TY - JOUR

T1 - Comparison of different methods for the measurement of ammonia volatilization after urea application in Henan Province, China

AU - Pacholski, Andreas

AU - Cai, Gui-Xin

AU - Fan, Xiao-Hui

AU - Ding, Hong

AU - Chen, Deli

AU - Nieder, Rolf

AU - Roelcke, Marco

PY - 2008/6/1

Y1 - 2008/6/1

N2 - Ammonia losses following urea fertilization of maize and winter wheat were determined in field trials carried out at Fengqiu Experimental Station in the North China Plain in 1998 and 1999. Four experiments were carried out using two simplified micrometeorological integrated horizontal flux methods [IHF(L) and IHF(S)], a chamber method (calibrated Dräger-Tube Method DTM) and the 15N-balance method using 15N-labeled urea. The IHF(L) was taken as the reference method. Both IHF methods showed good agreement in one experiment only, while the IHF(S) overestimated as well as underestimated cumulative ammonia losses compared to IHF(L) in the other experiments (deviation ranged from 12.5% to 64% based on cumulative ammonia losses). Regression analysis of the fluxes showed that in particular different sensitivities of the samplers to wind speed accounted for the discrepancies observed. The IHF(L) and the DTM flux curves were very similar in three experiments, while the values obtained with DTM considerably deviated from IHF(L) results in one experiment. A comparison with apparent fertilizer-N losses determined by the 15N-labeling approach showed that ammonia volatilization was the major pathway of fertilizer-N loss in this study.

AB - Ammonia losses following urea fertilization of maize and winter wheat were determined in field trials carried out at Fengqiu Experimental Station in the North China Plain in 1998 and 1999. Four experiments were carried out using two simplified micrometeorological integrated horizontal flux methods [IHF(L) and IHF(S)], a chamber method (calibrated Dräger-Tube Method DTM) and the 15N-balance method using 15N-labeled urea. The IHF(L) was taken as the reference method. Both IHF methods showed good agreement in one experiment only, while the IHF(S) overestimated as well as underestimated cumulative ammonia losses compared to IHF(L) in the other experiments (deviation ranged from 12.5% to 64% based on cumulative ammonia losses). Regression analysis of the fluxes showed that in particular different sensitivities of the samplers to wind speed accounted for the discrepancies observed. The IHF(L) and the DTM flux curves were very similar in three experiments, while the values obtained with DTM considerably deviated from IHF(L) results in one experiment. A comparison with apparent fertilizer-N losses determined by the 15N-labeling approach showed that ammonia volatilization was the major pathway of fertilizer-N loss in this study.

KW - Chemistry

KW - N

KW - Ammonia loss

KW - Dräger-tube method

KW - Integrated horizontal flux method

UR - http://www.scopus.com/inward/record.url?scp=54549108755&partnerID=8YFLogxK

U2 - 10.1002/jpln.200625195

DO - 10.1002/jpln.200625195

M3 - Journal articles

AN - SCOPUS:54549108755

VL - 171

SP - 361

EP - 369

JO - Journal of Plant Nutrition and Soil Science

JF - Journal of Plant Nutrition and Soil Science

SN - 1436-8730

IS - 3

ER -