Abstract:
Objective The paper aims to explore the mechanism of bio-organic fertilizer application effect on tobacco rhizosphere bacteria, fungal community structure and Ralstonia solanacearum abundance.
Method The field research was carried out for a consecutive five-year fertilization experiment in Huayuan County, Xiangxi, Hunan Province. Here two fertilization treatments, conventional fertilizer (CF) and bio-organic fertilizer (BOF) were set up in the experiment to study the effect of fertilization on soil physicochemical properties and microbial communities.
Result Compared with CF treatment, the incidence of tobacco bacterial wilt disease was reduced by 89.8% and the relative abundance of Ralstonia solanacearum (R.solanacearum) was significantly decreased by 40.1% after applying bio-organic fertilizer. Soil pH, alkaline nitrogen (AN) and available phosphorus (AP) increased by 1.2%, 12.1% and 60.2%, respectively. Furthermore, the rhizosphere microbes, such as Roseiflexaceae, Gemmatimonadaceae, Nitrospira, Ramophialophora, Preussia, were significantly enriched after applying bio-organic fertilizer, and these potential beneficial bacteria were also negatively correlated with the relative abundance of R.solanacearum. Potential beneficial bacteria were found to be the most important biological factors affecting the relative abundance of R.solanacearum through ABT prediction model analysis.
Conclusion A consecutive five-year fertilizer regulation results indicated that the application of bio-organic fertilizer not only improved the soil condition of plants growing, with a significantly increase on soil pH, AN and AP, but also enrich the bacteria and fungi indicator species. The applying of bio-organic fertilizer also makes it possible for the increasing of rhizosphere potential beneficial bacteria and fungi, these microbes can inhibit the growth of R.solanacearum and prevent the occurrence of bacterial wilt disease.
下载: