Winter is almost over, and with it the time for introspection also draws to a close. The heavy rains and shorter days have given us time to create a sign system that illustrates our priorities in the garden. In the coming year some focuses like crop selection and soil building will stay the same, and this season they will be enhanced by a winter of planning that we did not have last year.

Education is also a key priority as we enter the 2008 growing season, and one of the primary tools that we developed this winter is our garden didactic system. This collection consists of 23 concept signs and 30 profile crop signs. They will be scattered throughout the garden to greatly enhance its accessibility.

This project was beneficial to the Energy Garden initiative because in the process compiling the content, we were able to summarize our work to date. In addition, the signs helped us to identify the focal points of the garden and the methods that influence its development.

The concept signs consist of:

· Goals of the Sebastopol Energy Garden

· Community Compost Collection

· The Sebastopol Energy Garden Growth Collage

· Square Foot Gardening Method

· Natural Farming – The “Do Nothing” Method

· Cover Crops

· The Water Catchment System

· Drip Irrigation

· Culinary Herb Spiral

· Mandala Garden: The Sheet Mulch Technique

· Methods of Season Extension: Towards a “Four Season Harvest”

· Appropriate Technologies

· Processing and Harvesting Techniques

· Tree Guilds: Edible Forest Gardening

· Garden Cycle Tracking

· Ethanol Production

· The Fractional Still

· Recycling and Compost: Designing “From Cradle to Cradle”

· Chickens

· Biointensive Concepts

· Permaculture Principles

Each sign corresponds to something that is happening in the garden or that has influenced its progression. There are also 30 profile crops that we have chosen because of their ability to help us adapt to Peak Oil. Instead of a lawn, we are selecting a great range of crops to benefit humans and the environment. Please see http://www.energyfarms.net/node/1495 for a list of these crops.

These signs will enable people with a wide range of understanding of sustainability to experience a transformed suburban lawn. When people visit this year, during our second growing season, they will be introduced to a diversity of crops with a large variety of functions. In addition, they will be exposed to techniques and technologies that are easy to learn and have the potential to make a big difference in their lives.

The rains will soon stop, and spring will bring a time of action. We will sow seeds of diversity in the garden and hopefully, inspiration in the community. The Energy Garden is always open to visitors and we look forward to helping more people experience the resilience of the Earth.

This past weekend was a busy one at the Sebastopol Demonstration Energy Garden. After a summer of soaking in sun and filling their stalks and seeds with sugars and starches, our Dale Sorghum crops went full cycle. From the 212 sq ft. that we had under cultivation we harvested 9 kg of dry seed and 115kg of sugar rich stalks. From the stalks that we harvested in addition to the 110 kg of stalk that were donated to us by Live Power farms (225 kg in total), we produced 10 gallons of sorghum juice. Of the 10 gallons produced, we fermented 8 gallons and with the other two produced approximately 57 oz of sweet sorghum syrup; this demonstrates the multiple possibilities that the crop offers. In addition we were able to utilize the carbon in the pressed stalks by adding what we didn’t use as a layer in our sheet mulch as an ingredient to our compost piles. The chickens quickly consumed the fresh leaves that topped each pile.

It took three of us approximately three hours on Friday to harvest the stalks and seeds; this includes removing the leaves from the stalks. The process entailed one man cutting the stalks at their base with a pair of hand held clippers while another tied the stalks in bundles and removed the seeded florets which were processed by a third. The seeds were separated and laid thin upon screens in the sun to be dehydrated and the stalks were stacked in the shade to be pressed the next day.

To press the stalks it required three people an additional 3.5 hours of labor on Saturday. We used the Improved Chattanooga #12 to press the stalks and caught the juice in 5 gallon buckets; the juice that emerged was a pea green and contained 15% sugar by volume. By comparing the measured weights (lbs) of bundles of four stalks with the volume (mL) of liquid that emerged we determined that on average 162.3 ml of juice is produced for every 1 kg of stalk pressed.

Overall harvesting and processing the stalks required about 21 hours of labor. We produced 10 gallons at 15% sugar from the 225 kg of stalk that we pressed giving us a 22.5:1 ratio of kilograms of stalk for each gallon of juice produced.

[video]

Data published in the Alternative Field Crops Manual reports yields of 10 ton/acre for Dale Sorghum, of which 70% is comprised of the stalk. This is synonymous to 6350.3 kg of stalk/acre, which would indicate that 282.24 gallons could be achieved for each acre of Dale Sorghum under cultivation. Seeing that the juice produced from pressing the stalks is 15% sugar, fermentation should yield 282.24 gallons of mash at 7.5% alcohol. This shows that from one acre of Dale Sorghum, 21.17 gallons of 200 proof ethanol can be produced; the theoretical yield that they indicate however is over 400 gallons/acre.

Data published by Morris J. Bitzer at Blairsville, GA, and Quicksand, KY shows yields of Dale Sorghum at 20 tons of stalk/acre, 20321.28 kg stalk/acre, double the yield proposed by the Alternative Field Crops Manual, whose data was compiled from Waseca, MN.

Data published by Oak Ridge National Labratory, acquired from 4 different test sites in Indiana and Alabama, reported yields of 22.2 Mg/ha (9.9 tons/acre), similar to that published by Alternative Field Crops Manual.

Data Published by Texas A&M Extension agronomist, Juerg Blumenthal said the highest yield he'd acheived was 12.4 tons of dry matter per acre with the production of 395 gallons of ethanol per acre.

No indication of the proof of alcohol produced was provided in any of these studies, but I do not see how it is possible to yield such high volumes per acre. In each case either the juice pressed from the stalks is of a higher sugar percentage, their method of pressing is more efficient, or the sorghum is being grown in higher densities; none of this information was provided. Somehow, in each case, higher volumes of ethanol per acre were produced from lower masses of stalks per acre

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Proposed yields of sorghum stalk/acre: 10 ton/acre, 12.4 ton/acre, 22.2 Mg/ha (9.9 tons/acre), 20 ton/acre

Average = 13.075 ton per acre

1 acre = 43559.46 sqft

Harvested 212 sq ft = 0.005 acre

0.005 * 13.075 = 0.065 ton/acre

1 ton = 907 kg

Harvested 115 kg stalk = 0.127 ton stalk/0.005 acre = 25.4 ton stalk/acre

*25.4 tons stalk/acre being grown on site > 13.075 ton/acre proposed yield

Proposed yields of ethanol/acre: 400 gallons of ethanol/acre, 395 gallons

Average = 397.5 gallons ethanol/acre

Produced 10 gallon juice from 225kg stalk, of which 115 were grown on site

115/225 = 0.51 * 10= 5.1 gallons juice produced from grown sorghum

1 acre/0.005 acre = 200 * 5.1 gallons of juice produced = 1020 gallons of juice/acre

15% sugar will ferment to 7.5% ethanol

1020 gallon juice/acre * 7.5% ethanol after fermentation = 76.5 gallons ethanol/acre

*76.5 gallon of ethanol/acre produced < 397.5 gallon ethanol/acre proposed. This data correlates more with the projected 21.17 gallons of ethanol/acre that I proposed based on the obtained 22.5 kg stalk:gallon juice ratio and the assumption that starting with a 15% sugar content will produce a 7.5% alcoholic mash after fermentation.

Heres a video of Sorghum Syrup being made at Kentucky State University.

[video]

My name is Michael Bomford. I work for the Community Research Service at Kentucky State University, an historically black land grant university in Frankfort, Kentucky's capitol city. My research focuses on developing sustainable organic agriculture systems suitable for adoption by small farmers. Check out some of the projects I'm working on here.

KSU energy farm project, with food crops (foreground),
high tunnel, and energy crops (background).

1. 1. Biointensive - using human labor and hand tools in small beds, according to the methods of John Jeavons
2. 2. Market garden - using no machinery larger than a walk-behind tractor in medium-sized beds
3. 3. Small farm - using standard four-wheeled tractors for crop production at the field scale.

While we are collecting fallen apples for the production of ethanol, we are also collecting those that are ripe for human consumption. So as to avoid contamination we rented a commercial device very similar to ours which runs off an electric motor.

Despite this device using an electric motor, the process of mascerating the apples and then pressing them took about as long as if we'd used our own manual contraption. The motor often jammed; each time this occured we had to remove the apples and refill the funnel.

The device did have many desireable traits however. The barrel which collected the mascerated apples was on the same platform as the pressing barrel; this made sliding one over to be swaped out very easy. Also the device was on wheels making it portable.

We filtered out the pulp of the cider using cheese cloth, and sealed each bottle by baking them at 200 degrees farenheit in the oven. In total, over the course of 4 hours we produces approximately 12 gallons of cider.

Due to the apple press' limited ability, we constructed a much more sophisticated tool to aid in our goal of fermenting fallen apples as a means of producing ethanol.

It functions as both a grinder and a press and we were able to construct it out of basic hardware, including parts from the previous apple press (all lumber used was recylced).

The grinding mechanism was built using 3/4" steel nipples attatched to a 5" in diameter cut of fir. Screws were then distributed around the circumfrance of the wood to act as the teeth of the grinder.

The grinder was mounted by drilling 1 1/2" holes through the diagonal support beams that connect the leg posts and a handle was added for easy torque. We then added a funnel to hold the apples to be ground and added horizontally placed 2x4s to support the press.

The construction of the press was more demanding because it required that the platform be waterproof and that we provided a faucet of some sort to dirrect the pressed liquid. The platform that we made was first caulked with silicone to avoid any leaks and then coated with a sheet of galvanized steel. The faucet was made from PVC parts left over from the drip irrigation system and was installed just as the grinder was, by drilling a 1 1/2" hole within which it rested. Silicon was also used to make sure no liquid escaped around the sides of the faucet.

We are able to easily remove the press and fill/empty the contents because rather than permanently attatching its parts, they are simply clamped down before and after each pressing.

With one person opperating the machine, we are able to produce 4 gallons of liquid per hour; this includes collecting the apples, grinding them, and pressing them.

After producing eigh gallons of wort, measurements of the temperature, the sugar content, and the pH were taken.

A pH of 3.5 was measured at 78 degrees farenheit with a sugar content of 12% prior to bringing the wort to a boil.

The wort was then poured into a stainless steel kettle, and brought to a boil so as to kill any bacteria that might compete with the yeast we would soon add. By doing so we were also boiling out water, hence increasing the sugar content as well as neutralizing the pH.

After boiling the wort and allowing it to cool, yeast nutrients were added and measurements were once again taken. As the temperature of the wort cooled, the hydrometer's reading of the sugar content became more accurate. I was able to boil out enough water to bring the sugar content to 20% and the pH to 4.5. The sugar content could have even been higher and this has been noted for the next batch.

Once a temperature of 80 degrees farenheit was reached, the yeast was added, the lid was put on the bucket and the bucket was placed in a cool place to ferment for the next three days.

As the crops grow, we are racing to equip the garden with the tools required for the production of ethanol as a fuel source.

Ethanol Production

1. Fermentation

To produce ethanol from the crops that we are growing we must first mascerate and press the sugar/starch rich part of the plant into what is called the wort.

By bringing the wort to a boil in a stainless steel kettle we are able to kill off the bacteria and other microbes that would compete with the distillers yeast that we introduce once the wort has cooled down. The quicker the cooling process the better; this reduces the risk of bacteria reestablishing residence in the mixture. Once the yeast has been added the contents of the kettle are refered to as the mash. It is the mash that we add to our airtight fermentation containers and allow to ferment for 1-3 days.

Before adding the yeast it is important to check the temperature of the mixture. Yeast prefers temperatures of 80-90 degrees farenheit.

Before adding the yeast it is important to check the sugar content of the mixture. Because yeast converts about half of the sugar to alcohol (the other half into CO2) and because yeast commonly perishes in alcohol percentages of 15% and higher, it important to dillute your wort to sugar percentages of 20-30%. By adding cooled sterilized water you can quickly cool the wort while reducing the sugar content.

C6H12O6 → 2CO2 + 2C2H5OH

Before adding the yeast it is important to check the pH of the mixture. Yeast performs best at a slightly acidic pH of 4-4.5. By using lithmus paper and adding an acid or base accordingly this pH can be obtained.

Yeast can be added once the mixture meets these conditions. Allow the mash to ferment for three days before disturbing the anaerobic process.

2. Distillation

After fermentation the mash should have an alcohol percentage ranging from 10-20%. So as to obtain the higher percentages required for running a vehicle distillation is necessary. Using a reflux still, obtaining alcohol percentages up to 95% is possible. The remaing 5% water can be removed using zeolite or corn grain as a filter. Constructing a still and obtaining our experimental distillers license is the next step in our goal of producing fuel from the crops that we are growing at the Sebastopol Demonstration Energy Garden.

The motto of Post Carbon Institute is “Reduce Consumption: Produce Locally”. We are demonstrating that motto at the Willits Energy Farm located at Brookside Elementary in a number of ways. For example, a mini-farm is being established that can operate with intermediate tools that do not consume petroleum. As a Community Supported Agriculture project, the food is intended for local distribution within the community. Additionally, rotations of compost crops are being grown to cycle nutrients back to the soil in the form of aerobic compost. Through this practice, we generate a form of fertilizer that is used on-site (local production) and is capable of maintaining the long term viability of the farm by securing healthy soil (reduced consumption).

The plan for this summer is to grow a small area of biofuel crops at Brookside. The fuel can be used to cover our on-farm use. However, since we do not rely heavily on petrol, we can potentially distribute the ethanol to another local farm that intends to grow food for the town hospital. I will speak more about the ethanol project as we near the time to plant the Dale Sorghum in mid May. If you are interested in learning about how sorghum can be used for ethanol and food check out the following links:

A Sweet Idea Converting Sweet Sorghum into Ethanol

Sweet Sorghum Culture and Syrup Production

The Spring Grains project gave us the opportunity to test the new Earthway Seeder. I was initially inspired by the series of Earthway seeder’s that Mark Bomford strung together at the Vancouver Energy Farm in October. We used the seeders to sow overwinter cereal crops, fava beans, and crimson clover. At the Vancouver Energy Farm three separate seeders were purchased and Mark performed a custom connection that worked quite well. When deciding to purchase a seeder for the Willits Energy Farm I found a farm supply that sold three seeders as one unit. The main difference between the Willits seeders and the Vancouver Seeders is that the one we purchased has one hand-grip for the three seeders instead of three separate grips.

The seeds are dispensed by a rotating seed plate. The seeder comes with various sized seed plates for drilling different seeds. The rotation of the plate is driven by the rotation of the front wheel. If the front wheel does not spin the seed is not sown. Since the Earthway seeders are so light weight they sometimes float over the surface of the soil and the front wheel tends to “plow” more than spin. I find this to be the main drawback to these seeders when I worked with them both in Vancouver and in Willits. I am ready to add weight over the front wheels to make sure that they are driven into the ground, turn, and distribute the seed.

As you would expect, pushing three seeders at once saves time and footsteps. I think that it will be cool to drill seed a row of corn and two rows of clover at the same time. This is a useful companion planting and shows what can be accomplished with three seeders in one pass.

Close-up of Three-Wide Earthway Seeder

Another Shot of the Seeder

In the second part of this investigation, I want to discuss the general topic of net energy gains and losses and fully introduce the idea of intermediate technology.

In brief, a net energy equation asks the question: “Do we put more energy into some item or process than we get out of it in the end?”

Many agree that modern agricultural methods are too dependent on petroleum, electricity, and other mechanistic inputs to efficiently grow and harvest crops; and are therefore, net energy losers. Work in modern agriculture uses numerous BTU’s to create the calories stored in food. While they do create huge amount of calories (i.e. 100 acres worth of grain), it is likely that the calories produced do not match the amount of energy used to grow, harvest and process the crop.

Conversely, when processed on a small scale (i.e. 1/3 of an acre), the high calorie wheat crop will probably yeild a net energy gain for that person.

In the agricultural practice in North America, grain production is designed to feed hundreds of people with minimal human labor. Diesel powered machines, and herbicides are substituted for manual labor and presumably more area is grown and harvested. This practice has allowed a small percentage of our population to feed the masses in locations often very far away from the towns or cities we live.

Remember, we want to consider the possibility of creating grain and seed crops on 20-30 acres to support the immediate community. This means that food is produced locally for local users. At present, modern agricultural practice can provide for the nation and part of the world. However, in a context of energy scarcity, it is clear that we will not be able to rely on petrol-based and energy inefficient methods of centralized food production. We must seek ways to bring our food production closer to home and to an even or positive net energy ratio. At present, I am uncertain that we can simply switch modes and completely replicate the practices that have developed over centuries in places like India. We will have to look for a way that is appropriate for the cultural context that we live and is adapted to the environment in which we exist.

This brings me to the topic of intermediate (appropriate) technology. Intermediate tools are those that allow us to bridge the gap between very complex technology and very simple technology. It is technology suited for the environment and cultural context of its users. Again, some of our modern tools consume too many resources and are too big to be sustainable, while some basic tools require too much human energy and are too time consuming to be utilized efficiently. When thinking about tools in a post petroleum context we need to be careful that we do not rely on tools that consume resources that will become scarce. Nevertheless, in certain contexts we cannot afford to break our backs, expending precious time and labor to accomplish the same task with primitive tools. When a tool or methodology is found that accomplishes the most amount of work with the least resources (both human and environmental) then it can rightly be considered appropriate technology. Where then could intermediate technology serve us in the context of harvesting and processing oilseed crops?

I believe that we can use a basket of practices that integrate the both human labor and the use of the machine. True, we will not be able to use a giant combine; however, it does not make sense to throw over 100 years of innovation and technology out the window without considering a few options. What if certain labor intensive processes were replaced by a machine? Furthermore, what if that machine ran on renewable energy technology? Where would human labor and traditional methodology prove to be simple and useful? I hope to address this in the third and final part, as I propose a middle road between total human labor and over reliance on machines.