The Carbon Cycle in Soil & Water Conservation
By Malcolm Beck
first experience at seeing the carbon cycle at work (however I didn't
understand what I was seeing) was out on the West Texas Desert where
they were dumping trainload after trainload of New York belt press
sludge directly on top of the dry desert soil.
size chunks of stinky, wet, biologically active biosolids (processed
human waste), was being spread several inches apart in the native
grass that was very poor and scarce. The annual rainfall in that area
is less than ten inches. During that visit one of the tractor operators
came close and in a low voice, as if he didn't want anyone else to
hear, and said “there is something strange about this stuff,
it hasn't rained for month, surely none of the moisture was getting
to the roots, but it seemed like within just a few days the grass
actually turned greener and seemed to be growing some”.
first thoughts were wishful thinking. But I too noticed the same thing
happen when we put moist biosolids compost on the shoulders of a highway
for the Texas Dept. of Transportation to help stop erosion. It was
a dry year but the few bunches of established grass that still existed,
greened up anyway.
Later I again visited the
West Texas site where they spread the first New York Biosolids. In
areas where there was soil the native grass was green, healthy and
so thick you couldn't see the ground. This is good indication
of what the grass in the area was like before it was abused with improper
grazing and what it could be like again if properly managed.
After reading some NASA
research on global warming I found the missing clue of how plants,
especially grass, can green up without rain or irrigation. When there
is a concentration of Carbon Dioxide (CO2) around a plant leaf the
pores, called stomata, which have the ability to open and close, stay
shut much longer and close quicker after opening. When the stomata
are open they release moisture to the air, which has a cooling affect.
The NASA scientist concluded that, with the stomata staying shut longer,
the lessening of the cooling effect was contributing to global warming.
The NASA scientist didn't
mention that a plant transpires, to the air, ninety nine percent of
the water it pulls from the soil. And when the stomata stay closed
longer, especially with large volumes of plant leaves, an immense
volume of soil moisture could be saved.
Anytime the insect and
micro soil life digests something (rots), there is a release of Carbon
Dioxide. Carbon Dioxide is slightly heavier than air. When it is being
released from rotting organic material under and around plants it
tends stay in or near the plant canopy before it eventually diffuses
into the atmosphere. The stomata on the leaves of plants now have
an abundance of carbon dioxide for photosynthesis to create carbohydrates,
the energy source, for all human and animal life.
Plants do need to transpire
some water to the air. The up movement of water in the plant carries
nutrients from the soil to the leaves. Also it takes water from the
soil that already is, to some degree, depleted of the nutrients that
were dissolved in it.
Diffusion now moves more
water toward the roots that hopefully will be saturated with more
plant nutrients. However this all needs to be in balance. The soil
needs to be rich in soluble nutrients so little water needs to be
moved up to transpiration.
The decay of organic material
is greatest when temperature and moisture is also correct for plant
growth. The decaying organic material on and in the soil releases
plant nutrients and holds moisture and at the same time allows the
plants to need less moisture. All this puts still more importance
on the organic content of the soil.
The plants need the carbon
dioxide from the decay of organic matter on and in the soil, but the
organic material must be kept on or near the soil surface so the soil
doesn't get saturated with CO2 since the plant roots also give
of Carbon Dioxide.
The carbohydrates manufactured
by the leaves of plants are not all used by the leaves, they only
keep a portion, and fifty to eighty percent is sent down to the roots.
And the roots don't keep it all either. A high percent of the
carbohydrates is shared with the high population of soil life that
live in the root zone.
Scientist tell us there
are around ten thousand species of bacteria and three thousand species
of fungi that use or get some benefit from this carbohydrate energy
source. Then, in return, these microbes perform many services for
the plants. Science is continually discovering more and more of the
benefits such as protecting the plants from troublesome insects and
diseases and gathering nutrients and moisture for the plants.
As long as the plant is
able to create carbohydrate/energy this symbiotic relationships of
life forms helping each other continues. The more energy that is created
the more each species prosper and can help each other.
Sir Albert Howard, an English
soil scientist, way back in the 20s and 30s discovered that when he
put compost around plants they thrived with much less insect and disease
problems. Howard had his compost tested and discovered the nutrient
content just wasn't high enough to give those good results.
When Howard checked the plant roots he noticed a fungi growing in,
around and extending from them. Research proved this to be the mycorrhizae.
The mycorrhizal fungi are
now known to be extremely important to the health and production of
plants. Some recent research by the USDA ARS has shown that the mycorrhizae
are responsible for a large percent of the humus content formed in
The plant physiology books
tell us, a plant will grow and prosper more and more as the concentration
of Carbon Dioxide goes up, even as high as ten times the normal. However,
the soil plants are grown in must also be rich and balanced in the
major, minor and trace nutrients the plants need. When growers tried
to pump Carbon Dioxide into a greenhouse without balancing the soil
it would not work.
The Carbon Cycle
and Range Management
The big ranchers that follow
Allan Savory’s Holistic Managements teachings have a pretty
good handle using the carbon cycle to full advantage. I have been
on some of these ranches, the ranchers all claimed that they have
doubled their stocking rates, seldom fed hay, almost no vet bills
and now showing profits even in dry years.
These Holistic ranchers
have learned to use animals to manage the grass. Even though many
don't realize it, they are really managing the carbon cycle.
These ranchers divide their spreads in to many small pastures or paddocks.
They graze these paddocks with heavy stock density.
They discovered when the
cows are crowded they seem to eat on all the grasses, shrubs and forbs,
not just the ice cream. Then after the paddock is eaten down to a
point, but still leaving plenty green for photosynthesis, they move
the cattle to the next paddock.
This high stocking rate
of cattle leaves behind a lot of urine and manure. The moist urine
and manure with the litter on the ground quickly begins to decay and
gives off Carbon Dioxide. The green grass blades left standing quickly
capture this Carbon Dioxide. Then the grass can quickly re-cover,
even in some pretty dry conditions, without straining the roots or
using excessive soil moisture. This grazing process also sequesters
carbon back into the soil instead of allowing it to disperse into
the atmosphere and be called pollution.
Many of these ranchers
manage to go through winters without supplemental feeding by saving
paddocks of certain species on native grass for winter grazing. Some
paddocks will be green with winter growing species. In others it may
be dry summer species from winterkill but still standing and full
of nutrients or a combination of both.
For more information on
this natural grazing concept contact - The Allan Savory Center for
Holistic Management, in Albuquerque, NM - (505) 842-5252.
Carbon Cycle and
When Delphine and I moved
to our new farm one of the first things we did was to build a greenhouse
to grow bedding plants of tomato, eggplant, cabbage etc. so we could
transplant after frost and get a jumpstart on the season.
Whenever some dignitary
from Texas A&M came to San Antonio, they sooner or later came
to our farm to see what these organic faddists were doing. Four of
them were out one day and when they saw my new greenhouse one of them
commented, ”Beck, there is one thing you won't be able
to go organic with”, and they all chimed in with agreement.
The greenhouse was put
up in 1972 and has been in use every since and to this day there has
never been a problem with troublesome insects or disease in it. We
did nothing to prevent these problems. But looking back I think I
now know why. Naturally, we used all organic fertilizers but the main
reason, instead of gravel or a concrete floor, we maintained a wood-chip
mulch for the floor that stayed moist from the nutrient rich drippings
from the potted plants above. The decaying mulch gave off an abundance
of carbon dioxide for the plants, especially on bright sunny but cold
days when the greenhouse had to remain closed.
A friend of mine, Rosco
Jordon, had a six thousand sq. ft. greenhouse where he grew tomatoes
in each year. Rosco had our same experience of no diseases or insects.
And he had very few culls, almost every tomato was perfect. To cut
costs he operated his greenhouse similar to ours. For fertilizer he
used two pickup truck loads of half rotted, chicken house, wood chip
litter-manure mix. For cooling it was natural ventilation by opening
the north and south walls. For heating he burned waste crankcase oil
in efficient heaters that created no pollution.
At one time I belonged
to the Greenhouse Vegetable Growers Assn. and had the opportunity
to tour many greenhouse operations. Rosco Jordon’s was by far
the cleanest, most productive and profitable I had ever seen. A tornado
destroyed the green house after the fourth year ending some valuable
research. However, I see no reason the same production could not have
continued under these natural methods for many years. Rosco had the
carbon cycle working to his advantage.
Carbon Cycle Vegetables
and Row crops
From many years of growing
row crops, vegetables, fruit and pecan trees and grape vines, organically
on my own farm and garden, I have learned that building the soils
organic content to the highest point possible by using compost and
organic mulches and without tilling or disturbing the soil any more
then necessary, will put the carbon cycle to work to save moisture
and up production and profits. It also lowers insect and disease problems
to where little or no control was needed.
When growing vegetables,
we sometimes use that fine row cover called Plant Shield or Grow Web
over plants as a tent. We would put it up before the seeds emerged
or as soon as transplants were put in. The web would trap Carbon Dioxide,
give a few degrees frost protection and screen insects out, which
also stops plants from being infected with a virus. It slows down
the wind. Diffuses the sunlight for greater photosensitizes and protects
against light hail. Under this web, if there is ample sunlight, the
plants will grow three times faster and produce up to three times
more. This may get expensive on large acreage but can really pay off.
Carbon Cycle and
Trees and Vines
If trees and vines are
not yet established, concentrate on building the organic content of
the soil with cover crops and/or compost for a few years before planting.
If vines and trees are already established, keep an organic mulch
around plants at all times. Grow adapted winter cover crops in the
centers. In the spring when the trees and vines are actively growing
and beginning to need soil moisture, cut the cover crop down to form
a mulch. Never disc or disturb the soil between trees or vines more
than one-inch deep or drive vehicles un-necessarily near plants when
soil is moist enough to make tracks.
The Carbon Cycle
and Hay Crops
With the new cutting, conditioning
and windrowing machines used to make hay, I believe the carbon cycle
could be used to up production, build soil and sequester extra carbon
from the air into the soil. It would probably take some research to
fine tune it, but if these mowing machines were set to mow the grasses
high enough to allow some green blades to remain the grass could continue
trapping CO2. The crop could then recover much quicker without straining
the roots. The grass could continue to make carbohydrates and feed
all the life on and in the root zone that supports the grass.
This could result in getting
an extra cutting while soil quality is increasing. It would also be
beneficial to let the last mowing of the year lie in the field as
mulch. If need be, use feed-grade molasses (one gallon per acre) with
nitrogen fixing microbes (Micro-Soil or Agri-Gro) in ample water and
spray it on the mulch hay to decay it and make fertilizer faster.
It would also be decayed away so it wouldn't interfere with
bailing the next hay crop.