Carbon sequestration and estimated carbon credit values as measured using 13 C labelling and analysis by means of an optical breath test analyser

Abstract

Recent developments in optical systems (isotope-selective non-dispersive infrared spectrometry) for breath testing have provided a robust, low-cost option for undertaking (13)C analysis. Although these systems were initially developed for breath testing for Helicobacter pylori, they have an enormous potential as a soil science research tool. The relatively low cost of the equipment, US$15,000-25,000, is within the research budgets of most institutes or universities. The simplicity of the mechanisms and optical nature mean that the equipment requires relatively low maintenance and minimal training. Thus methods were developed to prepare soil and plant materials for analysis using the breath test analyser. Results that compare conventional mass spectrometric methods with the breath test analyser will be presented. In combination with simple (13)C-plant-labeling techniques it is possible to devise methods for estimating carbon sequestration under different agronomic management practices within a short time frame. This enables assessment of the carbon credit value of a particular agronomic practice, which can in turn be used by policy makers for decision-making purposes. For global understanding of the effect of agricultural practices on the carbon cycle, data are required from a range of cropping systems and agro-ecological zones. The method and the approach described will enable collection of hard data within a reasonable time.

Stable isotope methods in biological and ecological studies of arthropods

“…It is also possible to label the plant only using stem/tree injection or leaf‐labelling techniques that introduce 15 N into the plant only, allowing soil communities to be studied (Hood & Blair, 2001). 13 C labelling of plants using chamber or tent systems is relatively simple and could also be used for such studies (Hood et al., 2004).…”

Measuring δ13C of atmospheric air with non-dispersive infrared spectroscopy

“…An NDIR type instrument for measuring δ 13 C was first used in 1996 for the diagnosis of Helicobacter pylori infections, and was soon also applied in hepatology, gastroenterology, and in dietary studies, as well as in studies of lactose deficiency and pancreas function [2][3][4][5]. These breath tests have the advantage of being non-invasive and easy to perform.…”

“…Monitoring sources of CO 2 is important for studying the ecosystem balance, as well as for verification purposes, for example, related to the Kyoto protocol. In medicine, the incorporation of a 13 C label into a substrate that undergoes a metabolic cycle may reveal the presence or stage of a disease, or may be used to monitor a variety of bodily functions [2][3][4][5].…”

Using the stable isotope marker 13C to study extrafloral nectar uptake by parasitoids under controlled conditions and in the field

“…The method allows to precisely label individual plants without contamination of the environment (Mahieu et al., ) which may be a problem with other plant‐enrichment techniques such as soil labelling and subsequent uptake from the soil (Unsicker et al., ). Gas‐tight labelling chambers (Hood et al., ) provide an alternative method to prevent environmental contamination but the set‐up is more complex and costly, in particular in the field. Foliage spraying (Hood & Blair, ) and foliage brushing (Putz et al., ) are more adapted to the field, but marker acquisition by the plant is more variable, solution uptake cannot be monitored, the rain can rinse out the labelling solution, and insects could acquire the marker just by walking on plants.…”

“…Various plant enrichment techniques have been developed, using soil watering and plant culture in isotopically enriched soil (Unsicker et al., ), gas‐tight labelling chambers (Hood et al., ), foliage spraying (Hood & Blair, ), foliage brushing (Putz et al., ), and stem injection (Russell & Fillery, ; Mahieu et al., ). These methods vary in the dynamics of marker absorption, the ability to label a particular plant species, the loss of labelling solution, and the required amount of marker.…”