Biochar Amendment and Nitrogen Fertilizer Contribute to the Changes in Soil Properties and Microbial Communities in a Paddy Field

Abstract

Biochar amendment can influence the abundance, activity, and community structure of soil microbes. However, scare information is present about the effect of the combined application of biochar with synthetic nitrogen (N) fertilizer under paddy field condition. We aimed to resolve this research gap in rice field conditions through different biochar in combination with N fertilizers on soil nutrients, soil microbial communities, and rice grain yield. The present study involves eight treatments in the form of biochar (0, 10, 20, and 30 t ha–1) and N (135 and 180 kg ha–1) fertilizer amendments. The soil microbial communities were characterized using high-throughput sequencing of 16S and Internal transcribed spacer (ITS) ribosomal RNA gene amplicons. Experiential findings showed that the treatments had biochar amendments along with N fertilizer significantly advanced soil pH, soil organic carbon (SOC), total nitrogen (TN), soil microbial carbon (SMBC), soil microbial nitrogen (SMBN), and rice grain yield in comparison to sole N application. Furthermore, in comparison with control in the first year (2019), biochar amendment mixed with N fertilizer had more desirable relative abundance of microorganism, phyla Acidobacteria, Actinobacteria, Proteobacteria, and Verrucomicrobia with better relative abundance ranging from 8.49, 4.60, 46.30, and 1.51% in T7, respectively. Similarly, during 2020, bacteria phyla Acidobacteria, Actinobacteria, Bacteroidetes, Gemmatimonadetes, Planctomycetes, and Verrucomicrobia were resulted in higher and ranging from 8.69, 5.18, 3.5, 1.9, 4.0, and 1.6%, in biochar applied treatments, respectively, as compared to control (T1). Among the treatments, Sphingopyxis and Thiobacillus bacterial genus were in higher proportion in T7 and T3, respectively, as compared to other treatments and Bacillus was higher in T6. Interestingly, biochar addition significantly decreased the soil fungi phyla Ascomycota, Basidiomycota, Chytridiomycota, and Rozellomycota, in 2020 as compared to 2019. Whereas biochar addition to soil decreased Echria, Kohlmeyeriopsis, and Westerdykella fungal genus as compared to non-biochar treatments. The redundancy analysis showed that soil biochemical traits were positively correlated with soil bacteria. In addition, correlation analysis showed that soil bacteria including Acidobacteria, Actinobacteria, Bacteroidetes, Planctomycetes, and Proteobacteria strongly correlated with rice grain yield. This study demonstrated that soil nutrients and bacteria contribute to an increase in rice yield in combined biochar amendment with lower N treatments.

Changes in Soil Microbial Community along a Chronosequence of Perennial Mugwort Cropping in Northern China Plain

“…This could alleviate the soil acidification process under fertilization in the short-term. By contrast, previous studies have demonstrated that most soil microbes favor acidic or neutral environments [2,45], which could lead to the negative dependence of microbial PLFAs on soil pH in this study.…”

“…Previous studies have shown that pH is an important factor affecting the microbial community in agro-ecosystems [31,32,44]. However, it was observed that negative relationships of microbial PLFAs with soil pH (except for fungi PLFAs) are inconsistent with those found in previous studies [2,32]. The difference may result from the different soil types, crops, as well as management.…”

“…Soil microorganisms play critical roles in regulating key and fundamental ecosystem processes, such as decomposition of organic matter, nutrient mineralization and cycling, as well as plant nutrient uptake and growth [1][2][3]. Evidence has shown that land-use types/intensities could have vital impacts on soil microbes [4][5][6][7].…”

Effect of Biochar Application to Fertile Soil on Tomato Crop Production under Saline Irrigation Regime

“…The properties of soil such as pH, bulk density (BD), water-holding capacity (WHC), and cation-exchange capacity (CEC) could be relatively improved upon by biochar efficient addition [4,5]. The central factors behind the positive effect of biochar on soil properties thus crop productivity could be briefly arranged as follows: (i) increasing cationexchange capacity (CEC) of soil due to increased negative surface charged area by carboxyl groups; enhanced CEC soils absorb more nutrients and subsequently enhance nutrient availability for plants, in particular, that of N [6], (ii) enhancing crop tolerance to drought by elevating soil water holding capacity (WHC) [7], (iii) the potentiality to enhance microbial activity which could be beneficial to plant growth and development, and in addition, enhance plants' defenses against several diseases [8], and (iv) reducing the bioavailability of heavy metals, sodium ions, and organic pollutants in the soil by adsorbing them through biochar-extended charged surface areas [9].…”

Combined Application of Manure and Chemical Fertilizers Alters Soil Environmental Variables and Improves Soil Fungal Community Composition and Rice Grain Yield

“…Furthermore, the use of synthetic fertilizers alters fungal community structure and decreases external mycelium arbuscular mycorrhizal of soil fungi, whereas the use of organic fertilizers increases it (Paungfoo-Lonhienne et al, 2015 ; Jin et al, 2022 ). Alternatively, organic manure fertilization (i.e., farmyard and green manure) improves soil structure and fertility by increasing soil nutrient availability and organic matter (Zhang et al, 2021 ; Ali et al, 2022 ). The application of organic amendments has been reported to maintain microbial diversity and sometimes increase microbial populations (Liu et al, 2021 ).…”