Wednesday, 8 October 2008

George R. Brown Convention Center, Exhibit Hall E

Roland J. Buresh, International Rice Research Inst., DAPO Box 7777, Metro Manila, Philippines, K. R. Reddy, Wetland Biogeochemistry Laboratory, University of Florida, Soil and Water Science Department, 106 Newell Hall, Gainesville, FL 32611 and Chris Van Kessel, 1210A PES Building, University of California-Davis, University of California-Davis, Dept. of Plant Sciences, Davis, CA 95616-8515

Soils with continuous or intermittent submergence by water occur in a range of ecosystems including rice (Oryza sativa L.) fields, wetlands, estuaries, and floodplains. Rice is a staple food for nearly half the world’s population, and about 95% of the global rice production occurs on fields with soil submerged during at least part of the rice-cropping period. The sustained productivity of rice relies heavily on the input and management of N. Nitrate is the dominant form of inorganic N in drained, aerated soils; whereas ammonium is the dominant and stable form of inorganic N that accumulates in submerged soils. Submerged soils as compared with aerated soils are favorable environments for loss of N by nitrification-denitrification and ammonia volatilization and for addition of N via biological dinitrogen fixation. During the past 20 years considerable progress has been made in developing management practices for increasing the efficiency of fertilizer N use for rice. Adjusting the basal and mid-season applications of fertilizer N to optimally match the field-specific needs of the crop for supplemental N can increase yield, increase efficiency of fertilizer N use, and increase profit for farmers, while also reducing losses of reactive N in Asian rice production.

See more of: Nitrogen in Agricultural Systems - Monograph (Posters)
See more of: S04 Soil Fertility & Plant Nutrition

2008 Joint Annual Meeting (5-9 Oct. 2008): Nitrogen Transformations in Submerged Soils.

749-12 Nitrogen Transformations in Submerged Soils.