Measure and Manage to Achieve High Yielding Wheat

Posted February 27, 2015

Mother Nature always has the final influence on the wheat crop, but producers can help maximize their wheat’s potential. To learn how, participants from 10 states attended Farm Journal’s Wheat College on February 24 in Manhattan. The event was sponsored by Great Plains, Verdesian and WestBred.

High yield wheat expert Phil Needham and Kansas State University Research & Extension Soil and Crop Fertility Specialist Dr. Dave Mengel discussed a range of topics from soil nutrient management to proper planting depth to effective disease management.

“The most profitable producers I work with are the ones who make the most informed decisions,” Needham wrote in the program’s Official Guide. “These include soil tests, tissue tests and regular field scouting, all of which can help determine which inputs need to be applied to each field, plus how much and when.”

Testing Soils to Effectively Apply Nutrients

Farmers can still establish a nutrient management program for the emerging wheat crop, according to Mengel. To start, Mengel suggested producers test their soils. He reported that less than half of Kansas fields are sampled on a regular basis and recommended testing soils every one to three years, depending on crop rotation.

Mengel recommended taking soil samples between November and March (not too late!) to measure existing nutrient levels. He reported that the most important elements for wheat include nitrogen, potassium, sulfur and chloride. He recommended taking soil samples at two or three different depths to capture nutrient levels for different elements. This includes a surface sample from 0 to 6 inches to measure pH, lime, organic matter, phosphorus, potassium and zinc. A second profile sample from 0 to 24 inches measures nitrates/nitrogen, sulfur and chloride. Mengel said no-till producers should consider an additional 0 to 3 inches sample to match pH and lime recommendations for no-till fields.

Mengel also suggested producers consider utilizing soil/topography maps, grid samples, management zones and plant tissue analysis. He stressed that the best nutrient management system utilizes multiple layers of testing and takes a long-term view. 

“You do not want to stress your wheat either by having too much of a good thing or not enough,” he said. “Keep records and look at those trends.”

Managing Current Crop Conditions to Achieve High Yields

Needham stressed that to achieve higher yields, producers must focus on achieving uniformity of distribution across wheat fields. To do so, he encouraged producers to regularly scout and test fields and soil to match the wheat’s needs with inputs applied.  

For example, Needham suggested splitting spring nitrogen applications so that producers can adjust the levels applied at the jointing stage based on how much total nitrogen the plant will need.

“As expensive as nitrogen is, we have got to apply it as close as possible to when the plant can take it up and utilize it,” Needham said.

As the flag leaves emerge, Needham stressed regular observance of fields to spot diseases, since the flag leaf and ear of the wheat plant contribute 65 percent of yield. Needham said the goal is to keep healthy and green flag leaves at the end of grain fill when the heads start to dry down.

“I want the wheat to physiologically mature, not die off,” he said.

Start Early

However, Needham stressed that if producers do not start management programs early, then they cannot increase the plant’s maximum potential. The only way to accomplish that is at planting.

“Remember that unless you create the potential for high yields at seeding time, you should not expect bin-busting crops at harvest,” Needham wrote in the program’s Official Guide.

For planting, Needham stressed ensuring the seeds are planted deep enough – 1 to 1.5 inches deep – especially for crops planted into heavy residue. Additionally, producers should conduct soil tests on nitrogen levels and apply just enough nitrogen to fuel the plant’s growth. Too much nitrogen too early and the wheat plants will produce too many tillers and result in heavy biomass and lodging at harvest time. Too little nitrogen and wheat plants will have reduced tiller numbers, heads and head size.

Calculate plants per square yard
Needham also encouraged producers to conduct stand counts at emergence. Needham suggested conducting 20 stand counts per field and calculating how many wheat plants have emerged in a square yard. To do so, producers should measure the number of plants in a 3-foot segment (the length of a yardstick) and multiply that number times a calculated figure based on row spacing (see chart). This provides the number of wheat plants per square yard. Needham said producers should strive for between 200 to 300 emerged plants per square yard, depending on rainfall and planting date.

Adjusting Equipment to Achieve Uniformity

Needham also stressed updating or re-calibrating equipment to ensure an even distribution of inputs. This could include adjustments to existing machinery like adding extra weight to a planter to increase the downward pressure on each opener and ensure seeds are planted to the same depth. However, Needham said producers should also consider technology to allow for variable rate application for fertilizer, maximizing the nitrogen’s impact for the parts of the field that need it and minimizing extraneous costs. 

Needham said that the ultimate goal for all these strategies “is all about coverage” and ensuring the all inputs are applied as uniformly as possible across the wheat field.

As he wrote in the Official Guide, “There are almost always opportunities to make simple changes that can boost stand uniformity, increase yields and put more dollars in your pocket.”

By Julia Debes

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