Early samples of wheat indicate surplus of nitrogen
(March 18, 2018) Farmers may be able to spend less money on spring fertilization this year, thanks to Mother Nature.
Some issue samples from wheat are coming in with higher than normal nitrogen content, which could negate the need for that initial fertilizer trip over the field.
How come? It was that warm and wet February.
Dr. Wade Thomason, Virginia Tech grain specialist, informed his growers of the tissue sample results he had seen in a number of early season nitrogen reports.
“The vast majority,’ he said, “have shown wheat N content that is higher than we normally see.”
“It’s important to understand,” he told growers, “that these levels indicate that little to no additional N may be needed this year.
“I suggest we encourage growers and consultants to collect tissue samples when possible to ensure we are getting the best N rate recommendation”.
He added that his caution for high tissue N did not apply to all wheat fields, “but it’s important to understand where we stand as too much N can cause significant wheat lodging.”
Thomason’s counterpart and colleague at the University of Maryland, Dr. Robert Kratochvil, attributed the high tissue sample results to the drier-than-normal September-January period that much of Maryland experienced — 50 percent less than normal during that period.
“Those dry conditions supported keeping the residual nitrogen and any nitrogen that mineralized after fall crops were harvested within the root zone of the wheat during the winter,” Kratochvil explained.
“February supplied us with much needed rain, and it also gave us some pretty warm days during the latter half of the month,” he said. “These warmer temperatures, along with adequate water in the root zone, allowed the wheat to start growing and that growth was accompanied by nitrogen uptake.”
Kratochvil noted that most farmers want to put out nitrogen as soon as possible once spring growth starts so if they make the decision based on higher than normal tissue analysis, he had these thoughts.
“I would caution growers who get high tissue N tests against choosing to not supply any spring nitrogen to their wheat, especially if that wheat followed corn.
“There was a good corn crop across the state last year. This meant that the amount of residual N was little after that crop was harvested. We may have gotten some additional N via mineralization during the fall and some during late February but I think that pool of N is going to be depleted once the (wheat) crop goes into rapid vegetative growth this spring.
“Without any additional N, the crop will be relying on what can be supplied by mineralization and it likely will not be enough.
“My suggestion to farmers, who are basing their spring N decision on tissue samples that are high for N content, is to reduce or eliminate the amount of N supplied with first application and follow up with their normal rate with the second application when the crop starts to joint.”