3.2. Root growth traits
The root traits decreased with increasing soil depth (Fig. 2). The
root weight was greatest in C2 under DT in the whole plough layer
and lower in C1 than in C2 in the 50–150mm depths particularly
under ST (Fig. 2a). The average root length was shorter under DT
than ST in both C1 and C2, and in C2 than in C1 under both DT and
ST in the whole plough layer (Fig. 2b). The average root length was
shorter in C2 than in C1 in all depths except for the 50–100mm
depth under DT and the >150mm depth under ST. The number of
root tips in the whole plough layer and the surface soil (0–50mm)
was smallest in C1 under ST (Fig. 2c).