HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Müller, C. Articles by Jäger, H.-J. Search for Related Content PubMed Articles by Müller, C. Articles by Jäger, H.-J. Agricola Articles by Müller, C. Articles by Jäger, H.-J. Related Collections Microbial Processes Soil Organic Matter

Soil Respiratory Quotient Determined via Barometric Process Separation Combined with Nitrogen-15 Labeling

^a Dep. of Plant Ecology, Univ. of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
^b Soil, Plant and Ecological Sciences Division, Soil and Physical Sciences Group, P.O. Box 84, Lincoln Univ., Canterbury, New Zealand
^c Agriculture, Food and Environmental Science Division, The Dep. of Agriculture and Rural Development, Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK

View larger version (18K): [in a new window]   Fig. 1. Gross nitrification rates [avg ± standard deviation(15N) or ±error (BaPS)] determined by BaPS and the 15N dilution techniques (using the default value for the respiratory quotient, RQSOM, of 1.0) for soil incubated at 20°C (the error calculated by BaPS is based on error propagation instead of standard deviation, see Materials and Methods above for further explanations).

View larger version (25K): [in a new window]   Fig. 2. Gross nitrification rates [avg ± standard deviation (15N) or ±error (BaPS)] determined by the 15N dilution technique and by the BaPS technique after adjustment of aut/(aut + het) ratio with measured ratios and optimization of the respiratory quotient (RQSOM) for soil incubated at 20°C.

View larger version (21K): [in a new window]   Fig. 3. Carbon dioxide respiration and O2 consumption by the SOM and nitrification at the three measurement times after N addition to soil incubated at 20°C.

View larger version (16K): [in a new window]   Fig. 4. Relationship between the difference of RQSOM – RQnet expressed as a fraction of RQnet and the ratio of total soil CO2 production to gross nitrification from BaPS measurements performed on the same grassland soil at field conditions between 2001–2003.

View larger version (18K): [in a new window]   Fig. 5. The influence of gross nitrification rates on the calculated respiratory quotient (RQSOM) of the barometric process separation calculations at 1.4, 22.5, and 69.9 h after N application to soil incubated at 20°C (regression lines are in the form of a quadratic equation: Y = a + bx + cx2).