Multi-purpose equipment aids efficiency, and current practices could qualify for soil and water conservation payments.

NAME: Randy Norby

TITLE: General Manager, Norby Green Country Inc.

LOCATION: Osage, Iowa

YEARS IN NO-TILLING: 14 (4 years strip-tilling)

CROPS NO-TILLED: Corn, soybeans

When I started no-tilling soybeans with a John Deere 750 drill in 1992, hardly anyone in our area of north central Iowa had even thought about planting directly into corn stalks.

I was intrigued with the cost- and labor-savings from eliminating a fall tillage trip and at least one spring tillage operation. I was anxious, of course, about what might happen to my yield, and I was pleased that there was no yield difference between no-till and our conventional methods that fall.

The next year, the 750 drill proved itself again. We had a very wet spring, and people were asking how I was going to plant soybeans through the corn stalks in the cold, wet fields that hadn't been fall-tilled.

As it turned out, I was drilling through the corn stalks before my neighbors were able to work their ground and my yields were actually better than I had been getting from tilled fields. I learned that you can successfully no-till soybeans into heavy corn residue when soil conditions are less than optimum.

Over the next several years, my brothers Dana and Steve, with whom I share equipment, and I increased no-till soybeans to more than 1,600 acres, including some custom work with the 750.

No-Till Corn Challenge


MULTI-PURPOSE MACHINES. The Blu-Jet strip-till system rides on a 9400 LandTracker caddy equipped with a 1,000-gallon fertilizer tank. It is pulled by a 190-horsepower tractor that doubles as a self-propelled sprayer with two 450 gallons tanks.

Planting corn into soybean stubble, however, was a bigger challenge. We were growing soybeans in 7 1/2-inch rows at that time, and the heavy trash mat we got from a population of 225,000 plants per acre prevented the soil from warming up in the spring to meet our desired planting dates.

For the most part, we had settled on doing a single spring pass with a field cultivator on soybean stubble, and I also experimented with one pass in the fall with a field cultivator to speed up the spring soil warm-up.

What I didn't like was that on our flat, open fields, winter was an invitation to serious wind erosion, and it wasn't uncommon to see black snow in the road ditches. I knew there had to be a better way. I didn't start no-tilling soybeans only to see the ground blow away every other year.

Equal Yields, Drier Corn

Strip-tilling seemed to address our primary concerns, which were to have earlier soil warm-up and a mellow seedbed while retaining the reduced cost, fewer field passes and labor savings of complete no-till. And as far as the NRCS is concerned, strip-tilling with minimal soil disturbance in the fall satisfies the technical requirements to qualify as no-till for participation in programs such as the Environmental Quality Insurance Program (EQIP) and the Conservation Security Program (CSP).

As with our original shift to no-tilling soybeans, we were concerned about any affect on corn yields when we decided to start strip-tilling 4 years ago. However, side-by-side comparisons showed that strip-till yields were consistent with conventional tillage, and corn from strip-tilled rows was actually 2 percentage points dryer than conventional corn harvested the same day.

This is hard to explain, but I was reassured to find I'm not alone in this observation. A neighbor recently tested two corn varieties in a replicated trial comparing strip-till with conventional tillage, and he also reported corn shelled out dryer from strip-till plots.

I'm not an agronomist, but I've noticed that if the weather is cold, corn seeds in the strip-till slots will often germinate in the warmer soil and develop 4 or 5 inches of early root growth as they spike through the soil surface. This might have something to do with getting dryer mature ears.

While strip-tilling does involve a fall pass preceding corn, we think the benefits more than make up for the cost. The 12-row strip-till unit burns just under 9/10 of a gallon of fuel per acre, but our fuel savings are still dramatic compared to the cost of conventional tillage.

Multi-Use System Design

One of the justifications for the cost of a strip-till rig is designing a system that can be used for multiple operations. Multi-use translates into less capital cost per acre than for conventional, single-use tillage tools.


A PREFERRED CHOICE. Berm baskets are optional equipment, but Randy Norby recommends them to help break up lumpy soil and provide better seed placement and seed-to-soil contact.

Our Blu-Jet 12-row strip-till system rides on a 9400 LandTracker caddy equipped with a 1,000-gallon liquid fertilizer nurse tank.

The LandTracker converts into a nitrogen sidedress applicator by taking off the strip-till rig and attaching another toolbar equipped with injector nozzles. We remove the residue managers and use the same coulters for sidedressing as we do for strip-tilling.

We pull the strip-till units with a 190-horsepower, John Deere 8220 tracked tractor that doubles as a self-propelled sprayer throughout the season. A 750-gallon, three-point sprayer and the 450 gallons we carry in the tanks between the tractor tracks provide plenty of capacity for a 90-foot spray boom. Likewise, the John Deere 7720 we use to pull the fertilizer sidedressing bar also serves as our planter tractor.

Agronomic Benefits

The past 2 years with strip-tilling have shown us a dramatic difference in spring soil temperatures. At a 4-inch depth, we measured a 12-degree difference between the soil in the strip and the soil between the strips on April 14, 2005. This difference allows us to start planting about a week earlier than if we waited for the soil to warm up after spring tillage.

We've also seen much better spring moisture conditions in the seed zone. In the fall of 2004, we strip-tilled a rented farm that had no artificial drainage. This farm has always been a problem drying out with conventional tillage, and it also was difficult to get uniform emergence.

At planting time in 2005, the effect of strip-tilling was dramatic. Soil within the strips was dry over the entire field, while soil between the strips was wet and shiny. We got the best overall corn stand we had ever had.

With strip-tilling, we have less trash in the seed zone. By setting the mole knives to run 8 to 9 inches deep, soil exploding upwards removes trash from where the next spring's seed zone will be located. This allows for better seed-to-soil contact and results in earlier germination and emergence.

Saving labor by strip-tilling can lead to other benefits. By freeing up one person because we don't do spring tillage anymore, we have more help to tend the no-till planter so it keeps running more hours. This in turn lets us reduce our planting speed from 6.5 to 5.5 mph, be more precise and still cover the same acres per day.

Economical Nutrient Placement

Being able to apply a liquid 2-6-12 starter at 35 gallons per acre in the bottom of the slot is another big benefit of strip-tilling. Our soil tests generally show a need for potash, so we go with as much as we can and still keep it in suspension. We chose liquid instead of dry because we already had the equipment to apply it and an economical supply from a nearby fertilizer plant.


"Corn from strip-tilled rows was actually 2 percentage points dryer than conventional corn harvested the same day ..."


The balance of the fertilizer is custom-applied in a liquid mix on the surface. I think that by placing some fertilizer 8 1/2 inches deep and the rest on top, we avoid nutrient stratification. All rates are based on recommendations from a professional agronomist. I'm still building baselines to allow fine-tuned fertilizer rates based on soil and yield variability.

We are looking closely at reducing nitrogen costs. My standard rate is 140 pounds per acre with a corn yield goal of about 180 bushels per acre. Last year I evaluated replicated rates at 90 and 140 pounds per acre; both of my brothers compared 100 pounds where they normally apply 125.

Our goal is to determine the best rate for each soil type so we get away from a shotgun approach. Researchers like the late Alfred Blackmer at Iowa State University have proven that the old standard of 1.2 pounds of nitrogen per bushel is way out the window.

Swith To Coulters

When I went into a total strip-till system, I replaced the unit-mounted row cleaners on our 1760 12-row, wing-fold planter with 13-inch wave mounted coulters. I did this for several reasons, and the result has been even better than I expected.

First, we don't get a heavy residue cover on the seed strip like you might with total no-tilling or after field cultivation, so we don't need the aggressive action of a spiked row cleaner.

When heavy rains delay planting, our high-clay soils tend to crust in the planting strips. When this happens, the coulters do a nice job of lightly working the soil in front of the openers.


"At a 4-inch depth, we measured a 12-degree difference between 
the soil in the strip and the soil between the strips ..."


We prefer coulters because we have a variety of soil types and conditions, including limestone shelves in some fields. When we're strip-tilling over the top of these areas, we pull the rig out of the ground and continue applying fertilizer on the soil surface. By running a coulter on the planter, we can create a good seed zone in those non-stripped areas and reduce the chance of getting sidewall compaction.

We've also changed to heavy-duty down pressure systems and get less seed bounce and more uniform seed spacing in the trench.

Berm baskets on the Blu-Jet are optional, but after the first time I used mine, I told the distributor they should be standard equipment and never taken off. I like the way the baskets help form our strips.

While the berms don't stand up as high after we're done in the fall, they also don't settle a lot during the winter. The baskets help break up lumpy soil, resulting in flat, uniform strips in the spring. We seem to get better seed placement in the bottom of the furrow, resulting in better seed-to-soil contact.

Auto-Steering Fits Strip-Till

While auto-steering might not be a necessity for successful strip-tilling, we see many benefits. We use a Starfire SF2 receiver with our AutoTrac system, which is accurate to plus or minus 4 inches, for all strip-tilling, planting and spraying operations. The auto-steer system lets us pay closer attention to the implements to make sure everything is operating correctly and that we are getting precise fertilizer placement at the bottom of the strip.

I'm convinced that auto-steering saves us money by avoiding overlaps and gaps. Once we lay out our rows in the fall, we are in the same controlled pattern in the spring and summer, so we never create any compaction in the row.

And again, we're getting multi-use from a major investment. Another benefit of auto-steering is that you use the same equipment for steering that you use for documentation; the only difference is the software you install. As we get more involved in EQIP or CSP programs, we can quickly access the data the NRCS office requires to qualify. The data also back up insurance claims and have allowed us to start doing "what if" experiments that help maximize the management of soil type variability.

Changing Programs

No one can be certain what the next farm bill will look like, but there are many signals that a Congress seeking budget relief might target direct payments. I expect that tax-supported soil and water conservation practices will become as important or more important to producers than current farm policies.

We're already seeing more watersheds becoming eligible for CSP programs in our area. In 2005, close to 860,000 acres were opened for eligibility along the upper Wapsipinicon River in northern Iowa. As a result, some producers are eligible for payments of up to $45,000 per year for long-term projects. There is speculation that our county will probably become eligible for CSP as early as 2007 or 2008.

Meantime, 3-year EQIP programs are a good stepping stone to longer-term CSP projects. EQIP requires the same type of records needed for CSP. Documenting production practices like no-tilling and strip-tilling that reduce soil and nutrient runoff can help producers comply and qualify for maximum participation when new programs come along.