| Posted
April 20, 2004: “There are lots of casinos
up and down the river,” observed Estevan Arrellanos
of the Rio Grande during his heirloom fruit tree workshop
at the recent New Mexico Organic Farming & Gardening Expo
2004.
“But I think the biggest gamblers are the farmers.
We buy seed, but we don’t know if it is going to rain!”
Rain or shine, it was a safe bet that love of farming and
good food would attract 500 people to Albuquerque, New Mexico,
on Valentine’s Day weekend for the sixteenth annual
Expo. Attendees from the Land of Enchantment and the surrounding
region, especially Colorado, Arizona, the Navajo Nation, and
Texas, had twenty-two workshops from which to choose.
From building soil to building markets to water conservation
in the desert, Expo 2004 had no shortage of learning opportunities.
Below we look closely at three: The Farm as Natural Habitat;
Organic Sustainable Greenhouse Design and Production; and
Choosing Appropriate Equipment for Vegetable Production Systems.
Organic sustainable greenhouse design and
production
Greenhouse growers who made the Friday morning session enjoyed
a thorough presentation by Paul Cross of Charybda, a certified
organic nursery that produces tomatoes, basil, and a full
line of bedding plants in Arroyo Hondo, New Mexico. Cross
frequently tailored his advice for desert Southwest growers,
who get more annual sunlight than growers anywhere else in
the continental U.S. With this in mind, Cross quipped that
Southwestern growers need to pay attention to where their
greenhouse experts come from.
“If you follow Eliot Coleman’s Four-Season Harvest
in New Mexico, you’re gonna end up with fried compost
on the floor.”
For example, while most areas of the country use an east-west
axis for siting conventional greenhouses, Cross urges a north-south
orientation in New Mexico, where there is plenty of solar
gain. A north-south axis gives row crops even light on both
sides, minimizes the problem of fixed shadows, and minimizes
the amount of frozen snow trapped on the north side, where
it blocks ambient light instead of melting into water catchment
systems.
Another siting objective is to orient one narrow end of the
greenhouse to catch the wind and pull it through to minimize
stress on the structure. Asked what to do about the axis orientation
when prevailing winds are from the west, Cross said stick
with a north-south axis and plant windbreak hedgerows to send
wind up and over the greenhouse.
“The biggest mistake people in New Mexico make is wondering,
how am I going to heat this?” said Cross. “You
should be thinking, how am I going to cool this?”
To reduce heat in the summer, Cross says paint everything
you can white. Aluminum structures reflect only 60% of sunlight,
which means the remaining 40% becomes heat. White paint is
80% reflective. Southwestern greenhouses also should be covered
50-70% with shade cloth—Cross recommends Aluminet—from
the time temperatures climb in May until October or November.
Farmers trying to extend growing hours anywhere with supplemental
light can use Cross’s advice to turn lights on before
dawn, stretching hours in the morning instead of the evening.
Turning lights on at sundown does not work well because plants
are already going to sleep by then, and shutting lights off
at night confuses beneficial insects such as bees, who cannot
find their way home in sudden darkness.
Water conservation, another topic of particular concern in
the southwest, is a good practice for any sustainable farmer.
“You want your water slightly on the acidic side, about
6.8 pH, and there’s no better water than the rain running
off the roof. It’s rich in nitrogen and carbonic acid,”
Cross said.
For water catchment, Cross recommends using gutters on the
greenhouse and UV-stabilized pond liners on the ground next
to the greenhouse with small channels leading to cisterns.
The pond liners serve double-duty as weed blockers, eliminating
pest habitats the recommended fifteen to thirty feet from
the greenhouse.
For water storage, Cross suggested tanks buried partially
inside the greenhouse—three feet below ground, two feet
above ground. Designed this way, the tanks serve the permaculture
principle of stacking by storing water (which ideally should
be 65-80° F. for watering), providing thermal gain in
the winter, and offering a level surface on which to work
with seedling flats.
Growers who want to install a pond might find pond liners
expensive, so Cross gave instructions for a poor man’s
pond: dig a hole, line it with carpet remnants, cover that
with builder’s plastic, lay another remnant upside down,
and cover with stone. Southwestern growers just need to remember
that ponds can evaporate thirty-three inches annually, while
New Mexico gets only twelve. And ponds need to be fenced for
safety.
While too much heat is a problem in southwest summers, heat
supplementation is necessary for winter germination and growing.
If looking at a manufactured heater, Cross said to de-rate
the heater 4% for every 1,000 feet of altitude.
With natural gas prices projected to double in the next four
years, however, Cross suggested supplementing with alternative
heat sources. Barrels of water stacked one foot off the ground
can provide thermal mass, preferably on the north side of
the greenhouse, and compost piles inside are great heat sources.
Cross also suggested using a fan in an intake box to blow
warm daytime air through perforated drain pipe snaked beneath
greenhouse soils.
After covering greenhouse design, Cross turned to production
tips. For nursery production, consumers have come to expect
short, stocky plants, which industry growers achieve with
chemical growth regulators. As an organic grower, Cross built
a giant rolling pin made of a center spindle with a plastic
pipe around it. Holding the spindle with a partner, Cross
brushes the top of his plant canopies with the pin, simulating
the action of wind outside to reduce internodal length on
the plants.
For seeding, Cross preferred a manufactured plastic handheld
seeder until he lost it and fashioned a replacement out of
clay. Unlike the manufactured seeder, Cross’s has a
lip that allows him to pour seeds back into storage easily
when seeding is done.
Finally, Cross shared his twenty-first century technology
for monitoring pests: yellow plastic plates, sprayed with
cooking oil and suspended six inches above the plant canopy,
one for every 500 square feet of growing space. Beneficial
insects tend not to be attracted to the yellow plates; some
growers use light blue plates to monitor thrips. Cross checks
the plates one a week to see what he has, then washes them
in soap and water.
Choosing appropriate equipment for vegetable
production systems
“Choosing and using the right farm or garden tools
can mean the difference between a happy, healthy, prosperous
growing season and one full of stress and disappointment,”
says organic grower Michael Alexander. “Or worse yet,
the difference between continuing to farm or giving up.”
Alexander reprised his equipment workshop for vegetable and
fruit growers at Expo 2004. Attendees received a thorough
handout covering everything from tractor types to bat houses
to equipment sources and enjoyed a slideshow featuring Alexander’s
equipment on his farm.
Inside the greenhouse, Alexander has a number of recommendations
for optimum production. For seeding, he uses the Seed E-Z
vacuum seeder, which uses a vacuum to hold seeds onto indentions
in an aluminum plate that is inverted for dropping the seeds
into flats. The vacuum seeder has cut Michael and wife Sharlene
Grunerud’s planting time “to a fraction of what
it was.”
Their potting mix is 1/4 vermiculite, 1/4 sand, 1/4 of their
finest compost, and 1/4 Coco Grow, an environmentally friendly
peat moss substitute that reduces harmful dust and is easier
to re-wet when dry. For watering seedlings, Alexander has
settled on the Red Head water breaker, which “produces
a very soft flow with high volume for quick, safe watering.”
To reduce temperature in the greenhouse, Alexander recommends
building a “wet wall” on one end. Connected to
a thermostat and made of a tube that dribbles water down through
stacks of six-inch pads of corrugated cardboard, the wet wall
acts like a giant evaporative cooler when fans at the opposite
end of the greenhouse pull the moisture through the structure.
Place greenhouse thermostatic controls at the center near
the plant canopy rather than on an outside wall, as Alexander
mistakenly did with his first greenhouse.
For organic growers of nursery plants who are not forcing
flowers, Alexander suggests compiling a photographic catalog
so customers can see what the flowers will look like.
Taking attendees out to the fields with his slideshow, Alexander
shared advice for irrigation, cultivation, and clearing. Southwestern
growers using flood irrigation should consider leveling their
land using laser technology, says Alexander. Leveling eliminates
soaked beds that prevent seedling emergence and dry beds that
prevent germination.
“Now that we’ve laser leveled,” said Alexander,
“we sow squash down the center of a 36-inch bed, water
in the furrows, and the seeds germinate.”
Alexander’s handout warns, however, that leveling more
than an inch or two is hard on the soil, so be prepared to
restore fertility with green manures and amendments.
For cultivation, Alexander’s favorite tractor attachment
is the rotary cultivator, or Lilliston Rolling Cultivator.
Rotary spikes on the cultivator slice and twist through the
soil to uproot small weeds, cut larger ones, and break soil
crust. The spikes are followed by a sweep that cuts missed
weeds and cleans furrows for irrigation. Supplement with hand
cultivation using a stirrup hoe. When kept razor sharp, it
glides lightly and quickly under the soil surface to uproot
small weed seedlings.
To save back labor when cleaning rocks from furrows, Alexander
bent the ends of a garden rake upwards, shaping the rake to
fit into the furrows without harming the beds.
Alexander finished his presentation with advice for wildlife
enhancement. Bat houses provide a habitat for controlling
pests, especially coddling moths in orchards. Bat Conservation
International has great information at www.batcon.org,
said Alexander.
After noticing that birds disappear from his fields when
he removes the tomato stakes, Alexander installed permanent
perches to encourage insect control. According to Alexander’s
handout, drilling 5/16-inch holes six inches into the ends
of 2x4’s or 4x4’s and hanging them around the
farm provides habitat for Orchard Mason bees. Finally, when
using his rotary mower on the farm, Alexander mows slowly
and raises the blade as high as practical to minimize harm
to snakes, which are important for rodent control.
The farm as natural habitat
Keynote presenter Dr. Laura Jackson, editor (with mother
Dana Jackson) of The
Farm as Natural Habitat: Reconnecting Food Systems with Ecosystems,
held two workshops structured around the theme of her book.
(For a review of her book, click
here.) An ecologist and Associate Professor of Biology
at the University of Northern Iowa, Dr. Jackson led attendees
at both workshops through an exercise for mapping natural
habitats on their farms and marketing those habitats to customers.
Jackson began by sharing her ecological perspective on the
importance of organic farming. First on her list was not the
elimination of chemical residues on food (which she said concerns
her more as a mother), but a broader issue: the management
of ecosystem processes. Examples included biological diversity,
tight nutrient cycling, efficient decomposition processes,
intact food chains, natural animal health, and water migration.
“Because you rely on ecosystems,” Jackson told
the farmers, “you preserve and protect them.”
Jackson also sees organic farming as important because ecologists
do not, or at least should not, look at things in isolation.
“While it seems like we are less attentive to landscape
processes as a modern industrial society,” said Jackson,
“we’re actually just as dependent on the water,
soil, and climate for our food as we always have been.”
For example, climate scientists did research in Florida in
the aftermath of severe freezes in 1997, which destroyed $300
billion of vegetable and fruit crops. They calculated whether
the freezes would have been as bad if Florida’s wetlands
had not been drained, which eliminated thermal mass and heat
trapping humidity. The scientists found that with intact wetlands,
many areas would not have frozen at all, and some would have
frozen for shorter periods of time.
The third reason Dr. Jackson cares about organic agriculture
is survival of the earth’s organisms.
“I’m a human, I’ve got children, I care
about people,” said Dr. Jackson. “But, humans
currently appropriate one-half of the plant biomass produced
on the terrestrial part of the earth. The rate of species
extinction is between 100 to 1000 times faster than it was
in pre-colonial times, and U.S. agriculture is a leading cause
of plant and animal endangerment, second only to urban expansion.”
To help organic farmers explore and articulate the way in
which organic farms preserve natural habitats, Dr. Jackson
led workshop attendees through a small-group exercise.
Using graph paper and colored pens, attendees began by mapping
the natural features on their farms, those features important
to birds, wildlife, wild plants, and people. Then they mapped
farm inflows and outflows, including water, soil builders,
seeds, feeds, insects, wildlife, pollen, nectar, petroleum,
weeds, and knowledge. Finally, the small groups were to explore
how to communicate the habitat benefits of organic farming
to customers, perhaps convincing them to pay a premium for
food that serves ecological systems. (Unfortunately, the workshop
ran short of time for this exercise.)
“Here’s the thesis of the book my mother and
I edited together,” said Dr. Jackson. “For a large
number of environmentalists and consumers, farms are ecological
sacrifice areas where we have written off the possibility
of nature. Farms are just for production.”
“Farms aren’t natural,” interjected
a participant.
“That’s the way a lot of people think,”
urged Jackson, “and I think there’s a lot of room
in the middle that’s good for society, that’s
good for just general quality of life, that’s maybe
good for the way the farm works.” 
|
