Calibration of a simple method for determining ammonia volatilization in the field - Comparative measurements in Henan Province, China

Research output: Journal contributionsJournal articlesResearchpeer-review

Authors

  • A. Pacholski
  • Gui-Xin Cai
  • Rolf Nieder
  • Julia Richter
  • X.-H. Fan
  • Z. Zhu
  • Marco Roelcke
The determination of ammonia volatilization with sufficient spatial and temporal resolution requires a simple and versatile in situ measurement technique, particularly in developing countries. Therefore, a simple chamber method for determining ammonia (NH3) volatilization in the field (Dräger-Tube Method; DTM) was calibrated by comparison with simultaneous measurements with a micrometeorological Integrated Horizontal Flux (IHF) method. Five field experiments were conducted following urea fertilization on summer maize and winter wheat plots (1998-1999) at Fengqiu Experimental Station, Central China. The simplicity of the chamber method allowed for measurements to be carried out by trained farmers. The measurements with both methods yielded very similar patterns of NH3 fluxes and similar differences between fertilization treatments. Cumulative NH3 losses determined by the IHF method ranged from 14.6 to 47.9% and from 0.6 to 17.9% of urea-N applied for surface broadcast and incorporated fertilization, respectively. As expected, cumulated NH3 losses were underestimated by the DTM as compared to the IHF by about one order of magnitude. A calibration equation was calculated by multiple linear regression which included NH3 flux data as well as temperature and wind speed values. The calibration model yielded a modelling efficiency c 2 of 0.86 resulting in an average estimation error of cumulative NH3 losses of 17%. The equation was validated by comparison of IHF measurements and DTM fluxes not considered in the derivation of the calibration formula. The calibration approach can be used under similar meteorological and field conditions irrespective of the soil characteristics or type of N fertilizer applied. © Springer 2006.
Original languageEnglish
JournalNutrient Cycling in Agroecosystems
Volume74
Issue number3
Pages (from-to)259-273
Number of pages15
ISSN1385-1314
DOIs
Publication statusPublished - 01.03.2006
Externally publishedYes

Bibliographical note

Funding Information:
This study was supported by the Deutsche For-schungsgemeinschaft (DFG Ri 269/42, Ni 311/3), the Gesellschaft für Technische Zusammenarbeit (GTZ VN 810 12 840) and the National Natural Science Foundation of China (NSFC). The authors particularly like to thank Dr. Hong Ding, Dr. Shunyao Zhuang and Mr. Yu Peng for their help and support during the measurements and Mr. Qiao Jiang, the manager of Fengqiu Experimental Station.

    Research areas

  • Management studies
  • Ammonia partial pressure, Chamber method, Integrated Horizontal Flux method, Nitrogen loss, Urea