until I get more of my home infrastructure set up this will work just fine for me. Though there are serious drawbacks, namely having constantly changing available area to turn the pile in order to keep it hot, and the chickens kick the pile all over my work area. Ultimately I intend on building a three bin system to make turning hot compost easier, and a worm tower for keeping in the kitchen in place of the gross bucket that we use for collecting daily refuse.

         The hot compost pile with wheelbarrow on left, chicken coop and shed on the right, mulch madness along back fence.

          Well that in a nutshell is my Soil Building 101. It's by far not exhaustive as there are many ways to build soil that I'm sure I don't know about. I would love to go into greater detail on several of these because they are all worthy of a blog all in themselves. So in the future I will cover some or all of these. I did not go into soil amendments like biochar or rock dust, however I plan on dedicating an entire blog post to each of them as well. Next week, in light of Sao Paulo running out of water within the next month or two, California in a drought and running out of water within the year, the entire U.S. Southwest running dry within the next two to three years, and the U.S. Midwest following closely behind, I going to talk about water, drought, and some permaculture solutions. Have a great week and I look forward to sharing with you then.

Lets Talk About Dirt

          Welcome back. To recap, last week I shared a bit of my experience and knowledge base as it relates to renewable forms of energy, organic urban farming, ecology, and social influences on these subjects. Today I want to share what I know about dirt, specifically soil and why dirt is not soil, why that's an important distinction to make, and why soil is so important for all terrestrial life. I'm going to cover in brief the current state of soils worldwide and the effects soil health has on global warming, water availability, and regional climate stability. Because this is a dense topic and even with simplifying most of its content this blog will run long, I'm splitting it in half and next week I'll cover the most effective, simple, and easy things that everyone, regardless of income or resources, can and should do to build soils.

          While I believe most everybody knows that in general things are not looking good for our planet and our species and that our future is bleak, I believe most people willfully look away from the problem because it's so overwhelming and it's easier to not face reality, this is a form of cognitive dissonance. If this is you don't feel ashamed, like any skill it takes time to develop the ability to face these kinds of problems on a daily basis and take action in spite of the overwhelming feelings they generate. Some of the following paragraphs are grim and spell out our future in no uncertain terms, however I don't care for shock doctrine and fear mongering. My intent here is to educate, offer simple solutions, and inspire you to take action. With this in mind, lets begin.

          Soil is a living organism. While there is no scientific founding to that statement, as in it is my belief and not necessarily fact, it's accurate to say soil is biological organic matter comprised of and home to an incalculable number of biological organisms that by their presence or absence determine soil health and viability. Dirt on the other hand is not alive and does not support life. Comprised of inorganic mineral compounds, dirt is inert. Rhyme intended a as mnemonic device to help remember why dirt, though a component of soil, is not soil. The reverse however is true, soil is a form of dirt. This is an important point to make because without adequate water in the form of moisture and without a healthy and diverse community of soil biota, soil rich in organic matter is just dirt and dirt cannot support complex forms of life, where soil can and inevitably will.

SOIL.

Photo credit: http://www.radionz.co.nz/national/programmes/ourchangingworld/20141030

DIRT.

Photo credit: http://www.huffingtonpost.com/2013/01/22/ne-quittez-pas-dirt-menu_n_2526088.html

          Plants are primary producers. This means that plants take inorganic compounds (dirt) and convert them into organic compounds, most often by means of photosynthesis. However, it's not exactly that simple. If it were, there would be no deserts because plants of all kinds could and would establish themselves and convert lifeless desert expanses into lush paradises without much effort. One of the keys to making it possible for plants to establish and flourish, especially more complex and food producing plants, is a bare minimum of three percent organic matter in the soil and the accompanying soil biota that make soil and facilitate nutrient cycling. Another key to healthy viable soils is moisture, which is held in the soil by both high levels of organic matter and a complex community of soil organism. If soil moisture is depleted, then biota die off and soil formation and nutrient cycling slow, then less or no plant life can survive. If organic matter is depleted, then less moisture can be held in the soil and soil biota die off, then nutrient cycling and soil formation slow or stop and almost no plant life can survive without irrigation and fertilization. If biota are killed off, then soil formation slows or stops, nutrient cycling stops, pathogens and disease rise in number and plant life can only survive with added fertilizers, pesticides, and fungicides while no new healthy beneficial biota can establish because chemicals meant to kill pathogenic life forms also effectively kill off the beneficials. I hope you are starting to see the connectivity and cyclicity here. Everything stems from healthy soil.

          In the U.S. alone, since the 1950's we have depleted some thirty percent of our arable soils to less than one percent organic matter and of the seventy percent left, seventy percent of those are expected to be depleted of organic matter by the year 2100. Even more alarming, this trend is closely mirrored worldwide. That is to say most of the world will be without arable land within the next seventy to ninety years. This is not even considering rates of erosion from over plowing fields, soil salinization and water depletion from poor irrigation practices, and expanding desertification from overgrazing and global warming. To add perspective, it takes natural processes thousands to tens of thousands of years to develop just one inch (2.5cm) of soil and to sustain intensive agriculture a minimum of one foot (30cm) of soil is needed. The sobering reality is that by 2050 most parts of the planet, including the U.S., will not be able to supply the food necessary to support our population as it exists today, let alone the projected population of ten billion people. To put the timeline in perspective I'll only be 65 and my kids late 20s to early 30s. What age will you be?

The dust bowl will become a worldwide phenomena.

 Photo credit: http://kansaspublicradio.org/kpr-news/pbs-air-ken-burns-documentary-dust-bowl

          Are you ready for the rabbit hole to get deeper? There is a way out, its not all doom and gloom, I promise. Remember, the solutions are rather simple and easy to do. We'll get to that next week, but first lets take a look at how soil health relates to global warming, water availability, and regional climate stability.

          Organic matter in soil equals carbon in the soil and carbon tends to stay locked up in the soil for thousands or even millions of years. Carbon is also locked away in all living things, large amounts being in trees and grasses. So when we talk about carbon emissions and global warming, we are talking about releasing carbon that has been sequestered from the atmosphere by biological processes and locked into the soil or fossil (oil, natural gas, coal) and non-fossil (wood, syngas, biomass) fuels. When forests are clear cut, or grasslands converted to monoculture cropland, or soils are depleted of organic matter, that stored carbon doesn't just disappear, it leaves with whatever was harvested and more often than not ends up in the atmosphere thus increasing the amount of solar radiation in the form of heat that gets trapped on our planet and increases rates global warming. At the same time, those carbon sequestering biological processes are stopped dead in their tracks; the system is thrown out of balance as more carbon leaves the soil than enters the soil. When the carbon is released in the form of methane, most notably from drilling for fossil fuels and modern livestock farming practices, the effect is ten times worse than carbon dioxide alone. Likewise, plants cannot grow well, or at all, in unhealthy and depleted soil. This makes it that much harder to sequester atmospheric carbon by biological processes.

The carbon cycle.

Photo credit: http://cnx.org/contents/b3c1e1d2-839c-42b0-a314-e119a8aafbdd@8.24:98/Concepts_of_Biology

          Carbon rich organic matter and a healthy community of biological organisms in the soil also generally means more water in the soil. this is because decomposed and decomposing organic matter (humus) acts like a sponge, retaining up to ten times its own weight in water. Likewise, soil biota increase  the water holding capacity of any soil. As well, soils rich in humus, water, and biota can support a large variety of plant life that store large amounts of water in their tissues, again most notably trees and grasses. Here's where things get really cool, more water in the soil means more water percolating deep into the ground and eventually recharging aquifers as a water savings account. As well, increased water in the soil and diverse plant life leads to greater levels of  evaporation from the soil and transpiration from plants (evapotranspiration), which creates higher local humidity and rainfall. Higher humidity buffers local and regional climates against severe temperature changes and drought while increased local rainfall contributes to a healthier water cycle and supports healthier river and tributary systems, thus stabilizing local and regional climates.

          With all the problems our world faces, from peak oil, to climate change, to ocean acidification, to destabilizing geopolitics, and so on, dirt just seems like another thing to add to the already out of control list. However, as we've covered, dirt is not soil and soil is innately tied to and a primary influencing factor of climate change, which is the primary influencing factor of ocean acidification, though we didn't cover the topic of oceans. Soil can also be a mitigating or exacerbating force for geopolitical relations as it relates to food production and the coming food shortages if we do not heed the warning signs that have been documented since the mid 1960s. Though GMO's are a topic for another day, it's pertinent to say that GMO's will not save us from depleted and degraded soils. The fact is no plants, not even modified ones, are going to grow in lifeless pure mineral dirt. Remember dirt is inert. Certainly carbon emissions need to be greatly reduced worldwide and resources need to be reused and recycled to a far greater extent than they are today, however soils are the most pressing and influencing problem we face. No matter what else we do to address other issues, if we can't feed ourselves, well be in really bad shape. By focusing on soil repair we will ensure our own future and the future of our children while simultaneously mitigating many of the other problems our planet and our species are facing. I look forward to sharing a more positive and upbeat look at how anyone and everyone can and should help rebuild soils worldwide. I look forward to next week for sharing soil building 101.