No-till soybeans can cut production costs, hold their own on yield and pump up profit - if managed right.

Those are findings of a recent eight-state Midwestern study. That's good news for growers. It's also great news for concerned soil conservation and environmental officials on the heels of a recent slowdown in conservation tillage adoption.

No-till soybean acreage, however, has increased from 6% of U.S. acres in 1988 to 32% in 1998. Despite challenges of tough springs in many areas, most Midwestern states have shown a steady increase in no-till soybean acres during the past five years. And in Ohio and Indiana, no-till is the predominate soybean system.

Most reasons for adopting no-till are related to economics.

"The most common justification for no-till is the ability to either farm more acres with less help or less machinery or both," says Ed Oplinger, University of Wisconsin agronomist and study co-author. "For many growers, it has been the labor issue as much as the machinery issue, but both obviously impact on economics."

The study states, all part of the North Central Soybean Research Program, included: Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, South Dakota and Wisconsin. Nineteen scientists cooperated in the study, summarized by Oplinger; Keith Whigham, Iowa State University; and Jim Beuerlein, Ohio State University.

The soybean checkoff boards in those states invested grower checkoff funds to support the study and produce an extension publication. No-Till Soybean Practices For The Midwest soon will be available from your county extension office.

One objective in the largest-of-its-kind study was to "enhance the adoption of no-till and reduced-till production practices by conducting on-farm trials to verify research recommendations." No-till soybean production was the basis for each study objective.

Several important reasons for adopting no-till weren't included in this study. One is erosion control.

"If there is any erosion potential, no-till will cut that down to 10% of what it would normally be with conventional tillage," says Ohio State's Beuerlein. "That is good for the farmer and the environment."

But here are the bottom-line, hard economic conclusions in each of several management areas studied:

Tillage intensity. In 25 replicated trials across six of the eight states, no-till yields ranged from 33 to 72 bu/acre, while reduced-till and conventional tillage had a range of 30 to 71 bu/acre. When averaged across all trials, no-till yields were 48.4 bu/acre, reduced and conventional tillage, 48.2 - a tossup.

No-till soybeans cost $4.10/bu to produce compared to $4.18 when some form of tillage was used. Thus, no-till averaged a $116 return per acre compared to $112 with tillage, based on costs, prices and returns during the three years of the study.

Row spacing. Drilled beans (7-10" rows) had significantly higher yields than wide-row (30-36") beans in only six of 21 trials in five states. And in Iowa, most trials showed no difference in response to row spacing. However, with all trials combined, the narrow-row beans averaged 47.5 bu/acre, 13% higher than the 42.1 bu/acre for wide rows.

The production costs averaged $4.62/bu for narrow rows; $5.11 for wide rows. Returns per acre: $58.52 for wide rows; $89.30 for narrow rows.

Nine growers in three states (Iowa, Ohio and South Dakota) compared 7-10" vs. 15-22" row spacings. Results suggest that yields and profitability are nearly identical for narrow and intermediate row spacings. Therefore, it appears that producing soybeans with a row-type no-till planter in intermediate row spacings is a viable option for Midwestern growers.

Seeding rate. Its impact on yield was evaluated in 90 trials in eight states. Nearly one-third of the trials were in 25 Iowa counties. The results:

Yields increased 2.04 bu/acre for every 50,000-seed increase per acre, with maximum yields occurring at about 225,000 seeds an acre. But in many cases, yields were not significantly different down to 150,000 seeds an acre.

In other Wisconsin tillage studies, increasing the seeding rate was necessary with no-till to reap yields equal with those of conventional tillage.

A word of caution, say researchers: As seed costs increase with new technologies, such as Roundup Ready, the increase in yield needed to pay for increased seeding rates becomes greater.

Fungicide seed treatments. Early planting dates and no-till often spell cool, wet soil conditions - favorable for certain soil pathogens, not good for vigorous soybean seedling growth. So treating soybean seed with a fungicide may result in higher seedling survival and higher plant populations at harvest.

Fungicide seed treatments were evaluated in five states (Illinois, Iowa, Michigan, Ohio and Wisconsin) during the three-year study period. In on-farm trials, seed treatment increased harvest stands by 3,000-7,000 plants per acre. Yields were slightly higher two years and equal the other year. Per acre returns ranged from -$7 to +$11. In five of eight trials in Iowa, seed treatment had no effect on yield.

In other fungicide seed treatment studies in Wisconsin using early planting, narrow rows and no-till over a seven-year period, yields were increased an average of 6.2 bu/acre. So seed treatment was profitable in that situation. Soil temperatures were most likely cooler than in the multistate project.

Inoculation. Recommendations vary among states, and apparent justification for this variation was demonstrated in this study. When grain yields and cost of production were compared in 18 tests in the three more southern states (Illinois, Indiana and Ohio), there was little difference due to inoculation. But in 26 tests in the four northern states (South Dakota, Minnesota, Wisconsin and Michigan), inoculated soybeans yielded 3.8 bu/acre (8.6%) more than non-inoculated soybeans.

Weed control. Herbicides are a significant cost in producing no-till soybeans. So one goal was to identify situations where lower rates or lower-cost herbicide treatments would provide cost-effective weed control. A total of 45 reduced-rate weed-control studies were conducted in six states.

Treatments consisted of 1/4 or 1/2 labeled rates applied either as a single or a sequential post application compared to a single full-rate treatment.

The results: When averaged over all years and locations, the 1/4 rate applied as a single application lost 3 bu/acre compared to the full rate applied once.

But when herbicide costs were considered, returns were a tossup.

There were no yield differences when the 1/4 rate was applied twice, 1/2 rates were applied once or twice and full rates once. And the most profitable treatment when averaged over three years was the 1/2-rate herbicide applied once.

A caution: The success of these reduced-rate herbicide treatments was due in part to careful assessment of weed size as the season progressed to determine the ideal time for herbicide application - and the ability to match herbicide selection with the weed spectrum.

Also, researchers emphasize, with no-till the emerged weeds must be controlled ahead of planting. Use an effective early preplant or burndown herbicide.

Don't try to cut rates of herbicide on fields with intense weed pressure or big perennial weed problems, warn these scientists. Reduced rates are for fields with normal weed pressure.

Note: This study was launched before Roundup Ready soybeans exploded on the market. And this approach fits particularly well in no-till programs.

In the study summary, the researchers say: "Most soybean producers in the Midwest will experience a decrease in the cost of production when switching from conventional tillage to no-till. Many will also produce a greater profit. The bottom line depends on how well a producer manages the crop using no-till practices and how well yields are maintained with this system."