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 nitrogen and phosphorus fertilizer 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 the Loess Plateau in China 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 ploughing (SP),
ploughing and no-tillage (PN)) or continuous ploughing 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, thereby
increased SOC storage, and the highest effect was found in BF+NS
treatment. Simultaneously, BF produced higher contents of SOC, readily
oxidizable carbon (ROC), particulate organic carbon (POC) and dissolved
organic carbon (DOC) and C pool management index (CMI) at 0-10 cm depth.
For tillage, rotational tillage increased labile C contents and CMI at
0-10 cm, 20-35 cm and 35-50 cm depths, which improved soil quality. Crop
yields showed an increase tendency with the increases of SOC content,
labile C fraction contents, and CMI. Therefore, the higher yields of
wheat and maize were found in BF and rotational tillage; the highest
were in BF+NS treatment. Our finding suggested that NS combined with BF
may be the best management to increase SOC storage, improve soil quality
and productivity on China’s Loess Plateau.