Optimizing the use of open chambers to measure ammonia volatilization in field plots amended with urea  

作　　者：Márcio R.MARTINS Leonardo F.SARKIS Selenobaldo A.C.SANT’ANNA Camila A.SANTOS Karla E.ARAUJO Ricardo C.SANTOS Ednaldo S.ARAÚJO Bruno J.R.ALVES Claudia P.JANTALIA Robert M.BODDEY Mohammad ZAMAN Segundo URQUIAGA 

机构地区：[1]Embrapa Agrobiology,Rod.BR 465,km 7,Seropédica RJ CEP 23891-000(Brazil) [2]Federal Rural University of Rio de Janeiro(UFRRJ),Rod.BR 465,km 7,Seropédica RJ CEP 23891-000(Brazil) [3]Agroscope,Research Division Agroecology and Environment,Climate and Agriculture Group,Reckenholzstrasse 191,Zurich 8046(Switzerland) [4]Soil and Water Management&Crop Nutrition,Joint FAO/IAEA Division of Nuclear Techniques in Food&Agriculture,P.O.Box 100,Vienna A-1400(Austria)

出　　处：《Pedosphere》2021年第2期243-254,共12页土壤圈（英文版）

基　　金：supported by the International Atomic Energy Agency(IAEA),Vienna,Austria through a Coordinated Research Project(No.D15016);the“Carlos Chagas Filho”Foundation for Support of Research in the State of Rio de Janeiro(FAPERJ)of Brazil with grants awarded to BJRA,CPJ,RMB,and SU and postdoctoral scholarships to MRM and SS。

摘　　要：Measuring ammonia(NH_(3))volatilization from urea-fertilized soils is crucial for evaluation of practices that reduce gaseous nitrogen(N)losses in agriculture.The small area of chambers used for NH_(3)volatilization measurements compared with the size of field plots may cause significant errors if inadequate sampling strategies are adopted.Our aims were:i)to investigate the effect of using multiple open chambers on the variability in the measurement of NH_(3)volatilization in urea-amended field plots and ii)to define the critical period of NH_(3)-N losses during which the concentration of sampling effort is capable of reducing uncertainty.The use of only one chamber covering 0.015%of the plot(51.84 m^(2))generates a value of NH_(3)-N loss within an expected margin of error of 30%around the true mean.To reduce the error margin by half(15%),3–7 chambers were required with a mean of 5 chambers per plot.Concentrating the sampling efforts in the first two weeks after urea application,which is usually the most critical period of N losses and associated errors,represents an efficient strategy to lessen uncertainty in the measurements of NH_(3)volatilization.This strategy enhances the power of detection of NH_(3)-N loss abatement in field experiments using chambers.

关 键 词：chamber method experimental error gas emission low-cost chamber nitrogen cycling nitrogen loss soil variability 

分 类 号：S181[农业科学—农业基础科学]