Nitrogen is the unsung hero of food production—an essential nutrient for plant growth and health. Nitrogen is found in the chlorophyll needed for photosynthesis, the amino acids that form proteins, the adenosine triphosphate compounds that release energy, and the DNA that codes all plant life.
Yet, because nitrogen leaks from agricultural systems, nitrogen deficiency is a common nutritional problem for plants. There’s also the question of the excessive use of nitrogen fertilizers and their effect on sustainable croplands, as well as the environment.
As part of an international study, researchers sought to improve nitrogen management and better understand the global nitrogen cycle. The team, including Tai Maaz from the University of Hawaiʻi at Mānoa College of Tropical Agriculture and Human Resources (CTAHR), compared 13 nitrogen budget datasets covering 115 countries and regions over the past half-century.
They found that while most datasets collected show similar patterns, some estimates vary quite widely. The authors propose a common benchmark for nitrogen budgets, based on median values and the range of estimates.
“I am honored to be part of this international team of researchers led by Dr. Xin Zhang,” said Maaz, a junior researcher in CTAHR’s Department of Tropical Plant and Soil Sciences. “I am hopeful this study will help us find ways for more sustainable management. Proper and robust nitrogen budgeting is important for Hawaiʻi to protect our water and sensitive ecosystems from nitrogen pollution.”
The benchmark will facilitate apple-to-apple comparisons between model structures, rather than apple-to-orange differences in data inputs, so scientists have a better tool for ecological modeling. In addition, policymakers commonly use nitrogen budgets to evaluate the risk of environmental impacts and set effective policies.
“Nitrogen budgets tell us how much nitrogen is present and moving through our systems, but they’re notoriously difficult to construct on regional, national and global scales,” said Maaz. “This study provides an opportunity to create a benchmark so that people who are interested in comparing models can use a common dataset.”
The study, “Quantification of global and national nitrogen budgets for crop production,” appears in a recent Nature Food.
This work is an example of UH Mānoa’s goal of Excellence in Research: Advancing the Research and Creative Work Enterprise (PDF), one of four goals identified in the 2015–25 Strategic Plan (PDF), updated in December 2020.