No one can say Tim Renger played favorites when he built a 13-row strip-till machine with help from his father Walter. The Bancroft, IA, farmer pulled parts from several manufacturers' shelves, plus added some custom modifications before he was finished.

Renger started with the toolbar from a three-point-mounted Hiniker 5000 cultivator, welded on a second 7×7 toolbar spaced 34 in. behind the front bar and mounted a 5×7 toolbar underneath that frame. He uses a caddy cart from Elk Creek Mfg. to create a pull-type strip-till bar.

To create field strips, Renger mounted free-floating Yetter SharkTooth row cleaners on the front bar along with a Great Plains Turbo Till coulter. The center bar carries two Blu-jet ripple coulters that run 5 in. to either side of the front coulter, and the rear bar carries the original cultivator row units with Blu-jet wavy covering disks. Renger also cut the original coulter mount and shank wings off the cultivator row units.

“I kept the original 13-row configuration to help reduce implement drift,” he explains. “When I make my strips, I skip every other pass. That keeps the outside shanks going down in previously worked soil when I fill in the skips.”

AN RTK GUIDANCE system keeps Renger on track when he plants over the strips. “It's critical that you plant right over the strip so the seed sits above the nutrient band. When you sit down to eat you like to have your plate in front of you, not across the table,” he says. “There's data that shows if I'm 4 in. off the strip, I lose up to 10 bu. of yield.”

You have to be careful when you use different guidance equipment in different tractors, warns Renger. “Different systems interpret the data differently and will shift your AB line. If you use a different tractor to plant, you need to center your planter and adjust the AB line to match.”

Renger uses all liquid fertilizer in his strip-till system.

When he builds strips in the fall, he injects 5 gal. of 2-16-14 and 5 gal. of KC28 (potassium carbonate) 10 in. below the row on all his acres.

“I split the old row and run my tires on the ridges so I don't compact where I want to plant next year,” he says. In the spring, corn acres receive 30 gal. of 32% nitrogen (N) on soybean fields and 40 gal. on corn going back to corn.

Soil conditions determine which coulter Renger runs in front of the strip-till machine in the spring. “If it's dry I'll run the turbo coulter, but if the soil is a little wet I'll switch to the ripple coulter so I disturb the soil less,” he says.

“I just run one coulter in front and the rear coulters behind the shank to rebuild the strip,” he says. Row cleaners and the center-mounted coulters are bolted up and out of the way.

AT CORN PLANTING Renger applies another 5 gal. of 7-25-5 tankmixed with 2 qt. of potassium thiosulfate, a pint of sugar and micronutrients.

Soybean acres receive 3 gal. of 2-16-14 mixed with 2 gal. of water (to lower the salt index) as a starter fertilizer. Renger sprays soybeans twice with Roundup and tank-mixes 8 oz. of micronutrients each time. Originally he used two tractor-mounted, stainless-steel 250-gal. tanks for fertilizer. In fall 2008, he increased capacity with the addition of a Bourgault 1,800-gal. cart that he pulls behind the bar. “It saves a lot of time with fewer refills,” he says.

Banding fertilizer in the seed row saves him 41% N (corn-bean rotation) and 20% N (on continuous corn ground). He applies 106 units of N on corn going into soybean ground (instead of 180 units on average for conventional) and 160 units of N on corn-on-corn, he says. “In this area, 180 units of N for soybean ground and 200 or more units of N for corn-on-corn would be more normal.”