Soil Microbial Community Structure Shifts Induced by Biochar and Biochar‐Based Fertilizer Amendment to Karst Calcareous Soil

Abstract

Biochar‐based fertilizer treatments induced significant microbial community structure shifts compared with no‐biochar and biochar alone. Biochar‐based fertilizer especially at higher biochar addition rate increased soil microbial biomass and fertility. Soil microbial species were strongly correlated with soil nutrients under biochar and biochar‐based fertilizer into karst soil. Karst ecosystems are vulnerable to degradation and constitute a significant proportion of southwestern China. Here, we explore the amendment of these soils with wood biochar in combination with N‐P‐K fertilizer and swine manure compost with the goal of improving microbial community structure and soil nutrient status of these soils. A pot experiment with six treatments, including control (CK, no amendment), swine manure compost plus N‐P‐K fertilizer (MF), wood biochar at 2% in soil (W2), wood biochar at 4% in soil (W4), wood biochar‐based fertilizer at 2% in soil (W2MF), and biochar‐based fertilizer at 4% in soil (W4MF), was set up for 20 months. The results showed that soil organic matter and soil available nutrients N, P, and K in W4MF increased by 63.95, 66.23, 284.96, and 94.56%, respectively, compared with CK. Soil microbial biomass C, N, and P increased in sequence by 60.05, 87.64, and 307.85%, respectively. Soil bacterial and fungal diversity indices (Simpson and Shannon) and richness index (Chao1) were generally higher in biochar‐based fertilizer treatments (W2MF and W4MF) than biochar alone (W2 and W4). The bacterial and fungal community structures of biochar based fertilizer treatments differed from those of biochar amendment alone or control (P < 0.05). Linear discriminant (Effect Size) analysis showed that the bacterial biomarkers of the W2MF + W4MF group were mainly the phylum Acidobacteria and class Alphaproteobacteria, and the fungal biomarkers were the phylum Rozellomycota and Glomeromycota. Redundancy analysis revealed strong relationships between microbial community structure and soil organic matter and soil available nutrients N, P, and K (P < 0.05). In conclusion, either sole biochar or biochar‐based fertilizer amendment improved karst soil nutrient conditions and induced microbial community structural shifts. The performance was better in biochar‐based fertilizer treatment than that in biochar addition alone.

Optimization of tobacco water‐fertilizer coupling scheme under effective microorganisms biochar‐based fertilizer application condition

“…Moreover, it can increase soil microbial diversity, induce microbial community structure shifts, improve tobacco‐planting soil nutrient conditions (Zhou et al., 2019), enhance soil aeration, increase water holding capacity, and cation exchange capacity (Zheng et al., 2013). Combined with proper irrigation, it promoted the absorption of nutrients by the roots, thereby improving the quality and yield of flue‐cured tobacco.…”

A scoping review on biochar-based fertilizers: enrichment techniques and agro-environmental application

“…Studies have shown that biochar-based organomineral fertilizers maintained higher labile carbon content in soil than compost and compost combined with biochar in a short-term incubation trial (Darby et al, 2016;Nguyen et al, 2017). Zhou et al (2019) observed an increase in SOM and nutrient contents in a karst region when using biochar enriched with NPK fertilizer. Similar results were reported by Wali et al (2020), whereby they noticed an increase in soil organic matter after using P enriched biochar.…”

“…The application of enriched biochar could also affect the soil microorganisms by altering the soil microbial community's abundance, activity, and diversity. In the study conducted by Zhou et al (2019), the addition of biochar fertilizer increased microbial biomass and bacterial biodiversity in karst calcareous soils, showing that this material had significant benefits in restoring degraded karst soils. In addition, there was an increase in the size and complexity of the microbial correlation network, which was reflected in the greater number of nodes, links, and nodules in the cladogram derived from the LEfSe analysis.…”

The Trends in Research on the Effects of Biochar on Soil

“…As a young and active research field, given the functional complexity of biochar, it is still necessary to conduct in-depth studies of the mechanisms by which biochar affects soil. This includes those that employ molecular biological methods, such as high-throughput sequencing, to study the biochar effects on soil microbes [81]. The effects of the long-term, continuous application of biochar on soil remain to be studied.…”