From Yale E 360
“Growing up in rural Iowa in the 1990s, Isaac Larsen remembers a unique herald of springtime. The snowbanks piled along roads, once white or gray, would turn black. The culprit was windblown dust, stirred from barren farm fields into the air...Larsen and his coauthors estimate that more than one-third of the Corn Belt — nearly 30 million acres — has lost all of its nutrient- and carbon-rich topsoil. Similar processes also are taking place on the neighboring Great Plains, a sprawling region that includes Kansas, Nebraska, and the Dakotas, as well as parts of Texas, Oklahoma, Missouri, Montana, and Colorado...countless such storms have swept across the Midwest and Great Plains, they have removed the legacy of thousands of years of plant life and death there. The most striking example was the 1930s Dust Bowl, the environmental and agricultural catastrophe that stripped topsoil from millions of acres across the American interior, “
I remember in the ’70s when I was traveling in Iowa on a regular basis, I would see fence rows that had dirt drifted like snowdrifts. These disappeared later on as farmers went to strictly row crow farming and the fences were removed to allow for larger fields with larger equipment. I go even farther back in time as I was raised on a farm in NW MO. Close to Iowa, the soil is a dark, rich, loam. In 2010, over 50 years later, I was on that same farm. The house I grew up in had been sold along with a 5-acre plot. The owner asked me if I could dig a pit with my skid steer.
The spot was covered with grass, but had been our garden spot some 50 years ago. As I removed the topsoil, I went down 3 feet before I hit clay. Except for the time I was growing up, this spot had been a part of the yard with no cultivation occurring. The spot was about halfway down a slightly sloping hill one-quarter of a mile long. On the other side of the hill, my brother has put in terraces to prevent water from washing more soil away from that patch of continuously farmed ground. I doubt if one could measure the topsoil that is left. He recently approached me concerning a part of the family farm my sister rents out. Soil erosion has become a problem on her farm.
I don’t know where she learned it, but I still remember my mother saying that it takes a hundred years to make an inch of topsoil. Of course, she grew up during the dust bowl. My father had gone to no-till farming, but that meant more chemicals which meant more loss of life in the soil. Nobody knew about cover crops.
Dust is a symptom of too little water because of uncovered soil. We can see dust storms, but when water drains off the ground carrying soil, that is not seen except in the streams and rivers carrying the water. Beginning about the time I was born, over two and one half million ponds have been constructed with government monetary assistance. The result has been a reduction of flooding on many rivers. Usually, these ponds are built on pastures because if built on cultivated land, they will soon fill up with soil. They probably did little to stop the erosion of farmland.
The runoff from farms became a problem for cities and their drinking water as farmers began adding more nitrogen and phosphates with the degradation of the living soil, these items poured their excesses into our streams. Some like Des Moines, IA, had water so bad they couldn’t make it drinkable. From the New York Times:
“Art Cullen, the editor of The Storm Lake Times, a twice-weekly newspaper in rural Iowa with a circulation of 3,000, was awarded the Pulitzer Prize for editorial writing….Because of changes in farming, nitrates were being dumped into local waterways at an alarming rate, the pollution ending up downstream, in places like Des Moines.”
In addition, The Circle Of Blue:
“The Des Moines River is “essentially unusable” as a drinking water source for 500,000 central Iowans because of toxins from algae, leaders of the Des Moines Water Works said Wednesday.
Des Moines River levels of a toxin that comes from blue-green algae, microcystin, have recently been more than 10 times the federal recommendation for drinking water, said Laura Sarcone, Water Works spokeswoman. The river is one of the two largest sources of water treated to provide tap water.
“The Des Moines River is essentially unusable” due to the hassle and expense of added treatment that would be needed to ensure the toxins were removed, Sarcone said.
Blue-green algae fed by fertilizer runoff and manure are the main source of the toxins, which can cause skin rashes, intestinal problems, and in severe cases, liver damage. The foul-smelling toxins can quickly kill dogs and other animals that drink the contaminated water.”
New York City also had a problem: The New York City (NYC) water supply system is the largest surface storage and supply complex in the world, yielding 1.2 billion gallons of water daily. Within this watershed is the Catskill Mountain region of New York, an area primarily agricultural and forested but facing development pressure. The U.S. Environmental Protection Agency's (USEPA) 1986 Safe Drinking Water Act required filtration for all U.S water systems, including NYC's. The potential cost for the implementation of a filtration system for NYC's water supply was enormous, approximately $6 billion for the construction and an annual operation and maintenance cost of $300 million. Fortunately, the USEPA granted NYC the opportunity to seek alternatives to the filtration system through watershed protection.
NYC's Department of Environmental Protection (NYCDEP) proposed a series of watershed regulations in 1990. In an effort to limit pathogens and nutrients entering the watershed, severe restrictions were placed on agricultural runoff. “
“Results Achieved
The Whole Farm Program was initiated in 1992. The Watershed Agricultural Council recently announced that it has achieved its 85% participation goal ahead of schedule. The implementation of best management practices on the farms is also ahead of schedule. The program is expected to continue until at least 1999, with an extension likely. The program has resulted in a strengthened agricultural presence in the Catskills, improved management practices by the farmers, and improved water quality. The program will likely remove the necessity of installing a costly filtration system for NYC's water supply. Most importantly, the program addresses the source of pollution rather than treating the resulting impacts, and results in environmentally and economically sustainable communities in the Catskills.”
Water flowing down rivers into the ocean creates problems. Those engaged in fishing and collecting other marine creatures for us to eat, see their stock shrinking and sometimes eliminated. One of the worst happens in the Gulf of Mexico. From Dive Training:
“The Gulf of Mexico dead zone is an oxygen-starved area devoid of most marine life. It is off the Louisiana coast where the Mississippi River empties into the Gulf of Mexico. In 2003, this killer swath of ocean reached a record size of 8,492 square miles (22,079 sq km), larger than the state of Massachusetts...The dead zone is a seasonal phenomenon that forms each spring as excess nutrients, primarily nitrogen, wash down the Mississippi River and empty into the Gulf of Mexico. An overabundance of nitrogen stimulates the growth of phytoplankton (microscopic algae and other plants) at the water’s surface...In addition to wreaking ecological havoc, the dead zone can be a financial drain on coastal communities. Changes in the distribution of fish, shrimp and oyster beds can translate into economic losses for the Gulf of Mexico’s multibillion dollar seafood industry. And recreational fishermen go elsewhere, taking their wallets with them.,,”
With Cover Crops, we can stop wind erosion, water erosion, water pollution and even stop the elimination of food sources. But even more, we can store water. Of almost all the examples I have learned about crops, the one constant is; ” In drought, cover crops help produce more product!”
Of all places, AUSTRALIA would be the last place I would want to farm. Most of the country is always dry. But a couple of years ago, Australia had 7 months without rain. A picture of one farm showed up green while the neighboring farms were brown. That farm had no water that ran into the area, yet a stream flowed with clean water off the land. Although this farm-raised sheep, the owner had used regenerative methods to slow the flow of water so that it could enter into the subsoil. I use this as an example of just how much water can be stored in the subsoil. “a stream flowed with clean water off the land”
Planting cover crops can do this as well as provide other benefits. The cover crop needs to grow during the off season and needs to provide sufficient residue that there will be a carry over from the previous season. The cover crop is rolled or in some way broken over so as it is killed, it lays on top of the ground providing protection. Lehman a fifth-generation from Iowa Polk county in Iowa had this to say:
“Provide protection for our soils so that we don’t see any noticeable erosion through some of those heavy rains in early spring”...The most common misconception is that it is going to lead to reduced yields...We finding that when we use cover crops in the right way, it can actually enhance what we grow and the amount we grow.” they did “... a water infiltration test, my infiltration rate was a half-inch an hour. After 5 years of no-till and cover crops, we are at seven to 9 inches an hour...in one hour we get 10 inches and then it stays hot and dry for a month...if you can’t put that moisture in a piggy bank so to say…”
From I Treating the Farm as an Ecosystem Part 2 with Russell Hedrick for another example:
“...everybody knows that North Carolina was in a drought in 2015. I had neighbors that got insurance checks, their crops weren’t harvestable...we averaged 25 to 30-bushel beans... you could simply walk out into a bean crop, move the canopy apart...still had a nice residue cover...where we had bare ground our temperatures were about 100 to 105 degrees. Where we had cover crops there, we were about 75 to 80 degrees. “
The elevated temperature of the ground is going to make the transpiration rate increase meaning even more moisture will escape.
I think the example from Australia gives a great example of the storage of water in the earth. I know that Independence Mo began as a stop for covered wagons at a spring. Springs were common and many yielded water year-round. The water was stored in the ground. This was ground that naturally existed with a cover crop all year.
With cover crops, the humus level of the soil will increase. All those roots growing will eventually die and become humus. All those other microorganisms will expand the soil allowing for space to store water. The earthworms will leave tunnels that allow for water to seep lower and have a storage place. I don’t know what the total amount of water that can be stored in the soil and it will vary depending on the type of soil, but farmers who cover crop talk of having rains where there is no muddy runoff. If there is any runoff, it will be clear water. With rains increasing in amount and having varying amounts of drought between them, we need to catch every drop.
So the answer to “How much water can one store in the subsoil?” Of course, the answer will be;
If, your “infiltration rate was a half-inch an hour”, and you have an in or rain in an hour, the most that you will acculumate in the soil is ½ inch of water.
But, if you “are at seven to 9 inches an hour” and you have a gully washer, then your soil will acculate wate at a greater volume.
How Much? Your cover crop may be knee high by spring or after a number of years, it may as tall as your head. The amount of roots, earthworms, bacteria, cyanobacteria, and fungi and otherorganisms will be equal to, if not greater than what we see above the ground.
Some cover crops having roots that will extend 50 feet or more into the ground; With microorganisms numbering in the trillions; With active worms and other creators making tunnels in the soil; With decaying vegetation leaving gaps and absorbing moisture; With mulch that will protect the soil; With soil that will absorb several inches an hour. Over time, maybe enough water will be stored that a spring will establish itself on your land.
PRES BIDEN’S COMMENT ABOUT FARMERS AND 'cover crops'! Part II What is Fertilizer anyway?