TY - JOUR

T1 - Global Research Alliance N2 O chamber methodology guidelines

T2 - Introduction, with health and safety considerations

AU - de Klein, Cecile A M

AU - Harvey, Mike J

AU - Clough, Tim J

AU - Petersen, Søren O

AU - Chadwick, David R

AU - Venterea, Rodney T

N1 - © 2020 The Authors. Journal of Environmental Quality published by Wiley Periodicals LLC on behalf of American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

PY - 2020/9

Y1 - 2020/9

N2 - Non-steady-state (NSS) chamber techniques have been used for decades to measure nitrous oxide (N2 O) fluxes from agricultural soils. These techniques are widely used because they are relatively inexpensive, easy to adopt, versatile, and adaptable to varying conditions. Much of our current understanding of the drivers of N2 O emissions is based on studies using NSS chambers. These chamber techniques require decisions regarding multiple methodological aspects (e.g., chamber materials and geometry, deployment, sample analysis, and data and statistical analysis), each of which may significantly affect the results. Variation in methodological details can lead to challenges in comparing results between studies and assessment of reliability and uncertainty. Therefore, the New Zealand Government, in support of the objectives of the Livestock Research Group of the Global Research Alliance on Agricultural Greenhouse Gases (GRA), funded two international projects to, first, develop standardized guidelines on the use of NSS chamber techniques and, second, refine them based on the most up to date knowledge and methods. This introductory paper summarizes a collection of papers that represent the revised guidelines. Each article summarizes existing knowledge and provides guidance and minimum requirements on chamber design, deployment, sample collection, storage and analysis, automated chambers, flux calculations, statistical analysis, emission factor estimation and data reporting, modeling, and "gap-filling" approaches. The minimum requirements are not meant to be highly prescriptive but instead provide researchers with clear direction on best practices and factors that need to be considered. Health and safety considerations of NSS chamber techniques are also provided with this introductory paper.

AB - Non-steady-state (NSS) chamber techniques have been used for decades to measure nitrous oxide (N2 O) fluxes from agricultural soils. These techniques are widely used because they are relatively inexpensive, easy to adopt, versatile, and adaptable to varying conditions. Much of our current understanding of the drivers of N2 O emissions is based on studies using NSS chambers. These chamber techniques require decisions regarding multiple methodological aspects (e.g., chamber materials and geometry, deployment, sample analysis, and data and statistical analysis), each of which may significantly affect the results. Variation in methodological details can lead to challenges in comparing results between studies and assessment of reliability and uncertainty. Therefore, the New Zealand Government, in support of the objectives of the Livestock Research Group of the Global Research Alliance on Agricultural Greenhouse Gases (GRA), funded two international projects to, first, develop standardized guidelines on the use of NSS chamber techniques and, second, refine them based on the most up to date knowledge and methods. This introductory paper summarizes a collection of papers that represent the revised guidelines. Each article summarizes existing knowledge and provides guidance and minimum requirements on chamber design, deployment, sample collection, storage and analysis, automated chambers, flux calculations, statistical analysis, emission factor estimation and data reporting, modeling, and "gap-filling" approaches. The minimum requirements are not meant to be highly prescriptive but instead provide researchers with clear direction on best practices and factors that need to be considered. Health and safety considerations of NSS chamber techniques are also provided with this introductory paper.

KW - New Zealand

KW - Nitrous Oxide/analysis

KW - Reproducibility of Results

KW - Research Design

KW - Soil

U2 - 10.1002/jeq2.20131

DO - 10.1002/jeq2.20131

M3 - Article

C2 - 33016437

VL - 49

SP - 1073

EP - 1080

JO - Journal of Environmental Quality

JF - Journal of Environmental Quality

SN - 0047-2425

IS - 5

ER -