Moisture Pendulum Impacts Growers AgainThe word “quirky” best describes the drought-vs.-flood seesaw weather and its ongoing impact on farming. Folks in production agriculture hoped that the climate-based logistical nightmares of growing season 2022 had toned down into something more normal.

A little review of last year’s craziness – as it centered on the Mississippi Basin – is in order. The ag products and the huge agribusiness industry that has developed in that basin produce 92% of the nation’s agricultural exports, 78% of the world’s exports in feed grains and soybeans and most of the livestock and hogs produced nationally. Sixty percent of all grain exported from the U.S. is shipped on the Mississippi River through the Port of New Orleans and the Port of South Louisiana (PSL).

The PSL is one of the largest volume ports in America. The major inbound cargoes that travel through the PSL are crude oil, fertilizers, ores and rock phosphate, chemicals, petrochemicals, concrete and stone products, steel products, coal, wood and wood chips, lignite, coke and edible oils. The PSL’s major outbound cargoes include animal feed, soybeans, wheat, corn, coal, milo, lignite, petrochemicals, rice, fertilizers, chemicals, crude oil and edible oils.

This basin also drains 41% of the continental U.S., from Montana to western New York, including all or parts of 31 states and two Canadian provinces. Parts of our region’s real estate situated in the basin include most of Ohio, much of Pennsylvania and some of New York.

Lest we forget about how disruptive the widespread 2022 drought was on agriculture (and domestic commerce in general), let me refer to the Nov. 4, 2022 American Commercial Barge Line (ACBL) Bulletin titled “ACBL’s Daily River Conditions.” Quoting that bulletin: “Historic low water conditions (persist) – River levels continue to fall on the Mississippi River, with severe impacts to navigation not seen since 1988. Industry is incurring catastrophic impacts to boat capacity, which will, in turn, drastically decrease ton-mile productivity for the inland rivers.”

That writer noted that the inland water transportation industry reduced lower Mississippi drafts to nine feet on Oct. 17. And that change reflected a 24% – 30% reduction in cargo tons per barge compared to normal conditions. (Draft is the distance between the waterline on a boat’s hull and its bottom or keel.)

Quoting ACBL again: “(Our) liquid (cargo) drafts have been reduced to 8’6” as of October 17, reflecting approximately 17% reduction to tons per barge versus normal conditions. Industry has agreed to 25-barge max tow size, reflecting a 17% – 38% reduction to boat capacity. Groundings have been driving intermittent closures of 12 – 36 hours daily over the past month. Docks and harbors may see further draft restrictions locally, some reportedly at 7’ max.”

The “gorilla in the room” that few talk about, in terms of moisture extremes, is the tremendous loss of soil organic matter (OM), which can serve as an enormous reservoir. In the last 175 years most of America’s “bread basket” Heartland has lost approximately three-quarters of its topsoil. I calculated that typical topsoil reduction from 16 inches to four inches, in that timeframe, has reduced water-storing effect for Illinois and Iowa by an amount equivalent to water volumes of New York’s Seneca and Cayuga lakes. The inability to store that quantity of moisture increases the severity of drought. When the moisture pendulum swings the other way, flood damage threat increases in similar fashion.

In the Mississippi Basin, the all-too-prevalent culture of corn and soybean crops, absent off-season cover cropping, slowly but surely degrades soil structure and health. As soil degrades, reducing OM, almost all the liberated carbon goes into the atmosphere as carbon dioxide (CO2). The mineral fraction of such soil, which lacks fibrous roots, easily erodes and heads downstream toward the Gulf of Mexico. A lot of this mineral fraction drops out from the Mississippi River in its Gulf-bound meandering. Some soil arrives in the Gulf, carrying with it soluble commercial fertilizer nutrients, which leads to Dead Zone formation.

Here’s how: Excess fertilizer nitrogen and phosphorus cause explosive phytoplankton growth. These tiny plants are crowded to death, and are then consumed by bacteria, which gobble up any available oxygen, causing that part of the Gulf to become dead.

Dead Zones destroy ecosystems, particularly those sustaining shrimp. CO2 released into the atmosphere is the most prevalent greenhouse gas, which is the key factor triggering climate change. Climatologists are increasingly attributing increased drought to climate change.

Drought upstream in the Mississippi Basin was responsible last year for record low water levels. Add to low water levels megatonnages of eroded soil particles deposited in the lower Mississippi – not just the Gulf – and we see elevated riverbeds. These happenings mandate draft reduction (lessening the distance between a vessel’s waterline and its bottom), resulting in much smaller payloads.

Back upstream on the cropland which sheds all this soil, we see that lowered OM reduces water-holding capacity: on an acre, each 1% loss of soil OM kicks loose 11,600 lbs. of carbon in the form of CO2 into the atmosphere – and reduces water-holding capacity by 16,000 gallons. Clearly a lose lose-lose scenario.

On May 1, 2023, we learned that Mississippi River closures, not just restricted river commerce, were caused by too much water, which actually forced grain shippers and fertilizer companies to choose alternate methods to move their products parallel to the rivers. Some fertilizer shipments had to be off-loaded from barges to trucks and rail cars. Most of the flooding was caused by protracted moisture release due to unusually higher snowfall upstream last winter.

According to spokespersons from the U.S. Army Corps of Engineers, in the 670 miles of river between Minneapolis and St. Louis, the river falls about 420 feet. Moreover, this system of locks and dams was created to ease barge traffic on the river. This system was never intended to provide flood control, but only to function as a “stairway of water.”