Integrating bio-organic fertilization increases twice-yearly cabbage crop production by modulating soil microbial community and biochemical properties in Northwest Plateau

Abstract

Decreasing the reliance on chemical fertilizers and integrating bio-organic fertilizers are effective strategies for enhancing soil quality, promoting sustainable agricultural development, and protecting the environment. However, their impact on cabbage (Brassica oleracea L. var. capitata) cultivation in the Northwest Plateau remains unclear. The study investigated the impact of reducing chemical fertilizer by 30 %, combined with different amounts of bio-organic fertilizer (3000 kg·ha−1 for T1, 6000 kg·ha−1 for T2, and 12000 kg·ha−1 for T3), were examined in comparison to a conventional local fertilizer treatment (CK2), which served as the control. Our findings demonstrated significant improvements in soil properties and enzyme activities for T1, T2, and T3 treatments compared to CK2. Specifically, the contents of soil organic matter (SOM), available potassium (AK) and available phosphorus (AP) increased significantly by 10.06 %, 10.63 % and 18.33 %, respectively. Meanwhile, accompanied by a decrease in electrical conductivity (EC) values. Soil sucrase and urease activities can be enhanced by 10.43 % and 19.61 %, respectively. Redundancy analysis confirmed that SOM, AP, AK, and EC were the primary factors driving fluctuations in the microbial community structure. The addition of bio-organic fertilizer led to an increase in beneficial soil microorganisms. The abundance of Proteobacteria and Actinobacteria increased most strongly by 4.24 % and 8.75 %. The microbial community suggested that these beneficial microorganisms played essential roles in the cycling of nutrients, suppression of pest and disease, and the promotion of robust plant growth. Moreover, the addition of bio-organic fertilizer (T3) significantly improved plant growth, root/shoot ratio, and nutrient content, and increased the yield by 6.78 t·ha−1. Therefore, we suggest that a reduction in the use of chemical fertilizers along with the incorporation of bio-organic fertilizer, is an important measure for improving soil fertility, enriching soil microbial communities, and ensuring the safety of crops and the environment in the Northwest Plateau.