Rice straw is the main source of organic C inputs in the paddy
fields and is often attributed to the increase in SOC concentration
after returning to paddyfields (Pan et al., 2004; Ji et al., 2012; Liu
et al., 2012). Rice straw is often incorporated to different soil depth
by using different powered machines (Liu et al., 2012), resulting in
a larger amount of rice straw incorporated to the shallow plough
layer. Using a three year experiments, the general objective of this
study was to examine the effects of rice straw incorporation and
tillage depth on soil puddlability, soil physical properties during
the rice growth period and then root growth traits. The specific
objective was to determine how soil mechanical properties from
puddling tillage, through the rice growth period, to harvest are
correlated with SOC concentration. It is hypothesized that SOC
concentration will positively influence soil mechanical properties,
but the correlation will be affected by wetting and drying cycles
during the rice growth period.