Combined chapters: The hope in healthy soil


Every day, we’re learning more about our
living and life-giving soil – and how dependent we are upon it. In the past, little thought was given to the
vast kingdom of microbes below ground. However, we now realize without healthy life below
ground, there’d be little life above it. Not so long ago, it was thought that the best
hope for our soil was to slow its loss—by using conservation practices to reduce wind
and water erosion. But farmers and scientists have discovered
that we can actually build better functioning, higher performing AND more productive soils. In fact, healthy soils, rich in organic matter
and microbial life, may well be the key to feeding the world’s growing population—sustainably—well
into the future. And by farming in ways that protect and enhance
soil microbes and improve soil health, farmers and ranchers are breathing new life into our
soils. This video series will show you how they’re
doing it and what that means for all of us. There is an amazing, hidden, living kingdom
beneath our feet. In fact, millions of species and billions
upon billions of organisms—bacteria, algae, microscopic insects, earthworms, beetles,
nematodes, ants, mites, fungi and more reside in the soil. This life represents the greatest
concentration of biomass anywhere on the planet. While scientists work to more fully understand
this complex and elegant ecosystem, many producers already know that when they farm in ways that
protect and enhance the soil’s microbial communities – good things happen. They understand that microbes build better
soils, and help make farms more profitable and resilient to weather extremes. Plus, producers
who farm with soil-building practices use less energy, improve water quality and create
better wildlife habitat. These soil health farmers…
• (Do not disturb) Disturb the soil as little as possible;
• (Keep it covered) Keep the soil covered with plants or plant residues;
• (Tap into roots) Keep living roots in the soil as much of the year as possible;
and • (Mix it up) Use diverse species. There are four primary conservation activities
that enable farmers to achieve these principles on their farms —planting without tilling,
growing cover crops, rotating diverse crops, and grazing diverse plants. When used in systems over time, the benefits
of these soil health practices can be substantial—both on- and off-the-farm. Which is good for the
farm, the farmer and all of us. Do not disturb: No-till farming
So how exactly do these farmers plant without plowing? Most use “no-till” planters,
which are designed to slice through plant residues from previous harvests, while minimizing
soil disturbance as they plant the seeds for their crops. Here’s how it works…
Pulled by a tractor, a no-till planter uses thin rotating disks to make a narrow slice
through plant residue and into the soil. Next, a tube places the seed at an appropriate depth
in the soil while a second wheel gently presses or “firms” the seed into the soil to ensure
proper seed-to-soil contact. Once the seed is placed, and covered, “presto,” we’re
ready to grow—with very little disturbance to the soil or to the organisms that reside
there! And here are some of the other benefits of
no-till… • Farmers reduce labor, fuel, and machinery
costs and they also improve how well soils function.
• Fewer tillage passes prevent compaction and surface crusting of soil, making it easier
for plants to sprout and grow deep roots. • No-till farming reduces erosion by leaving
plant residue on the soil surface, which protects the soil from the damaging impacts of rain
drops and the wind. • Since there is no plowing with no-till,
much less airborne dust is created—which helps everyone breathe easier.
• Crop residue left on the soil surface from no-till also limits evaporation, conserving
water for plant growth. • That crop residue is also a source of
carbon, the essential energy source for living organisms that make up the soil food web.
• No-tilled fields often have more beneficial insects and earth worms, and a larger, better
balanced microbial community that can even resist disease outbreaks.
• Those organisms increase the soil’s organic matter content and build soil structure—Aggregates
are like a house with walls and rooms! – It’s a city down there!
• Soil in no-till systems with better “rooms” or pores absorbs and stores more water and
plants are able to grow their roots deeper into the soil to get to that water. This means
that farmers can prevent floods, and grow crops that survive droughts. We all know what crops are, but do you know
what a cover crop is? Simply put, a cover crop is planted to keep cropland “covered”
between the time a “cash crop” is harvested and the next one is planted. Cover crops aren’t usually harvested. They’re planted to improve soil health,
to feed those many beneficial organisms in the soil that make nutrients available for
the next “cash crop” a farmer will grow to harvest and sell.
Cover crops are also known as “green manures,” which feed the soil’s microorganisms. Those
microorganisms, in turn, make nutrients available for the next cash crop harvest.
Since cover crops usually aren’t harvested, they don’t have to grow to maturity. Typically,
they grow during the late summer and fall, before the onset of winter, or in the early
spring before the cash crop is planted. After cover crops grow, many naturally die
in the winter, but some are terminated by herbicide or by mechanical means like a roller/crimper
right before the next cash crop is planted and grown. More farmers throughout the nation are planting
cover crops after harvesting their cash crops, to benefit the soil AND their farming operations.
Cover crops play a key role in soil health management systems and have many on- and off-farm
benefits. (Ref. OSU Cover Crop Fundamentals AGF-142-99, Sundermeier.) 1. Building better soil—When a tilled field
doesn’t have growing plants in it, the surface structure of the soil is damaged by the impact
of rain drops so that it can “seal”. When that happens, much of the water will then
run off into streams and lakes instead of infiltrating into the soil. Cover crops protect
the soil surface and can help eliminate that “sealing” effect. Water infiltrates better
through these continuous pores that roots create. Roots also improve soil tilth (or
structure) by growing through layers of soils that are hard and compacted. By breaking up
these layers, cover crops make it easier for cash crop roots to grow deeper. 2. Behold our living soil—Beneficial organisms
in the soil, such as earthworms and microscopic bacteria, protozoa and others, thrive when
they have plenty of cover crop plant material to eat. As they decompose this material, soil
organic matter levels and aggregation, or structure, improve—which further improves
the health and function of the soil. Did you know there are more microorganisms in a hand
full of HEALTHY soil than there are people on the planet? 3. Bye-bye soil loss–Cover crops reduce wind
and water erosion on all types of soils. By having the soil stuck together into strong
aggregates and held in place by cover crops during the fall, winter, and early spring,
loss of soil from erosion can be reduced or eliminated—which also helps reduce nutrient
run-off into rivers, lakes and oceans. 4. Natural nutrient recycling—Legume type
cover crops can add substantial amounts of available nitrogen to the soil. They collaborate
with symbiotic bacteria called Rhizobia to “fix” nitrogen from the air and turn it
into a form that plants can use. Some legume cover crops like peas, alfalfa and clovers
usually “fix” more than 50 pounds of nitrogen per acre, and even 300 pounds is possible!
(Oklahoma State University PSS-2590, Clarke et al, 2007). Non-legumes cover crops can
take up excess nitrogen and other nutrients applied for previous crops and recycle them
to make available for the following crop. 5. A good bug’s life—Cover crops provide
habitat for beneficial insects, such as lady beetles and pollinators. And those pollinators
are important because, worldwide, approximately 1,000 plants grown for food, beverages, fibers,
spices and medicines need to be pollinated by animals in order to produce the resources
upon which we depend. (Source Pollinator Partnership.) 6. Covers keep their cool—Cover crops and
their plant residues help keep the soil cooler in the heat of summer, which improves plant
health. The soil temperature of “tilled” or plowed soil can be 20 degrees hotter than
soil protected by cover crops. Surface residue also reduces evaporation in the heat of the
summer. In the long term, building healthier soils and maintaining cover makes farms more
resilient to drought. 7. FEED ME! Living roots in the soil throughout
the year create root channels and feed microorganisms. Roots and organisms together produce biotic
glues, and build the porous soil structure, or aggregates. Those tiny organisms are so
important that plants exude substances through their roots to attract them to live in their
root zones. 8. A weed’s worst nightmare: A dense stand
of winter rye or other cover crop can suppress weeds by keeping them in the dark—unable
to get the sunlight they need to grow. Some cover crops even produce natural chemicals
(called allelochemicals) that can further suppress the growth of weeds. Rather than planting one or two crops year-after-year
on the same fields, soil health farmers use cropping rotations—featuring a diversity
of crops, cover crops, and forages for grazing animals over multiple years to build healthier
soils. Crop rotations have been used for centuries
to improve plant nutrition and to control the spread of pests and disease. Here are
just some of the benefits of “mixing it up”…
• Diverse rotations improve plant nutrition. Legume type crops, for example, contribute
nitrogen to the soil, which the next crop can use. Some crops are better at releasing
certain nutrients like potassium from soil mineral particles, which will become available
to the next crop, too. Some roots bring up nutrients from deep down in the soil so that
crops with shallower roots can use them, as well.
• Mixing it up also deters pests and diseases in various ways. For example, growing a crop
in only one out of four years deprives pests from their specific food source for multiple
years, so their populations can’t grow and take over.
• Scientists are discovering that diverse plant roots create habitat and food for soil
organisms that compete for space with pathogens so diseases can’t take over.
• Many of these beneficial organisms are also predators of disease-causing organisms.
• Other organisms simply cover the plant root, creating a barrier so that pathogens
can’t get to the root. The more we “mix it up” with diversity,
the more we can enrich the soil with bacteria, fungi, yeasts, algae and protozoa—all of
which help plants acquire nutrients, regulate growth and resist pests and diseases. On the farm, healthy soil provides many benefits.
But that’s only part of the story. Here just a few of the off-farm benefits we also
get from healthy soil… 1. Since one acre of healthy soil can store
as much as 160,000 gallons of water, maybe more. Healthy soils keep more water on-the-farm,
which reduces flooding downstream. 2. Much of the precipitation that falls on
unhealthy soil runs off—carrying with it sediment, nutrients and pesticides that can
harm rivers, lakes and oceans. But by improving soil health, we can also improve water quality. 3. There is no plowing with no-tilled and
continuously covered cropping systems, so much less airborne dust is created—which
helps everyone breathe easier. 4. Soil health farmers also use far less fuel
compared to conventional tillage operations, which saves energy and reduces greenhouse
gas emissions. 5. And healthy soil makes farms more resilient
to weather extremes, which allows farmers to provide a stable food supply to help feed
us all. Without a doubt, healthy soils have a lot
to offer all of us. That’s why we’re working with farmers, ranchers, researchers and others
to harvest this new hope in healthy soil. To learn more, visit nrcs.usda.gov.

4 thoughts on “Combined chapters: The hope in healthy soil

  1. This is an excellent video! One of the best I have seen. It answered a number of questions I had about no-till farming and cover crops. Very well done!

  2. The next step is to move to ultra narrow rows so we use and protect all of the soil that we are stewards for and pay taxes or rent on.
    With the harvesting equipment that is available today there is no longer any reason to grow feed and fuel and field crops in rows.
    We can harvest the maximum levels of light, and moisture, better manage heat, shade out most weeds, capture the maximum amount of carbon dioxide and make it a whole lot easier to no till into.

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