title: Suppression of soil nitrification by plants.
abstract: Nitrification, the biological oxidation of ammonium to nitrate, weakens the soil's ability to retain N and facilitates N-losses from production agriculture through nitrate-leaching and denitrification. This process has a profound influence on what form of mineral-N is absorbed, used by plants, and retained in the soil, or lost to the environment, which in turn affects N-cycling, N-use efficiency (NUE) and ecosystem health and services. As reactive-N is often the most limiting in natural ecosystems, plants have acquired a range of mechanisms that suppress soil-nitrifier activity to limit N-losses via N-leaching and denitrification. Plants' ability to produce and release nitrification inhibitors from roots and suppress soil-nitrifier activity is termed 'biological nitrification inhibition' (BNI). With recent developments in methodology for in-situ measurement of nitrification inhibition, it is now possible to characterize BNI function in plants. This review assesses the current status of our understanding of the production and release of biological nitrification inhibitors (BNIs) and their potential in improving NUE in agriculture. A suite of genetic, soil and environmental factors regulate BNI activity in plants. BNI-function can be genetically exploited to improve the BNI-capacity of major food- and feed-crops to develop next-generation production systems with reduced nitrification and N2O emission rates to benefit both agriculture and the environment. The feasibility of such an approach is discussed based on the progresses made.
authors.affiliation: Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan. Electronic address: subbarao@jircas.affrc.go.jp.
authors.forename: Guntur Venkata
authors.initials: GV
authors.lastname: Subbarao
authors.affiliation: Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshihashi
authors.affiliation: Centro Internacional de Agricultura Tropical (CIAT), A.A. 6713, Cali, Colombia.
authors.forename: Margaret
authors.initials: M
authors.lastname: Worthington
authors.affiliation: Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakahara
authors.affiliation: Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ando
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Andhra Pradesh, India.
authors.forename: Kanwar Lal
authors.initials: KL
authors.lastname: Sahrawat
authors.affiliation: Centro Internacional de Agricultura Tropical (CIAT), A.A. 6713, Cali, Colombia.
authors.forename: Idupulapati Madhusudhana
authors.initials: IM
authors.lastname: Rao
authors.affiliation: Sorbonne Universities, UPMC Univ. Paris 06, UMR 7618, InstitutiEESParis, Ecole Normale Superieure, 46 rue d'Ulm, 75230 Paris Cedex, France; Department of Geoecology and Geochemistry, Institute of Natural Resources, Tomsk Polytechnic University, 30, Lenin Street, Tomsk, 634050, Russia.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Lata
authors.affiliation: CIMMYT (International Maize and Wheat Improvement Center), Apdo Postal 6-641, 06600 Mexico, D.F., Mexico.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kishii
authors.affiliation: CIMMYT (International Maize and Wheat Improvement Center), Apdo Postal 6-641, 06600 Mexico, D.F., Mexico.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Braun
mesh_terms: D000383:Agriculture; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D009609:Nitrous Oxide / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil; D009609:Nitrous Oxide; D009584:Nitrogen
keywords: Biological nitrification inhibition (BNI); Climate change; Global warming; Nitrification inhibitors; Nitrogen use efficiency (NUE); Nitrous oxide emissions