Long-Term No-Tillage and Straw Retention Management Enhances Soil Bacterial Community Diversity and Soil Properties in Southern China

Abstract

Conservation farming practices, such as no-tillage and crop residue retention, have been proposed as sustainable management practices. However, it remains unclear how different tillage practices and rice straw retention affect the soil bacterial community (SBC) and the soil C/N ratio in the long term. The objective of this study was to evaluate changes in SBC composition and abundance and soil properties (e.g., carbon (C), nitrogen (N)) and determine their relationship to the soil C/N ratio under long-term no-tillage and straw retention techniques. This study investigates the effect of a long-term field experiment begun in 2008 and continued until 2019 to measure the response of the SBC and soil properties and their relation to different tillage practices, including no-tillage (NT), no-tillage and straw mulching (NT-SM), conventional tillage (CT), conventional tillage and straw mulching (CT-SM), and conventional tillage and straw retention (CT-SR). Soil samples were collected at depths of 0–5 cm (A), 5–10 cm (B), and 10–20 cm (C) after rice harvesting in the early and late growing seasons in 2018–2019. The Illumina MiSeq sequencing and quantitative polymerase chain reaction (PCR) technology was used to analyze changes in SBC diversity in soil and determined the changes in the soil C/N ratio and their relationship with the SBC diversity. The results showed that the Proteobacteria, Acidobacteria, and Chloroflexi were the dominant phyla in the soil and accounted for 61.26%, 59.39%, and 55.62% of the total bacteria in the A, B, and C soil layers, respectively. The NT treatment increased SBC diversity, the number of operational taxonomic units (OTUs), and the proportion of Proteobacteria across the soil depths. Similarly, straw retention also significantly improved SBC diversity, soil organic C(SOC), total N (TN), soil C/N ratio, and the abundance of Proteobacteria and Acidobacteria in the soil layers A and B. The NT-SM treatment increased the SOC, TN, and soil C/N ratio by 30%, 21%, and 6% in 2018 and by 33, 25% and 7% in 2019, respectively, across the seasons and layers compared to the CT treatment. The NT-SM treatment had the highest soil bacterial diversity index, and the CT-SR treatment had the highest soil bacterial abundance and number of OTUs. The redundancy analysis showed that Acidobacteria were highly positively correlated with the soil C/N ratio. The results demonstrate that conservation tillage practices, i.e., no-tillage and straw retention, increase the SBC diversity and soil C/N ratio, thereby enhancing soil organic C and total N and changing soil microbial ecology. As a result, sustainable crop production and profitable agro-ecosystems are ensured.

Co-incorporation of manure and inorganic fertilizer improves leaf physiological traits, rice production and soil functionality in a paddy field

“…Long-term use of chemical N fertilizer has also caused the acidification, degradation, and compaction of arable soils, thereby suppressing plant growth and productivity 9 , 10 . Moreover, the extreme use of N and phosphorus fertilizers also reduces the soil microbial population and increases soil acidity 11 , 12 . Therefore, the continued reliance on synthetic N fertilizer for cereal crop production is not sustainable.…”

Long‐term straw mulching in a no‐till field improves soil functionality and rice yield by increasing soil enzymatic activity and chemical properties in paddy soils

“…The improved grain yield of rice grown under CTP, compared with CT, is consistent with outcomes from many other studies (X. Wang et al., 2015; P. Zhang et al., 2016). The possible reasons for the enhanced grain yield are (1) straw incorporation returns nutrients into the soil that can be absorbed by plants (Luo et al., 2020); (2) straw incorporation adds organic matter thereby improving the soil physical, chemical, and biological parameters, which in turn contributes to increased grain yields (Kashif et al., 2018; P. Zhang et al., 2016); (3) higher soil total and available macronutrients and associated enzyme activities. Prior studies have reported that increased available N, P, and K and enzyme activities under CTPs led to higher grain yields (Das et al., 2017; Steward et al., 2019).…”

“…Compared with conventional tillage (CT), CTPs such as no‐tillage (NT), mulching, green manure, and straw retention (SR) on the soil surface decrease soil disturbance and enhance soil fertility, thereby increasing crop yields (W. Huang et al., 2021; Jaskulska & Jaskulski, 2020). Furthermore, these practices also lead to substantial changes in soil chemical and biological and change the activities of soil microbial communities (Kraut‐Cohen et al., 2020; Luo et al., 2020; Man et al., 2021). In NT systems, there is no actual tillage of land, and crop residues are left in fields to naturally decompose.…”

Contribution of enzymes to soil quality and the evolution of research in Brazil

“…Sustainable soil management systems (e.g., no-tillage; NT) can not only minimize soil organic carbon loss but create favorable conditions for balanced and healthy soil biological activity (Luo et al, 2020;Ramos et al, 2021). Different management systems in an Oxisol (Typic Haplorthox) were evaluated in a 24-year study.…”