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

The new weather station installed at the Willits Energy Farm is able to collect a variety of metrological variables. This blog will discuss the three main hardware components of the system, namely, the Integrated Sensor Suite, the Vantage Pro 2 Console, and the data logger. These three parts work together to gather, transmit, store, interpret, and present data related to our on-site weather conditions. The Energy Farm network currently has two sites capable of broadcasting weather data-the Energy Farm site in Willits, California and another at the Energy Farm site at the University of British Columbia.

Close Up of Integrated Sensor Suite (ISS) on Willits Energy Farm

The Integrated Sensor Suite (ISS) is mounted eleven feet in the air in the northwestern section of the Willits Energy Farm. Notice that the unit is equipped with an anemometer. As you might guess, this device is used to capture wind speed and wind direction data. The large black surface is a rain collection bucket. The bucket has a conical shape that channels water down into a spout. This spout pours water onto what looks like two cups situated on a teeter-totter. Situated at the fulcrum of this teeter-totter is a digital sensor used to measure the amount of hourly precipitation. On top of the unit and to each side of the rain bucket are two gauges which measure Ultra Violet Radiation and Solar Insulation. In the picture you can only see one gauge- the UV detector. Many people quickly notice the mini solar panel mounted on the front of the unit. This does not collect specific variables of data, and instead powers the sensors, assists the transmission of the wireless data, and recharges the battery. The ISS uses a Nickel Cadmium battery, which, no doubt, serves as a back-up and nighttime power source. Most of the other devices are housed inside the white portion of the unit, under the rain collection bucket. This is a radiation shield and is where measurements of temperature, humidity, and barometric pressure are derived. The radiation shield is designed to protect the sensors from interference from direct solar radiation that may confound the accurate measurement of data.

 Vantage Pro 2 Wireless Console

The second aspect of this system is the Vantage Pro 2 Console. The console is mounted on the wall inside the computer lab and receives data from the ISS via wireless transmission. The Vantage Pro 2 Console was bundled with the ISS and is used to present the data in a means in which we can read it. It is capable of producing graphs, making forecasts based on its data, and simply displaying the data in real-time. It runs on three “C” batteries or can be plugged into an AC power source.

There is a small section in the Vantage Pro 2 box to insert a data logger (not pictured). The device is sold separately. Without this it is impossible to connect the weather station to the computer and therefore impossible to store a large amount of meaningful data. The data link connects to the computer with a USB cable and is packaged with Davis Instrument’s Weatherlink software. Weatherlink is the windows-based interface and can make colorful graphs, adjust the Vantage Pro 2 console settings from the computer, and share the data on the internet.

It has been a week since the initiation of the probiotic fertilizer and the batch-style biogas system at the Local Energy Farm Demonstration Project located at UBC. At present, certain aspects of daily farm upkeep rely on the work of dedicated volunteers. I considered this in the creation of the biogas digesters and attempted to make a system that was as easy to maintain as possible for the volunteer workforce.

At minimum, the biogas digesters need to be agitated once a day. In my perfect world, agitation would occur three times—once in the morning and twice during the heat of the day. Remember, agitation breaks up the hard layer of scum that tends to form on the surface of plant based substrates and it mixes the plant matter in order to allow bacteria to come into contact with new material to digest. Agitation should take about thirty seconds for each digester. A volunteer cycles the handle clockwise for about 5-10 revolutions and then counter clockwise for another 5-10 cranks. Simple!-Finished and on to the next farm task!

The probiotic fertilizer needs less frequent agitation (once a week instead of daily). The “airtight” lid is taken off the brew, a wooden oar is inserted into the mix, and the contents are mixed and churned for a minute or two. Usually this makes a lot of foam as carbon dioxide is released from the mixture. After mixing the lid is re-secured and awaits the next week.

As you consider the infrastructure and process you are going to develop on your farm try to make it use as less energy as possible for up keep and maintenance. To invest a little extra thought and energy in the planning and design phase can allow you to have multiple initiatives underway, which, once started, can continue without a lot of extra physical input.

For a little over a day, the feedstock materials have been undergoing aerobic decomposition in hopes of breaking down the plant matter before feeding the digesters. One of the digesters (a.k.a. David) will be fed a charge of 9Kg clover and 11Kg of dry maple leaves. Once David is filled with water the substrate will have a total solids concentration of about 11 %. The other digester (a.k.a. Ludwig) will be fed a mix of 4.5Kg of clover and 5.5Kg of dry maple and alder leaves. At about 6% solids this is a less dense concentration of material.

When these prototype batch-style digesters I decided to make two subtly different machines. Ludwig’s agitation system differs from David’s in one way—the depth of the agitation shaft. While David’s agitator is situated 6 inches below the top of the lid, Ludwig’s is positioned at 8 inches below the top. What this difference amounts to is as follows:

Ludwig’s system will be able to disrupt scum formation and will be able to mix the slurry from a deeper position. The intended idea was that the deeper agitation position would churn the substrate and allow the bacteria to come in contact with new bits of material to eat. In contrast, David’s agitation system is position higher on the drum. It too will be able to disrupt the scum formation and it has the advantage of allowing more material to be put into the digester. Given suitable conditions, more material is more biogas. Hence, I have decided on a smaller solids concentration in digester Ludwig because it might be too hard to turn the agitation handle through such a dense mixture. David, on the other hand, can handle the denser material and will break up the scum, allowing the digestion process to sort itself out below. In subsequent tests of the machines more material will be added to Ludwig to really get a test of what is the limit of the deeper agitation system as it attempts to churn dense plant matter.

We are moving forward with the biogas system at the Vancouver Energy Farm. The paint will be fully dry by tomorrow and we could technically start the digestion process. However, I will wait at couple of more days to let the clover and leaf feedstock undergo a little more aerobic decomposition. I picked up all the "plumbing" fittings at Vancouver Irrigation. These folks were quite helpful and allowed me to purchase the pipe-fittings at a wonderfully discounted rate--Thank You.

Potions of the pipe-fittings are intended to be a scrubbing chamber for hydrogen sulfide gas. Hydrogen sulfide smells like rotten eggs and is corrosive to the metal or brass in any system that you feed the gas to. However, the hydrogen sulfide gas can be scrubbed by corroding some other type of metal- in this case steel wool. The steel wool is placed inside an 18-inch long chamber. As gas pressure builds up in the digester the gas is forced through the steel wool on its way to the gasholder. Below are pictures that show the process of making the scrubbing system and how it is built into the digester lid.

Unrolled Steel Wool

Feeding Steel Wool Into Scrubbing Chamber

Biogas Digester with Scrubbing Chamber Extending from the Lid

Today was a very exciting day for the biogas project. The construction of the agitation system is completed! I worked with Vic at C.W. Brockley to install the agitation arms earlier this afternoon. I also gave the inside of the drums, the lids, and the agitation arms a thick coating of paint. Since the environment for biogas digestion is corrosive to steel, we must use corrosion resistant paint to give the digester protection and a longer lifespan. I decided that stainless steel would not be used on these digesters because (1) it contains chromium-a poison to the anaerobic bacteria and (2) it is very expensive. If this design is going to be practical to replicate, specialized or expensive metals probably won't be the best choice.

I had to make an alteration in the feedstock. I was going to feed one digester clover-hay and dry alder leaves, aged 1+ years. But a majority of the alder leaves had too many wood chunks and other debris. Given the effort to pick through 10Kg of dry leaves to remove most of these items I decided that the alder leaves were unsuitable for this demonstration. So, I have reverted to using maple leaves and a mix of cleaner alder leaves to feed one of the digesters. It was not a major setback because maple leaves are abundant around the manicured UBC campus.

Today I hand-shredded 10Kg of dry maple leaves and I had time to ponder the carbon component of the feedstock. Although we need both carbon and nitrogen to make the bacteria happy while they consume the plant matter and respirate the biogas-it is really the carbon that is the methane forming aspect of the substrate. I was amazed at how much carbon is in 10Kg of dry leaves. While the weight of clover to carbon is almost equal in proportion, there seems to be a lot more leaves taking up space in the digester than clover.

The plan is to load the prototype batch digesters later this week. Each batch, (aka. charge), will be a mixture of chopped clover-hay, dry leaves, and a small portion of fresh lama or sheep dung. To prepare, I have processed all the clover and laid it out to rot. The dry leaves were collected about two-weeks ago. I want to mix the dry leaves with the clover at the proper proportions in order to create a carbon-nitrogen ratio of 25-30:1. By my estimates this will be roughly 10kg dry leaves (40:1) and 10kg chopped clover-hay (15:1).

After letting the clover rot overnight and part of Tuesday, I will mix in the dry leaves. This will entice aerobic mesophilic and thermophilic bacteria to break down the leaves and the clover. On Thursday or Friday I plan to add each composting “charge” into each digester and add water until about 4in/10cm from the top of the drum.

Since the aerobic bacteria will be decomposing the plant matter inside the biogas digester, the substrate will become acidic. Therefore, I need to “buffer” the charge by adding lime to the water. This should stabilize the pH of the substrate and set up a friendly environment for the methane forming bacteria that prefer a pH of about 7-8.

When the pH is in the healthy range I will finalize the process by adding the bacterial cultures that have been growing inside the greenhouse since the 14th of September. The cultures include mixes of lama dung and clover, pure sheep and lama dung, pig dung and leaves, and clover and leaves.

Anareobic "Seed" Cultures Inside Greenhouse Since September 14th

I have recently returned from a seven-month trip in South America. While in Ecuador I lived at a farm that employed an agricultural engineer. He was very calm and friendly and would answer many questions related to the farm. I was curious about a particular liquid that the farmers used to spray on mature plants, new sprouts, and freshly tilled soil. Since this was an organic permaculture farm, I was certain that they were not using industrial pesticides or fertilizers. The engineer told me that the mixture was a type of specially prepared compost tea. The preparation uses mixtures of nitrogen rich plants (legumes) and animal wastes to generate a pro-biotic organic fertilizer.

What this means is that we can expect an addition of useful nutrients and acids to the soil, but we also introduce helpful and healthy strains of bacteria. The bacteria provide the utility of adding diverse life to the soil and defending the plant from harmful competitive strains of bacteria. In short, a symbiotic relationship.

I was inspired with this information and feel that this special style of tea is worthy of a demonstration at the Vancouver Energy Farm at UBC. Yeast, molasses, sawdust, and rock phosphate powder have been gathered along with 25KG of clover. As to be expected at an organic style farm, there is an abundant amount of pre-composted material which is also going into the pro-biotic brew. The demonstration mixture will be brewed in a 55 gallon plastic barrel. After the process has finshed brewing, the final mixture will be applied at roughly a 10:1 ratio of ten parts water to one part tea.

Sawdust, Molasses, Clover, Urine, Yeast, Rock Phosphate Powder, Humus

Yeast, Molasses, Urine, Rock Phosphate

Clover for Probiotic Tea

At the Energy Farm we are experimenting to find useful intermediate technology that maximizes the amount of work done while involving little to no petroleum input. Since many processes that are assumed in today's system of agricultural practice rely on machines, we are looking for ways around these assumptions in order to adapt to an energy constrained future.

Today I worked on discovering the methodology for collecting and processing materials to be used in the biogas digester and organic fertilizer that I am experimenting with. My aim was to harvest and process clover, (a nitrogen rich legume), without using petroleum powered machines like a gas mower or chipper/shredder. I was excited to try the new human-powered push lawn mower that has been purchased for the for the energy farm. As might be expected the mower easily cut the leafy tops off the clover. The clover was then collected using a fine-toothed grass rake. However, when it came to chopping clover that was much more over-grown a machete was used to complete the job. After I cut a full wheelbarrow of clover (about 11KG) I took the fresh greens over to be processed.

Regardless of whether we are making compost or collecting biogas digester materials we have to chop the ingredients into smaller pieces in order for the bacteria to break the plant matter down further into more simple molecules. Again the aim is no petrol, so I decided to grab handfuls of clover from the wheelbarrow, roll the handfuls into logs and chop it with a cleaver. This creates bits of plant that should mix nicely with the dry leaves that we intend to feed the biogas digesters.

Unprocessed Clover For Biogas Digesters and Fertilizer

Harvesting Clover with Machete

Chopping Clover with a Cleaver

The whole process of collection and processing took me around an hour. Although the push lawn mower and the cleaver seemed to work nicely for cutting and shredding, using the machete seemed a little awkward. Since there was so much bending over and sweeping arm motions I don't think I have found the right way to collect overgrown clover. I think I might try to collect materials later using a different tool.