Table 1. The types and amounts of fertilizers used in the experiments, the unit used is g.

Fertilizer types	Low-level (1)	Medium-level (2)	High-level (3)
SF	0.677	1.354	2.708
SY	2.03	4.06	8.08
CN	0.2187	0.4374	0.8748
CK	0

Notes.

SF

inorganic fertilizer

SY

organic fertilizer

CN

nitrogenous fertilizer

CK

no fertilization treatment

1, 2, and 3 represent the different fertilization levels according to the pure N setting.