<Fig. 11>
4.3 Implications and
limitations
Our study explored the spatiotemporal changes of cropland SOC in a
rapidly urbanizing area and identified their primary drivers. We found
that, although the enhanced soil C input benefited the cropland SOC
accumulation during 1980-2000, the rapid urban expansion and industrial
economic growth during the subsequent 15 years may lowering SOC due to
the decreased soil C input. The urbanizing and industrializing area may
overlook the development of agriculture, and the low economic investment
in cropland management often caused decreased C input in cropland soils,
which implied that the coordinated development of industry, agriculture,
and urbanization process is particularly important for cropland SOC
sequestration.
Our study investigated the spatiotemporal changes of SOC at a time scale
of more than 10 years. However, using the geostatistical method to
explore changes in SOC over a shorter time period (i.e., a time period
of fewer than five years) may be not feasible, because the detectable
changes in SOC still can not be directly measured due to the high
stability of SOC pools and slow turnover time of SOC (Yang et al., 2015;
Yang et al., 2020). Therefore, the development of new methodologies for
incorporating SOC dynamical mechanism into the geostatistical mapping
framework (i.e., through the “space for time” method) is necessary.