Strip-tillers from South Dakota and Iowa explain why they strip-till and Purdue University scientists summarize their work on the response of strip-tilled corn to deep-banding versus broadcasting phosphate and potash.
Precisely Placing Fertilizer Saves Money
Darren and Brian Hefty are known to many farmers for their Ag PhD TV program, but they also strip-till.
“A few years ago, when fertilizer prices started getting crazy, we went to strip-till for the nutrient placement,” says Darren, in a Case IH news release. “We were putting our nutrients down about 6 to 10 inches deep, and planting right over the top. We invested some money in RTK GPS guidance.
“One of the best things we’ve done with it is to put nutrients on in the fall and come right back to that same spot in the spring and plant directly over it. We’ve had better yields and we’ve also been able to get by with less fertilizer.”
Nutrient placement was one of the questions that the Baltic, S.D., strip-tillers answered at an educational session Case IH sponsored for farmers at the Ag Connect Expo in Orlando, Fla., last winter.
Brian Hefty recommends that strip-tillers also include secondary micronutrients when they lay down strips and build berms in the fall.
“It would only cost a few bucks more to put them out there, but these secondary micronutrients are important, too,” he says. “And a lot of times, we find that secondary micronutrients are the biggest limiting factor on a lot of farms.”
Focus First On Strip-Till’s Savings
Dave Nelson, an Iowa strip-tiller and co-owner of Brokaw Supply Company, Fort Dodge, Iowa, passionately promotes strip-till.
But Nelson, who helped develop the “Operation Strip-Till” program so could try strip-till before buying equipment, recommends that strip-tillers focus on increased savings before they look for increases in yields.
“We were not looking for a yield increase immediately from strip-tillage,” Nelson wrote in the Winter 2010 issue of the Nelson Family Farms newsletter. “Reduced labor, fuel, machinery and custom-spreading charges are all ways that strip-tillage is benefiting our operation.
“After 2 years of strip-tillage, we can already see the next benefits to come with the strip-tillage system. Better water infiltration allows the crop more available water.
“Minimal compaction issues gives us healthier soil for plant life. The soil structure is changing, giving us more earthworms, better soil aggregation and creating ‘gopher mound’ type of soils.”
Strip-Tilled Corn Response To Fertilizer Placement
Some studies have suggested that the degree of corn response to deep-banding phosphate and potash depends on factors such as the initial soil-test levels for these nutrients, the degree of nutrient stratification and possibly the weather and hybrids, according to Purdue University scientists.
From 2001 through 2006, Purdue University scientists Matias Canepa, Tony Vyn and Ann Kline tested the response of two corn hybrids each year to broadcast versus deep-banded phosphate and potash at a single high rate and control treatments on a dark-prairie, silt-clay-loam soil near West Lafayette, Ind.
Strip-tilled corn with additional starter-banded fertilizer followed no-tilled soybeans. The study was conducted in two fields with similar soil texture, but with very different soil-test results for phosphorus and potassium and vertical stratification.
The site tested medium-high for phosphorus (24 ppm) and medium for potassium (142 ppm) in 2001, 2003 and 2005. It was vertically stratified for exchangeable potassium, but not for available phosphorus.
In 2 of these 3 years, broadcasting phosphate and potash yielded significantly more than the control treatment. The banded treatments of phosphate and potash — alone or combined — generally did not yield differently than the control.
But in 2002, 2004 and 2006, the other site tested extremely high for phosphorus (93 ppm) and medium for potassium (141 ppm). There was little vertical stratification of phosphorus or potassium in the 0-to-8-inch depth of the soil. At this site in 2002 and 2004, deep-banded treatments — including those with potash — yielded significantly more relative to broadcast application of phosphate and potash, but not compared to the control.
Hybrids never affected the yield response to phosphate and potash placement treatments, but yields did vary with the environment.