Potato Fermented Fertilizer Modulates Soil Nitrification by Shift Niche of Functional Microorganisms to Increase Yield in North China

Aims: Potato starch wastewater contains higher contents of essential nutrients, which can be feritilizer to help crop growth. However, the effects of potato fermented fertilizer on soil ecology and soil microbial community structure have not yet been elucidated. The objective of this study was to investigate the shifts of active ammonia oxidation microbial communities under different fertilization in a typical soil from North China. Methods The different levels of potato fermented fertilizer without or with chemical fertilizer were designed by field experiment. Results The results showed that the application of potato fermented fertilizer could significantly increase crop yields by 165–399% compared to Control. The content of available soil nutrients and the activity of saccharase and cellulase were increased when potato fermented fertilizer was applied, and the combination fertilizers further increased the content of Olsen-P by 145.6-166.7%, NO 3 − by 15.2–81.1%, Total C by 13.8–14%, and Total N by 27.2–34.7% compared with potato fermented fertilizer (PW) treatments. Furthermore, the fermented potato fertilizer significantly stimulated the diversity of soil microbial community, and increased the differentiation and stability of soil microbial networks in deep soils. Finally, the change of niche of soil Comammox(COM), ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB) was found after PW treatments, showed a significant positive correlation between AOA and COM (r = 0.79, P < 0.01), AOB and NOB (r = 0.7, P < 0.05) instead of theoretically the competitive relationship between AOA and COM. Conclusions Potato fermented fertilizer modulates soil nitrification strategy by change the niche of soil functional microorganisms to increase fast-acting nutrients and increase crop yield.