Lecture

1. Principles of Permanent Agriculture
By Jeff Poppen
I have really good news. We know how to grow food and we know how to do it without hurting
the land, air, or water, in a way that is good for us, too. It’s simple and easy, but we need four
things: some kind of ashes, some kind of legume, some kind of cattle, and some way to loosen
the soil. Also, we can’t be too greedy.
The abundance of the earth is made possible by just a few elements, and the primary ones are
free. Carbon, hydrogen, oxygen and nitrogen are everywhere, in air and rain. Our farm has
been exporting 100,000 pounds of produce annually for 25 years with no irrigation, fertilizers, or
other agricultural inputs. This produce has been mostly these four elements in the form of
carbohydrates, sugars, starches and proteins.
Farming is a scam! Most of what I sell is simply transformed air and water. It only works
because at least 95% of the farm’s annual growth stays on the farm. Only a small percentage
leaves. We do this by incorporating forests and wetlands, grass and clover, cover crops,
composting, intensive grazing, crop rotation, and re-mineralizing, which are all tried and true
methods of sustainable agriculture.
Here are a few quotes that touch on the importance of ashes for minerals, of growing legume
cover crops in the rotations, utilizing cattle and their manure, and thorough cultivation and
plowing.
“The use of ash is viewed so favorably by farmers, that they actually prefer it to the manure
furnished by their cattle”.
“A field is not sown entirely for the crop which is to be obtained the same year, but partly for the
effect to be produced in the following [year]; because there are many plants which, when cut
down and left on the land, improve the soil.”
“Some of the leguminous plants manure the soil, and make it fruitful, while other crops exhaust
it and make it barren. Lupines, beans, peas, lentils and vetches are reported to manure the
land.”
“A soil to be fertile must, above all things, be light and friable, and this condition we seek to bring
about by the operation of plowing.”
“Wherein does a good system of good agriculture consist? In the first place, in thorough
plowing; in second place, in thorough plowing; and, in the third place, in manuring.”
The reason why ash is so important is because it contains the other mineral elements
necessary for plant growth; calcium, silica, potassium, magnesium, phosphorous, and the trace
elements. Slash and burn agriculture worked because of the release of these minerals through
combustion. We also get minerals by mining from limestone or phosphate mines. Many pounds
of minerals are in the soil and subsoil, but are locked up and unavailable for plants.
The reason we grow legumes is to bring nitrogen into the soil. They do this through a symbiotic
relationship with a specific bacteria. With 70 million pounds of nitrogen in the air above every
acre of land, farmers traditionally plant legumes so their next crop can have nitrogen. Nitrogen
in the soil can be the major limiting factor in crop production, but not if the crop rotation includes
legumes.
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2. Principles of Permanent Agriculture
By Jeff Poppen
All farms need cattle, cattle meaning ruminants of some kind. You’ll notice that the rise of
civilizations are always connected to the domestication of livestock. They go hand in hand. We
either wander nomadically, following large herds of herbivores, or we tame them and settle
down.
Something magical happens in a cow’s belly. The grass that goes in does not come out until 18
days later, and it is totally transformed. The manure is not only the perfect plant food, it has the
ability to fertilize more soil than is needed to grow what the cow lives on. A full grown cow needs
two acres of pasture, but can potentially make four acres fertile. The flora and fauna
engendered in the ruminant’s digestive system, when incorporated into the soil, helps to make
the unavailable minerals available.
Holy cow! The cow is sacred in many cultures where the practice of vegetarianism attests to the
necessity of keeping livestock. The wise men in these countries knew that if a famine came and
the people ate all of the cattle, their civilization would disappear. So they forbid the eating of
meat, and because they still have cattle, their civilization is still here.
When we look at the great soils of the world, we can see these three principles of permanent
agriculture in practice. The prairies have the grasses and clovers that together structure the soil
and incorporate nitrogen. The grass roots finely divide the soil particles, and they decay after
the tops are grazed. The mobs of bison on small acreages of the great plains for short periods
of time ate a small percentage of the growth and tromped the majority of the carbon back into
the soil. The heavy animal impact included manure, urine and tillage from their split hooves.
Afterwards, the land rested with no animals, and grew back up. Over years, this built up a
phenomenal soil humus.
This same thing happened in Northern Europe with wolves chasing reindeer, or in the Savannah
of Africa, with lions chasing water buffalo. Everywhere you find great soils in nature, you’ll find
mobs of grazing herbivores moved by predators. This is how humans will reverse climate
change- by sequestering carbon with the use of grass, legumes and large herds of herbivores
on small acreages for short periods of time.
Glaciers are another great factor in building soils, by the grinding up of rocks. It took me a long
time to learn how to grow stuff, because I grew up in the beautiful black soils of Illinois, where a
glacier had been just 15,000 years ago. It has been a million years since a glacier went through
Tennessee, and our soils need minerals. I learned that rock phosphate and lime really help on
our farm.
Periodic flooding of the Nile brought glacial minerals to the fields of Egypt. Volcanoes blow out
ash and minerals, but although handy for plants eventually, I’m glad we don’t have one. By
burning bones or limestone rocks and spreading the ash, we can add these minerals in a more
available form.
By the way, do you know when those quotes came from? They are taken from writings from
2,000 years ago by Pliny the Elder, Varro, Columella, Virgil and Cato. Even in the Bible, in
Deuteronomy, we are advised to eat only the animals that are ruminants, so these would be the
species on our farms. We’ve known how to grow food and eat it for a long time.
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3. Principles of Permanent Agriculture
By Jeff Poppen
The fourth principle, plowing, is not so natural. I find the term “natural farming”, a bit misleading.
Agriculture is anything but natural. Nature grows stuff really well, and we do best to mimic her
systems. But to grow a bunch of food, we need thorough plowing and cultivation, a distinctly
human activity that can be either beneficial or detrimental.
If you take a book and fold it, the leaves all slip a bit from each other. When we plow, this same
action of layers of soil slipping incorporates air. Microbes propagate when air is added, and they
can make the unavailable minerals available to the plants. Here is how that works.
The biology in the soil is enhanced by composting manures with crop residues and soil. As a
plant grows into a humus soil, bacteria and fungi colonize the roots and live off of root exudates.
This is the stuff that sloughs off of the root as it penetrates the soil. There are more than
100,000 species of these microbes, and each species works with a specific plant species. There
can be a million bacteria in a spoonful of soil, or 1,000 times that many, which is why we make
compost.
A bacteria can have babies in three seconds, be a grandma in six seconds, and have a lot of
great grandkids running around in 9 seconds. We have seen huge microbial activities happen in
our soils literally over night. It is simply amazing.
There’s no hard and fast line between where the root ends and the soil begins, because the
fungal hyphae (fungus roots) stretch out through the soil. These microbes are experts at getting
minerals loosened from the unavailable state. Since they have a vested interest in healthy plant
growth, their food source, they pick up on signals the plant gives for nutrient requirements. A
hydrogen ion is swapped for a cation nutrient, and off it goes, up into the plant.
Farming with nature’s intelligence is so easy. The microbes do all of the work, we just have to let
them. A stable clay-humus complex forms a microbial connection underground that boggles the
imagination. There exists a single fungi as big as the state of Rhode Island. Dye put in a tree
shows up on the opposite end of a forest by the end of the day. Everything in nature is
interconnected.
A larger transport system moves these liberated nutrients around. Protozoa, nematodes,
earthworms, bugs, reptiles, birds and mammals all contribute to the distribution of necessary
plant foods. It is arrogant for humans to think we have to “feed” plants. Nature does a great job,
but we have to somehow loosen the soil.
We use the mold board plow, but only on sod in the fall. The winter freezing and thawing of the
exposed soil thoroughly pulverizes it in a better way than any tool can. The chisel plow is our
primary tillage implement, it tills but does not invert the soil. A spike-tooth harrow levels the
fields, and is used to conserve soil moisture.
Tilling has a bad reputation these days, because it destroys soil microbes and can cause
erosion. But guess what? Microbes that die become plant food and then more microbes grow.
The trick is to be gentle and wise in the use of tillage, and to always work along the contours.
An exciting system we do is called “keyline plowing”. With a transit, we find the contours along
our hillsides. Every other shoe is removed from the chisel plow so that only four remain, two feet
apart. It is put in four inches deep, and pulled along the contours. I go deeper the next year, as
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4. Principles of Permanent Agriculture
By Jeff Poppen
the top soil increases. After a rain, the furrows stay muddy for days. Water that would have left
the farm stays and soaks in, and the farm will use that extra moisture next summer.
The principles of agriculture are summer up in this quote from the USDA’s experimental station
at the University of Illinois, 1910:
“To maintain adequate amounts of phosphorus and calcium in the soil makes possible the
growth of clover and other legumes and the consequent addition of nitrogen from the
inexhaustible supply in the air; and, with the addition of decaying organic matter in the residues
of these crops along with the wastes from livestock fed on these pastures and hay fields, comes
the possibility of liberating from the immense supplies in the soil sufficient potassium,
magnesium and other essential elements for the production of large crops at least for thousands
of years”.
In other words we need the 4 kingdoms of nature:
1. Minerals of the earth, supplying nutrients to
2. Legumes and other plants, which feed
3. Cattle and other animals, whose wastes are
4. Tilled in by humans for crop production
All we have to do is to restore the elements cattle keep in their bones, calcium and
phosphorous, and be wise in the use of crop rotations, grazing, and tillage. Now I’d like to end
with some quotes from the Agriculture for Southern Schools, Tennessee Edition 1908, along
with experiences I have using these principles.
“The difference between a rich soil and a poor soil consists largely in the fact that a rich soil is
usually able to maintain enough moisture, but not too much; while the unproductive soil does
not hold enough water for the use of the plant during dry weather, and becomes too completely
saturated during wet weather.”
“The farmers part in preparing the ground and cultivating the soil consists of chiefly controlling
the movement of capillary moisture. The farmer first loosens the soil, then permits the lower
layers to become settled, and later, after the crop begins to grow, stirs the surface. The surface
layer is stirred in order to make large air spaces that will prevent moisture a little deeper down
from coming to the surface and being evaporated and carried off by the wind.”
I’m always thinking about water. So much of Tennessee’s farmland is hard and packed, it just
doesn’t absorb water. The impervious clay stays too wet, and then dries out rock hard. It needs
plowing, settling and stirring. Tennessee gets plenty of rain, the trick is to conserve it for later.
This is why we plow along contours and cultivate to create a “dirt mulch” on the surface, which
checks evaporation. In backyard gardening, we often add mulch. We never irrigate, it is simply
not necessary when you get 40-50 inches of rain each year.
“The surest and cheapest way for the farmer to enrich their land, and to make large profits in
farming, is by constantly adding vegetable matter.”
Compost, compost, compost. We have to continually re-enliven the soil that we disturb when we
crop it. The farm is full of new organic matter every year, with plenty to go around, as long as we
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5. Principles of Permanent Agriculture
By Jeff Poppen
feed most of it to our animals and microbes and don’t export more than sustainable agriculture
allows.
“Enough livestock ought to be kept on all farms to consume legumes that are grown. The little
fertilizer factories on the roots of leguminous plants are worth more than all the gold in the whole
world”.
Isn’t that beautiful? I emphasize the word “all”. The value of soil microbes is truly the real wealth
of the world, and it is through the ruminants digestive system and legumes that they proliferate.
For gardeners, here is some good advice from this text book, which was written for 7th graders:
“To make a garden productive treat it as follows:
1. Manure it heavily, using 20-40 wagon-loads of compost or manure per acre each year.
2. Keep every part of it busy, growing 2 or 3 crops per year on the same rows.
3. Plant such vegetables that will furnish something for the table every week of the year.
4. Plow the garden deep in the late fall or early winter, and keep it so clear, that a crop of rank
weeds will not need to be plowed under. “
Liberal use of composted manure annually has made our gardening easy. High sugar in the
plants means no leaf-eating bugs, plenty of microbes in the soil keeping the plants fed, and
organic matter creating loose and fluffy soil.
We like to keep our rows busy because we have a lot invested, and farming has got to make
financial sense. So we are always following crop after crop, rotating as necessary, and sowing
cover crops if we don’t need more vegetables.
Despite my altruistic rhetoric, I grow food for one main reason. We get hungry. Not only should
the livestock be fed from within the farm, so should the farmers.
Deep plowing in the fall allows the winter’s rain to soak into the subsoil. This moisture becomes
available through capillary action next summer. As the roots of the crop use up water, the damp
subsoil yields its moisture to the drier soil around the plants. Surface tillage prevents it from
evaporating into the air.
In summary, I’d like to say that the most important aspect of farming is people. That’s what we
do it for, and that’s who does it. Farms stimulate the economy when they are locally based.
Farms conserve and protect the rural landscape when they are locally owned and operated.
Farms build communities and offer places to take walks and enjoy nature. Farms teach moral
ethics and practical skills. Healthy farms sequester carbon and positively affect climate
problems. And, farms are also a good place to get food.
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