Optimization of tillage rotation and fertilization increases the soil
organic carbon pools and crop yields in a wheat-maize cropping system on
China's Loess Plateau
Abstract
Long-term application of high rates of nitrogen and phosphorus
fertilizers and mono-tillage practices can adversely affect soil health,
carbon sequestration and crop growth. A 10-year field experiment was
conducted in a wheat-maize cropping system on China’s Loess Plateau to
explore fertilization and tillage methods that improve SOC sequestration
and crop yields. We evaluated the effects of (1) fertilization (balanced
fertilization (BF), low fertilization (LF), and conventional
fertilization (CF)) and (2) alternating years of different tillage (no
tillage and subsoiling (NS), subsoiling and plowing (SP), plowing and no
tillage (PN)) or continuous plowing tillage (PP) on input-C, SOC pool,
and crop yields. BF and rotational tillage (NS, SP, and PN) increased
the amount and stabilization rate of input-C. BF increased SOC storage
compared to CF. Simultaneously, BF produced higher contents of SOC,
readily oxidizable C (ROC), dissolved organic C (DOC) and particulate
organic C (POC) and C pool management index (CMI) at 0-10 cm depth. For
tillage, SOC storages were increased by rotational tillage, the highest
was in NS. Rotational tillage increased SOC content, labile C contents
and CMI at 0-10 cm depth. Moreover, NS also had positive effect on these
parameters at 35-50 cm depth, which improved soil quality. Crop yields
were positively correlated with SOC, labile C, and CMI. Crop yields were
increased by BF and rotational tillage, the highest were in BF+NS
treatment. Therefore, NS combined with BF may be the best management for
increasing SOC storage, improving soil quality and productivity on
China’s Loess Plateau.