North Carolina wheat growers faced a dilemma with regard to fertilizing their crop this past season. Even though favorable grain prices were being anticipated, drought and skyrocketing fertilizer costs made it seem economically risky to apply nitrogen at standard rates.
Savvy growers turned to an agronomic test known as plant tissue analysis to accurately determine the nitrogen needs of their wheat. Many of these growers were so pleased with the cost savings and higher yields they have vowed to use tissue testing routinely from now on.
Satisfied growers include Jed Brooks of Sunnybrook Farms in Stanly County and Everett Medlin in Union County. Both had tried tissue testing sporadically in the past, but turned to it in earnest this spring — thanks, in part, to the urging of J. Ben Knox, a regional agronomist with the North Carolina Department of Agriculture and Consumer Services.
“Tissue test results let growers concentrate nitrogen where the wheat really needs it,” Knox said. “This spring, due to the drought, some fields still contained residual nitrogen unused by the previous crop. Growers who used tissue tests were able to pin-point which fields needed nitrogen and which didn’t. It’s made believers of them.”
Brooks was already familiar with tissue testing, but this year he used it intensively. Whereas in a normal year he might collect one or two samples, this year he collected eight to 10. He had planted 500 acres of wheat because the price looked good, and he wanted to safeguard his investment.
“Tissue testing did save me money,” Brooks said. “I had put out some poultry litter earlier, so there was already some nitrogen in the soil. If I had followed up with my normal rate of nitrogen fertilizer, it would have been too much. The plant analysis report showed which fields needed nitrogen and which didn’t.”
On some fields, Brooks was able to reduce his nitrogen application by 5 gallons per acre. He calculates he easily saved $10 to $15 per acre on nitrogen alone. He also saved $7 per acre — his dealer’s fertilizer application fee — on fields where tissue tests indicated no additional nitrogen was needed.
If Brooks had applied his standard rate of nitrogen to all his fields, some wheat would have had too much nitrogen. Not only would this have been unnecessarily expensive, but also it most likely would have reduced yield. When wheat receives too much nitrogen, it grows too quickly and tends to fall over, or lodge. As a result, harvesting equipment misses much of it, leaving it in the field.
“I don’t know about other crops, but tissue testing is getting to be a necessity on wheat,” Brooks said. “It helps you reach an optimal yield without laying your wheat on the ground. I’ve seen a clear benefit, and I’ll continue to take tissue samples from now on.”
Union County grower Everett Medlin has come to the same conclusion, though he required a little more coaxing than Brooks.
Knox, the regional agronomist, has advised Medlin for many years, and he knew Medlin would want proof. So Knox proposed they conduct an on-farm test to measure his standard fertilizer rate against the rates recommended by tissue test results.
“I’ve had numerous fertilizer fights with Knox,” Medlin said, “and this time, just like always, we disagreed. He and I put out a test plot with alternating strips. I did what he told me, and it worked. Where tissue tests called for additional nitrogen, I put it out and increased my yield by 17 bushels per acre over that where I applied my standard rate. That amounts to $119 per acre more.
“I trust him,” Medlin said of Knox. “He has the opportunity in his job to view a lot of farming operations. That gives him a wide knowledge base, and he’ll share it with you. He’s changed my attitude about fertilizing.”
Brooks and Medlin both send their plant tissue samples to the NCDA&CS Agronomic Division laboratory in Raleigh. Analysis requires about two working days, and results are posted online for easy access. The cost is $5 per sample or $25 for out-of-state growers. North Carolina growers have the added benefit of being able to consult with an NCDA&CS regional agronomist about sampling strategy and report findings.
North Carolina growers have access to one of the most comprehensive agronomic testing and advisory services in the nation. Details on fees and sample submission are available online at www.ncagr.gov/agronomi/sampleinfo.htm.