Global nitrogen budgets in cereals: A 50-year assessment for maize, rice, and wheat production systems.

Journal Article (Journal Article)

Industrially produced N-fertilizer is essential to the production of cereals that supports current and projected human populations. We constructed a top-down global N budget for maize, rice, and wheat for a 50-year period (1961 to 2010). Cereals harvested a total of 1551 Tg of N, of which 48% was supplied through fertilizer-N and 4% came from net soil depletion. An estimated 48% (737 Tg) of crop N, equal to 29, 38, and 25 kg ha(-1) yr(-1) for maize, rice, and wheat, respectively, is contributed by sources other than fertilizer- or soil-N. Non-symbiotic N2 fixation appears to be the major source of this N, which is 370 Tg or 24% of total N in the crop, corresponding to 13, 22, and 13 kg ha(-1) yr(-1) for maize, rice, and wheat, respectively. Manure (217 Tg or 14%) and atmospheric deposition (96 Tg or 6%) are the other sources of N. Crop residues and seed contribute marginally. Our scaling-down approach to estimate the contribution of non-symbiotic N2 fixation is robust because it focuses on global quantities of N in sources and sinks that are easier to estimate, in contrast to estimating N losses per se, because losses are highly soil-, climate-, and crop-specific.

Full Text

Duke Authors

Cited Authors

  • Ladha, JK; Tirol-Padre, A; Reddy, CK; Cassman, KG; Verma, S; Powlson, DS; van Kessel, C; de B Richter, D; Chakraborty, D; Pathak, H

Published Date

  • January 2016

Published In

Volume / Issue

  • 6 /

Start / End Page

  • 19355 -

PubMed ID

  • 26778035

Pubmed Central ID

  • PMC4726071

Electronic International Standard Serial Number (EISSN)

  • 2045-2322

International Standard Serial Number (ISSN)

  • 2045-2322

Digital Object Identifier (DOI)

  • 10.1038/srep19355


  • eng