On Tuesday I went to a field day on no-till tobacco production. Tobacco is a warm season solanaceous crop -- like tomatoes or peppers -- that is usually transplanted into freshly-tilled soil in late spring. After fall harvest the remaining stubble is usually left to decompose in the bare soil until the next spring, when the plow comes around again.

In recent decades people have started to recognize that soil suffers when it's left bare, or routinely disturbed by cultivation. Bare soil is susceptible to wind and water erosion. Cultivation destroys the soil structure, further increasing its susceptibility to erosion. Cultivation also introduces a lot of oxygen to the soil very quickly, resulting in a brief boom in the microbial population, and a rapid depletion of the soil organic matter that the microbes eat. (Organic matter is a valuable component of soil because it holds on to the nutrients and water that plants need; soil microbes help release nutrients into the soil solution, making them accessible to plants, and exude sticky material that holds soil particles together, reducing soil's susceptibility to erosion.) In the long term, cultivation reduces soil organic matter content and soil microbial populations.

No-till grain production is now fairly common, but very few farmers grow transplanted crops, like tobacco, without cultivating. It turns out that one of them happens to be a sixth-generation Kentucky farmer who took the 'Introduction to Sustainable Agriculture' course that I co-taught last semester. The field day was at his farm.

We saw a nice demonstration of how soil that hasn't been tilled holds together better than soil that is routinely cultivated. Clods of soil collected from sections of the farm that hadn't been cultivated for 10 years were suspended in water next to a clod collected from a routinely cultivated section. You can see the clod on the left disintegrating while the clod in the middle holds firm:

After harvest the land is seeded to a winter cover crop that protects the soil from winter erosion, saves nutrients that might leach out of the soil in the absence of plants, and feeds soil microbes. The farm is experimenting with different winter cover crop mixes, most of which include a nitrogen-fixing legume species.

At the Kentucky State University Research and Demonstration Farm we often use a mixture of rye, which grows quickly and out-competes weeds; and hairy vetch, which fixes nitrogen and twines its way up the rye. Here are the two plants together, towering over a yardstick:

Nitrogen-fixing crops like hairy vetch harbor bacteria in their roots that are able to convert nitrogen gas from the air around us into nitrogen that is available to plants. A winter cover crop of hairy vetch can add more than 100 pounds of nitrogen to the soil per acre (Kansas State University pdf), enough to feed a nitrogen-demanding crop like corn.

Of course organic farmers have been using nitrogen-fixing cover crops for decades; the organic standards don't allow synthetic nitrogen fertilizer. Conventional farmers have known about the advantages of cover cropping, but using nitrogen fertilizer has long been cheaper than managing cover crops. Soaring fertilizer prices have changed that. Suddenly tactics like no-till production and cover cropping aren't just better for the soil; they're cheaper, too.

Michael Bomford provides research and extension services related to organic agriculture and small-scale renewable energy production through Kentucky State University's Land Grant Program.

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.

Chris and I recently finished a Brookside Farm site map and
fertility plan. This is a great thing to do in general, and we were
encouraged to get it done now by a local organic certifier, Mendocino Organics. I am
glad to report that we passed muster!

The process of making this plan brought to mind some
differences between what we are doing at Brookside Farm and your typical local
organic farm or backyard gardener with respect to fertility inputs. Brookside Farm is in Little Lake Valley, home
to numerous piles of manure of various stripes-horses, sheep, goats, etc. Anyone with a pick up truck can drive a couple
of miles and load up with tons of free, aged manure. So why don't we just go ahead and get that
stuff? Chris and I spend a lot of time
building and monitoring compost piles, and fretting about how we are going to
maintain good soil in the future. We
could avoid ourselves much hassle with a few pick up truck loads a few times a
year.

If you think about it though, where did those animals get
the food that created the poop in the first place? If they are pastured some of it certainly has
come from Little Lake Valley, but if there are piles of compost lying around
this is probably because these animals are in pens much of the time and being
fed hay and perhaps supplemented with grains. For example, one local goat dairy farmer had
me really interested in the sustainability of his operation when he told me
they grow all their own hay. Then he let
the other shoe drop-they import about 100 lbs of grain per day and admit they
don't have the acreage to grow it themselves.

That goat poop is therefore full of imported fertility.

When we think about local, sustainable agriculture, we have
to start working through all our inputs, and many of the inputs to our inputs,
and not assume that one bit of organic matter is as good as another. The embedded energy of the giant manure piles
in Little Lake Valley don't represent the bounty of local fields alone, and if
we want to establish sustainable food systems we need to work towards living
within our local carrying capacity.

Some of the details of how to use local carrying capacity
are given for Brookside Farm (and we cheat a bit with accepting imported food
scraps), but we still don't have a grasp on what that might mean for our little
area, let alone the big blue planet.

Our site map and fertility plan is available for download.

Over the weekend a group of thinkers working with Post
Carbon Institute have been discussing the mineral content of rain. Often
when we discuss minerals and rain we are talking about the manner in which
minerals and inorganic nutrients are readily leached from the soil. Leaching is when minerals are not able to hold
in the soil and are thus washed out by the natural flow of groundwater. A soil’s
tendency to leach is influenced by the way that the soil is tilled, cropped,
and fertilized.

For instance, inorganic fertilizers provide crops with plant
available nutrients in the form of chemicals like nitrate (NO₃^-).
The problem is that nitrate readily washes out of the soil if the plants are
unable to utilize it before heavy rains. Many farmers are beginning to realize that
heavy fertilizer application in the fall amounts to a waste of money since a majority
of the nutrients are lost by spring due to sever washout by winter rains or
spring snow melt.

Leaching of minerals also occurs when soil is left bare to
face winter rains. In this case, leaching is accompanied by a loss in top soil
from the process of erosion. Imagine rain drops as tiny explosions on bare
soil, blasting minerals loose, collecting in water particles, and flowing away
as surface runoff.

Fortunately, farmers do not need to resign to the fact that
rains always mean a loss in minerals and nutrients. By cover-cropping and the
addition of compost, a farmer can protect the soil from direct rainfall and increase
the organic matter in the soil in the form of root biomass. Roots and organic matter
create a healthy habitat for soil microbes that play a key role in mineralizing
soil nutrients and forming soil aggregates that resist leaching.

One great benefit to having a diverse soil food web of
fungi, bacteria, and protozoa is because organic minerals are “sequestered” in
the biomass/bodies of microbes and recycled through in their metabolic
processes. Instead of washing out of the soil, the minerals actually become the
body of bacteria and fungi! In a series of food chain and energy exchanges the
minerals in the soil are converted from one form to the next; changing from plant
detritus to the body of a soil organism, then to metabolic wastes of that
organism and into plant available forms of, and then consumed and incorporated into
the body of another soil microbe. All these changes occur in and around in the
rhizosphere (root-zone) of plants, and demonstrate an interconnected web of
energy and nutrient cycling and nutrient retention.

Also consider the fact that bacteria and fungi create a natural
glue that sticks to everything. Through the production of “glomulin”, nutrients
are retained and soil aggregates are formed. As organic matter is decomposed, the
biology in the soil help to form stable negatively charged humic (humus)
molecules which bind together with positively charged cat ions, electrically holding
minerals and preventing them from leaching. Important cat ions retained in
colloidal humus particles include: calcium, iron, magnesium, potassium, sodium,
and copper.

As you can see, there is a lot happening below the
soil, and farmers and gardeners have an opportunity to utilize cover crops, compost,
soil biology, and appropriate timing of fertilization to prevent soil erosion
and leaching of nutrients.

Broadcasting a Cover Crop of Crimson Clover in October to Protect Bare Soil from Winter Rain

Recently Sown Cover Crop of Legumes mixed with Rye and Barley Provides Root Biomass and Use Boilogy to "Fix" Nitrogen from the air

There has been a cover crop at the Rogue River Energy Farm test site since late September. Since then it has shot up considerably and has produced excellent biomass and beautiful flowers for the bee hives located at the site. The soil has been slowly drying out during April as the temperatures have reached highs into the low 80’s. Since most of the soil seemed dry enough to work, it was a good time to turn the cover crop under in order to add the biomass to the soil. Turing the cover crop under will allow the biomass to decompose before the ¼ acre test site is planted in Peredovik Sunflowers later this May or in early June.

This Cover Crop Provides Excellent Bee Forage

The Cover Crop Has Grown Over 3.5 Feet Tall and Should Add Biomass To the 1/4 Acre

Using the 35 HP Diesel New Holland (Running on B-20) To Incorperate The Cover Crop

Cover Crop Mixed With the Soil

Each day this week, we worked to prepare approximately 2880 Sq Ft for spring grains and legumes. This process involved clearing away and removing rooted sod with the Thatch Rake, loosening the soil with the Glaser Wheel Hoe, and then sowing the grains and legumes with an Earthway Seeder. Since we currently lack the processing equipment for grains and legumes, we will use them as supplementary feed for the egg-laying chickens that are planned for the site. These cover crops will also provide the farm with an abundant supply of dry biomass to use as a compost feedstock. At present, we will provide initial watering for germination and allow these crops to grow dryland.

The varieties of grains and legumes that were sown include:

• Hard Red Spring Wheat (1204 Sq Ft)
• Green Brown Lentils (387 Sq Ft)
• Jet Barley (129 Sq Ft)
• AC Baton Oats (215 Sq Ft)
• Chickpeas (129 Sq Ft)
• Pacific Blue Stem Wheat (430 Sq Ft)
• French Green Lentil (258 Sq Ft)

The polyculture system at Brookside is an advantage because:

1) The diversity of crops avoids the susceptibility of monocultures to disease

2) The greater variety of crops provides habitat for more species, increasing local biodiversity

3) We get an idea of which grains may be best suited for the site

4) We can add a variety of materials to the compost and the different plants participate in a diversity of interactions with the soil

When you add the newly planted spring grains to the cover crop that was sown in November on the "compacted infield” there is over 7650 Sq Ft dedicated to the growth of biomass. The aim of these sections is to add some organic matter to our soil (already at 6% OM) and to convert the plant matter into compost. Since we have chosen an intensive method of mini-farming, it will be crucial to keep a portion of land in rotation that is dedicated to growing biomass crops for composting. Intensive mini-farming has the potential for high yields; nevertheless, without seasonal additions of compost it is possible to deplete the land of the micronutrients and vitality. Intentional compost feedstock is one methodology to try and confront a paradigm where compost inputs are "mined" from one piece of land and exported to another. At the Willits Energy Farm we aim to cycle nutrients in the form of compost and through maintaining a healthy soil food web. Although it may not always be possible to achieve 100% self-sufficiency, the intention is to keep the land as self-sufficient as possible in a majority of the micronutrients necessary to grow healthy food.

Using Thatch Rake to Clear Sod

Using Three-Wide Earthway Seeder to Drill Seeds

Approx. 2880 Sq Ft of Spring Grains and Legumes

November Sown Cover Crop on Infield (Approx. 4770 Sq Ft)

In 2005, the Local Energy Farm Demonstration Project, located at the University of British Columbia, experimented with the production of flax. The stalk of the flax plant can be used to create fine fibers for textile or it can be shredded and combined with recycled paper pulp or hemp to provide an alternative to wood-based paper products. Flax is also grown for its oil rich seed (linseed). The seed can be used for feeding livestock (35% crude protein) and for industrial use as a drying agent in ink, paint, and lacquer.

In brief research related to companion planting, and variety of web resources and books report that the growth of carrots, onions, and potatos are enhanced when they are planted next to stands of flax. Flax deters the potato bug, a nusicence of certain tuber crops. I am eager to test this later in the spring.

Other sources report that clover grows well with flax because it is not overly shaded by the thin flax plants. Sowing flax with clover could prove to be an effective way to grow a useful energy crop and improve the land at the same time. Once the flax is harvested you would then be able to incorporate the nitrogen rich clover into the surrounding soil and add organic matter at the same time. To get two crops out of one area, and potentially improve the land is an example of companion planting and good use of cover crops.

There are many symbiotic relationships in nature. Plants and herbs can be grown together to enhance growth, helpful predator insects are attracted by a specific flower to combat a specific crop pest, and even bacteria interact with special leguminous plants to transform nitrogen into a form that plants and animals can use. In this blog, I would like to focus on nitrogen fixation, a very special relationship between bacteria, plants, the soil, and the atmosphere.

In brief, nitrogen fixation is a process where inert N2 (nitrogen gas) is converted into usable ammonia (NH3). This form of nitrogen is important to plants and animals as it helps to manufacture amino acids, proteins, nucleic acids and other nitrogen-containing components necessary for life.

Nitrogen fixation by legumes is a partnership between a bacterium and a plant. The plant supplies all the necessary nutrients and energy for the bacteria. Examples of legume plants include Alfalfa, Fava Beans, Vetch, Peanuts, Soy Beans, and Clover. Other plants benefit from nitrogen-fixing bacteria when the bacteria die and release nitrogen to the environment or when the bacteria live in close association with the plant.

A common soil bacterium, Rhizobium, invades the root of a legume and multiplies within the root cells forming bump-like masses called nodules. Within these nodules, nitrogen fixation is done by the bacteria, and the NH3 (ammonia) produced is absorbed by the plant. A way to determine whether or not nitrogen fixation is occurring in a plant is to investigate the roots. When fixation occurs the nodules turn from white or gray to pink.

It is a common misconception that nitrogen fixing plants deliver nitrogen directly to the soil via their root systems. The following is from the W.C. Lindemann, a Soil Microbiologist from New Mexico State University:

The amount of nitrogen returned to the soil during or after a legume crop can be misleading. Almost all of the nitrogen fixed goes directly into the plant. Little leaks into the soil for a neighboring non-legume plant. However, nitrogen eventually returns to the soil for a neighboring plant when vegetation (roots, leaves, fruits) of the legume dies and decomposes. When the grain from a grain legume crop is harvested, little nitrogen is returned for the following crop. Most of the nitrogen fixed during the season is removed from the field. The stalks, leaves and roots of grain legumes, such as soybeans and beans contain about the same concentration of nitrogen as found in non-legume crop residue. In fact, the residue from a corn crop contains more nitrogen than the residue from a bean crop, simply because the corn crop has more residues. A perennial or forage legume crop only adds significant nitrogen for the following crop if the entire biomass (stems, leaves, roots) is incorporated into the soil. If forage is cut and removed from the field, most of the nitrogen fixed by the forage is removed. Roots and crowns add little soil nitrogen compared with the aboveground biomass.

Taking the implications of the above paragraph seriously, it is important to till in a legume cover crops in order to utilize the nitrogen fixed from the atmosphere. This process is similar to carbon sequestration process mentioned in the previous blog. When we incorporate plant matter back into the soil we feed the microbial life of the soil foodweb. These microbes mineralize nutrients in the soil, aid aggregation of soil particles, and help to form humus that improve overall health and vitality of the soil.

To read W.C. Lindemann’s paper and to learn more about nitrogen fixation check out the following links:

http://www.cahe.nmsu.edu/pubs/_a/a-129.pdf

http://overton.tamu.edu/clover/cool/nfix.htm

At the beginning of November, initial soil preparation began at the Brookside Farm. Soil tests were taken and the results indicated that the soil is teeming with microbial life and lacks nothing in regards to nutrients for the growth of healthy crops. The soil type we are working with is “Felix loam”. Because loam is evenly composed of sand, silt, and clay it has the duel advantage of being able to both hold water and drain when there are no significant water inputs. This loam compacts less than clay, while it containing more nutrients than sandy soils.

We are beginning with healthy soil and intend to maintain it through organic farming methods including cover cropping, crop rotation, and compost teas. Furthermore, the aim is to back away from machine powered soil cultivation and harvest methods which have the disadvantage of soil compaction and large monetary investment in a non-sustainable method of farming.

The acre at Brookside Elementary was an unused baseball field. The infield was markedly more compacted than the sod-covered outfield. Initially, there were doubts that the cover crops would be able to make a dent in the compacted soil that had been turned over only about 2.5 inches. These doubts have been put to rest as the winter rye and barley are beginning to make headed way. Clover and fava were also seeded and they too are beginning to spout. The overturned outfield is already showing significant clover growth.

If you want more information about the soil at the Willits Energy Farm, check out the Brookside Soil Report.

Winter Rye Cover Crop

Barley Cover Crop Growing in Overturned Sod

Crops Sprouting in Overturned Sod and Compacted Infield