%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Barthès, Bernard
%A Kouakoua, Ernest
%A Moulin Esmard, Patricia
%A Hmaidi, K.
%A Gallali, T.
%A Clairotte, M.
%A Bernoux, Martial
%A Bourdon, Emmanuel
%A Toucet, Joële
%A Chevallier, Tiphaine
%T Studying the physical protection of soil carbon with quantitative infrared spectroscopy
%B Near infrared spectroscopy of soils
%D 2016
%E Viscarra Rossela, R.A.
%E Stenberg, B.
%L fdi:010067291
%G ENG
%J Journal of Near Infrared Spectroscopy
%@ 0967-0335
%K SOL ; MATIERE ORGANIQUE ; CARBONE ; SPECTROSCOPIE ; REFLECTANCE ; RESPIRATION ; ANALYSE MULTIVARIABLE
%K TUNISIE
%M ISI:000381677800002
%N 3
%P 199-214
%R 10.1255/jnirs.1232
%U https://www.documentation.ird.fr/hor/fdi:010067291
%> https://www.documentation.ird.fr/intranet/publi/depot/2016-07-27/010067291.pdf
%V 24
%W Horizon (IRD)
%X Near infrared (NIR) and mid-infrared (mid-IR) reflectance spectroscopy are time- and cost-effective tools for characterising soil organic carbon (SOC). Here they were used for quantifying (i) carbon (C) dioxide (CO2) emission from soil samples crushed to 2 mm and 0.2 mm, at 18°C and 28°C; (ii) physical C protection, calculated as the difference between CO2 emissions from 0.2 mm and 2 mm crushed soil at a given temperature; and (iii) the temperature vulnerability of this protection, calculated as the difference between C protection at 18°C and 28°C. This was done for 97 topsoil samples from Tunisia, mostly calcareous, which were incubated for 21 days. Soil CO2 emission increased with temperature and fine crushing. However, C protection in 0.2–2 mm aggregates had little effect on the temperature vulnerability of CO2 emission, possibly due to preferential SOC protection in smaller aggregates. In general, NIR spectroscopy, and to a lesser extent mid-IR spectroscopy, yielded accurate predictions of soil CO2 emission (0.60 ≤ R2 ≤ 0.91), and acceptable predictions of C protection at the beginning of incubation (0.52 ≤ R2 ≤ 0.81) but not over the whole 21 day period (R2 ≤ 0.59). For CO2 emission, prediction error was the same order of magnitude as, and sometimes similar to, the uncertainty of conventional determination, indicating that a noticeable proportion of the former could be attributed to the latter. The temperature vulnerability of C protection could not be modelled correctly (R2 ≤ 0.11), due to error propagation. The prediction of SOC was better with NIR spectroscopy and that of soil inorganic C (SIC) was very accurate (R2 ≥ 0.94), especially with mid-IR spectroscopy. Soil CO2 emission, C protection and its vulnerability were best predicted with NIR spectra, those of 0.2 mm samples especially. With 2 mm samples, mid-IR spectroscopy yielded the worst predictions in general. NIR spectroscopy prediction models suggested that CO2 emission and C protection depended (i) on aliphatic compounds (i.e. labile substrates), dominantly at 18°C; (ii) on amides or proteins (i.e. microbial biomass), markedly at 28°C; and (iii) negatively, on organohalogens and aromatic amines (i.e. pesticides). Models using mid-IR spectra showed a negative influence of carbonates on CO2 emission, suggesting they did not contribute to soil CO2 emission and might form during incubation. They also suggested that CO2 emission and C protection related to carboxylic acids, saturated aliphatic ones especially.
%$ 068ANASOL