Figure 1

Soil organic matter as affected by tillage treatments, 0–30 cm.
(a) Soil organic matter over 0–10 cm depth. (b) Soil organic matter over 10–20 cm depth. (c) Soil organic matter over 20–30 cm depth. (d) Dynamic changes of soil organic matter on six treatments at 0–30 cm soil depth. The colorimetric scale colors represent the soil organic matter content (g·kg−1).