Partial Substation of Organic Fertilizer With Chemical Fertilizer Improves Soil Biochemical Attributes, Rice Yields, and Restores Bacterial Community Diversity in a Paddy Field

Abstract

Conventional farming systems are highly reliant on chemical fertilizers (CFs), which adversely affect soil quality, crop production and the environment. One of the major current challenges of current agriculture is finding ways to increase soil health and crop yield sustainably. Manure application as a substitute for CF is an alternative fertilization strategy for maintaining soil health and biodiversity. However, little is known about the complex response of soil bacterial communities and soil nutrients to manure and CFs application. This study reports the response of soil nutrients, rice yield, and soil microbial community structure to 2 years of continuous manure and CFs application. The study consisted of six treatments: no N fertilizer control (Neg-Con); 100% CF (Pos-Con); 60% cattle manure (CM) + 40% CF (High-CM); 30% CM + 70% CF (Low-CM); 60% poultry manure (PM) + 40% CF (High-PM), and 30% PM + 70% CF (Low-PM). We used high-throughput sequencing of 16S ribosomal RNA gene amplicons to characterize the soil bacterial communities. Results revealed that the addition of manure significantly altered the soil bacterial community composition and structure; and enhanced the relative abundance of phyla Proteobacteria, Chloroflexi, Firmicutes, Acidobacteria, and Planctomycetes. Organic fertilizer treatments, particularly high CM and PM had the highest measured soil bacterial diversity of all treatments. Similarly, integrated application of manure and CFs increased the soil biochemical traits [i.e., pH, total N (TN), soil organic C (SOC), microbial biomass N (MBN), and microbial biomass C (MBC)] and rice grain yield. Average increases in SOC, TN, MBN, and MBC were 43.66, 31.57, 24.34, and 49.45%, respectively, over the years in the High-PM compared with Pos-Con. Redundancy analysis showed that the dominant bacteria phyla were correlated with soil pH, SOC, TN, and microbial biomass, but the relative abundance of Proteobacteria was strongly correlated with environmental factors such as soil pH, SOC, TN, and MBC. We employed a structural equation model to examine the relationship between microbial biomass, soil nutrients and grain yield among treatments. This analysis supported the hypothesis that soil nutrient content and availability directly affect rice grain yield while soil bacteria indirectly affect grain yield through microbial biomass production and nutrient levels. Overall, the findings of this research suggest that the integrated application of CF and manure is a better approach for improving soil health and rice yield.

Microbial community composition in the dung of five sympatric European herbivore species

“…We observed significant correlations between microbial communities and nutrient concentrations and/or ratios in the dung of herbivores. The abundance of Firmicutes was significantly positively correlated with P, C, and C:N, while the abundance of Proteobacteria and Bacteroidota were positively correlated with N and N:P. The dominant fungal flora, Ascomycota was positively correlated with C and N:P. These observations on the correlation between the abundance of these microbial species and environmental factors in the herbivore dungare in line with the results of previous studies about the variation of the microbial community in the soil fertilized by dung (Iqbal et al., 2022 ; Tayyab et al., 2019 ). The diversity of both fungi and bacteria increased with C and C:N in our study, which is in line with studies about the variation of soil microbial community relating to its stoichiometry (Yang et al., 2022 ; Zhu et al., 2022 ).…”

Effect of different fertilization strategies on the yield, quality of Euryales Semen and soil microbial community

“…In our study, the T3 treatment exhibited the highest relative abundance of Proteobacteria, consistent with the findings of Iqbal et al (2022) , who reported higher Proteobacteria abundance in response to high organic fertilizer rates.…”

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

“…The fungal abundance was positively correlated with soil organic carbon content ( Figure 7C ) demonstrating that organic fertilizer application increased fungal substrates to improve soil fungal abundance, which might, in turn, increase fungal function in nutrient cycling (Chen et al, 2021 ; Hou et al, 2022 ). Prior studies have reported that soil pH determined microbial diversity (Ali et al, 2020 , 2021 ; Iqbal et al, 2022c ). This study also found that soil fungal diversity showed a significant positive correlation with soil pH ( Figure 7C ), as the sole application of chemical fertilizers decreased soil pH, resulting in lower belowground fungal diversity ( Figure 5 ).…”

“…The application of organic amendments has been reported to maintain microbial diversity and sometimes increase microbial populations (Liu et al, 2021 ). Manure application can change a soil's physical and biochemical properties, improve soil enzyme activities, and decrease or eliminate harmful impacts of the CF-only overuse on soil health (Zhang et al, 2022; Iqbal et al, 2022a ). Therefore, a change in the source of N fertilizer is urgently needed to reduce the adverse effects of synthetic N fertilization.…”