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.

Brookside Farm has accomplished an initial goal of getting
our veggies to young children and into a local institution! North Coast
Opportunities pre-school has agreed to purchase two shares from the CSA at
Brookside Farm. The kitchen staff is looking forward to utilizing fresh farm
produce and cooking according to the harvest season. It is exciting to see that there is demand
for our produce and the goods of a Relocalized food system.

View of North Coast Opportunities Preschool

To meet the demands of the CSA, we set to work preparing our
first beds in order to transplant spinach and lettuce and to direct seed
onions, beets, carrots, lettuce, and parsnips. We removed cover crops with a
scythe, broke the soil with the low-wheel cultivator, loosened the soil with
the broadfork, and cross cut a final time with the low-wheel cultivator in
order to ready vegetable beds. The following is the sowing dates and area for
the crops that we direct seeded.

Direct Seeding Beets by Hand

According to our planting schedule, March was slated to be one
of the most active months in the greenhouse. Lettuce, cabbage, chard, spinach,
kale, tomatoes, eggplant, peppers, and tomatillo were on the list of a
scheduled 1600 starts. Unfortunately, we had poor germination on many of the
starts that were seeded early in the month (kale, spinach, and cabbage). We
monitored the Max-Min thermometer in the greenhouse and were noticing overnight
lows in the 30 and daily highs in the 70’s. After considering what might have
led to the poor germination and we finally concluded that the average soil temperatures
and nighttime temperatures were too cold. We utilized the warming temperatures
toward the middle of March to catch-up on the plants that did not do so well
earlier in the month and continued to sow starts to remain on pace with our
greenhouse schedule. By the second week of the month we had sown our peppers
and tomatoes in David Drell’s greenhouse. David used electric heating mats to
secure sufficiently warm germination temperatures, and by the end of the month
we had excellent stands of little peppers and tomatoes awaiting transplant from
their seed-flats into four-inch pots. It was amazing to see the difference
between plants started with the heated soil mats and those that fended for
themselves in the early part of March.

Tomatoes and Peppers in Four-Inch Pots

This month we also began a relationship with a local welder
to make adjustments to our low-wheel cultivator and the broadfork. Last year we
had a terrible time shearing off
the bolt that connected the stirrup hoe implement to the low-wheel
cultivator. Kevin, at KLR welding, suggested that he weld a small plate near
the back of where the stirrup hoe connects to the frame. By adding the plate
excess and needless motion has been eliminated, the implement base remains
rigid, and we have significantly reduced the threat of shearing the bolt. We
are also asking Kevin to weld reinforced tines onto the broadfork. This should
make the tines sturdier and less apt to bend and break off as they did last
year.

Glaser Hoe with Metal Block to Limit Excess Movement

Broadfork with Reinforced Tines

Winter is the time for making plans for the main growing
season. While the sometimes frenetic
activity of a farm is invigorating, I really enjoyed the time to study and
think for the past few months. January
was filled with bouts of mouth-watering pleasure when considering which peppers
and melons to eat in August.

One of my main projects was developing detailed plans for
what to put in the ground when, and the natural implications for preparing of
beds, distributing finished and building new compost, space-time relationships
in our little greenhouse, harvest duration, and number and varieties of seeds
in stock and to be ordered. I like
working with numbers and wanted a way to efficiently go through iterations and
refinements of our crop plan. There are
so many variables that optimizing one can cause problems elsewhere. As we explore these relationships we find
compromises and end up with a plan we have confidence in—knowing that the real
world will “interfere.” Plans are useful
for organizing time and resources, and signaling to us when we are ahead or
behind, but we also know that a change of course may be needed if new
information demands it.

Attached below is a spreadsheet file with many linked
pages. Each page is drawing attention to
a particular issue of farm life. It
starts with the decisions of what crops to grow (e.g., tomatoes), and how much
of each we want (e.g., pounds per week).
The amount of food can be translated into approximate areas (e.g., 200
square feet). Each plant that gets put
in the ground starts as a seed, so we can estimate backwards from harvest time
to seed time and therefore greenhouse space if required (e.g., tomatoes harvested
in early July begin in the greenhouse in early March). When clearing an area for a vegetable crop,
the cover crop sown in the fall is removed.
This becomes material for compost piles that are applied a year
later. Does our crop plan allow cover
crops to fix enough nitrogen and produce enough carbon to make sufficient
compost for our site (ca. 2600-5200 lbs per year)?

The spreadsheet is made specifically for Brookside Farm, but
could readily be modified to suit farms of different sizes and locations. It is modeling the annual pattern of
intensive vegetable cultivation with cover crops. If you find this useful for your situation
please let us know.

"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

Brookside Farm provides produce year-round. After all, people eat even when the days are
short and cold and plants go into a hibernation mode. Before supermarkets could place a call to a
vegetable broker and have a truck deliver boxes of tomatoes from anywhere in
the world, humans planned for seasonality by growing during the summer the
kinds of foods that would keep during the winter. Brookside Farm is a bit unique among veggie
CSAs (locally at least) by growing storage crops. As a result, our baskets in January are still
pretty hefty.

These baskets are from January 15^th. Potatoes, onions, shallots, and winter squash
make of the bulk, and are all from storage.
Carrots, beets, parsnips, Jerusalem
artichokes, tree collards and kale are still harvested fresh.

The farm has experienced a cold and wet January, including a
few days of snowfall, but without much accumulation. Snow is not very troublesome, even to the
greens. Much more concerning would be a severe
frost at night (in the low teens) and bright sunny days. The wet soil can expand and contract, harming
root crops in the ground. Above ground
greens can be tissue damaged by extreme lows and fluctuations. A sunny day could light and warm the leaf
surface enough to provoke strong photosynthesis, the need for gas exchange and
the opening of leaf pores, but since the soil is still frozen root activity
could be limited and the leaf could become water stressed.

We don't get a lot of snow in Willits, so its presence is an
exciting novelty and the transformation of the beautiful landscape is
captivating. The picture is from January
31^st, and shows in the foreground a row of kale and cabbage, middle
of the frame are former potato beds in compost crops, and the conifer trees
from the neighboring property dominate the background.

A particularly hardy crop around here is a variety of leek
known as "elephant garlic" (Allium
ampeloprasum). Once established, it
is practically impossible to get rid of because it propagates by sending out
subsidiary bulbs that form new plants the next year. During the summer it goes dormant and can be
harvested for the edible bulbs. Like
regular leeks, you can try eating the immature leaf stalks, though these are
generally tougher than the familiar leek.
Two big advantages to elephant garlic are that the plant requires no
watering around here to produce well, and it is high in calories. Most don't think it tastes as good as true
garlic, but it is milder and so can be eaten in larger quantities--providing
some significant calories if need be. I
think of elephant garlic in the same way as Jerusalem Artichokes-not the best
to eat but oh so easy to grow.

I don't have a lot to do on
the farm this time of year, but work for
the farm is continual. A tree pruning is
scheduled for next week as we expect a break in the weather. Seeds have been ordered and organized. I started some flats of leeks in the
greenhouse. Going to get some folks to
look over the work plan for the coming season and refine as I see fit. Should probably take stock of tools and
equipment, making sure everything is in good repair and blades are sharp;
organize the workshop so it is ready when called upon. And there are relationships to cultivate with
the school system, the after school program, community service clubs and
potential farm volunteers and donors.
Oh, and my wife reminds me to do sit ups and push ups regularly!

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

For this essay I think it would help to step outside of
ourselves as humans, and consider us as another species of animal that depends
upon a daily supply of resources in the forms of food, water, and air for
survival. Strip the emotions from the
implications as best we can. Calling us
by our scientific name, Homo sapiens
Linneaus may adjust the frame of mind accordingly. Linneaus was the man who, in 1758, described
and named humans in a taxonomic system.
In official scientific protocol, the author of a species name must be
given with that name to avoid confusion because sometimes the same name is accidentally
given for different species. But from
now on I will abbreviate and just use H.
sapiens.

Now that we are examining the population of H. sapiens, let us bring the insights of
an ecologist to bear on the question of what resources must flow from the
environment to support this species? Food
derives from soil mediated ecological processes. Good soil by itself doesn't
guarantee biological productivity. The
other chief factor on land is fresh water available in proper quantities and
frequencies. The potential for soil to
produce food is not evenly distributed on Earth. Some places are more richly endowed than
others, and historically I suppose population density would correspond to
biological productivity. With cheap
fossil fuels the limits of local ecology can be temporarily overcome and
millions of H. sapiens now casually
occupy mega-cities in deserts.[i]

The United States Department of Agriculture has codified and
mapped environmental heterogeneity in the form of soil maps.[ii] These will be used to help answer the
question of whether Mendocino
County's current
population of nearly 90,000 H. sapiens
could theoretically be fed with the local land-base available. Previous essays established a hypothetical
diet and calculated the land area needed to grow that diet for the current
population.[iii] A summary table from the diet and area
calculations is given below.

I should remind readers that I modeled the food output per
area according to practices that I considered sustainable, or nearly so. I also assumed a low availability of energy
compared to today, which would impact irrigation capacity. I believe the United States produces so much food
today that half could be lost and there would still be enough to feed the
resident population of H. sapiens. Of course livestock population and nations
dependent upon our exports would be drastically impacted. Among the chief reasons for high crop
productivity in the U.S.
include irrigation and artificial fertilization of wheat and corn. Absent the necessary preparations to
transition to a renewable energy-based agricultural system, and considering
what climate change might do, I would not be surprised if the United States
produced half as much food in 50 years.

Is There Enough Land?

For Mendocino
County no single
reference resource exists regarding soils, but two published soil surveys roughly
dividing the county in half were conducted in the mid-80's.[iv] The text from the Western Survey is on-line
and reports: "About 14,105 acres, or
nearly 1.4 percent of the survey area, would meet the requirements for prime
farmland if an adequate and dependable supply of irrigation water were
available." I have a text copy of "Soil
Survey of Mendocino County, Eastern Part, and Trinity County, Southwestern
Part, California," while the soil data are online for both surveys. Page 127 of the Eastern survey reports: "About
55,000 acres, or nearly 5 percent, of the survey area would meet the
requirements for prime farmland if an adequate and dependable supply of
irrigation water were available."

Only a very small portion of Trinity County
is actually surveyed in the Eastern Part publication and can therefore be
safely ignored. Therefore, Mendocino County as of the mid-1980s had (14,105
plus 55,000) 69,105 acres of potentially
prime farmland.

Regarding non-prime land, the 2006 Mendocino County
crop report estimates that 720,000
acres of range and pasture land were in use.[v]

Compared to what is required to feed the current population
of H. sapiens in Mendocino County
given the modeled diet, adequate non-prime land exists, but prime farmland
falls short.

It May Be Even Worse

The main concern I had with the USDA figures is that they
represent field work from the mid-1980s. Unfortunately, as far as I can tell
local land-use decisions since then have not made protection of farmland a high
priority. So I decided to take a look at
what might have happened to prime farmland over the approximately 20 years
since the soil surveys were completed.

The most recently available, area-wide environmental review
documents relate to plans for local freeway construction, much of which would
go right through farmland. A draft
Environmental Impact Report from the California Department of Transportation
(Caltrans) had this to say about farmland conversion and extent remaining.[vi]

Out of 2,246,400 acres of land in Mendocino County,
94,039 acres or 4.19 percent is considered prime agricultural soils (NRCS-USDA
figures). Of that amount, much is unavailable and covered by roads, highways,
cities, parks, and other land uses. While growth is very slow in Mendocino County, settlement patterns have tended
to occur in areas dominated by prime soils. Only one third, or approximately
35,000 acres, of prime farmland remain available for agricultural use. Besides
the unavailability of prime farmland, changes in hydrology as a result of
agricultural and other human uses have affected the quality and use of prime
farmland.

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.

Can We Just Import
Our Food?

Subpopulations of H.
sapiens are unusual in their extensive exchange of non-food items for food
items and the transport of food over vast distances. When food is viewed as the embodiment of
land, water and nutrients, the importation of food into a subpopulation
requires the export of environmental carrying capacity from other places
occupied by other subpopulations.
Therefore, a subpopulation dependent upon imported carrying capacity
should be aware of consumption patterns in the subpopulations of exporters it
relies upon.

An importing population should ask whether the following
statements are true or false:

1. We can
   feed ourselves without these food imports.
2. Consumption
   of the food we are importing is decreasing among those exporting it to us.
3. Production
   of the food exported to us is not being undermined by unsustainable
   activities that degrade productivity over time, such as loss of top soil,
   pollution, and conversion of farmlands to other uses.
4. Production
   of the food exported to us does not require that the exporting populations
   import supporting resources, such as fuels, fertilizers and water.

To my knowledge, in the case of the population of H. sapiens occupying Mendocino County,
the answer to all these statements is false, which means this population faces
food insecurity.[vii] The nearest source of importation into Mendocino County
would be from within the great agricultural state of California.
Yet the California
population is so large that the tillable cropland (usually equal to prime
farmland) available per person is only 0.30 acres.[viii] Where might California turn? Of the three neighboring states, Nevada and Arizona
are mostly deserts and mountains. The
cropland available per capita in the U.S. overall is 1.45 acres per
person, suggesting sufficient land continent-wide but highlighting a misalignment
of population distribution with carrying capacity.[ix] Furthermore, how can land fertility be
maintained in the Midwest if the nutrients extracted
from the soils are shipped in the form of food to coastal populations who then
flush them down the toilet?

What Would an
Ecologist Think?

H. sapiens are
omnivorous with highly flexible diets.
This enables them to exploit different food resources, and to find
alternatives to a preferred diet when it becomes scarce--a practice called
"resource switching" in foraging theory.[x] The diet modeled in part 1 was based loosely
on cultural norms for consumption of grains and animal products. It might be possible that the Mendocino County population will be able to feed
itself on a diet with greater conversion rates of land area into edible
food. Methods for doing this might
include more extensive irrigation and a diet richer in foods with high caloric
yields per area.

If food imports decline and the Mendocino County
population is unable to feed itself, the population will decline. Population decline occurs through emigration,
lower rates of birth and/or higher rates of death.

In part 4 of this series I will revise the diet model to be
more area efficient. Can sufficient
calories per day be grown using 0.4-0.8 acres per person?

[i] http://www.satellite-sightseer.com/id/1008/United_States/Nevada/Las_Vegas/Las_Vegas_Strip

[ii] http://websoilsurvey.nrcs.usda.gov/app/

[iii] http://www.energyfarms.net/node/1489;
http://www.energyfarms.net/node/1490

[iv] Soil
Survey of Mendocino County,
California, Western Part. http://www.ca.nrcs.usda.gov/mlra02/wmendo/ and http://soildatamart.nrcs.usda.gov/Manuscripts/CA694/0/MendocinoWP_CA.pdf;
search for Mendocino
County at http://soildatamart.nrcs.usda.gov/

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

[vi] http://www.dot.ca.gov/dist1/d1projects/willits/chapter6_10.pdf

[vii] http://www.energyfarms.net/node/1488

[viii] http://www.ers.usda.gov/StateFacts/CA.HTM

[ix] http://www.ers.usda.gov/StateFacts/US.HTM; Note that two soil data sets are used in the U.S. The main data set used for my analyses is
from surveys by soil scientists (NRCS-USDA) to reflect agriculture
potential.In many other cases,
including references viii and ix in this paper, the USDA agricultural census data
are used. These data reflect what land
owners or farm operators report. From my
reading of the reporting guidelines for the 2007 census, what farmers are asked
to report as “cropland” would come close to what is judged by soil scientists
to be prime agricultural farmland. See
section 2 of the census instructions for details: http://www.agcensus.usda.gov/Help/Report_Form_&_Instructions/2007_Report...

[x] http://en.wikipedia.org/wiki/Optimal_foraging_theory;
http://en.wikipedia.org/wiki/Foraging;
http://links.jstor.org/sici?sici=0011-3204%28198312%2924%3A5%3C625%3AAAOOFT%3E2.0.CO%3B2-L&size=LARGE&origin=JSTOR-enlargePage

In the first part of this series I established a
hypothetical diet appropriate to the area I live (Mendocino County)
and the culture (i.e., non-hunter-gatherers, based on familiar domestic foods).[i] Growing food requires land, water, fertilizer
and energy resources and I want to know for a given diet + population do the
resources exist? I am leading myself
through the following series of steps to address that question:

(1) Establishing
a diet, (2) Translate this diet into land area requirements, (3) Scale the land
area from an individual level to the population of Mendocino County,
and (4) Compare to the actual land-base.

As a review, the diet being considered for now is given
below. Perhaps it will have to be
reconsidered following the initial results, which is not difficult to do the
way spreadsheets work.

Farmland
Classification

Classification of farmland merits a discussion. Soil nomenclature and taxonomy is complex,
but by most accounts USDA's Natural Resource Conservation Service's Land
Capability Classes I and II are considered "prime agricultural farmland,"
meaning the soils are deep and fine enough to be tilled, not highly subject to
erosion when disturbed, and not severely hampered by potential seasonal
inundation.[ii] These soils tend to form where alluvial
deposits build up layers of sand, silt and clay in more or less even
proportions. Most of the crops in the
diet designed here require such prime land.
Land suited for grazing may include non-prime land, that is class III
and above, but the productivity of this land class is lower. Tree crops, including fruits, olives and
nuts, may also be sown on non-prime land but with lower yields. Yields on non-prime land can be improved by
seeding with desired species, managing livestock smartly, and fertilizing.

Area Required per
Person

I will begin by taking columns 1 and 2 from the table above
and calculating how much area is required for this diet for one year, i.e., a
per capita land requirement given the above diet. To do this, I must apply estimated yields per
area for Mendocino
County of the specific
crops considered. The results are as
follows:

The tricky part of this step is finding decent, contemporary
information about crop and livestock productivity for Mendocino County.
One issue is that the local ag business is currently dominated by a single,
ethanol crop, rather than a diversity of products as in the past.[iii] Previously, I explored this issue with
respect to grains, and was forced to use data several decades old.[iv]

Because projected grains yields dominate the area
requirements, understanding the yields per acre figure used is most
important. Grains being modeled are the
small grains, chiefly wheat, oats, barley and rye. They all give similar yields per acre. California
is a major producer of wheat, and the yields from most growers in the Central Valley are fantastically high-6000 lbs per acre
is considered normal. Why then the 1000
lbs per acre for this worksheet? The
resources required to achieve 6000 lbs per acre are substantial and
include: pre-planting application of
herbicide, precision seed drilling at high density but even spacing,
application of fertilizer at time of planting, irrigation, and additional
fertilizer application.[v] From my conversations with grain farmers and
UC extension agents I expect the following changes in yield absent the given
input: remove irrigation and yields fall by half (3000 lbs/acre), remove
artificial fertilizer application and yields fall by nearly half again (1800
lbs/acre), remove pre-planting herbicide and precision planting and yields fall
once more (1100 lbs/acre). Because 100
lbs are needed to sow an acre of grains, a 1100 lb harvest nets an edible yield
of 1000 lbs. So my number assumes dry-land
farming methods, lack of sophisticated planting equipment, and no herbicides or
artificial fertilizers. 1000 lbs per
acre is also the yield from historic data when Mendocino County
did grow grains, and it could be argued that soils were less depleted
then. This may be considered a
worst-case scenario, but given current conditions in the County it may be
reasonable. The capital stock of
equipment to grow high yield grains is lacking and energy constraints may limit
use of agro-chemicals and fertilizers as well as irrigation pumps. To avoid yield problems with staple foods
requires planning ahead, considering what inputs may still work in an
energy-constrained County, and investing today in infrastructure that could
last in such an environment.

For olive oil I could find state-level information only and
I assumed 3 tons of olives per acre with 40 gallons per ton oil extraction.[vi] Olive trees are becoming more common within
vineyard operations and small-scale commercial production has increased lately,
including local processing equipment.

As explained in part 1, I use honey as the sugar source so
it doesn't have a direct land area requirement.
It would be good the check with local bee keepers about how many hives
they believe the county can support without seasonal transportation to almond
orchards. My estimate is that one hive
per person would cover the honey/sugar quota.
Another option would be to grow sweet sorghum, which requires summer
irrigation and prime farmland.

Meat and dairy yields are especially difficult to estimate
because they rely on lands of variable quality and encompass a diversity of
production models. As far as I can
gather, livestock here are rotated between winter pasture in the hills and
summer pasture in the valleys. Valley
pastures include both prime and non-prime farmland. Stockman operations sell half-grown cattle
out of the county once rangeland dries in the summer. Conceivably these exported animals could be
eaten when not fully grown, as is done with male dairy cows. Cow-calf operators bring animals into summer
pastures in the valleys. A single
cutting of hay is typically given to valley pasture before animals are placed
on it, which is an important supplement during late summer and fall. In addition to cattle, sheep and goats are
raised, but cattle are preferred here-perhaps based on cultural norms or
because sheep are more susceptible to predation. Animals are usually culled in the fall, reducing
food requirements while the herds are re-established on new grass that emerges
during the rainy season (Oct-May). The
Mendocino County Department of Agriculture gives estimates of the productivity
of different forms of pasture land in the unit of measure called AUM, or Annual
Unit Month, which is the food required to feed a 1000 lb steer for one month
(or ca. 5 sheep), which works out to about 1000 lbs of forage. [vii] The county crop report doesn't give hay
yields, but discussion with local ranchers suggests 5 tons per acre is probably
a good yield. County soil surveys also
give estimates for the rangeland productivity in terms of above ground dry
weight in lbs per acre.[viii] Values
are typically about 2000 lbs per acre, which would provide 1000 lbs of forage,
or enough for 33, 1000 lb cows for 1 day. [ix] But
this is a standing biomass figure at a particular stage of growth and doesn't
indicate how a pasture responds to grazing and then re-growth. Will an acre of rangeland with 2000 lbs of
above ground biomass grazed by 33 cows down to 1000 lbs biomass re-grow to 2000
lbs in 2 weeks or 5 weeks? The answer
likely depends upon the quality of the land, the weather, and the season.

I simply don't have the expertise to sort out all these
variables from first principles. Another
way to go about this is to use total weight of animals produced and divide this
by rangeland and pasture land acreage. The
average live weight for cattles+calves and sheep+lambs for Mendocino County
in 2005 and 2006 was 10.7 million pounds.[x] The actual weight of meat consumed is about
40% of the live weight.[xi] This gives about 4.3 million lbs of meat
produced in the county. There are no
feedlots here and the county does produce a lot of hay, but I am not sure this
represents the meat production of county land only. If we assume it does, however, the following
calculation can be made: Take the 4.3
million pounds of meat and divide by the acres of range and pasture land in use
(720,000 acres) according the county crop report, to yield 6 lbs of meat per
acre.

Humans may consume milk in its liquid form or as
cheese. The table computes in cheese
units equal to about 1.6 cups (12.8 oz) of milk per day. Dairy cows need to be fed in close proximity
to the milking barns, so they are kept on highly productive irrigated or
naturally sub-irrigated pasture, on fog-swept coastal plains, fed grains,
silage and hay or some combination. The
1400 milking cows in Mendocino
County yielded, on a per
cow basis, 6.4 gallons of milk per day in 2006, or 18,800 lbs of milk per
year. From the table below, the land
required to produce these yields can be estimated.[xii] If we assume irrigated pasture for the
forage, Mendocino County irrigated pasture produces about 9200 lbs per
year. Then the other area would come
from grain yields of about 1000 lbs per acre.
So, one milking cow requires (8096/9200) 0.88 acres for forage and
(8275/1000) 8.28 acres of dry-farmed grain, for a total of 9.16 acres per cow. (The grain area could be cut about in half if
irrigated). Since each cow produces
18,800 lbs of milk, this is 2052 lbs of milk per acre. Since cheese is 1/3 the weight of milk, this
yields 684 lbs of cheese per acre. The
grain area could be reduced by more extensive grazing on highly productive
pasture, but this would generally be prime farmland anyway and may not reduce
total area required.

For eggs I have a book called "Living with Chickens" that
advises a quarter pound of grain per layer per day. My logic then went as follows: assume 200 eggs per hen/year, fed 90 lbs of
grain/year/bird, so 90 lbs of grain yields 200 eggs, or 0.091 acres of grain
per 200 eggs, with each egg weighing about 0.1 lbs. 200 eggs/0.091acres = 2192 eggs/acre at 0.1
lbs per egg = 220 lbs of eggs/acre. Even
when chickens are pastured (which I prefer) they still require these grain
inputs to get high egg yields. Note that
old laying hens can go in stew pots but this contribution to the meat diet
isn't included.

Fruit and vegetable production yields are in line with county
records for tree crops and my own experience with intensive vegetable
cultivation. These yields assume summer
irrigation water.

Discussion of Initial
Results

I am concerned by the total of 9 acres. From my previous readings, the number "about 1
acre per person" stuck in my head (about 0.4 hectares) as to what is required
for a diet familiar to people in North America and Europe.[xiii] Of course, many countries are already well
below 0.4 hectares per person for cropland.
They have diets with fewer animal products, less area demanding crops
like grains, and more root crops with high yields and decent caloric density, such
as potatoes. Will a "local diet" run up
against land (and water) limits, forcing a change in the kinds of foods we can
hope to eat?

The reason for the 9 acre per capita value is the inclusion
of meat that depends upon low productivity rangeland and pasture. The previously cited value of 1 acre per
person refers to the area of high quality land, or prime farmland. For Mendocino County,
I am going to assume that meat is produced on non-prime farmland, whereas the
other foods are more reliant on good tillable acreage. When the meat area is excluded, a more
comfortable figure of ¾ of an acre per person is calculated for the remainder. From part 1 of this series we see that the
food produced on this ¾ acre represents 96% of daily calories-basically an
ovo-lacto-vegetarian diet.[xiv] Notice also how fruit and vegetables, which
are the darlings of farmers markets, only use 3% of the ¾ acres (Fig. 1). True food security requires growing the high
calorie crops. In this diet grains and
dry beans are estimated to require 50% of prime farmland area directly, and
since eggs and dairy rely on grains 90% of the ¾ acres is actually grain plus
dry bean area.

Fig. 1. The acreage
required to produce each class of food per person, absent meat. Note that because sugar is based on honey it
is given no area.

Area Required for the
Population

In 2005, the human population of Mendocino County
was estimated at 88,161.[xv] I will divide land requirements into two
categories: prime farmland and non-prime
land. On a per capita basis for this
diet the prime farmland need is 0.76 acres and the non-prime 8.33. Multiplying each per capita allocation times
the population yields 66,778 prime and 734,675 non-prime acres (these are
spreadsheet derived numbers that include more than 2 decimal places in the per
capita figures). For the prime farmland
portion, the assumed irrigated area in this diet-land model is 6803 acres (10%)
and the non-irrigated 59,975 acres (90%).
Land area could potentially be reduced significantly if much more area
can be irrigated.

There is an additional factor that needs to be considered
however. Lands that are not tilled and
are subject to low intensity grazing do not have any crop rotation patterns to
consider. Rangelands and pasture may be
rested, animals of different species may be placed on them to balance the plant
species being consumed, and desired plant species may be over-sown, but their
fertility does not rely on incorporating "green manure." Fertilizers may be frequently needed for
pasture if it is used for hay that is exported from the land, and less often if
used to feed a resident grazing herd.
The removal of animal flesh from a land-base does eventually require
nutrient replacement.

If organic agricultural methods are used (part of my
assumption) then the area devoted to food classes grains, sprouting seeds,
vegetables and food reliant on grains will need to be rotated with nitrogen
fixing legume crops. For example, if a
field is sown in wheat for two years, the following year it may be a field of
clover. Clover can be under-sown with
grains to improve cover crop establishment time and reduce erosion. To ensure that the nitrogen being fixed by
the clover doesn't all go into the clover seed, mowing or grazing is done. This creates some overlap, therefore, between
the land-base devoted to animal and non-animal production. By grazing and spreading manure, animals can
improve the land needed to produce crops.

What this means is that some proportion of the prime
farmland is not directly involved in food production each year, thereby
increasing the prime farmland area required.
At the same time, the area being set aside for green manure can be used
for grazing or making hay, thereby decreasing the non-prime land required. It is also possible to lightly graze animals
on fields of annual winter grain crops, though opportunities for this may be
limited in non-irrigated production systems since early and vigorous fall seedling
establishment is not reliable. Pasture
hens may be ideal for this practice since they cause less soil compaction in
recently tilled land.

To sort out how many acres of cover crop are needed to fix
nitrogen for a given acre of food crop, I started with the pounds of nitrogen
fixed per year by clover, which is about 100 for irrigated conditions and I
estimate about 60 lbs for non-irrigated land.[xvi] The nutrients removed by a crop is
proportional to the yields. Using the
pounds of nitrogen removed by a crop per year given the estimated yields, I was
able to compute a "Green manure factor" that became a multiplier for the actual
area required for that crop.[xvii] For example, if wheat removes 30 lbs of nitrogen
per year from the soil when dryland farmed, then growing 1 acre of wheat will
require a half acre of green manure. A
farm could theoretically have 3 acres, with a rotation pattern of clover,
wheat, wheat, and be balanced for nitrogen.
In this situation if you multiplied the 2 acres in wheat by the "Green
manure factor" of 1.5, you would get the 3 acres required to support the
nutrient cycle. This is the same basic approach
used by Bagdley et al. in their review paper of the yields of organic
agriculture.[xviii]

The total prime farmland needed is therefore the area for
crops requiring green manure rotation plus the area of those that do not, which
sums to 95,401 acres.

Because about a portion of the prime land can be lightly
grazed, subtracting this area from the non-prime land allocated to meat
production reduces the non-prime land needed to 706,052 acres.

The adjusted per capita prime land requirements are
therefore 1.08 acres of prime farmland and 8.01
acres of non-prime farmland. I am
somewhat astonished that after all these complex computations we arrive at the
number "about 1 acre" per person.

Beyond Nitrogen

Green manures fix nitrogen and add organic matter to the
soil, but most commercial fertilizers add nitrogen, phosphorus and potassium
(NPK). It may also be necessary to apply
other, more minor nutrients, as well as lime to adjust pH and add calcium, less
regularly. So even if the nitrogen issue
is covered by green manures, what about the rest? Imports to the land may come in the form of
rock phosphate, wood ash, oyster shells, green sand, and kelp meal-some of
which are produced in energy intensive mining operation, and most of which
currently require long-distance transport.

The amount of nutrients needed to grow the food for one
person per year can be estimated by the sum of the multiplication of the area
per crop by the nutrient demand per area.
Local sources of nitrogen would be legume cover crops. Potassium is extracted from the soil by trees
and can be used agriculturally by adding wood ashes to compost. Phosphorus may be the most difficult to
gather as a field supplement.[xix] In the natural nutrient cycling of this
bioregion, salmonoids would bring the richness of their flesh back to the land,
essentially countering the process of water removing minerals from continental
lands over time. A strong salmon run
could therefore be important for future agriculture.

Another plentiful but usually overlooked local source exists
for nitrogen, phosphorus, potassium and other vital minerals. The Chinese figured out thousands of years
ago that human excrement (feces and urine to be precise) is a valuable source
of fertilizer. Here in the U.S.
we spent gobs of money trying to get rid of it, but that may have to change.

Data on the fertilizer value of a year's supply of human
excrement is hard to come by. Two
references I have cite a 1956 report from the World Health Organization.[xx] Table 1 from "Future Fertility" is reproduced
here:

Nitrogen can become a gas and be lost during decomposition
unless care is taken to balance the carbon:nitrogen (C:N) ratio of the
composting process.[xxi] Human wastes have a 5:1 C:N ratio, but
starting a compost pile with 35:1 is best for retaining nitrogen. Assuming most of the nitrogen and other
nutrients can be efficiently retained; human waste can be recycled to yield
about 50% of nitrogen needs, all phosphorus needs, and 40% of potassium
needs. This topic warrants a detailed
discussion on its own, but that will have to wait for another paper.

Improving Non-prime Land

Some may feel tempted to "improve" non-prime farmland and
thereby increase the area available for intensive cultivation. I don't find it credible to rely on non-prime
agricultural land for significant productivity of major staple foods. The required inputs per area to make a naturally non-fertile soil and poorly textured
soil able to be cultivated are immense.
This can be done in someone's backyard, no doubt, but on a scale to
significantly contribute to grain production is not viable. However, non-prime land can be an important resource
for grazing animals, some perennial crops, and through intensive modification small-scale
cultivation of specialty crops or vegetables.

Research done for New York
State, for example, found that the
most area efficient diet was vegetarian and required 0.6 acres per person-very
close to the ovo-lacto-vegetarian diet plan for Mendocino County. By adding 0.1 acre per person in the form of
permanent pasture, the total number of people that could be fed in NY State was
increased.[xxii] (Note:
this was the thesis work of a Cornell
University graduate
student and so is far more thorough than my own!) While this addition of permanent pasture in
NY was 17% above the tillable cropland, in this exercise for Mendocino County
the non-prime acreage is 6.3 times greater.
Reasons I can think of for this huge difference are much more productive
pasture in upstate New York due to summer rains, and methodological flaws on my
part in estimation of Mendocino County range and pastureland productivity (the
amount of meat in the NY and Mendocino diets is similar).

The next essay will examine the actual land-base of Mendocino County.

Acknowledgement

Christoffer Hansen deserves thanks for reading drafts of
this work. He questioned my assumptions,
forcing me to explain them more clearly, and double checked the math in many
places. Any remaining errors are my
own.

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

[ii] http://soils.usda.gov/technical/handbook/contents/part622.html
and http://www.dot.ca.gov/ser/vol1/sec3/community/ch23farm/chap23farm.htm#Ch24Definitions

[iii] http://www.mendowine.com/

[iv] http://www.willitseconomiclocalization.org/files/well/FoodSecurityReport.pdf

[v] http://anrcatalog.ucdavis.edu/pdf/8208.pdf

[vi] http://ucce.ucdavis.edu/files/filelibrary/2161/29131.pdf

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

[viii] Soil
Survey of Mendocino County,
California, Western Part. http://www.ca.nrcs.usda.gov/mlra02/wmendo/ and http://soildatamart.nrcs.usda.gov/Manuscripts/CA694/0/MendocinoWP_CA.pdf;
search for Mendocino
County at http://soildatamart.nrcs.usda.gov/

[ix] http://www.bakewellrepro.com/sarahflackarticle.html

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

[xi] http://www.shutersunsetfarms.com/index_files/Page949.htm

[xii] http://www.oznet.ksu.edu/library/lvstk2/mf754.pdf

[xiii] http://dieoff.org/page40.htm

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

[xv] http://www.city-data.com/county/Mendocino_County-CA.html

[xvi] http://attra.ncat.org/attra-pub/covercrop.html

[xvii] I
can't find a web-available reference for the table I used, but a similar table
using non-organic agricultural demands and so generally with higher values is
here: http://benson.byu.edu/Publication/Lessons/EN/Agronomy/SoilFertility.asp

[xviii] http://www.journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1091304&fulltextType=RA&fileId=S1742170507001640
and related press release: http://www.ns.umich.edu/htdocs/releases/story.php?id=5936

[xix] http://www.energybulletin.net/28720.html

[xx] http://www.jenkinspublishing.com/humanure.html;
with quantities in terms of pounds produced per person per year given in John
Beeby "Future Fertility: Transforming
Human Waste in Human Wealth" Table 1.
Ecology Action.

[xxi] http://en.wikipedia.org/wiki/Denitrification

[xxii] http://www.news.cornell.edu/stories/Oct07/diets.ag.footprint.sl.html

I live in a rural part of northern California in a county named Mendocino. There are about 90,000 people here, in an
area of about 3500 square miles, for a population density of 25 people per
square mile.[i] This is considered, and it feels like, a low
population density. So naturally I think
most people assume that if we had to grow our own food here we absolutely
could.

But as a data-driven empiricist, I wanted to do the math on
this. I posed the question: Could the land-base of Mendocino County
support its current population of people if it needed to? This initial question leads to many others,
including: What is the theoretical diet
being consumed? What are the yields per
area of the parts of the diet? What
kinds of soil, water and energy systems are needed to produce those yields? And, do the requisite land-water-energy
resources exist at the levels implied by the diet demands?

If you don’t live here why should you care about an analysis
done for Mendocino
County? Well, the point is that this exercise can be
done any place and is generally instructive on how our diets are dependent upon
a whole suite of resources. How do you
feel about the future of those resources globally, nationally or closer to
home? Does thinking about these topics,
running the numbers and considering scenarios influence your thoughts about
where to live, who to talk to, and what to invest in?

Before I get into those questions, it is important to
explain some of my basic operating assumptions.
First, I am interested in this question for a number of reasons that
revolve around energy and security. I
believe that global energy availability will decline this century as fossil
fuel reserves are depleted. I also
believe that burning those fossil fuels is a bad habit anyway since they muck
up the climate system upon which food production depends. Now, amazingly, our current food production,
distribution, storage and preparation systems are highly dependent upon the
very fuels that are going into depletion and spewing pollution into the
environment.[ii] When envisioning what it means to produce food
in the future for Mendocino County I therefore assume a low energy input
agriculture, meaning organic fertilizers, limited irrigation, and local
distribution systems. As it turns out,
this is also the system that would produce the fewest greenhouse gas
emissions. I don't want to argue about
the merits of conventional vs organic methods, or localism vs globalism in
trade, but simply state my position that whether out of necessity or moral
choices, the only option for sustainable production of food over the long-term is
through relatively local and organic systems.

Quite astonishingly to me, the potentially important goal of
local or bioregional food self-sufficiency is rarely considered. For example, my chin almost hit the floor at
a climate change conference in Sacramento
a few years back when the following actually happened. A senior professor of hydrology from UC Davis
gave a presentation of what looked to me like severe water shortages in California due to climate change melting winter snow
packs, not to mention the potential for severe flooding of the Central Valley, one of the most important agricultural
regions on the planet, from sea level rise.
The maps he showed of the havoc-ridden area included a complete build
out of the Central Valley into suburban
housing, which was presented as sort of a pre-ordained eventuality. When someone pointed out to him that it looks
like there's almost no more food production in California in this scenario, and
that the state would, under the conditions of less water, higher seas, longer
and more severe heat waves, etc. still have 60-90 million people to be fed,
which begs the question where might their food come from he replied, "We'll
import it." As far as I could tell, this
position was the standard one not only of the academics in the room, but of the
state bureaucrats organizing the event.

In any case, soon afterwards I began exploring some
alternative scenarios, one of them a few years ago being a rough estimate for what
food self-reliance would entail around here.[iii] Recently others have done similar work, such
as analyses for the state of New York[iv]
and Britain.[v] Not having a degree in agriculture I don't
feel highly qualified to do this, but I do have a doctorate in biology and am
comfortable with basic math and spreadsheets.
I have also become a vegetable farmer recently, so do have some personal
expertise in a limited aspect of food production. If readers find glaring errors, poor
assumptions or better data I am keen to hear about it. As a scientist, my main goal is to get as
close as possible to the truth, wherever that leads.

The Diet

Every locale has a combination of climate, soils and culture
that when combined with other assumptions related to future energy and food
system methodologies will limit the reasonable range of food species available. It is difficult to be purely scientific in
this situation because what people prefer to eat is governed by personal taste
and physiology. So I made some judgment
calls when proposing the basic mix of foods given a local, sustainable system
in place. Keep in mind I am also
considering this from a population level.
So while some may see "beef" and say that they are vegans, or see
"dairy" and fuss about their food allergy, that is beside the point.

Human nutrition is highly complex and controversial. In this case I envisioned a culturally
appropriate healthy diet based on a mixture of factors and guiding principles,
including: (1) maximizing food diversity,
(2) emphasizing fresh produce for vitamins and minerals, (3) considering the
relationship between soil health and rotation among production types (e.g.,
pasture and field crops), (4) the importance of food storage, and (4) the
weight of food ingested per day. I also
set a goal to produce close to 3000 calories per person on average. The population can get by with less, perhaps
2400 calories per person, but food waste can't be totally avoided and good
years may be followed by bad ones. Food
is so important that we should plan for excess just in case. This is common sense and used in engineering
all the time, such as building the bridge a bit stronger than the maximum load
it is supposed to carry.

With that lengthy explanation, I offer the following table
of foods, their proportions, and how they form a complete diet at an individual
level. Each row deserves some further
discussion.

Because of our winter rains and dry summers, grains will be
dominated by plants with C3 metabolic pathways, chiefly wheat, rye, oats and
barley, also known in the trade as "small grains." By contrast, corn, sorghum and rice would
require summer irrigation for high yields.

Dry beans can also be grown in the cool season if lentils
and chick peas are chosen. Pinto types
are summer-irrigation dependent. For
both grains and dry beans I will assume yields from dry-land (i.e.,
non-irrigated) methods. Irrigation could
potentially double yields.

My calculations for oil use olives. I prefer olives because, unlike field crops,
they can be established on non-tillable soils and so don't necessarily compete
for prime ag lands. Trees can also find
deep water sources and may not require irrigation once well established. Olive oil is also versatile and prized for
its flavor.

Honey is the sugar source in my diet mix. Other potential sugars include sweet sorghum
and sugar beets. I prefer honey because
of lower processing costs relative to sugar crops, and honey bees are
synergistic with food crops rather than competitive for land area. About one hive provides enough sugar per
person.

Sprouting seeds are included as a storable and portable
source of high calories and nutrition, including vitamin C. The crop modeled in this diet plan is
sunflowers. I like sunflowers because they
are a prolific summer source of nectar for honey bees, they can be used as an
oil crop if necessary, and they produce good biomass in stalks and seed
heads. Tree nuts could also be
included/exchanged in this part of the diet and have the advantage of not always
needing prime ag land.

Fruit and vegetables are a diverse assortment of standard
crops, including lettuce, cabbage, potatoes, carrots, grapes and apples. The caloric density ranges about 10-fold
(zucchini, 64 calories/lb, garlic 676 calories/lb) but averages 200/lb when
calorie staples such as potatoes are included.

Dairy calculations are based on a soft cheese, such as
mozzarella, which has 3 times the caloric density as whole milk. The allotment here is equivalent to 1.6 cups
of fresh milk a day, but cheese is used for ease of comparisons among mostly
sold foods. Cheese also stores and
transports well so should be encouraged.
In reality I'd expect a mixture of consumption patterns, such as a cup
of milk a day and a modest piece of cheese.

I am using chicken eggs, about 1 per day per person.

Meat assumes domestic animals such as fowl and
ruminants. I prefer rotational grazing
systems that mimic multi-species flocks.
Chicken is less calorie dense than beef, so an average is used. The most common livestock here are cattle and
sheep, so I will likely emphasize their needs when calculating land area though
other species warrant consideration. The
amount of meat in the diet, 50 lbs per year, is about 1/3 the current U.S. average
and works out to 2.2 oz per day, or just under a pound per week. I am not expecting people to eat tiny
portions of meat each sitting, but perhaps a pot roast or leg of lamb shared
among a family on Sunday dinner. While
this quantity of meat seems low by current U.S.
standards it is the same as modeled for an area-efficient diet in New York State and would be the envy of many
parts of the world.[vi]

An additional factor when considering a diet is the total
weight of the foods being consumed each day.
Human stomachs get uncomfortable when given too much food, so foods with
high caloric density offset the weight of foods with low density. Some foods are eaten with their natural
content of moisture, whereas others are stored dry and are hydrated during
cooking. The table multiplies the dry
weight of certain foods (grains, dry beans and sprouting seeds) by a factor of
three to estimate their weight when ingested.
Keeping the diet below 6 lbs per day is a goal.[vii]

I like this diet because it feels normal to me, and appears
very healthy. A quarter of the daily
weight of food is in the form of fruits and vegetables (Fig. 1). Eggs, dairy and meat are present but not in
unhealthy proportions. Oils and sugars
are recognized as important but their presence is moderated appropriately. Whole seeds are the main caloric staples,
including cereals, legumes and other seeds (Fig. 2). I would like a nutritionist to look this over
and let me know if I am especially high or low on anything in their view. Overall, I think I struck a nice balance that
will likely provide enough calories, protein, minerals and vitamins without
excessive food weight (5.2 lbs per day), using a mix that stores well and is
culturally familiar.

Fig. 1. The daily wet
weight (ounces) of food is given by food class.

Fig. 2. The daily
calories of food are given by food class.

Okay, so step 1 is complete, establishing a diet. The next steps are: (2) translate this diet
into land area requirements, (3) scale the land area from an individual level
to the population of Mendocino
County, and (4) compare
to the actual land-base.

[i] http://www.city-data.com/county/Mendocino_County-CA.html

[ii] http://www.cias.wisc.edu/pdf/energyuse.pdf

[iii] http://www.willitseconomiclocalization.org/files/well/FoodSecurityReport.pdf

[iv] http://www.news.cornell.edu/stories/Oct07/diets.ag.footprint.sl.html

[v] http://transitionculture.org/wp-content/uploads/2007/CanBritain.pdf

[vi] http://www.news.cornell.edu/stories/Oct07/diets.ag.footprint.sl.html;
and original article here: http://www.journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1091328&fulltextType=RA&fileId=S1742170507001767

[vii] Duhon,
D. 1985.
One Circle: How to Grow a Complete Diet in Less Than 1000
Square Feet. Ecology Action, Willits, CA.

Most institutions, such as the food aid NGOs or the US
Department of Agriculture, express concern about food security in terms of the
ability for poor people to purchase adequate food. The USDA, for example, measures food security
by asking households a series of
questions (http://www.fns.usda.gov/fsec/FILES/FSGuide.pdf), including:

Q1 Which of these statements best describes the food eaten
in your household in the last 12 months: we always have enough to eat and the
kinds of food we want; we have enough to eat but not always the kinds of food
we want; sometimes we don't have enough to eat; or often we don't have enough
to eat?

Q1a (IF SOMETIMES
OR OFTEN NOT ENOUGH TO EAT) Here are some reasons why people don't
always have enough to eat. For each one, please tell me if that is a reason why
you don't always have enough to eat.

Not enough money for food

Too hard to get to the store

On a diet

No working stove available

Not able to cook or eat because of health problems

Income-based Food
Security

This is a valid way to think of food security. If food prices are high relative to income,
or if other compelling expenses such as housing, health care and transportation
also require a large portion of income, then securing adequate food on an individual or family level will be
problematical. I will refer to this kind
of food security as "income-based food security." Personal misfortunes or failings, structural
economic inequality, recessionary business cycles, and monetary crises are
examples of conditions that cause or exacerbate income-based food security. Asking heads of households is a proper way to
understand this class of food security.

In general, households don't actually produce food, nor do
they move food from producers to markets.
Given current environmental and resource trends, the income-based food
security perspective has some gaping blind spots. Instead of just asking food eaters questions,
should we also be querying food producers, distributors, fertilizer
manufacturers, supermarkets, energy experts and climatologists?

Distribution-based
Food Security

Globalization of food commodities has greatly distanced food
consumption from food production. Most
people in industrialized nations, and quite a few in poor but food importing
nations, are therefore highly dependent not only on the ability to pay, but on
the ability to distribute food from places of production, storage, and
processing to retail and home. Absent
either the liquid fuels for shipping vehicles, or sufficient roads, rails and
port infrastructure to carry and receive cargo, food becomes scarce no matter
how much money someone has in their wallet.
Examples include a place after a natural disaster or a war (Gulf coast
post-Katrina), a nation embargoed for political reasons (Cuba in the 1990s), and acute shortages of fuel
or trucks (UK trucker strike
in 2000, Italy
recently). With transportation
disruptions grocery store shelves can go bare within days. I will refer to this kind of food security as
"distribution-based food security." Just-in-time
delivery systems, oil depletion, violence in oil producing regions, and "acts
of god" threaten distribution-based food security.

Production-based Food
Security

Total food output has increased dramatically over the past
50 years, far outpacing even the rise in population. The reasons for this increase in production,
however, and the broader environmental costs incurred, suggest that food
production will flatten and perhaps decline in the coming decades. Productivity gains were driven principally by
increases in non-sustainable inputs, such as irrigation water from depleting
aquifers, nitrogen fertilizer from natural gas, and greater mechanization in
general requiring more fossil fuels. None
of these are sustainable solutions, meaning they are bound to fail in the end
without ample and timely substitutes.
Cultivation, irrigation, fertilization, herbicide and pesticide
practices have also led to massive erosion of topsoil, leading to a steady
decline in the quality of the land base supporting agriculture. Urbanization, severe erosion, and the long
history of forest clearing end up reaching the limit in the total quantity of
arable land as well. And finally, the
stable climate system upon which farmers, seeds, cultures and markets have
adapted to is wobbly. Expectations are
for extreme weather variance and a general decline in crop growth over
time. These related forces I term
"production-based food security."
Overall, the quantity of food is threatened by depletion of resource
stocks (fresh water, oil, natural gas, mineral fertilizers), degradation of
soils, and climate change. Many would
also add genetic diversity and aging farmers to this list.

These three classes of food security threats are not
unrelated, of course. Rising energy
costs impact the costs of production and distribution, which in turn lead to
food inflation. But by framing security
in these different ways, we can more clearly see the stresses in the food
system and their underlying causes. All
three classes of food security threats are occurring simultaneously, but at
different rates and severity among different populations. Social movements have arisen in response, and
their different emphases reflect the classes of threats summarized here. These movements also offer potential
strategies to deal with each situation (See Table 1).

The problems of our food system are so deep and connected to
so many other structures in our societies that only a multi-faceted approach
that recognizes these relationships offers meaningful, long-term change. Fortunately, many are aware of this. Take for example the Community Food Security
Coalition (http://www.foodsecurity.org/),
which describes itself as:

The Community Food Security
Coalition (CFSC) is a non-profit 501(c)(3), North American organization
dedicated to building strong, sustainable, local and regional food systems that
ensure access to affordable, nutritious, and culturally appropriate food for
all people at all times. We seek to develop self-reliance among all communities
in obtaining their food and to create a system of growing, manufacturing,
processing, making available, and selling food that is regionally based and
grounded in the principles of justice, democracy, and sustainability. CFSC has over 200 member organizations - join
us!

The CFSC connects groups from across the spectra of social
organizations throughout North America. I think it would be wise for each community
to find their own set of players, from food banks to farmer's markets to
community farms, and work together.

Imagine, for example, providing stable income to a local,
organic community farm for growing food distributed to a school with many low
income children? There, in one set of
connections economic justice, decreased transportation, and sustainable
agriculture strategies are integrated and reinforced. Who wouldn't be in favor of that?