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How Maryland Farmers Are Bettering the Bay

Farmers are boosting the Chesapeake Bay’s water quality. This strategy has Corn Belt potential, but different incentives may be needed.

“You’ll notice we haven’t passed a tilled field,” says Ray Weil as he chats up a busload of folks touring the springtime Maryland countryside. “You see cover crops on one side, cover crops on the other.”

Two decades ago, these fields would have sported either brown crop residue cover or bare soil. No more. 

“As you can see, the fields are pretty green,” says Weil, a University of Maryland soil scientist. “Some farmers will use rotational tillage from time to time, but most crops are planted under no-till.”

Why It’s Green

The Chesapeake Bay, which looms large in Maryland and nearby Virginia, forced this change. The bay, which flows 200 miles from its northern headwaters to its Atlantic Ocean outlet, supports thriving fishing, tourism, and recreation industries. It’s been a popular background for television dramas like Homicide: Life on the Street and The Wire. Its 64,299-square-mile drainage basin that covers parts of New York, Pennsylvania, Delaware, Maryland, West Virginia, and Washington D.C., hosts numerous birds, land and aquatic flora, fish, and shellfish. 

For centuries, the bay was the backdrop for Maryland agriculture. Farming in Maryland isn’t easy. Its soils range from coastal beach sands to highly weathered ones. Beach sand soils are droughty, although irrigation spurs productivity. Highly weathered clay soils have a low cation exchange capacity that lowers their nutrient-holding ability.

“After 350 years of farming, these fields show it,” says Weil. “You can find the original surface soil buried under 3 to 4 feet of sediment.”

Still, they can produce bin-busting corn and soybean yields. 

“These are not inherently fertile soils,” says Weil. “However, they can be productive, with yields of corn and soybeans that are competitive with the best soils in the Midwest. Our farmers aim for 200-bushel-plus corn yields and 60- to 70-bushel-per-acre soybean yields.” 

These fields have supported a booming poultry industry that has supplied Baltimore, Washington D.C., and New York City markets for decades. Lots of poultry, though, has meant much poultry manure that farmers applied to their fields. 

“They didn’t test the manure (for nutrient value) and applied commercial fertilizer, too,” says Weil. “This resulted in phosphorus (P) buildup and nitrate leaching.”

Over time, the resulting fertilizer runoff teamed with residential and industrial runoff to create one of the world’s first marine dead zones in the bay during the 1970s. These are oxygen-depleted zones that key fish and shellfish kills.

In the 1980s, the state of Maryland instituted a voluntary free manure-testing program. The technology of the day, though, didn’t permit manure spreaders to apply rates precise enough to meet nitrogen (N) and P soil test recommendations. Eventually, though, companies developed spinner spreaders that can apply recommended rates of several tons per acre. 

For a time, the voluntary program enabled farmers to optimize manure applications and to slice commercial fertilizer bills. 

“Then we realized even if manure was carefully applied to meet N recommendations, we would overfertilize with P,” says Weil. When manure recommendations were shifted to allow for optimal P rates, insufficient N applications occurred on farmers’ fields. 

Pfiesteria Hysteria 

Public pressure intensified when Pfiesteria piscicida, an organism associated with algal blooms, infested the bay in the late 1990s. Besides fish kills and rashes in swimmers, it also produced a toxin that spurred human memory losses. 

Scientists linked the algal blooms to excess plant nutrients. The Chesapeake Bay Foundation pegged agriculture as contributing 42% of the N, 58% of the P, and 58% of the sediment to the bay. 

Voluntary guidelines then morphed into mandatory regulations for farmers. “There was lots of kicking and screaming in the farm community,” says Weil. “No one likes to be regulated.”

Farmers could no longer apply fall N. “Most nitrogen now goes on at sidedressing, with the rest going on at preplant,” points out Weil. 

Any farm with more than $2,500 in gross sales also needed to have an approved nutrient-management plan. 

“The state developed a computer program to help with this,” says Weil. “When you put information in it, the program tells how many nutrients you can apply.” 

It wasn’t easy. Manure still can’t be applied on some fields, due to stratospheric soil P levels. In these cases, the state of Maryland subsidizes manure shipments to areas that need it.

“That is where the rub is hardest, if you have manure and cannot use it,” says Weil. 

On the other hand, the regulations made many farmers better nutrient managers. 

“Not many would admit it, but they will whisper, ‘That person from the university saved me $90,000 on my fertilizer bill,’ ” Weil notes. 

Enter cover crops

Pfiesteria piscicida keyed so much hysteria among state residents that Maryland legislators passed the ‘flush tax,’ ” says Weil. The state taxed the sewer and water bills of Maryland citizens and also charged them for installing a septic tank. The so-called flush tax generates around $26 million for planting cover crops and also supports other water-pollution programs like sewage plant upgrades.

Subsidies for planting cover crops vary. The base rate is $45 per acre annually, although it can extend up to $75 per acre in some cases.   

“People think of no-till as the Cadillac in water infiltration, but there is a huge difference in having cover crops, especially as rainfall increases,” says Steven Mirsky, a USDA-ARS research ecologist. “There is potential for runoff without a cover crop in no-till situations.” 

Taproots of brassicas like radishes can punch 1∕16- to 1∕8-inch macropores into the soil profile. 

“This can channel water up to 10,000 times faster than if the water were trying to go through fine pores in the soil,” says Weil.  Cover crops help keep water in the soil, rather than running off with nutrients into the bay. 

Cover crops have grown at Harborview Farms, Rock Hall, Maryland, to where they are now seeded across the farm’s 13,000 acres. “We are really happy with the direction we are going,” says Trey Hill, whose family owns Harborview Farms.

Still, not all is rainbows and puppies for cover crops. Wet late-summer and fall weather can nix cover crop planting, says Weil. 

Still, cover crop opportunities abound. Inserting wheat or barley in a crop rotation as a cover crop scrubs leftover soil nutrients in late summer and fall. Maryland has a long enough growing season that farmers can double-crop soybeans immediately following midsummer small grain harvest, Weil adds. 

The cover crop program uses incentives, not regulations, to boost water quality. Still, it has rules, which can stifle innovation. At one time, the program did not allow the brassicas like radishes and legumes like hairy vetch. Eventually, though, research showed both cover crop types nixed nutrients from entering the bay.

It’s working

Between 2009 and 2017, Chesapeake Bay Program computer simulations for the bay show:

  • Nitrogen loads fell 11% from 283 million pounds in 2009 to 253 million pounds in 2017.
  • Phosphorus loads fell 21%  from 19.2 million pounds in 2009 to 15.1 million pounds in 2017. 
  • Sediment loads fell 10%  from 8.7 billion pounds in 2009 to 7.8 billion pounds in 2017. 

Several factors affected the decreases, but scientists note that best-management practices by farmers – such as planting cover crops – helped boost water quality. “There’s still work to do, but things are headed in the right direction,” says Weil. 

Corn Belt Potential?

States like Iowa aren’t Maryland. Generous subsidies spurred cover crop innovation so much that Maryland farmers planted 560,000 acres of cover crops by 2017.

“That would be difficult to duplicate in other areas,” says Weil. With 1 million acres of corn and soybeans coupled with a bit over 6 million citizens, Maryland has a favorable ratio of taxpayers to acres. Iowa? Not so much. 

Cover crop acreage has zoomed in Iowa from approximately 10,000 acres in 2009 to an estimated 760,000 acres in 2017, says Jamie Benning, Iowa State University (ISU) Extension water quality program manager. Still, that’s a fraction of Iowa’s annual corn and soybean acreage of 23 million acres, which dwarfs Iowa’s 3.146 million population.  

Incentives exist. Farmers initially planning to plant cover crops can qualify for cost sharing of $25 per acre for seeding, says Julie Kenney, Iowa deputy secretary of agriculture. Cost sharing of $15 per acre for seed is available for veteran cover croppers. A $5-per-acre reduction in crop insurance rates is also available.

“We need to continue strong increases each year to reach the 12 to 15 million acres needed to meet Iowa Nutrient Reduction Strategy goals,” says Benning.  

Weil believes that as farmers become more familiar with cover crop benefits, they may not need the generous subsidies Maryland farmers have had to plant them.

4 R’s in Illinois 

Illinois has also struggled with water-quality issues. Agriculture has been fingered as a major contributor of N and P flowing through Illinois waters that eventually lead to the Gulf of Mexico. The Illinois Nutrient Loss Reduction Strategy calls for a reduction in nitrate losses by 15% and P losses by 25% by 2025. However, matters are heading in the right direction, says Jean Payne, president of the Illinois Fertilizer and Chemical Association (IFCA).

Payne says agriculture is making progress in reducing nutrient losses, due to a research program focused on four R’s:   

  • Right Source
  • Right Rate
  • Right Time
  • Right Place

To fund the research, the IFCA helped establish a new state law that assesses from 50¢ to $3 per ton on fertilizer to fund the Nutrient Research and Education Council (NREC).   

“One big difference between Iowa and Illinois is we asked the Illinois environmental groups to join agricultural groups on NREC to help us identify and promote research and educational efforts to reduce nutrient losses and how to best allocate the money (contributed by farmers and fertilizer dealers),” says Payne. 

“It took a lot of courage for the ag groups to swallow hard and say, ‘All right. Let’s give them a seat at the table.’ It also took a lot of courage for the environmental groups, such as the Sierra Club, to join NREC. Traditionally, their members want to enact regulations to stop agricultural pollution, rather than support voluntary programs. We are now six years into this program, with a lot of success to show for it, and with the side benefit of no legislation, regulation, or litigation on agricultural nutrient use in Illinois.” 


Collaboration was key in Maryland, says Hill. Rather than fire back at environmental and Chesapeake Bay groups, they, instead, invited a Chesapeake Bay lobbyist to their farm at harvest.

“We explained how we managed inputs for our crops,” says Hill. “It was a super learning experience for both of us. Rather than finger pointing, we collaborated on ways to fix the problem.”

Go Green  

The best innovations often occur by accident. Harborview Farms in Rock Hall, Maryland, had a cover-cropped field in which only the headlands were sprayed to kill a cover crop prior to a rain. This left the field’s outside brown but the inside green. Harborview Farms employee George Wilson went to plant and found a mess, says Trey Hill, who manages the operation. 

“He said, ‘It is green up to my knees,’ ” Hill recalls. Still, Wilson persisted and planted. 

“He called a couple hours later and said, ‘Trey, you have to come over and see this,’ ” says Hill. 

The headlands with the terminated cover crop were too wet at planting, which led to sidewall compaction. Meanwhile, the planter functioned perfectly in the green field. 

“He said, ‘It’s the best job of planting I’ve ever done,’ ” says Hill.

These days, Harborview Farms plants the majority of its acreage green. “Efficiency doesn’t have to be sacrificed to make a system work agronomically and environmentally,” says Hill.

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