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

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

Green Acres II:
When Neighbors
Become Farmers

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The concept signs consist of:

·
Goals of the Sebastopol Energy Garden

·
Community Compost Collection

·
The Sebastopol Energy Garden Growth Collage

·
Square Foot Gardening Method

·
Natural Farming – The “Do Nothing” Method

· Cover Crops

·
The Water Catchment System

·
Drip Irrigation

·
Culinary Herb Spiral

·
Mandala Garden: The Sheet Mulch Technique

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

·
Appropriate Technologies

·
Processing and Harvesting Techniques

·
Tree Guilds: Edible Forest Gardening

·
Garden Cycle Tracking

·
Ethanol Production

·
The Fractional Still

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

·
Chickens

·
Biointensive Concepts

·
Permaculture Principles

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

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

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

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: