5 Conclusions
The soil labile organic C fractions, except for basal respiration, were generally increased after bio-fertilizer application, which was helpful to C fixation in soil. The proportions of macro-aggregate and aggregate stability assessed by mean weight diameter were also significantly improved by bio-fertilizer. This research showed that bio-fertilizer supplement had significant positive effects on soil C sequestration and soil aggregate stability. It was recorded that the supplement of 50% bio-fertilizer combined with chemical fertilizer was more effective. Considering the increases of soil C and aggregate stability, it was believed that bio-fertilizer made markedly contributions to soil physical and chemical properties.
Therefore, we concluded that 50% bio-fertilizer supplemented chemical fertilizer could effectively improve soil C fixation and soil aggregate stability in a sustainable way. This study, however, was a snapshot record only after two year’s bio-fertilizer application. Thus, long-term experiment was required to complete assess the effects of bio-fertilizer application.
Acknowledgements This research was financially supported by the National Key Research and Development Program of China (2018YFD0300704), Foundation of He’nan Educational Committee (20B210025), and the School-based Project of Zhoukou Normal University (ZKNUC2018012).