Combined application of organic fertilizer and chemical fertilizer
(CAOFCF) is gaining more attention in sustainable agriculture
production. However, it remains unknown whether short-term CAOFCF can
improve soil properties and maize productivity simultaneously in a
medium-productivity meadow-cinnamon soil. In this study, a 3-year
(2019-2021) field experiment was established by arranging five
treatments: (1) CF, applying chemical fertilizer alone; (2) OFCF1, 15%
OF + 85% CF; (3) OFCF2, 30% OF + 70% CF; (4) OFCF3, 45% OF + 55%
CF; (5) OFCF4, 60% OF + 40% CF. The results showed that short-term
CAOFCF significantly increased topsoil aggregate stability with higher
percentage of macro-aggregate and mean weight diameter in topsoil.
Moreover, CAOFCF reduced soil bulk density and increased SOC
sequestration in topsoil compared to CF, especially for OFCF3 and OFCF4.
Although the soil bacterial diversity of CAOFCF treatments differed no
significantly with CF, OFCF1 and OFCF2 obviously increased soil urease,
sucrase, and acid phosphatase activities. Additionally, CAOFCF improved
the relative abundance of Actinobacteria and Chloroflexi, as well as
bacterial functional abundance. Compared with CF, OFCF1 and OFCF2
increased the root biomass, above-ground biomass, and grain yield
(p<0.05), but the difference in these indexes among CF, OFCF3
and OFCF4 were not obvious. The correlation analysis indicated that
there is no direct correlation between soil properties and grain yield.
Nevertheless, the soil urease and sucrase activities were positively
correlated with root biomass and root to shoot ratio, and root biomass
and root to shoot ratio were positively correlated with above-ground
biomass and grain yield. Overall, short-term CAOFCF with lower
application amount of organic fertilizer (i.e. 1.36-2.72 Mg ha
) can improve topsoil physicochemical properties,
soil enzymatic activities, as well as maize productivity in a
medium-productivity cinnamon soil, the higher crop productivity was
mainly attributed to the improved root system driven by urease and
sucrase activities.