1 Scope

2 Normative references

3 Terms and definitions

4 Procedure

4.1 General conditions

4.1.1 Soil sampling and storage

4.1.2 Measuring and incubation conditions

4.2 Choice of the measuring system

5 Measuring systems

5.1 Determination of O2 consumption by static incubation in a pressure-compensation system

5.1.1 Principle

5.1.2 Apparatus

5.1.3 Procedure

5.2 Determination of CO2 release by titration in a static system

5.2.1 Principle

5.2.2 Reagents

5.2.3 Apparatus

5.2.4 Procedure

5.2.5 Calculation of results

5.3 Coulometric determination of CO2 release in a static system

5.3.1 Principle

5.3.2 Test assembly

5.4 Determination of CO2 release using an infrared gas analyser in a flow-through system

5.4.1 Principle

5.4.2 Reagent

5.4.3 Apparatus

5.4.4 Procedure

5.4.5 Calculation and results

5.5 Determination of CO2 release using gas chromatography in a flow-through system and a static system

5.5.1 Principle

5.5.2 Reagents

5.5.3 Apparatus

5.5.4 Procedure

5.5.5 Detection

5.5.6 Calculation of results (method with syringe)

5.6 Determination of soil respiration by pressure measurement in a static system

5.6.1 Principle

5.6.2 Apparatus (see Figures 9 and 10)

5.6.3 Reagents

5.6.4 Procedure

5.6.5 Evaluation

Bibliography

ISO 16072:2002 (E)

		INTERNATIONAL STANDARD	ISO 16072 First edition 2002-12
		Soil quality — Laboratory methods for determination of microbial soil respiration Qualité du sol — Méthodes de laboratoire pour la détermination de la respiration microbienne du sol

Reference number

ISO 16072:2002 (E)

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester.

ISO copyright office

CP 401 • Ch. de Blandonnet 8

CH-1214 Vernier, Geneva

Tel. + 41 22 749 01 11

Fax + 41 22 749 09 47

E-mail copyright@iso.ch

Website www.iso.ch

Published in Switzerland

ISO 16072:2002 (E)

Contents Page

Foreword

Introduction

1 Scope

2 Normative references

3 Terms and definitions

4 Procedure

4.1 General conditions

4.1.1 Soil sampling and storage

4.1.2 Measuring and incubation conditions

4.2 Choice of the measuring system

5 Measuring systems

5.1 Determination of O2 consumption by static incubation in a pressure-compensation system

5.1.1 Principle

5.1.2 Apparatus

5.1.3 Procedure

5.2 Determination of CO2 release by titration in a static system

5.2.1 Principle

5.2.2 Reagents

5.2.3 Apparatus

5.2.4 Procedure

5.2.5 Calculation of results

5.3 Coulometric determination of CO2 release in a static system

5.3.1 Principle

5.3.2 Test assembly

5.4 Determination of CO2 release using an infrared gas analyser in a flow-through system

5.4.1 Principle

5.4.2 Reagent

5.4.3 Apparatus

5.4.4 Procedure

5.4.5 Calculation and results

5.5 Determination of CO2 release using gas chromatography in a flow-through system and a static system

5.5.1 Principle

5.5.2 Reagents

5.5.3 Apparatus

5.5.4 Procedure

5.5.5 Detection

5.5.6 Calculation of results (method with syringe)

5.6 Determination of soil respiration by pressure measurement in a static system

5.6.1 Principle

5.6.2 Apparatus (see Figures 9 and 10)

5.6.3 Reagents

5.6.4 Procedure

5.6.5 Evaluation

Bibliography

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 16072 was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 4, Biological methods.

Introduction

This International Standard is derived from the German standard DIN 19737 (see [1]). It describes methods for the determination of microbial soil respiration in the laboratory.

Microbial soil respiration results from the mineralization of organic substances. In this process, organic substances are oxidized to the end products carbon dioxide and water, with concurrent uptake of O2 for aerobic microorganisms. The soil respiration is measured by the determination of O2 consumption and/or by CO2 release. Respiration is a measure of the overall activity of soil microorganisms.

ISO 16072:2002 (E)

INTERNATIONAL STANDARD ISO 16072:2002 (E)

Soil quality — Laboratory methods for determination of microbial soil respiration

1 Scope

This International Standard describes methods for the determination of soil microbial respiration of aerobic, unsaturated soils. The methods are suitable for the determination of O2 uptake or CO2 release, either after addition of a substrate (substrate-induced respiration), or without substrate addition (basal respiration).

This International Standard is applicable to the measurement of soil respiration in order to:

—

determine the microbial activity in soil (see [3]);

—

establish the effect of additives (nutrients, pollutants, soil improvers, etc.) on the metabolic performance of microorganisms;

—

determine the microbial biomass (see [4]);

—

determine the metabolic quotient qCO2.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 10381-6:1993, Soil quality — Sampling — Guidance on the collection, handling and storage of soil for the assessment of aerobic microbial processes in the laboratory

ISO 11274:1998, Soil quality — Determination of the water-retention characteristic — Laboratory methods

ISO 11465:1993, Soil quality — Determination of dry matter and water content on a mass basis — Gravimetric method

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

3.1

basal respiration

microbial soil respiration without addition of nutrients

3.2

substrate-induced respiration

SIR

microbial soil respiration after addition of nutrients

Note 1 to entry: Glucose is an example of an added nutrient.

3.3

microbial activity

metabolic performance of microorganisms

Note 1 to entry: It can be measured, for example, as O2 uptake or CO2 release.

3.4

metabolic quotient

qCO2

specific metabolic activity of soil microorganisms, which can be calculated as the quotient basal respiration: microbial biomass

Note 1 to entry: Metabolic quotient is usually expressed as milligrams of CO2 carbon released per hour per gram of microbial biomass carbon.

3.5

rate of CO2 formation [O2 consumption]

RCO2 [RO2]

amount of CO2 released [O2 consumed] per time unit from a mass unit of soil

Note 1 to entry: Soil respiration is usually measured as the rate of CO2 formation or O2 consumption.

Note 2 to entry: It is usually expressed as milligrams CO2 [or O2] per gram per hour (mg CO2 [or O2]·g–1·h–1).

3.6

microbial biomass

mass of intact microbial cells in a given soil

Note 1 to entry: This is usually estimated from the measurement of carbon or nitrogen content of these cells.

ISO 16072:2002 (E)

Bibliography

[1]		DIN 19737:2001, Soil quality — Laboratory methods for the determination of microbial soil respiration
[2]		ISO 4796, Laboratory glassware
[3]		ISO 17155, Soil quality — Determination of abundance and activity of soil microflora using respiration curves
[4]		ISO 14240-1:1997, Soil quality — Determination of soil microbial biomass — Part 1: Substrate-induced respiration method
[5]		OECD Guideline for Ready Biodegradability
[6]		Nordgren, A. Apparatus for the continuous, longterm monitoring of soil respiration rate in large numbers of soil samples. Soil. Biochem. 20, 1988, pp. 955-957
[7]		Gupta, S.R. and Singh, J.S. Effect of alkali concentration, volume and absorption area on the measurement of soil respiration in tropical sward. Pedobiologia RO2, 1977, pp. 233-238
[8]		Watts, C.W., Eich, S. and Dexter, A.R. Effects of mechanical energy inputs on soil respiration at the aggregate and field scale. Soil Till. Res. RO2, 2000, pp. 231-243

ISO 16072:2002 (E)

ICS 13.080.30

Price based on 19 pages

ICS 13.080.30

Price based on 19 pages