Precious Percolation
Water is one of the many challenges presented
to us as farmers. We kicked off this season with many days of rain in a row,
while the past couple of weeks have been relatively dry. We need dry weather to
work the ground, but the plants in the field need water all the time to grow
and produce. So how do sporadic rain events nourish our (your) crops, and how
does the water get to them? What if it doesn’t?
Soil moisture can be lost in several ways:
·
By draining
out of the root zone
·
By getting
pulled up and out of the soil through capillary action and the chimney effect.
The combination of sun and wind will pull moisture from the topsoil in dramatic
fashion.
·
By
transpiration. Water moves from the roots up through the plant and out the
leaves as the plant grows. This is a combination of translocation of water and
respiration of the plant. Transpiration rates are higher in hot weather as the
plants attempt to stay cool. Some fruits may taste sweeter in dry weather since
there is less water available to fill the fruit.
We spend a lot of time talking about soil
because it's related to everything we do here, including how water gets to the
plants. The soil particles and the amount of organic matter among those
particles are responsible for delivering water to the crops well after the
rain.
When we get a good soaking rain, some of the
water percolates down into the soil through the worm holes and ant trails, but
most of it travels in the tiny channels and collection of cavities between the
soil particles. If you have ever had a septic field installed, a trained
technician will perform a “perk” test, to see how fast a given soil will drain
away water. Every square foot of soil in Kentucky has been classified and
mapped as to its capability to drain or hold water, along with dozens of other
attributes considered in farming or construction.
It is helpful to have the water drain away from
the surface of the soil so the roots can also have access to air. Too much
heavy clay in the soil (which you read about in last week's “Soil is the Soul”
newsletter article), and the water will “perch” on the surface, asphyxiating
roots. But you also want the soil to hold water for the plants waiting for the
next rain. The soil organic matter (OM) content has a direct correlation to the
water-holding capacity of a soil, as the OM acts like a sponge and breaks up
the tight clay areas. Here at Elmwood Stock Farm, we are running between 3 and
4 percent OM. Research has shown that each percentage point of OM will hold
20,000 gallons of water. For reference, 1 inch of rain over an entire acre
(43,560 square feet) is 27,154 gallons of water. With our organic cropping
systems, we are incrementally building soil by increasing the OM content, thus
buffering the impact of short-term dry spells.
To conserve precious rain water, we mulch some
crops with hay or straw. In other places, we plant
living mulches—such as rye grass and white clover—between rows to keep the sun off the soil. These plants grow slowly, do
not compete with the vegetables growing within in the rows and do not use much
water themselves. We also use thin strips of plastic mulch sheeting to hold
moisture in the soil and keep the weeds from growing along the base of the
plant rows.
Since
we often have dry spells in Kentucky, at Elmwood Stock Farm, we employ
mechanical irrigation techniques to ensure the soil, and then the crop, has
access to water to produce the food we all love to eat. The southern border of
the farm is Elkhorn Creek, at a location above an historic mill dam, which
forms a deep pool of water that we can draw from. With electric or
tractor-driven pumps, we send water through a series of underground and above-ground
pipes to the edge of each field. From there, we have two options: t-tape or
traveler. T-tape, or drip tape, is a flat, hollow, plastic tape that comes on a
4,000-foot roll. We lay it under the plastic mulch when the plastic is put
down, or we walk it out by hand along the plant row. It has little holes that
allow a single drop of water to drip out every 12 inches over a long period of
time. This is a very efficient means of providing water directly to the crop's
root zone. (Home-garden kits are available, too.) The traveler is a big-gun
sprinkler attached to a large reel. The sprinkler gun is parked at the end of a
field. As the pump pushes water out the sprinkler, which covers a 90’ diameter,
the water pressure turns a crank that slowly winds the
hose around the reel, thus moving the gun the length of the field. This puts
out a lot of water over the entire field in a fairly short amount of time.
So mulching and living mulches are the basis of
our moisture-management plan, but we have irrigation options in place so we
leave nothing to chance to ensure a good crop will be harvested.
We had to delay planting some crops this spring
because of all the rainy weather, but from here on out, nothing beats a good
soaking rain. —Mac Stone
In Your Share:
Broccoli
Napa Cabbage
Carrots
Red Russian Kale
Lettuce
Onions
Spinach
Recipes
Broccoli
with Caramelized Onions and Pine Nuts,
adapted from EatingWell
3 T. pine nuts or chopped
slivered almonds
2 tsp. extra-virgin olive oil
1 c. chopped onion
1/4 tsp. salt, or to taste
4 c. broccoli florets
2 tsp. balsamic vinegar
freshly ground pepper
Toast pine nuts (or almonds) in a medium,
dry skillet over medium-low heat, stirring constantly, until lightly browned
and fragrant, 2 to 3 minutes. Transfer to a small bowl to cool.
Add oil to the pan and heat over medium
heat. Add onion and salt; cook, stirring occasionally, adjusting heat as
necessary, until soft and golden brown, 15 to 20 minutes.
Meanwhile, steam broccoli until just
tender, 4 to 6 minutes. Transfer to a large bowl. Add the nuts, onion, vinegar
and pepper; toss to coat. Serve immediately.
Carrots,
Greens and Lentils,
adapted from Summer Tomato
This recipe originally calls
for collard greens, but it is equally delicious with kale or Swiss chard.
olive oil
1 small leek, thinly sliced
4-5 medium carrots, sliced
4-5 fresh greens leaves,
chopped (stalks removed)
sea salt
1 clove garlic or garlic
scape, finely chopped
1/2 cup green lentils, cooked
lemon juice
chopped fresh herbs
Heat a pan over medium heat, then add
olive oil. When the oil swirls easily in the pan, add leeks and cook 1-2
minutes, until tender and translucent. Add carrots and stir. Cook 2 minutes,
then add collards. Sprinkle with sea salt and continue to cook, stirring
occasionally.
When the collards turn bright green from
cooking (4-5 minutes), clear space in the center of the pan and add garlic. Add
a touch more oil, if necessary. Let garlic cook 30 seconds or so until
fragrant, then add lentils and mix.
Give a squeeze of lemon juice and a
sprinkle of your favorite herb. Cook 3-4 minutes, stirring every 30 seconds.
Adjust salt and serve. Serve over a grain as a main dish or on its own as a
side.
Roasted
Broccoli and Grilled Cheese Melt,
adapted from Bountiful
1 medium head broccoli,
florets chopped small
2 T. olive oil
1/2 tsp. salt
1/4 tsp. pepper
unsalted butter, softened
8 slices crusty, artisan bread
1 c. shredded cheddar or other
cheese good for melting
Preheat oven to 400°F. On a sheet pan, mix
broccoli, oil, salt and pepper. Roast 8 to 10 minutes, until broccoli is
roasted by not burnt. Remove from oven and allow to cool.
Butter one side of each slice of bread. On
the unbuttered side of four slices, layer an equal amount of cheese, broccoli,
and more cheese. Top with the remaining four slices of bread, buttered side
out.
Grill in skillet over medium heat until
cheese melts, flipping once so bread is evenly toasted. Serve with a green
salad.
Roasted
Napa Cabbage,
adapted from Food.com
6 T. olive oil
2 garlic cloves, crushed or
equivalent garlic scapes
6 c. Napa cabbage, roughly
shredded
salt & pepper
Preheat oven to 450° F. Heat
oil in a skillet on low; add garlic and cook very gently for 15 minutes.
Discard garlic and toss the cabbage with the oil, salt and pepper.
Place cabbage on a baking
sheet and bake for about 15 minutes or until the tops of the cabbage pieces are
browned. Serve hot.
