conservation in a watershed

The link between agriculture and water quality begins with how farmers farm the land. Two practices, conservation tillage and installing buffer strips, can go a long way in protecting our water.

By Pat Petzel

Understanding how contaminants make their way from farm fields to waterways is not such a simple thing to comprehend. What scientists do know is that contaminants, which can be soil, pesticides or fertilizer, hitch a ride on the soil and water moving from farm fields to creeks and rivers. In the case of soil, farmers would prefer that this precious commodity never move an inch from their land; with water, it's more a matter of slowing it down on its way from field to stream.

When agriculture's impact on water quality is the question, by and large two solutions are quickly mentioned: conservation tillage and buffer strips. Certainly these two things are not the only farming methods that help protect water, but they do figure prominently in the debate. When farmer-led watershed groups are formed, convincing and helping more farmers switch to conservation tillage is one of the goals. The other objective is installing buffer strips that help filter water coming off farm fields.

So what, exactly are these two practices all about? Conservation tillage, technically defined, is any farming practice that leaves after planting at least 30 percent of the soil covered with residue such as the leftover stalks and leaves from a previous crop. No-till farming, the most widely recognized form on conservation tillage, leaves most of the soil covered all of the time. No-till uses herbicides instead of tillage to control weeds. How can this help protect water quality? In several ways, explained Dan Towery, natural resources specialist with Conservation Technology Information Center (CTIC), an organization devoted to spreading the word about conservation methods. For one, the basic philosophy of conservation tillage -- keeping the soil and everything put on it in place instead of washing or blowing away -- helps lessen the potential for sediment and runoff from entering waterways.

"We start with the premise that healthy soil is the fundamental first step to environmental quality," said John Hebblethwaite, former executive director of CTIC. "If you have healthy soil you get better water infiltration, less sediment and pollutant runoff."

Second, herbicides today are used in much smaller quantities than in the early days of no-till. Perfecting the timing of when these products are applied to crops during their growth cycle has also made them more effective and environmentally friendly, Towery said. "Some products are applied less than one ounce per acre. There may be truth that you're making more trips across the field with the sprayer (compared to conventional systems), but what we've found is that the actual amount of product applied is no different between high residue no-till systems and conventional till systems."

If soil or herbicides do find a way to wash off a field, then buffer strips offer what Towery calls "a good second line of defense." Buffers or filter strips are areas of grass and other vegetation, usually about 30-feet wide, that are located between farm fields and streams. The vegetation acts as a filter -- removing sediment and pesticides on its way to the stream. Filter strips can remove as much as 70 to 80 percent of the sediments and 50 percent of the herbicides in water runoff. "Conservation tillage can only take you so far," Towery said. "When there is a big rain and potential for runoff, the buffer is second line of defense.

But before we dig any deeper (pun warning) into this topic, let's look at why there's such hubbub about conservation tillage and more specifically, no-till farming.

Rethinking the Plow

In the late 1940s and 1950s agricultural researchers began to question the centuries old practice of plowing the land before planting a crop. A decade earlier, a combination of drought, wind and millions of acres of plowed land created the dust bowl and brought about what one book called our nation's first environmental crises. "In May of 1934, the worst of the dust bowl years, clouds of dust up to 15,00 feet high obscured the sun from the Texas Plains through the Dakotas," described the book Fundamentals of No-Till Farming. "The Associated Press reported that 'the entire area from Montana on the west, Texas in the south and the Ohio Valley on the east was dusted in...On the 12th of May a film of dust hovered over the Eastern Seaboard, shutting out the sun for five hours in New York City and Baltimore."

The plow, which had cut through prairies and established pioneer farms throughout the last century, was on its way out by the late 1960s.

A by-product of World War II research was the development of new herbicides. "These new herbicides gave farmers, for the first time, a practical tool other than the plow, disc, cultivator and hand hoe to control weeds and help prepare a seed bed environment suitable for planting," the no-till history book said.

If crops could be planted without the use of a plow, then scientists quickly found that the decaying vegetation leftover would provide a soil and water-conserving mulch for the new crops. The no-till method of planting crops was born.

Bill Haddad was one of the first no-till experts to introduce the revolutionary system to Ohio farmers in the late 1960s. At that time he worked for Chevron, the company whose herbicide Paraquat made no-till possible in the early days. His job was to demonstrate that no-till could work on the hilly, erodible land in eastern Ohio.

"I used to begin my speeches with, "Ladies and gentlemen, in the next two hours, what I'm going to discuss with you is not anti-religious, it's not a communist plot, it's just a new way to conserve soil and grow crops'," Haddad now tells. "And I would have guys raise their hands and say, "What my dad did all these years is all wrong? Tradition is hard to break."

The New Tradition

CTIC's mission, like the work of Haddad back in the 1960s and '70s, is to continue to research and educate about no-till and other types of conservation tillage. For the first time ever, U.S. farmers planted more acres using conservation tillage than traditional methods that rely on the plow.

"One of the concerns we have is that in the recommendation for conservation farming practices, farmers have to have an economic benefit," Hebblethwatite explained. "If they are going to suffer financially, especially now, that can be a major concern. We're trying to show farmers that it's profitable for them to adopt conservation practices."

So if these farming systems are so great, they why aren't more farmers using them? Several reasons: one, conservation tillage requires farmers to purchase specialize equipment. Also, soil that is never tilled takes longer to dry out and worm up in the spring -- which is usually OK for soybeans but can be more of a problem for corn that must be planted earlier in the season. Here's another catch: no-till can mean more variable yields. But that's not always bad when, as farmers often say, "you put the pencil to it."

High yield doesn't always mean high profit. "You have to consider the inputs that are used," Towery explained. In other words, because no-till requires less fuel and plowing and disking, farmers have less overhead costs once a crop is planted. "What is the bottom line?" Towery asks. "You may be able to go to the coffee shop and brag about raising 220 bushel (per acre) corn, but if you neighbor is raising 175 bushel corn and doing a better job on the inputs, the 175 bushel may be a higher profit margin. It's the details where people need to pay attention."

Farmers employ many methods that both aid in protecting the environment and are wise investments that will help keep them in business in these tight financial times. Conservation tillage and buffer strips, while widely recognized for their effectiveness in protecting water quality, are only two pieces of a large and interrelated puzzle that farmers can use to protect natural resources. What we do know about farms and watersheds is that when information, education and cooperation are combined into a unified effort, only good things result.

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