Nuclear Technology Review 2011 - IAEA

ioinformatics. Access to genome databases and crop germplasm in gene banks
around the world through multilateral instruments provides valuable tools to
combat these key challenges facing food and agriculture.
Nuclear technology packages based on mutation induction and efficiency
enhancing biotechnologies can help to identify and exploit key traits for
adaptation to climate change and variability. These techniques can be extended to
forests, which also play a crucial role in climate stabilization.
E.4. Soil and water management
E.4.1. New frontiers for assessing soil carbon sequestration in farmlands
Soil organic carbon (SOC) is an important component of soil organic matter
that provides essential nutrients for crop growth, increases resilience against soil
erosion and improves water conservation. Increasing SOC storage, also known as
carbon sequestration, helps offset CO 2 emissions from farming activities such as
cropping and livestock production, while enhancing soil quality and water
retention, and decreasing nutrient losses. Soil carbon sequestration is the balance
between carbon inputs to soil through plant biomass and the release of carbon
from soil as CO 2 through microbial activity and the decomposition of organic
residues. Quantifying the extent of CO 2 released from soil and identifying its
source can help determine management factors that affect soil processes
influencing CO 2 release.
Stable isotopes of carbon (carbon-13 and carbon-12) in CO 2 released from
soil are used to assess organic matter dynamics, carbon sequestration potential
and the stabilization of carbon in soils. However, studies conducted in 2010 15
have shown that point measurements of carbon-13 are affected by soil and
atmospheric conditions at the given location and time of measurements. The
uncertainties in carbon-13 values associated with location and time can be
addressed through continuous and real time measurement of carbon-13. Gas
analysers, using near-infrared lasers with high analytical sensitivities have been
developed 16 to measure carbon-13 and carbon-12 in atmospheric CO 2 . These
portable analysers do not require frequent calibration and can be deployed in the
field. With such accuracy and robustness, these analysers provide more precise
quantification of soil carbon processes in agricultural landscapes across different
15 PHILLIPS, C.L., et al., Soil moisture effects on the carbon isotope composition of
soil respiration, Rapid Commun. in Mass Spectrom. 24 (2010), 1271-1280.
16 NICKERSON, N., RISK, D., Physical controls on the isotopic composition of soil
respired and CO 2, J. Geophys. Res. Biogeos. 114 (2009) G01016, doi:10.1029/2008JG000844.
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