Over the past two weeks we prepared the land in the Kentucky State University Energy Farm Study for planting. We started with a freshly-cut hay field that has grown an alfalfa and grass mixture for the past three years. It is rich in organic matter and naturally-fixed nitrogen, so we chose not to add additional fertilizer in the first year of the study. The soil preparation process differed between our three production systems:

1. Biointensive plots were cleared with a hoe, then double dug with a spade, spading fork, and broadfork. All labor was done by hand over the course of a week.
   
   
2. Market garden plots were prepared with two passes of a roto-tiller attached to a 13 hp BCS 852 walk-behind tractor, fueled by gasoline. The roto-tiller passes were spaced two weeks apart to allow sod to decompose after the initial cultivation.
   
   
3. Small farm plots were prepared with a single pass of a moldboard plow attached to an 89 hp John Deere 5520 tractor, fueled by diesel. The plow was followed, two weeks later, with two passes of a roto-tiller, pulled by the same tractor.
   
   

The following charts show the amount of labor and energy used to complete the soil preparation process at each of the three farm scales. Labor use is in minutes per square meter of land. Energy use is in megajoules per square meter of land (1 megajoule = 239 food calories). Error bars show the standard error, which is a measure of the variability between plots that were treated the same way.

The small farm plots cover about 40 times as much land as the biointensive plots, and 6.5 times as much as the market garden plots. (A previous blog post showed relative plot size on an aerial photograph of the site.)

We spent 20 hours clearing sod and double digging the biointensive plots, 2.5 hours using the walk-behind tractor in the market garden plots, and 3.0 hours on the 4-wheeled tractor in the small farm plots. The walk-behind tractor consumed 3.7 liters (1.0 gallon) of gasoline and the 4-wheeled tractor consumed 34.5 liters (9.1 gallons) of diesel fuel.

Michael Bomford provides research and extension services related to organic agriculture and small-scale renewable energy production through Kentucky State University's Land Grant Program. He thanks Brian Geier, John Rodgers, Hank Schweickart and Tony Silvernail for their help with preparing the land for planting.

The US Energy Information Administration (EIA) says that Americans consumed about 105 exajoules (EJ) in 2006, and predicts that energy consumption will exceed 120 EJ by 2025. That projection looks unrealistic. Here's my attempt to do better.

EIA records show that US energy consumption has increased almost every year for a long time. A look at the period between 1950 and 1973 shows each year's increase in energy consumption was even greater than the year before.

High energy prices caused energy use to decline between 1973 and '75 and again between 1979 and '83. When growth resumed after the second energy crisis there was a difference: Each year's increase was less than the year before.

If the trend established in 1980-2006 were to continue then US energy consumption would crest around 2015 before starting to decline. Consumption in 2025 would be about the same as in 2006. This projection is much lower than the EIA's, but I still think it unrealistically high. A more likely scenario is an immediate reduction in energy consumption in response to high energy prices, as occurred in the previous energy crises. A 1.2% annual decline in energy consumption, sustained until 2025, would bring the nation back to consumption levels of the mid-1980s.

Renewable sources currently provide just 7% of the nation's energy. The EIA predicts this will be up to 11% by 2025. Just as the EIA appears to have overestimated the availability of non-renewable energy sources in the near future, it appears to have underestimated the contribution of renewables.

A coalition of business, labor, and environmental groups is calling for plans to increase renewable energy production to meet 25% of the nation's energy consumption by 2025. The 25 by '25 vision has its opponents, particularly now that the corn ethanol push is widely recognized as an environmental, social, and financial disaster. Sooner or later, though, the nation and the planet must return to 100% renewable energy.

What might a 17 year transition to a 25% renewable energy economy look like? One scenario would involve a 30% reduction in non-renewable energy use coupled with a doubling of hydro, biomass and geothermal energy use and 12 and 24-fold increases in wind and solar energy use, respectively. That might have some pretty serious economic, environmental and social ramifications, but it would get us to 25%. The rate of decline in renewable energy use would be pretty similar to the rate of increase that got us where we stand today.

It is somewhat amusing to see the Wall Street Journal cover
this topic.  After all, they are the
paper of Wall Street, which I imagine has a “look down the nose” attitude about
the people who grow food for a living, especially small-scale farmers who don’t
use giant machines or buy inputs from Fortune 500 companies.   Perhaps I need to get over a prejudice?

Check out what this reporter did…and on page A1 to boot:

Green Acres II:
When Neighbors
Become Farmers

Suburban
Arugula Is
Organic and Fresh, but
About That Manure...

By KELLY K. SPORS
April 22, 2008; Page A1

http://online.wsj.com/article/SB120882472974233235.html?mod=todays_us_page_one

Not bad!  The people
doing this work are good looking, young, suburbanites.  Probably makes it more palatable to the
readers because they can relate to them. 

The music on the video included at the web site, however, is
kinda hill-billyish.  I enjoy banjos and
blue grass myself, but don’t know any farmers of the generation depicted who
listen to it regularly.  If more young
farmers are needed, it might be better to associate them with rock stars
instead. 

I appreciated the coverage of the SPIN farming method:  http://www.spinfarming.com/

It is great that there is now a marketed entry path to
farming in urban/suburban areas.  I would
like to point out where SPIN differs from what we are advocating in the Energy
Farm Program.  The article explains:

Start-up costs for a
one-eighth-acre farm run about $5,500, says Ms. Christensen of Spin-Farming.
That includes a walk-in cooler to wash and store fresh produce, a rotary tiller
and a farm-stand display. Annual operating expenses, including seeds and
farmers-market stall fees, can add about $2,000. Such a farm can generate
$10,000 to $20,000 in annual sales, she says. That's "an entry point into
farming to see if they have a talent for it," Ms. Christensen says.
"Those that do will eventually be able to expand and increase that income
level quite substantially."

Where we differ is in the use of hand tools instead of
rototillers, and passive cooling techniques instead of walk-in coolers
requiring electricity.  Also, we would
probably be more circumspect about the inputs of manure and other fertilizers
and ask farmers to work on green manure cover cropping and compost making on
site instead.  This is all about the need
to “get off the sauce” of oil, and fossil fuels in general.  Good hand tools are incredibly efficient at
the scale needed for home-scale veggies (http://www.energyfarms.net/node/1509
).

The Wall Street Journal does have some great reporters.  Good going Kelly!  Too bad the editorial pages of the WSJ are
full of garbage about energy and climate issues. 

I saw this today, had a morbid laugh, then got pensive.

(cartoonists web site: http://www.ibdeditorials.com/cartoons.aspx#cararch)

A couple of years ago, biofuels were hot. There were the promoters touting "green" fuels, getting off "foreign oil" and helping "American farmers." A perfect set of environmental, geopolitical and populist allies created a basket of incentives to boost corn-based ethanol production.

A few of us were decrying this as bad policy. The net energy of ethanol was around break even, so it couldn't be climate neutral or help with oil dependency. The rise in food prices would impact the poor around the world, causing much pain and unrest that could destabilize nations. And American farmers would go through another painful boom-bust cycle rather than transition to a sustainable agriculture system that is realistic about energy constraints.

Other issues are exposed by this fiasco. Why is it that so many people ARE dependent on cheap, often imported grains (especially in Africa)? Some have ridiculed the local food movement for potentially depriving farmers in the developing world of their markets in the wealthy nations. But if these developing nations are ones who can't feed themselves, shouldn't we ask if it might be better for them to focus on food self-sufficiency rather than production for export? Especially if our energy and financial policies can cut them off from our food so blithely.

Take a look at not only corn in the fuel tank, but coffee, tea, coconuts, palm oil, cane sugar, papayas, bananas, out of season vegetables, etc. All these tropical products may be produced in places dependent upon trade for money that is used to buy imported staples such as grains. What if they decided to relocalize instead? Would they be better off?

As
crude oil reaches record
highs of $110 a barrel, the connection between the cost of food and the
rise in energy prices can no longer be ignored. In a recent
statement, Josette Sheeran, executive director of the UN's World Food
Program, said the global economy had created "a perfect storm for the
world's hungry, caused by high oil and food prices and low food stocks."
Sheeran continues, “Higher food prices will increase social unrest in a number
of countries which are sensitive to inflationary pressures and are
import-dependent. We will see a repeat of the riots we have already reported on
the streets such as we have seen in Burkina Faso, Cameroon and Senegal."

Sheeran
notes that food prices have been aggressively increasing to historic highs
and cites four major drivers for this:

1.
The rise in oil and energy prices which affect the entire value chain of food
production from fertilizer to harvesting to storage and delivering and access
to water;

2.
The economic boom in nations such as India and China, creating increased demand
for all commodities including food and forcing China, which was a major food
exporter just a little more than one year ago, to now being an importer of
food;

3.
Increasingly harsh and frequent climatic shocks like hurricanes, floods and
drought, have made for some bad harvests in particular regions like Australia
and regions of Africa;

4.
The shift to increased biofuel production that has diverted hundreds of
millions of metric tons of agricultural output out of the food chain, and has
caused food prices to be set at fuel price levels in many places, including,
for example, palm oil in Africa which is now being priced out of household
reach because it is being set at fuel prices as a biofuel addition.

On
the energy front, Sheeran's claim is supported by recent reports coming from farms
across the globe. Although farmers appear to enjoy record commodity prices, the
recent spikes in the cost of fertilizer
and fuel are eroding gains. Not only has the price
of nitrogen fertilizer risen 113% since 2000, but also potash has risen
from $225 a ton to nearly $500 a ton and increasingly scarce phosphate has gone
from $312 to between $800 and $900 a ton this year. The ingredients of these
fertilizers are often imported to the United States from other countries
and these resources are mined and processed using markedly energy-intensive processes
that consume diesel and natural gas.

In
other news, the world’s
largest poultry processor closed a U.S.
processing plant-cutting 1, 100 jobs. The processor blames record feed prices
and U.S.
ethanol policy for the current industry-wide crisis. Even if you are a
vegetarian, the implication of this news is still hard to hear, as it is illustrates
the fact that agribusiness is designed to grow food in a way that creates high
profit. Once the profit margin is challenged the corporate producers of food
may simply quit the job of growing food.

These
trends should be clear indicators to all of us to reduce consumption of
non-renewable resources and begin to support those that are willing and capable
of producing food, fuel, and organic fertilizer close to where we live. Click here to see if there is a CSA or farm in
your area.

I enjoyed Josh's planting plans for the Sebastopol Energy Garden. It's easy to imagine the mixed beds of broccoli and celery, corn and beans, cabbage and onions, Swiss chard and carrots...

A friend says that seed catalogs have inspired more fantasies than Playboy.

There are good reasons for planting crops in mixtures:

• Mixed crops often have higher yields than monocultures because different species use different resources, making more efficient use of land;
• Mixed plantings often have fewer pest problems than monocultures because pests have a harder time finding suitable hosts, or because diverse plantings provide better habitat for natural enemies;
• Diversity helps reduce risk. (Promoting biodiversity is a stated goal of the USDA's national organic standards.)

But how, exactly, do we go about planting mixtures? If the seed packet, or a planting guide, tells us to space cabbages 15" apart and onions 4" apart, how far apart do we space cabbage and onion plants in a mixture?

A couple of answers are offered by John Jeavons, in his classic manual How to Grow More Vegetables. He suggests that a mixed bed of cabbage and onion could consist of rows of cabbages interspersed with rows of onions. If cabbages and onions are mixed throughout the bed, Jeavons says the plant spacing should be the mean of the recommended spacing for the component crops.

According to this second method, the spacing between plants in a cabbage and onion bed would be 9.5" -- the mean of 15" (cabbage spacing) and 4" (onion spacing).

This approach has a few problems. I think I have a better way.

First I'll explain the problems. The Jeavons method sets cabbage and onion spacing to 9.5" whether the mixture is 90% cabbage or 10% cabbage. This doesn't make sense to me. It is intuitive that plant spacing for a cabbage and onion mixture should be somewhere between the recommended spacings for cabbage and onion, but it also seems intuitive that plant spacing should be closer to the recommended cabbage spacing in a mixture that is mostly cabbage and closer to the recommended onion spacing in a mixture that is mostly onion. Crop ratio is important.

How to Grow More Vegetables offers a planting plan for a two crop mixture with a 1:3 crop ratio. Using this plan we would plant three onions for every cabbage, in an arrangement like this:

This leads to the second problem: Using the Jeavons plan gives us room for 33 cabbages and 80 onions in the 60 square-foot bed above. To plant 33 cabbages in a pure stand, spaced 15" apart, would require 45 square feet. To plant 80 onions in a pure stand, spaced 4" apart, would require only 8 square feet. The total area required for the two pure stands would be 53 square feet -- 7 square feet less than the area required for the mixture.

Mixtures should make more efficient use of resources, not less. A mixture should not require more land than two pure stands with the same number of plants.

So what's my solution?

I have developed an equation to calculate plant spacing in mixtures from the recommended spacing for pure stands:

where

• s_A and s_B are the recommended pure stand spacings for crops A and B, respectively, and
• p is the proportion of plants in the mixture (a value between 0 and 1) accounted for by crop A.

In the example above, cabbage account for one-quarter of the plants in the mixture, so p=0.25. The recommended spacings for cabbage and onion are 15" and 4", respectively, so s_A=15 and s_B=4. The calculated mixture spacing, according to the equation, is 8.25" instead of 9.5".

Since using this equation is more difficult than calculating a mean I have developed a spreadsheet and an online plant spacing calculator with this equation at their heart. Provided you have the Analysis Toolpak installed in Excel (check the Add-Ins feature under Excel's Tools menu) the spreadsheet will create planting diagrams like these:

The first two diagrams show a square meter of cabbage (white circles) and onions (black diamonds) planted in pure stands. The next three show cabbage and onion mixtures planted at ratios of 1:3, 1:8, and 1:15.

Learn more here.

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.

"Can
we rely on it that a ‘turning around' will be accomplished by enough people
quickly enough to save the modern world? This question is often asked, but
whatever answer is given to it will mislead. The answer "yes" would lead to
complacency; the answer "no" to despair. It is desirable to leave these
perplexities behind us and get down to work." E.F. Schumacher, Small is
Beautiful

I would rather have titled this essay "Where the Hoe Meets
the Soil" but that phrase is not part of our cultural lexicon, which is itself
a symptom of the problem I am working to address. Setting aside any prolonged discussion of
whether or what about the modern world should be saved, this essay is primarily
about what it means to "get down to work" as Schumacher puts it. But very quickly, to me saving the modern
world means setting a goal for the human economy to be properly scaled relative
to the global ecology, and maintaining a sufficiency of social stability
necessary to manage a transition.

Before getting to work, I want to make sure the work I do is
useful. This is where a clear
understanding of the big picture helps.

Ecological Economics

The question of proper economic scale is examined by the field of ecological
economics. In the ecological economics
model, the human economy is a subset of the Earth system, and therefore the scale
of the human economy is ultimately limited.
The human economy depends upon the throughput or flow of materials
from and back into the Earth system.
Limits to the size of the human economy are imposed by the interactions
among three related natural processes:

(1) The capacity of the Earth system to supply inputs to the human economy
(Sources),

(2) The capacity of the Earth system to tolerate and process wastes from the
human economy (Sinks), and

(3) The negative impacts on the human economy and the resources it relies on
from various feedbacks caused by too much pollution.

Fig. 1. The ecological economics model
of the relationship between the human economy and the Earth system highlighting
the importance of sources, sinks, feedbacks and scale.[i]

For an expanded look at the relationship between our economy and the planet
see the engaging on-line film "The Story of Stuff."[ii]

One measure of whether the human economy is too large is the
ecological footprint (EF), which calculates on a nation-by-nation basis the
consumption of resources and the build-up of wastes relative to resource regeneration
rates and the waste-absorbing capacity of the environment. According to two independent EF analyses (which
I will call EF 1 and EF 2) the human economy (population plus consumption and
waste generation) is in a state of overshoot, meaning it is too large relative
to the long-term capacity of the planet to cope.[iii] The Earth can provide for us beyond its means
for a long time before the consequences become severe, just like a millionaire
can, for a time, live high on the principal in a savings account instead of the
interest. The degree to which we are
drawing down principal as opposed to living on interest is called our
"ecological debt."

Figure 2. Change in
ecological footprint over time according to EF 1 with our cumulative ecological
debt in blue.[iv]

Getting More Specific:
Fossil-fuel Depletion and Climate Change

Indicators like the ecological footprint are important for
understanding we have a problem and giving us a sense of the scale, but they
aren't very specific. In order to do
something about reducing our footprint, it would help to know what is causing
the ecological footprint to be so large.
A significant portion of the ecological footprint represents consumption
of fossil fuels and the resulting waste, mainly greenhouse gases. The "carbon" footprint component is about 52%
for EF 1 and the similar "energy land" is 88% for EF 2.[v] According to EF 2, "energy land" is 93% of
the North American footprint. A priority
on reducing fossil fuel consumption appears justified. The human ecological footprint can be lowered
below "1 Earth" only by eliminating the pollution from fossil fuel
combustion.

EF analysis uses the capacity of the environment to absorb
greenhouse gas emissions, which, as seen in the model shown in Fig. 1, means EF
measures "sink" capacity. The real
picture is more complex and more disturbing for a couple of reasons. Firstly, fossil fuel extraction is reaching
limits sooner than expected. Since we
have not been weaning our economy off fossil fuels steadily for the past few
decades, rapid energy price inflation will likely make it difficult to maintain
the kind of economic vitality and stability needed for a smooth transition to
renewable energy alternatives. Secondly,
recent evidence suggests that climate change is happening faster than
expected. Ice sheet destabilization is
one major indicator that the Earth system is more sensitive to greenhouse
emissions than most scientists and policy-makers have presumed. Recent articles by Kurt Cobb[vi]
and Richard Heinberg[vii]
review all these points, and the "Climate Code Red" report[viii]
goes into truly excruciating detail so I won't elaborate further here.

The bottom line is that every measure must be taken to
rapidly eliminate fossil fuel consumption and dependency in every component of
our lives. The key word is
"rapidly." Don't passively assume
inexpensive alternative energy substitutes will arrive to replace fossil fuels-we
may have waited too long to respond to have a smooth transition. Therefore, focus most attention on reducing
energy demand rather than substituting a new energy supply. And finally, in the context of ecological
economics, fossil fuel depletion and climate change, ask whether what you do in
your life, vocation, hobbies, and habits, contributes to the long-term function
(or dysfunction) of society.

The U.S.
Food System and Fossil Fuels

It would be hard to argue against a claim that a secure and
healthy food supply is indispensable to society. A widely known and troubling fact is that the
current food system in the U.S.
(and most highly industrialized nations) is very dependent upon fossil
fuels.

As far as I am aware, the most comprehensive study on the
topic of energy use in the U.S.
food system is by Heller and Keoleian of the University of Michigan's
Center for Sustainable Systems.[ix] The report is from 2000 and makes use of data
from the mid-1990s. Although the data
are about 10 years old, I don't believe the basic structure and function of the
U.S.
food system has changed dramatically over the past 10 years. In fact, current trends of increased
industrial meat consumption[x]
and biofuels[xi], which
both rely on grains, make the following case even stronger.

We learn from the study that over 10% of the energy
consumption in the U.S.
can be attributed to the food system, and that about 20% of this occurs in the
agricultural production sector. Home
energy consumption (e.g., refrigeration and cooking) consume the largest share
at about 30%. Between the farm and the
home are everything else (transportation, processing, packaging and
retail). Much of this middle portion is
a function of the geographic disconnection between production and
consumption. Eating food out of season
either requires long-distance transportation or energy demanding
processing. Both transportation and
processing require investments in storage.

Sorting out the proper scale of operations for farms,
processing and transportation systems is very difficult, however, because optimization
for one factor (e.g., transportation), may be sub-optimal for another (e.g.,
heat intensive food processing). Within
a category, such as transportation, the technologies analyzed may be limited
too. A study comparing rail cars, large
semi-trucks and small produce trucks may conclude that bigger is better, but
what about hyper-local transportation systems using bikes, small electric
vehicles and bipedal locomotion? Another
complicating issue is that studies may assume the U.S. food system should be more or
less similar in its mix of products while lowering energy consumption. For example, tomatoes can be processed using
canning or drying. Canning lends itself
to centralized operations and so does drying if fossil fuels are used as heat
sources. But a naturally decentralized
and fossil-fuel free technique such as passive solar dehydration may not even
be considered. Large energy savings can
be found everywhere in the food system, but especially so if assumptions about scale
and consumer-level demand are allowed to change.

Fig. 3. The energy
inputs to the U.S.
food system are several times larger than the energy content of the food. A life-cycle analysis identifies how energy
consumption is partitioned among economic sectors.[xii]

Another graphic from the Heller and Keoleian report clearly
identifies a huge savings potential.
Over 50% of U.S.
grains are fed to domestic animals, and most export grains go to animal feed as
well. Overall, only 26% of U.S. grain
production in 1995 went to domestic human consumption.

Although poultry need grains, red meat and milk products
dominate the feed market and grains are not a natural part of their diets. If red meat and dairy production were reduced
to only what harvested hay and pasture could provide, perhaps half of annual U.S. grain
production could be eliminated. The
acreage out of food production could be used for green manure crops to build
soil and fix nitrogen. A 2004
Congressional Research Service report showed that fertilizers are the largest
part of farm energy use, and that natural gas to produce nitrogen comprised
75-90% of the fertilizer input (Fig. 5).[xiii] Fixing nitrogen naturally, therefore, saves
significant energy. Some of the vast
cropland area no longer producing grains could then be used for appropriately
scaled biofuels to power farm equipment instead of fossil fuels.

Fig.
4. A reprint of Fig. 3 from the Heller
and Keoleian report. See graph label
above.

Fig.
5. A reprint of Fig. 2 from a 2004
Congressional Research Service report.
See graph label above.

An older and less comprehensive on-line
review paper[xiv] titled "Energy Use in the U.S. Food System: a summary of existing research and
analysis" by John Hendrickson of the Center for
Integrated Agricultural Systems, UW-Madison concluded that:

"It appears that some of the greatest
saving can be realized by:

• reduced use of petroleum-based fertilizers and
  fuel on farms,
• a decline in the consumption of highly processed
  foods, meat, and sugar,
• a reduction in excessive and energy intensive
  packaging,
• more efficient practices by consumers in shopping
  and cooking at home,
• and a shift toward the production of some foods
  (such as fruits and vegetables) closer to their point of consumption."

Hendrickson's paper is helpful in republishing and comparing
tables from many previous studies, including "Table 5" reprinted here on the
energy consumption of home grown versus market-purchased fruit and
vegetables.

Taking Responsibility: Brookside Farm Examples

With this extensive background I introduce the project I
have been working on for about two years now, Brookside Farm. This is a 1-acre mini-farm in Willits, CA. It operates as a program of the non-profit
corporation North Coast Opportunities, functions as a working farm with a
community supported agricultural program serving 15 "shares" per year, exists
at an elementary school and is therefore open to classes and tours, and
conducts research and demonstrates aspects of a local food system with the collaboration
and support of Post Carbon Institute.[xv]

Brookside Farm thinks about food from a "farm to fork" and
back again perspective. Farmers create
artificial ecosystems, and we therefore look to ecology to guide our
practices. Highly productive and stable
ecological systems are noted for a diversity of species both in kinds and
functional forms. When these diverse
species interact effectively, they maximize the rates of productivity and
nutrient retention in the system using ambient energy sources. We view ourselves as human members of the farm
ecosystem with our labor and wastes as parts of the whole.

To get by on ambient energy as much as possible, we have
sought alternatives to fossil fuels in every aspect of the food system we
participate in. Table 1 considers each
type of work done on the farm, to the fork, and back again and contrasts how
fossil fuels are commonly used with the technologies we have applied.

Table 1. Feeding
people requires many kinds of work and all work entails energy. In most farm operations the main energy
sources are fossil fuels. By contrast,
Brookside Farm uses and develops renewable energy based alternatives.

Our use of food scraps to replace exported fertility also
reduces energy by diverting mass from the municipal waste stream. Solid Waste of Willits has a transfer station
in town but no local disposal site. Our
garbage is trucked to Sonoma
County about 100 miles to the south.
From there it may be sent to a rail yard and taken several hundred miles
away to an out of state land fill.

We are also planning to irrigate using an on-site well and a
photovoltaic system instead of treated municipal water or diesel-driven
pumps.

How much energy does Brookside Farm
save?

The complexity of the food system makes it difficult to
calculate how much energy Brookside Farm is saving. A research program at UC Davis now devoted to
just this sort of question is recently underway, but with few results to share
thus far.[xvi]

From previous studies we can find clues about the high
energy inputs to fruit and vegetable cultivation. From Fig. 4. above, we can see that fruits
and vegetables account for (102,370/921,590) 11% of crop production by weight. Table 3 (given below) of the Congressional
Research Service report shows that energy invested in fruit and vegetable
production is proportionally higher, accounting for (3759/18364) 20% of the
energy for crops at the farm level.

Much of the savings at Brookside Farm occurs off the farm by
replacing what would normally be imported, through passive solar preservation
and storage techniques, and by shifting consumer habits towards seasonally
fresh cuisine proportionally high in vegetables.

Does Brookside Farm Scale? Lawns to Food

Before it was Brookside Farm, it was a field of mostly grass
at an elementary school. The school
district watered and mowed it (Fig. 6).

Fig. 6. Brookside
Farm in early spring, 2007. The image
shows the farm site adjacent to the forest and bordered by grassy fields,
school buildings and a residential neighborhood. Arrows from a home contrast distance and
direction of food coming from the local Safeway supermarket and Brookside
Farm. The 1 acre Brookside Farm occupies
about a quarter of the available play field at Brookside Elementary School.

Using satellite imagery, the area of lawn in the United States
has recently been estimated:

"Even conservatively," Milesi says,
"I estimate there are three times more acres of lawns in the U.S. than irrigated corn." This means
lawns-including residential and commercial lawns, golf courses, etc-could be
considered the single largest irrigated crop in America in terms of surface area,
covering about 128,000 square kilometers in all.[xvii]

The same study identifies where and how much water these
lawns require:

That means about 200 gallons of
fresh, usually drinking-quality water per person per day would be required to
keep up our nation's lawn surface area.

Let me put the area of lawn from this study into a food
perspective. The 128,000 square
kilometers of lawns is the same as 32 million acres. A generous portion of fruits and vegetables
for a person per year is 700 lbs, or about half the total weight of food
consumed in a year.[xviii] Modest yields in small farms and gardens would
be in the range of about 20,000 lbs per acre.[xix] Even with half the area set aside to grow
compost crops each year, simple math reveals that the entire U.S. population could be fed plenty
of vegetables and fruits using two thirds of the area currently in lawns.

Labor Compared to Hours of T.V.

For its members Brookside Farm's role is to provide a
substantial proportion of their yearly vegetable and fruit needs. Using our farming techniques, we estimate
that one person working full time could grow enough produce for ten to twenty
people. By contrast, an individual could
grow their personal vegetable and fruit needs on a very part-time basis,
probably half an hour per day, on average, working an area the size of a small home (700 sq ft in veggies and fruits plus 700 sq ft in cover crops).

American's complain that they feel cramped for time and
overworked. But is this really true or
just a function of addiction to a fast-paced media culture? According to Nielsen Media Research:[xx]

The total average time a household
watched television during the 2005-2006 television year was 8 hours and 14
minutes per day, a 3-minute increase from the 2004-2005 season and a record
high. The average amount of television watched by an individual viewer
increased 3 minutes per day to 4 hours and 35 minutes, also a record. (See
Table 1.)

So if we imagine families having the discipline to cut out a
single sitcom viewing per day, or one baseball or football game per weekend
during the growing season, that would free-up sufficient time to become
self-reliant in fruits and vegetables and likely improve overall health.[xxi]

(A note of caution though, an article from The Onion warns
"that viewing fewer than four hours of television a day severely inhibits a
person's ability to ridicule popular culture.")[xxii]

Conclusions

For those wanting to contribute to a lower-energy food
system, starting with fresh produce makes sense for several reasons:

(1) Significant production is possible in a small area,
often what people already have,

(2) Tools and equipment are simple, inexpensive and readily
available,

(3) Fruits and vegetables are heavy due to high water
content, and therefore energy-intensive to transport and process either by
canning or dehydrating,

(4) Growing vegetables and fruits is generally more energy
intensive than other crops because of high fertilizer and irrigation inputs,

(5) Quality declines rapidly after harvest, so home or
locally available food has higher nutritional value and usually tastes better,

(6) Labor, packaging and storage demands of fruits and
vegetables are high in mechanized production systems, making the investment in
home-grown produce financially competitive, and

(7) Gardening and small-scale fruit and vegetable farming
lend themselves to physical and social activities across generation and income
gaps that improve health and enhance a shared sense of purpose and fun.

[i] This
graphic was developed based on the principles discussed in Chapter 2 of Daly
and Farley "Ecological Economics:
Principles and Applications" (2004, Island Press)

[ii] http://www.storyofstuff.com/

[iii] http://www.footprintnetwork.org and
http://www.rprogress.org/ecological_footprint/about_ecological_footprint.htm;
the original ecological footprint analysis (EF1) is at the first reference, and
the second type (EF2) at the second. The
major difference between the two is that the second attempts to incorporate
aquatic systems (e.g., oceans), total terrestrial productivity, and
biodiversity reserves.

[iv] Graphic
from: http://www.footprintstandards.org/

[v] For the
50% figure see: http://www.footprintnetwork.org/gfn_sub.php?content=global_footprint; for the greater than 90% and discussion of
differences between methods see: http://www.rprogress.org/publications/2006/Footprint%20of%20Nations%2020...

[vi] http://scitizen.com/screens/blogPage/viewBlog/sw_viewBlog.php?idTheme=14&idContribution=1397

[vii] http://globalpublicmedia.com/richard_heinbergs_museletter_big_melt_meets_big_empty

[viii] http://www.climatecodered.net/

[ix] http://css.snre.umich.edu/main.php?control=detail_proj&pr_project_id=29

[x] See
especially Table 2. in: http://www.fao.org/docrep/005/AC911E/ac911e05.htm

[xi] http://www.theoildrum.com/node/2431

[xii]
Graphic from: http://css.snre.umich.edu/css_doc/CSS01-06.pdf

[xiii] http://www.ncseonline.org/NLE/CRSreports/04nov/RL32677.pdf

[xiv]
Although no date appears on this paper, it is clearly related to a 1994
conference and workshop: http://www.cias.wisc.edu/pdf/energyuse.pdf;
http://www.cias.wisc.edu/archives/1994/01/01/energy_use_in_the_us_food_system_a_summary_of_existing_research_and_analysis/index.php

[xv] http://www.energyfarms.net/

[xvi] http://asi.ucdavis.edu/conferences/farmtofork/;
http://californiaagriculture.ucop.edu/0704OND/editover.html;
http://asi.ucdavis.edu/Research/ASI_Program_Proposal_Brief_-_Energy_Life_Cycle_Assessment_in_Food_Systems_9-13.pdf

[xvii] http://earthobservatory.nasa.gov/Study/Lawn/

[xviii] http://www.ers.usda.gov/Data/FoodConsumption/FoodGuideIndex.htm

[xix] An
acre is ca. 43,000 sq ft. Our experience
at Brookside Farm suggests about 1 lb of produce per square foot of cultivated
space is to be expected, with infrastructure and paths requiring significant
area. Fruit orchards in Mendocino County yield about 20,000 lbs per
acre: http://www.co.mendocino.ca.us/agriculture/pdf/2006%20Crop%20Report.pdf

[xx]http://www.nielsenmedia.com/nc/portal/site/Public/menuitem.55dc65b4a7d5adff3f65936147a062a0/?vgnextoid=4156527aacccd010VgnVCM100000ac0a260aRCRD

[xxi] http://www.csun.edu/science/health/docs/tv&health.html

[xxii] http://www.theonion.com/content/node/30863

PROPERTY ZONING:

The Sebastopol
Energy Garden is partitioned into three specific zones of use, with the lowest
numbered zone representing the area of highest traffic and crop yield (Zone 1),
and the highest numbered zone being that which requires only periodic care and
offers reduced yields (Zone 3). That zone which falls between Zone 1 and 3 (Zone
2) represents an overlap of the two. By viewing the garden as three separate
zones with individual characteristics, we can plan the layout of selected cropsmuch more strategically.

ZONES 1-2: BACKYARD

ZONE 1 is the portion of the garden in closest
proximity to zone zero of the property, the house. The crops grown in this area
are primarily consumed by humans. Crops in this zone fall within the categories
of nutrition, and root calorie crops. Water remediation occurs in the zone of
the garden as well as the growing systems.

ZONES 1-2: FRONTYARD

ZONE 2 is the portion of the garden beyond zone one that is still
used for annual crops. Crops grown in this area are primarily calorie and
carbon crops. This is the part of the
garden allocated towards testing and demonstration, and is where there is
opportunity to profile those crops that we see fit. Compost production, egg
production, tool storage, and processing and harvesting occur in this part of
the garden.

ZONE 3: BACKYARD

ZONE 3
is the portion of the garden farthest from the house. Crops grown in this part
of the garden are primarily perennials that provide nutrition and calories,
attract and repel insects, fix nitrogen, accumulate nutrients, or increase the
health of the garden ecosystem. This portion of the garden is independent from
irrigation and is self managing.

I wasn't happy with the news in Part 3 of this series, which
basically concluded that Mendocino
County could not be food
self-reliant.[i] To quote the most relevant and discouraging
passage from that essay:

The Caltrans EIR implies that in
about a ca. 20 year span, Mendocino County went from 69,000 to 35,000 acres of
prime farmland, down from and original endowment of 94,000 acres. This does
seem like a remarkably high rate of loss, totaling 34,000 acres or about 1700
acres per year for 20 years. In either case, whether the real figure is closer
to 69,000 or 35,000, both are far from the estimated need of ca. 95,000.

However, I knew that this conclusion rested on certain
assumptions, and that changing these might alter the conclusion. In the end we may be left having to decide
which assumptions are more realistic, or whether what may be theoretically
possible is probable given human nature/folly, or, if you are more inclined,
human spirit/ingenuity.

So I went in search of better news (and the resulting
dopamine reward this could potentially provide) by re-performed some
calculations, starting with the diet. I
will call the diet from part 1 of this series diet 1, and the one presented in
this essay diet 2.[ii] Before creating diet 2, I wanted to be
clearer on what the dietary needs and expectations are in North
America. The USDA has a
fascinating set of web pages. Included
is a survey from the Agricultural Research Service of what several hundred
people eat during a day, which can be extrapolated to the whole population
(standard errors noted) and then broken out by demographic category.[iii] According to this data set, on average, people
eat about 2200 calories per day. As
expected, the very young and old eat the least, and females eat less than males. Another branch of the USDA, the Economic
Research Service concludes that people consume closer to 2700 calories per day
on average.[iv] Changes in American consumption patterns over
time are also discussed in a report by the same sub-agency.[v] In general we are eating more calories than
30 years ago, but we are consistently wasting about 25% of the food produced.[vi]

New Diet Assumptions

For my second go at a model diet, I selected the 2200
calorie per day figure, and I assumed we could get by with half the food waste
of today, which means a production system is required that produces about 2600
calories per person/day. By contrast,
diet 1 used the figure about 3000 calories per day as a guide, which is still
about 700 calories per day lower than what Americans have available to them
from the current system. Diet 2
therefore has less calories available than diet 1, and far less than current U.S.
diets, but is still enough food overall if food waste is half of current
percentages.

Diet 2 is given below, and for comparison I give the current
U.S.
consumption patterns for the modeled foods.
I have made a change in the fruit and vegetable category, where potatoes
are segregated for analysis purposes. Significant
differences between diet 2 and U.S.
averages include much lower meat, sugar and egg consumption, and much higher
dry bean consumption. To compare U.S.
consumption of sprouting seeds (sunflower seeds in my model) I used data on
nuts, which are nutritionally similar. In
the U.S.
this mostly means peanuts, but locally it could be walnuts and
filberts/hazelnuts. I believe diet 2 is
a much healthier diet than current U.S. habits.

Diet 2 also took into account the calories yielded per area
for different food items. This is one
reason why potatoes were given stand-alone status-they efficiently make human
food. When grains are fed to animals,
as in chickens and dairy cows, area efficiency is very low. Diet 2 therefore has fewer animal products
than diet 1, and more veggies and potatoes.
I limited potato consumption to 180 lbs per year because potatoes are
typically edible for only 6-7 months at a time and eating more than one pound
of potatoes per day would get tiresome.
Even with the extra load from vegetables, fruits and potatoes, the total
diet weight is still low, ca. 5.2 lbs, because the total calories are reduced
and grains and dry beans still form the core of the plan.

New Inputs and Yield
Assumptions

In addition to fiddling with the diet, I made a giant change
when modeling the land-area required for the diet-I assumed no limits to
irrigation, which essentially doubles the yields of grains and dry beans.[vii] Remember
also that sugar is modeled as honey and, perhaps optimistically, is given no
direct land area requirement.

So what's in going to be?
Will eating lower on the food chain plus more intensive inputs change
the results? Are we gonna make it? Drum roll.....

First, we look at the acres per person for diet 2:

Not bad! The "acres
minus meat" for diet 1 was 0.76 per person.
Next, multiply by population size:

If you read previous essays you may recall that meat is
assumed to be produced on subprime farmland plus prime farmland in a green
manure rotation. This brings up the need
to account for crop rotations and green manure, thus:

And finally, adding rotation-demanding to non-rotation
demanding areas gives:

So the number here, ca. 38,000 acres, compares favorably to
the amount of prime farmland currently remaining according to the Caltrans
EIR.

Rwanda

Before getting too pleased with the results, I want to put
them into perspective. Let's assume for
the moment that Mendocino
County does have 38,000
acres of prime farmland left, which equates to 0.43 acres per person, or in
metric terms 0.17 hectares. The arable
cropland per capita in Mendocino County is currently slightly less than what Rwanda
had during the genocide period (0.20 hectares).[viii] Scholars have suggested that the tensions
that eventually led to the bloodshed came from the fact that the land base was
barely able to provide enough for the population, and that few subsistence
farmers had the cash to buy imported food.

I am not predicting that the same kind of events would unfold
in Mendocino County under similar circumstances. The point is that when populations are up
against their resource capacity it is normal for stress to build, which
increases the probability of violence.

Fertilizer Impact

Because irrigation is now assumed, the yields of the grains
and dry beans, and by extension the dairy and eggs, increase
substantially. Crops remove nutrients from
the land in proportion to their yield; therefore quantities of fertilizer are
increased per unit area. Three factors
offset increased fertilizer demand per area:
(1) green manure crops are also irrigated and increase in yields at the
same proportion as the crops they support, (2) increased yields means a
decrease in total area required to support the population, and (3) diet 2 is
smaller than diet 1, with fewer animal products.

My estimations are very crude right now, but the overall
impact is that much less fertilizer is required for the diet 2 plus irrigation
model than with diet 1 and no irrigation.

The proportion of fertilizer needs that can be recovered
from humanure is also higher with the diet 2 model. Here's another look at the only reference I
can find for the average nutrient content of human waste.

Adding the straw and other non-edible residue from farming to
the humanure could potentially provide sufficient closure of the nutrient cycle
loop and make the local agricultural not dependent upon large quantities of imports.

The Water Assumption

If about 38,000 acres of prime farmland need to be irrigated
to provide high enough yields, the obvious question to ask is whether the water
resources exist?

The Mendocino County Crop Report shows that about 19,000
acres are in production for apples, pears, and wine grapes.[ix] Another 6000 acres of pasture are irrigated. Perhaps another 1000 acres can be added for
vegetable cultivation, tree farms and nurseries. Therefore, currently around 26,000 acres are
irrigated.

The United States Geological Survey assessed ground water
resources in Mendocino
County in the mid-1980s.[x] In general, valley bottoms with prime
farmland have shallow water tables that are recharged annually given the
usually abundant rainfall regime of the county.

Because much of the area requiring irrigation is sown in
small grain crops, the period of irrigation is limited to late spring, i.e.,
May and June. By mid-late June these
crops will finish maturing and watering should be ceased. I don't currently see water being a limiting
factor for productivity on prime farmland in Mendocino County
as long as the infrastructure exists to access it.

Ground water pumping using shallow wells (usually less than
50 ft) is not extremely energy demanding and should be backed by renewable
energy resources. Encouraging existing
farms (mostly vineyards) to take advantage of any state or federal programs for
renewable energy could help prepare for a more diverse local food system.[xi] Since Mendocino County
likes to promote its wine industry as "organic," and one major winery is the
first to go "carbon neutral" this may not be a difficult sell in the southern
half of the county.[xii]

Alternative Food Sources

A quick mention of what I didn't evaluate: acorns, wild game, fish, seaweed, etc. I suspect acorns could provide for some
serious calories, and the others occasional protein and mineral
supplements. My main worry about wild
game is that it would be extirpated if our current population tried to rely on
it for long. The local ocean-going
fishing industry is probably fuel intensive, but it would be interesting to evaluate
the potential for low-energy input, sustainable fishing off the Mendocino
coast.

Conclusion

Population growth and land-use changes in Mendocino County
have created the surprising situation, in this largely rural area, of a very
low availability of high quality, prime farmland per person. While it is theoretically possible to feed
the current population of the county on likely available farmland, it would
require full-scale irrigation and a restricted diet-and no margin for
failure. Maintaining soil fertility over
the long-term would also mean cycling human body waste and agricultural residue
back to the land.

In this series I did not develop any scenarios about when Mendocino County might need to be more food
self-reliant, nor make a strong case for the benefits of a local food system,
but these arguments can be found elsewhere.[xiii] I found the exercise useful in that it
highlighted the resources on which our population depends-good soil, adequate
water, sufficient mineral nutrients, reliable climate-and quantified about how
much of that exists within our locale.
By following the references provided, similar analyses could be done
just about anywhere.

[i] http://www.energyfarms.net/node/1491

[ii] http://www.energyfarms.net/node/1489

[iii] http://www.ars.usda.gov/Services/docs.htm?docid=14958

[iv] See the
Calories spreadsheet here: http://www.ers.usda.gov/Data/FoodConsumption/FoodGuideIndex.htm

[v] http://www.ers.usda.gov/publications/foodreview/jan2000/frjan2000b.pdf

[vi] http://www.ers.usda.gov/publications/FoodReview/Jan1997/jan97a.pdf

[vii] http://www.energyfarms.net/node/1490;
diet 1 assumed about 18 bushels of wheat per acre, diet 2 about 37 bushels per
acre.

[viii] http://ideas.repec.org/p/wpa/wuwpdc/0409061.html; See Table 1, divide farmland per household by
adult equivalent household size.

[ix] http://www.co.mendocino.ca.us/agriculture/pdf/2006%20Crop%20Report.pdf

[x] http://www.willitseconomiclocalization.org/files/well/GroundWaterResourcesMendoCounty.pdf

[xi] http://attra.ncat.org/farm_energy/funding.html

[xii] http://www.mendowine.com/MendocinoCountyOrganicWineGuide2006rev.pdf;
http://www.winebusiness.com/news/dailynewsarticle.cfm?dataId=47813

[xiii] http://www.energyfarms.net/node/1488;
http://globalpublicmedia.com/relocalization_a_strategic_response_to_peak_oil_and_climate_change