Effects of different fertilization conditions and different geographical locations on the diversity and composition of the rhizosphere microbiota of Qingke (Hordeum vulgare L.) plants in different growth stages

Abstract

IntroductionThe excessive use of chemical fertilizer causes increasing environmental and food security crisis. Organic fertilizer improves physical and biological activities of soil. Rhizosphere microbiota, which consist of highly diverse microorganisms, play an important role in soil quality. However, there is limited information about the effects of different fertilization conditions on the growth of Qingke plants and composition of the rhizosphere microbiota of the plants.MethodsIn this study, we characterized the rhizosphere microbiota of Qingke plants grown in three main Qingke-producing areas (Tibet, Qinghai, and Gansu). In each of the three areas, seven different fertilization conditions (m1–m7, m1: Unfertilized; m2: Farmer Practice; m3: 75% Farmer Practice; m4: 75% Farmer Practice +25% Organic manure; m5: 50% Farmer Practice; m6: 50% Farmer Practice +50% Organic manure; m7: 100% Organic manure) were applied. The growth and yields of the Qingke plants were also compared under the seven fertilization conditions.ResultsThere were significant differences in alpha diversity indices among the three areas. In each area, differences in fertilization conditions and differences in the growth stages of Qingke plants resulted in differences in the beta diversity of the rhizosphere microbiota. Meanwhile, in each area, fertilization conditions, soil depths, and the growth stages of Qingke plants significantly affected the relative abundance of the top 10 phyla and the top 20 bacterial genera. For most of microbial pairs established through network analysis, the significance of their correlations in each of the microbial co-occurrence networks of the three experimental sites was different. Moreover, in each of the three networks, there were significant differences in relative abundance and genera among most nodes (i.e., the genera Pseudonocardia, Skermanella, Pseudonocardia, Skermanella, Aridibacter, and Illumatobacter). The soil chemical properties (i.e., TN, TP, SOM, AN, AK, CEC, Ca, and K) were positively or negatively correlated with the relative abundance of the top 30 genera derived from the three main Qingke-producing areas (p < 0.05). Fertilization conditions markedly influenced the height of a Qingke plant, the number of spikes in a Qingke plant, the number of kernels in a spike, and the fresh weight of a Qingke plant. Considering the yield, the most effective fertilization conditions for Qingke is combining application 50% chemical fertilizer and 50% organic manure.ConclusionThe results of the present study can provide theoretical basis for practice of reducing the use of chemical fertilizer in agriculture.

Fertilising Maize with Bio-Based Mineral Fertilisers Gives Similar Growth to Conventional Fertilisers and Does Not Alter Soil Microbiome

“…Cluster B, consisting of Skermanella, Flavisolibacter, and Microvirga, exhibited strong positive correlations with fresh weight (FW), dry weight (DW), and nitrogen (N), phosphorus (P), and potassium (K) content. This cluster comprises beneficial microorganisms such as Skermanella, a diazotroph commonly found in soil and reported as a biological control agent [76,77]; Flavisolibacter, a PGPR phosphate solubiliser and indole-3-acetic acid (IAA) producer [78]; and Microvirga, a nitrogen-fixing bacterium [79,80].…”

Deciphering key factors in pathogen-suppressive microbiome assembly in the rhizosphere

“…However, the utilization of pesticides and chemical fertilizers has remarkably increased since the green revolution, leading to consequential outcomes on the rhizosphere microbial community ( Newman et al., 2016 ; John and Babu, 2021 ; Sangiorgio et al., 2022 ), despite substantial achievements in transforming global food production ( Pinstrup-Andersen and Hazell, 1985 ). Regardless of the goals of reducing the effects through optimum utilization ( Tilman, 1998 ), chemical fertilizers and pesticides are being used extensively, and they continue to chronically affect the soil microbiome ( Wang et al., 2023b ).…”