Scientists Identify Link Between Plant Nitrogen Uptake and Greenhouse Gas Reductions
Corn management processes contributing to optimal levels of nitrogen uptake
could lead to lower greenhouse gas emissions, according to a study conducted
by Purdue University scientists. The results are published in the journal
Frontiers in Plant Science.
"Previous internationally accepted estimates were that for every pound of
nitrogen fertilizer applied in grain crop production, there is a loss of 1
percent as nitrous oxide to the atmosphere," said Purdue professor Tony Vyn.
"We found that when it comes to North American corn production, nitrous
oxide emissions are more of a function of two things, nitrogen balance and
nitrogen recovery efficiency, than simply nitrogen rate alone. Moderate N
rates cause less concern for nitrous oxide emissions, but when high rates of
nitrogen fertilizer exceed optimal plant nitrogen requirements, then we will
get higher nitrous oxide emissions."
He said that the findings of the study should be a guide in conducting
agronomic research on identifying the impact of agricultural production on
nitrous oxide emissions. "Our models indicate that a careful selection of
appropriate nitrogen rate applied at the right time can both increase
nitrogen recovery efficiency, lower the nitrogen balance left in the field,
and reduce nitrous oxide emissions," Vyn said. "If you're going to measure
greenhouse gas emissions, you must also measure the whole plant nitrogen
uptake for each nitrogen fertilizer management program being tested."