The spread of multi-resistant waterhemp has led to increasing use of Group 14 herbicides, the protoporphyrinogen oxidase (PPO) inhibitors that include Cobra, Flexstar, Ultra Blazer and others. Repeated use is exerting intense pressure on this diverse group of chemicals, weed experts warn.
A big challenge – nitrogen management – could have a small solution. Rowbot Systems, a Minneapolis startup company, has developed an multi-platform robot that, among other things, can side-dress nitrogen in tall corn.
Three years of tillage and residue field and laboratory trials at Ames, Iowa, found no differences in corn residue breakdown due to tillage or type of residue, says research leader Mahdi Al-Kaisi, ISU Extension soil scientist.
Andy Thompson kept a photo journal of residue breakdown in his cornfield near Niota, in west-central Illinois. The field has been in continuous corn since 2012. This series of photos shows how, in a single season, microbes in healthy soil break down large amounts of corn residue left on the surface.
Compared to putting all the nitrogen down in the fall, “we picked up at least 7-10 bushels per acre,” says Chuck Trainor, who grows corn and soybeans and raises cattle with his father, Charles, near Tower Hill. They also dropped their total nitrogen rate.
Midwest farmers are deploying many techniques for planting cover crops: broadcasting with fertilizer spreaders, flying on the cover crop and modifying high-clearance sprayers. Others are pairing cover crop seeding with another field operation, such as vertical tillage, manure application or even combining.
Steve Miller’s “double duty” drainage and sub-irrigation system lets him control the water table in his field year-round. “I thought, if you can suck water out of the field, you should be able to pump it back in!” says the Fairmount, N.D. farmer, who grows corn, soybeans, wheat and sugar beets with his daughters, Alicia Holubok and Amanda Fisher.
Sophisticated irrigation management tools are helping growers make the best use of their water resources. Nebraska farmer Greg Greving started using an interactive computer model to schedule irrigation, he now holds off watering soybeans in the early vegetative stage, saving water for grain fill.
Corn stover baling machines rolled across 2,500 acres of harvested cornfields last fall on Mike and Lyle Greenfield’s Jewell, Iowa, farm. The Greenfields’ stover is headed to DuPont’s new 30-million-gallon cellulosic ethanol plant in nearby Nevada, Iowa.
Precision ag expert Dan Frick analyzes four data layers to understand how costs per bushel vary within a field. Here, he looks at potassium soil test, yield and cost per bushel to determine where the field getting the most per acre.
A 120-foot-wide ribbon of deep-rooted switchgrass spools along the Yellow Medicine River, a meandering prairie stream that winds through Doug Albin’s Minnesota farm. For decades, this stream-side grass strip has filtered out pollutants in surface runoff from adjacent cropland.
Integrating financial data and geo-referenced field data is the most sophisticated level of precision ag management, says Dan Frieberg, president of Premier Crop Systems. Precision software captures direct input costs for every 60x60-foot square of the field. The software also allocates indirect expenses by bushel, including insurance, equipment and land costs.
Precision ag expert Kevin Kruize uses three steps to create management zones in a corn-soybean rotation field. Those steps include pulling data from different precision sources, analyzing data layers and compare productivity and defining preliminary management zones.