Last year we developed a toolset that allowed us to clear an
abandoned baseball field of perennial sod and convert it into a vegetable
producing mini-farm. This petrol-free toolset included a low-wheel cultivator made by Glaser
and a two-foot wide broadfork. It is quite likely that we used these tools
in a more rigorous way then they were intended, (opening new land instead of
working pre-established vegetable beds), yet the tools withstood hours of work
with only a handful of needed repairs. After last year’s experience we consider the combination of the broadfork and the low-wheel cultivator to be an appropriate
toolset for small-scale vegetable cultivation because they efficiently use manual
labor in place of fossil fuel powered equipment to prepare vegetable beds.

This blog will revisit our method for preparing vegetable beds
in light of the fact that we are no longer fighting against tough perennial sod,
and instead, we are removing our over-winter cover crops.

Step 1: Removing Cover Crop

We use a sharp scythe to cut the cover crop off as low to
the ground as possible. Once the crop has fallen we rake up the remains and
cart it off as a nitrogen input to our compost piles. In the earliest part of spring,
we are careful to remove only the cover-crop from the vegetable beds that we immediately
plan to prepare for transplant or direct seeding. This allows the other areas
of cover crop to continue growing as much as possible in the increased
temperatures and daylight hours of spring.

Jason Using Sharp Scythe to Clear Cover Crop

Cover Crop Cut Close to the Ground With Scythe

Step 2: Breaking Ground

After the cover crop has been removed we are left with the
gentle stubble of annual cereals and legumes. We have noticed that the loam soil is
quite soft and easy to work with, and we attribute this to the fact the area we are working was established last year. A prime consideration at this stage of bed preparation
is soil moisture. We want to be careful not to work the soil too wet or we will
remove an unnecessary amount of soil as we cut through the stubble of the annual
cover crops.

Low Wheel Cultivator Cutting Into Soil

Step 3: Loosening the Bed

After the stubble of the previous crop has been broken free
from the soil, the next step is to broadfork the soil. The broadfork is two
feet wide and includes five tines that sink into the soil about ten inches. It
is amazing how much easier it is to broadfork the soil this season than it was
last year. We have changed the width of our beds this year from 5-foot wide beds to
4-foot wide beds. This change has put us into some areas of soil that is
similar to last year when we had to combat the sod. Pushing the broadfork into
the previously worked sections versus the reclaimed sod sections really shows
what one-years-worth of work accomplished for reducing compaction and improving
aeration. Again we want to be aware of soil moisture, so that we do not smear
wet soil together in the prying and lifting action of the broadfork.

Chris Sinking Broadfork into and Prying Down

Step 4: Cross-cut the sod and rake

After the bed has been forked, there are entire clumps that
have been lifted and are uneven. We use the low-wheel cultivator with a 3-tine cultivator attachment to
cross cut the bed and thereby remove the clumps. By the time we are finished with
cross cutting we have up to five inches of loose soil on the surface which
makes a good seedbed. It is also easy to transplant into the newly cross
cut bed. If we intend to seed the bed we rake the surface smooth and make sure
there is no trash that could interfere with the drill-seeder.

Jason Cross-Cutting Bed with Three-Tine Cultivator

We like this toolset because it clears an area of grass or
cover crop and produces a vegetable bed that is suitable for
direct seeding or transplant. In this method the soil remains loose and aerated
up to ten inches and it does not entail the soil disruption of double digging
or rototilling. By making sure to compost the soil and debris that is removed from
the area in which you intend to make a bed, you make a good step toward sustainable
soil management in which no soil is lost and on-site nutrients are cycled back
into the beds in the form of compost.

If you are curious you can click here to check out and contrast our
bed preparation method from last year.

• • Manufacturing the materials for a plastic-covered house requires energy. I estimate the embodied energy in our structure to be about 6 GJ per year, over the lifetime of the materials we used. We have opted for two layers of plastic, held apart by a 60 W blower fan that operates continuously. The air pocket between the layers improves the insulating capacity of the tunnel, but producing the electricity to run the blower fan consumes another 6 GJ, assuming the coal-fired power plant that generated the electricity was 30% efficient. For that kind of energy investment we could truck lettuce to Kentucky from California.
  • High tunnels are cool and humid through the winter, creating ideal conditions for the fungus Sclerotinia sclerotiorum, which attacks many of our cool season crops we grow. Finding tactics to combat S. sclerotiorum that are compatible with organic standards has become a major research focus for us.
  • Because it never rains in a high tunnel, salts that accumulate near the soil surface don't leach away. We don't use synthetic fertilizers that tend leave salt deposits, but we have used some fertilizer derived from feather meal. Animal byproducts tend to lead to more salt accumulation than plant-based composts.

We have again added bed space to the Energy Garden, this
time in the shape of a mandala. Utilizing techniques from Gaia’s Garden
by Toby Hemenway, we are slowly building the hardpan barren “lawn”, read: super
invasive bermuda grass and clumps of dead sod, into nutrient rich humus. As double
digging was near impossible, we are letting the worms to the work by creating a
sheet mulch close to 18 inches thick.

First we created the design for the area and then marked the
edges of the mandala on the earth. Next we began creating the bed. Otherwise
known as lasagna gardening, we chopped away some of the clumps of grass and started
with an inch layer of manure. We followed that with cardboard, then with an
inch or two of organic vineyard compost from Grab and Grow in Sebastopol. According
to the grab and grow website, it is “made
from a simple blend of grape pumice, green waste and oyster shell flour, this compost
has no manures or supplemental nitrogen fertilizers added to this high
potassium mix.

This was
followed by a single “book” layer of wheat straw, then with another inch or two
of mango mulch. “It doesn’t have any mangos in it, but it does have horse and
cow manure to supply basic nutrients; grape and apple pumice which are high in
beneficial bacteria and yeasts to aid with the breakdown of organic matter;
rice hulls and straw for good soil tilth; soft rock phosphate and greensand to
boost the phosphorous and potassium.” This was followed by a layer of alfalfa
straw and wheat straw mixed together. We will plant by opening pockets in about
a month.

Next we created
the paths by laying burlap bags donated by Taylor Made Farms in Sebastopol. On
top of the burlap we put down woodchips. The irrigation was then laid under the
straw. We have also sheet mulched and
prepared a new berry patch next to the sunflowers and driveway in the front of
the house. In an epic battle with the Bermuda grass we have also sheet mulched
all of the paths on the property with cardboard and woodchips. We hacked down
most of it and hope it never comes back. It looks great right now.

Before...

After... let the worms do the digging!

This blogcast shows the final passes on the sorghum section with the wheel hoe. After battling through the tall, thick sod we cleared all the material off the field and carted it to the compost area for future integration back onto the land. The final step is to loosen the top layer of soil in order to drill seed the sorghum.

It was much easier to make the second pass with the wheel hoe after the roots and grass had been removed. After making the second pass there was 2-3 inches of loose soil to plant in (just enough to disrupt remaining weeds and allow the seeder to pass smoothly). 2-3 inches is not too shallow because sorghum prefers a firm seed bed.

Click here to watch the blogcast of Chris using the wheel hoe to prepare the seedbed.

Sod Raked Into Rows to be Removed Before Making Final Pass With Wheel Hoe

Loading Up To Take Sod To Compost Section

Almost Finished Clearing Sod

The Sorghum Section Has Been Cleared!!

Huge Pile of Sod and Soil To Be Composted Later (In the Foreground is the Carbon-Compost Crop)

Jason and I have been very pleased with the performance of the Glaser Wheel Hoe. The tool saves considerably more time than using a standard hand-hoe, it increases the power that a single person has to cultivate large areas, and it is capable of working both tough and smooth terrain. This tool is equipped to receive a variety of implements including a furrower, a seeder, and three-tine cultivator. We purchased the three-tine cultivator which we have integrated into Step 4 our bed preparation method.

The bed preparation method is as follows.

1. Use the Glaser Hoe to remove the top layer of sod.
2. Use a Thatch rake to remove debris and sod chunks off the bed and transport to composting area in a wheel barrow.
3. Use the Broadfork to aerate and loosen the soil within the bed.
4. Attach the three-tine cultivator behind the 8 inch blade and cross-cut the chunks created by the Broadfork.
5. Use a bow rake to create a smooth, uniform seedbed.

The three-tine cultivator, (situated behind the standard blade), double cuts the surface of the bed and digs into the large chunks created by the broad fork. After tearing through the chunks, the finished seedbed is uniform and fluffy to a depth of about five inches. It is exciting to incorporate a new element into the method because it has clearly improved the final product our efforts.

Three-Tine Cultivator attached to Glaser Wheel Hoe

Two Beds that Have Been Broad-Forked and Would Be Cross Cut With Three-Tine Cultivator

Three-Tine Cultivator Working Behind The Standard 8-inch Hoe Attachment

We have spent the last two days over turning sod at the Brookside Farm with two Toro rear-tine propelled tillers. There has been 0.9 inches of rain during the entire month of January. This has provided us the unique opportunity to over turn the sod and allow it to decompose during the final months of winter. As mentioned in previous blogs we were looking to overturn the uneven sod that was sure to be unsuitable for seedbeds. The sod was tilled for the first time at the beginning of November; since then, it has re-rooted and in some places began to grow again. Jason Bradford and I had been experimenting with methods of overturning the sod by hand, (cutting the top layer off and overturning it with a spade). We had allocated two weeks to complete the project with two people, doing 100 sq foot sections at a time and working fairly long days. If we waited to overturn the sod after the rains we would be pushing very close to the spring planting season and we might not have the opportunity to allow the sod to decompose enough to set seeds. After lengthy discussion about the use of petrol powered machines the choice was clear that we could incorporate the sod and allow it to rot over the winter in hopes that we could need minor raking and weed disruption to set seeds in spring.

Local business, Willits Rental, allowed us free usage of two Toro rototillers. The choice to use walk behind tillers was made for a couple of reasons. First, the tillers relive the soil of the compaction that can occur when one uses a tractor to address the soil. Tilling at a depth of approximately four inches, we did not create any undue compaction by driving heavy equipment over the soil and potentially compacting it below the fluffed-up top layer. Additionally, while it was possible to use a tractor before the perimeter fence was completed, it is no longer feasible to do so. The area that a tractor would need to turn around in to make its next pass was not enough without probably running against the tight confines of the perimeter fence. Needless to say we wanted to till as close to our walkways and boundaries as we could and not damage the fence at the same time. Finally, erosion by wind was likely to be less of a factor when tilling with the smaller, slower, rear-tine Toro machines. In this instance, the Toro’s served as intermediate tools allowing us to complete as much work as possible in the least amount of time and, we believe, with minimal petrol inputs.

We averaged a total of 8.5 machine hours on each tiller and a total of 5 gallons of unleaded gasoline for the entire project. The machines were used on approximately 16,000 sq feet (both the annual, perennial, grape, and orchard areas). As is standard we cross-cut the sod, with one machine moving east to west and the other tilling north to south. This practice helps the tilled layer to be uniform in depth and remove any ridges left by an incomplete pass. We noticed that there were two types of grass growing on the site, and one species was particularly rooted and hard to incorporate. At times we needed to make a second pass in order to insure that we had cut it. I fear that some of this grass has surely survived this tilling and we will have to deal with it in the early spring as we prepare the seedbeds. At present we feel ahead of schedule in relation to preparation of the land for seeds and starts. A project that was scheduled for two weeks has been completed in 2 days by two people and perhaps it is the last major machine cultivation that will be needed on the site.

Two Tillers Cross-Cutting The Soil

Pushing Tiller Through a Tough Spot

Breaking New Ground in the Orchard Section

Using Larger Toro Tiller

Shot of Tilled Soil

Jason and I are hoping to finish the toolbox project by Thursday and will perhaps transport the box down to the farm site by Friday. Three main objectives need to be completed in order to consider the project finished. These objectives include:

1. Installing the hinges for the lid

2. Installing a latch and lock

3. Painting the outside of the box with an oil-based primer for protection

We are considering the addition of locking hinges or a rod that would be used to prop the lid of the box open so that people can reach into it without the effort of holding the lid open. The lid is heavy and would be difficult to juggle as one reaches for tools.

It is quite cold in the mornings and then warms up in the afternoon until after sunset. Also, the winter has not brought a great deal of precipitation. This, in turn, has allowed the soil to dry out enough for us to overturn small sections of sod as we investigate a method for seedbed preparation. It will be important to find a method that can be replicated and scaled up.

Many people have made the suggestion of simply cutting the layer of sod; turning it over (upside-down) and placing it back in the same place. Indeed, this is an effective method and great option for people working with a uniform sod layer that might be encountered on a lawn. However, our situation is different because the soil was tilled (shallowly) in early November in hopes of disturbing the sod and encouraging it to decompose. Since then, a portion of the sod has decomposed while other parts have re-rooted. The soil is loose and un-uniform, and when sod is removed it removes a portion of soil near the root system. We are certain that we want to avoid removing the soil along with living organic matter in the process of preparing beds. However, without further decomposition it will be difficult to prepare appropriate seedbeds. While we have dry soil we will continue to explore hand-cultivation methods that could prove useful for laborers and safe for the living soil.

Toolbox With Lid

Edges of the Toolbox Lid Extend to Allow Water to Run Off the Sides and Front

Another View of the Box

E
Example of Un-uniform Sod