Time is money for Collin Jensen, who has better things to do than fall tillage. He appreciates the reduced equipment cost and fuel needs of reduced tillage, but even more he values every ounce of soil that stays on his West Union, IA, hillsides.

“In the 1980s, I liked the time savings concept since I worked full-time off the farm,” Jensen says. “So every year I moved a little further to reduce tillage on more acres.

“The first year I reduced my tillage (early 1980s) and had a neighbor with a coulter and row cleaners (on his planter) plant for me. The yields that year were excellent, and I hadn’t invested all that fuel and time on tillage,” he says.

Working as an independent agronomist exposed him to others’ successes and failures. “It was the best education I ever got,” he says. He devised a system at home based on the bare minimum in time and money to produce a corn crop within a bushel of his neighbors’ yield. No easy feat with one-fourth of his ground in continuous corn on heavy soils.

“Under the purest of situations, no-till probably means planting with only a seed opener to place the seed,” Jensen says. “I worked with a grower in the late 1980s and early 1990s in the purest no-till system: planting with only a seed opener and no tillage whatsoever. With our shorter season and cooler spring here in northeast Iowa, there were a lot of emergence problems and stand reductions in some years. In today’s high-cost-of-production environment, we’re not afforded the luxury of less-than-adequate stands,” Jensen says, explaining why he plants no-till with only a planter-mounted fertilizer coulter and shark-tooth row cleaners, creating a residue-free strip.

 “I consider my system no-till because I’m not making an extra pass, but I am moving the residue and lightly disturbing the soil ahead of the seed openers,” Jensen explains.

He delays spring planting on his heavy soils until soils warm up, but his yields prove that his crop makes up for lost time later in the growing season. He leaves fall stalks standing to anchor more soil. The previous three years of record Iowa rains have proven this practice to be especially wise.

He plants continuous corn on the contour on hillsides, since the planted rows lie lower than the crop residue. The high residue of the continuous corn helps reduce runoff on steep slopes, he says.

University of Minnesota Extension Educator Jodi DeJong-Hughes estimates the savings from reduced tillage to be around $32/acre in fuel, labor costs and machinery wear and tear (compared to disk ripping with spring field cultivation).

“For $7 corn, you’d need to be within 5 bu./acre of the aggressive tillage to make it pay,” she says.  

“I see producers with hilly ground and varied soils have problems with reduced tillage,” she says. “I think it’s because they don't contour-farm. Iowa is well versed with contours.”

Jensen farms on a variety of soils (Fayette, Downs, Port Byron, Otter-Huntsville, Kenyon loam, Floyd loam, Ostrander loam, Clyde clay loam); from flat to hilly, they all respond well to his no-till system. He’s increased corn populations to 35,000 plants/acre, and has learned a few pointers along the way to make no-till work well:

*Leave stalks standing in the fall.“Don’t chop your stalks; the standing stalks channel moisture into the soil and anchor soil through the winter,” Jensen says. “You want the ground to access sun and wind, and that only happens without a matt of chopped stalks keeping it cold and wet, so I leave them standing. Plus, if you get a big rain, that chopped up residue plugs culverts and washes away.”

*Put good row cleaners on the planter. “The most important thing is getting residue out of the planted row,” Jensen says. “You don’t need a new planter, but you need good row cleaners. In 25 years of farming this way, I’ve tried many different kinds, and for me the Yetter narrow fertilizer coulter with the shark-tooth row cleaners work the best getting through any kind of stalks in 20-in. rows without moving the residue too far.”

He plants corn 1.75-2 in. deep with a 24-row, 20-in. planter.

*Liquid fertilizer at planting. Jensen’s fertilizer program includes both fall-applied and planter-applied nutrients. After harvest, Jensen broadcasts dry poultry litter, which typically provides 80-100 lbs. N/acre, 160-200 lbs. P/acre and 85-100 lbs. K/acre. Jensen also fall-broadcasts potash fertilizer for an additional 120 lbs. K/acre.

At planting, Jensen uses fertilizer coulters mounted on the front of his planter toolbar to supply 60 lbs. N/acre via 32% UAN solution in fertilizer bands 3-4 in. to the side of each planted row and about 4-5 in. below the soil surface.

 Unfortunately, there is too little corn data on 20-in. row widths to conclude whether this is beneficial or not, says Tony Vyn, Purdue cropping systems Extension specialist. “Jensen’s soybeans may benefit more than the corn from 20-in. rows,” Vyn says.

“Iowa State research to date has yet to show a yield advantage in corn production for rows narrower than 30 in.,” adds Brian Lang, Iowa State University Extension field agronomist. “But narrower rows are not a disadvantage for corn either, and should canopy more quickly to better compete against weed emergence and growth.”

*Selecting hybrids and varietieswith good emergence and early vigor.

*Tile for improved drainage.Jensen has seen up to a 50-bu./acre corn-yield benefit from tiling. “When I tiled the worst 65 acres that I’d farmed for 15 years, the yield monitor showed exactly where that tile line ran,” Jensen says.

“I first tiled my side hills on Fayette and Downs soils. Besides improving the yields, it reduced my soil erosion; a huge benefit with these hills,” Jensen says.

His soil texture has improved enormously since being moldboard-plowed in the 1960s. Now his soil “looks like stuff in a compost pile,” he says, and has lots more earthworms. They redistribute nutrients and moisture, and help beneficial microorganisms, research shows.

“I’ve noticed that my ground has gotten softer at the surface and easier to plant into. I probably don’t run any more planter down pressure than on tilled ground. Everyone here in northeast Iowa is worried about yield loss because the ground doesn’t warm up as fast. Some think they have to warm up the ground through tillage,” Jensen says.

 “I think I’ve stabilized the organic-matter loss. When I started soil sampling in the 1960s, the hilly ground had 1.7% organic matter. Now it’s about 3-4%. I don’t have ruts in the soil anymore and I don’t have washouts like I did in the past,” says the former Fayette Soil and Water Conservation District commissioner.

It takes around four years to get a no-till or strip-till system up and running, says Minnesota Extension’s DeJong-Hughes. “This is because the soil structure is returning and all the pieces fall into place. The further north you are, the longer it takes. And the higher the soil organic-matter content, the higher the cation-exchange capacity (CEC) and the higher the soil clay content, the longer the soil takes to change. Soils with 1% organic matter can change in a year or two. Clays with 3-4% organic matter can take 4-7 years.”

Jensen “is running a total program,” says ISU’s Lang. “He’s worked hard on adjustments over time to improve the system, and he also scouts his crops through the season.”

If the benefits of no-till are so obvious to Jensen, why don’t more of his neighbors make the switch?

“Some are scared by the ugly look of no-till. Or they worry about the transition, making it work, and then there’s just plain habit,” Jensen says.

“There’s probably another bushel with a moldboard plow,” Jensen says, “but the soil loss that you risk and give up is almost unthinkable in my book.

Tillage math

"Once again this year, there’s very little yield advantage for conventional tillage,” says Purdue cropping systems Extension specialist Tony Vyn. “Minimum-till or no-till systems can save farmers more than $20/acre in equipment maintenance, fuel and labor.

“But the complete savings are realized when considering future soil productivity. Full tillage and subsequent soil loss can quickly lead to negative long-term productivity," Vyn says.

“Spring strip-till can also be a viable option after wet falls. Wait until soil conditions 4-5 in. deep allow you to strip-till without creating large clods of soil that may become excessively hard,” Vyn says. “Don’t strip-till very deeply (6 in.) in spring, and use rolling baskets and plant promptly to reduce risks of excessive seed-zone moisture loss.”

No-till soybeans and corn in rotation with soybeans continue to perform as well as conventional-tillage options, Vyn says.

“Here in Indiana, some growers are considering twin-row strip-tillage, which involves strip-tilling (for instance, between former corn rows), followed by planting soybean rows 7-8 in. apart near the center of the strip. The soybeans can form an earlier canopy cover,” Vyn says.

"Before making any tillage decisions, consider an accurate total cost. We've noticed very little yield gain from conventional tillage, so typically the expenditure isn't worth it,” Vyn says. “However, strip-till helps farmers gain additional planting days compared to no-till, and that’s even more important when corn follows corn.”

Subsoiling doesn’t pay for Jensen

These Iowa Learning Farm side-by-side replicated demonstration strips comparing no-till planting with row cleaners to fall inline subsoil tillage on Collin Jensen’s West Union, IA, farm reveal little economic benefit to subsoiling. In 2008, for example, the Iowa Learning Farms replicated demonstration showed subsoiling reduced Jensen’s per-acre returns by $77.19/acre, or 13%, and consumed 75% more fuel (relative to the no-till planted treatments).

Jensen’s Fayette County, IA, corn-soybean rotation plots are predominantly Port Byron soils. They’d been in continuous no-till from the early 1980s until these multi-year trials began in 2006.

Northeast Iowa ISU Extension Agronomist Brian Lang says, “If he didn’t have much compaction to start with (because of long-time reduced tillage), that would explain why there was little or no yield benefit to the fall subsoiling. However, sometimes in a cold spring the fall subsoiling pass moves some residue and creates a warm-up band. And if that’s your goal, then use fall strip-till. It’s less expensive than a subsoil pass,” Lang says. “That provides a warm, open zone the next spring relative to a no-till pass with row cleaner.”

Jensen adds, “Most years the no-till and the fall subsoiled plots looked alike through the growing season. There were some differences in the final stands, but there was not enough revenue difference to justify the cost, especially when I included the risk of spring soil erosion.” (Iowa had record rainfalls during these years, concentrated into large events.) The 2008 subsoiled plots had about seven times the soil loss as the no-till ones, the data shows.