Filter strips line the ditchbanks of Doug (left) and Jeff Martin’s farm. Other stewardship practices they use are no-till and strip-tilled continuous corn and precision technology.
As they plant, as they harvest, as they plan for next season, in the back of Jeff and Doug Martin’s minds is one goal: More corn from less fertilizer. “We think we can eventually produce a bushel of corn from ¾ lb. of applied nitrogen,” Doug says.
The father-son team, which farms near Mount Pulaski, Ill., applies 1 lb. of nitrogen per bushel of anticipated yield. Not long ago, they were applying the traditional 1.2 lb. per bushel.
Among the tools the Martins use to reduce rates while they increase yields are nitrogen-efficient hybrids and their long-term no-till/strip-till program. Doug’s father, Jeff, thinks converting from a corn/soybean rotation to continuous corn on most of their acreage is helping, too.
“With continuous corn, I think we’re seeing more nitrogen being mineralized from the soil,” he says.
Their efforts to grow more corn with less fertilizer led to the Martins being named Upstream Heroes by the Conservation Technology Information Center (CTIC). The CTIC wants to demonstrate that high yields, increased profitability and sound nutrient management go hand in hand.
Making sure fertilizer is used by crops, and not allowed to escape into water supplies, is important for the environment as well as for a farm’s bottom line, says CTIC
executive director Karen Scanlon. Nitrogen and phosphorus flowing down the Mississippi River into the Gulf of Mexico contribute to hypoxia, she explains. Excess nutrients result in blooms of algae that deplete the water of oxygen when they decompose, creating a “dead zone” where sea creatures can’t live.
No-till and continuous corn. Continuous no-till cropping helps prevent nutrients from being lost through soil erosion and runoff, says consultant Dan Towery, who operates Ag Conservation Solutions in Lafayette, Ind. “Key to the Martins’ success with no-till and continuous corn was doing their homework before they started, keeping a positive mindset, starting on a modest scale and expanding only as they became comfortable with each practice,” Towery says.
Some of the Martins’ fields haven’t seen a traditional full-width tillage tool, such as a moldboard plow, chisel or field cultivator, for 25 years, except for spot-tillage to fix ruts created during wet harvest seasons. Some of them have been in continuous strip-till corn for six years.
Continuous corn yields as well or better than rotational corn, the Martins say. That echoes two yield champions, the late Herman Warsaw and the late Francis Childs, who grew record yields with conservation tillage (although not no-till).
Strip-tilling corn on 90% of their acres required the Martins to change no-till and fertilizer application techniques, but nothing that jeopardized soil quality or reduced fertilizer efficiency, Towery says.
Managing residue. Continuous corn requires managing more crop residue. Residue on the surface protects soil from erosion, and the soil tests of yield champions Warsaw and Childs suggest that, in time, continuous corn and conservation tillage can increase soil organic matter content. But a blanket of residue also can keep soil cold and wet, interfere with seed placement and affect nutrient cycling.
For the Martins, the solution to residue was fall strip-tilling, which creates a mellow seedbed that dries out for timely planting. To size residue and eliminate plugging as they build strips, they run a Salford RTS (Residue Tillage Specialist), a shallow secondary-tillage tool, over the field.
As an advocate of 100% no-till, Towery wants to see as little soil disturbance as possible. “But you have to do what’s necessary to get a good, picket-fence stand of corn,” he says.
- November 2010