BOOST WHEAT YIELD ON A BUDGET
TIMING AND AMOUNT OF FERTILIZER APPLICATION ARE KEYS TO IN-SEASON SUCCESS.
Wheat prices have been an anchor the last several years, dragging farm income down. For 2019, however, wheat prices are one of the few bright spots in the grain business. It may make economic sense to invest more into the wheat crop to maximize yields.
Lyndon, Kansas, consultant Doug Shoup advises wheat growers to be strategic about nutrients that can boost wheat yields and to be cognizant of the right time to apply these products.
The building block
Nitrogen fertilizer is the single-most expensive input in your wheat crop. It is also arguably the most important addition, essential in developing protein within the wheat plant. It’s also vital to the efficient production of chlorophyll.
Soft cash wheat prices have prompted some farmers to withhold nitrogen application in the fall. That is good from a cash flow perspective, but Brian Arnall says be ready to apply nitrogen if winter brings moisture to wheat fields. Research at Oklahoma State University (OSU) suggests farmers can topdress wheat as late as Feekes Stages 6 (jointing) or 7 (two nodes on the stem) and still have enough time to boost yield. That is right when the wheat crop is poised for rapid growth.
“When we put it on at peak demand, we’re seeing better quality, our percent of protein is better, and yield is improved,” says Arnall, precision nutrient specialist at OSU.
Arnall cites two years of data that suggest the latewinter topdress application can improve yields 50%, compared with a preplant application of nitrogen by itself.
“It isn’t much different than corn farmers applying nitrogen in-season when the corn is getting ready to really take off,” he says.
Be cautious of how mature the crop is, he adds. January or February applications can be done with a dry fertilizer spreader since crop damage will be minor. Later winter applications require a wide applicator, which normally is a liquid rig with skinny tires. Keep in mind that nitrogen additives can help prevent nitrogen loss, says Shoup.
“There hasn’t been much research on that subject, but, anecdotally, I’m convinced we’ve lost nitrogen the last two years,” he says.
Arnall notes that a 40-bushel-per-acre wheat yield removes 85 pounds of nitrogen (60 pounds in the seed; 25 pounds in the straw). Few farmers manage nitrogen to maximize wheat yield. Arnall suggests using an N-Rich Strip in the wheat fields. Simply apply enough nitrogen in one strip of a wheat field so that no matter what, nitrogen is not the limiting factor. Use that strip as a reference throughout the growing season. If the wheat in the rest of the field is not as green as the N-Rich Strip, more nitrogen is needed.
Don’t overlook sulfur
Time was when farmers received atmospheric sulfur free of charge. However, the Clean Air Act of 1990 reduced sulfur dioxide emissions from electricity generation. Now, sulfur deficiencies in wheat are much more common.
“We don’t want to spend more money on something we don’t need, but it seems as if we see sulfur deficiency every other year,” Shoup says.
Sulfur is essential in the wheat plant’s formation of chlorophyll. Without adequate sulfur, yield and protein potential are limited, and the plant is not fully able to use nitrogen and phosphorous. A 40-bushel-peracre wheat crop contains 10 pounds of sulfur (4 pounds in seed; 6 pounds in straw).
“There is a high response to sulfur application in wheat. It’s important to not forget about it,” he says.
The products can be applied at topdress time in the winter or even into late spring, but use the right formation, Shoup warns. Ammonium sulfate, ammonium thiosulfate, or gypsum all contain readily available forms of sulfur. Elemental sulfur is not a good choice because it’s not available right away.