Humic acid (HA) and fulvic acid (FA) are dominating humic substances (HS) in soil. In this study, the effects of HA and FA addition (0.2%-1.5%) on arsenic (As) mobility and microbial community composition in paddy soil were investigated. FA significantly increased the concentrations of As (12-fold), iron (Fe; 20-fold), manganese (Mn; 3-fold) and acetic acid (3-fold) in soil porewater, and also caused significant enrichment of Desulfitobacterium (41-fold). Furthermore, the FA addition significantly increased the relative abundance of Bathyarchaeota (4-fold), a microorganism that is suggested to be important for FA degradation. In contrast, HA slightly increased As (1.2-fold) in porewater, had little effect on Fe, Mn and acetic acid, and 1.5% HA addition significantly decreased As in porewater at day 14 (45%). Both HA and FA addition promoted As methylation. HA increased dimethylarsenate concentration and FA increased monomethylarsenate concentration in porewater. These results highlight the contrasting effects of different (HA vs. FA) organic substances on As fate in paddy soil and advance our understanding of the associations among As, Fe and organic substances through microorganisms in paddy soil.
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http://dx.doi.org/10.1016/j.jhazmat.2019.03.113 | DOI Listing |
Plants (Basel)
December 2024
State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Rice is a critical crop for human sustenance worldwide. Food security has increasingly attracted public concerns, particularly due to heavy metal pollution, which adversely impacts crop yield and quality, with cadmium and mercury being the primary culprits. Excessive soil mercury not only hampers rice's growth and development but also leads to a substantial accumulation in grains, posing a significant threat to human health.
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December 2024
Agronomy College, Jinlin Agricultural University, Changchun 130118, China.
Straw return plays a vital role in crop yield and sustainable agriculture. Extensive research has focused on the potential to enhance soil fertility and crop yield through straw return. However, the potential impacts of straw return on saline-sodic soils have been relatively neglected due to the unfavorable characteristics of saline-sodic soils, such as high salinity, poor structure, and low nutrient contents, which are not conducive to crop growth.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.
Methylmercury in paddy soils poses threats to food security and thus human health. Redox-active phenolic and quinone moieties of natural organic matter (NOM) mediate electron transfer between microbes and mercury during mercury reduction. However, their role in mercury methylation remains elusive.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Molecular Biology and Biotechnology, University of Dar-es-salaam, Tanzania.
Sustainable agricultural practices are essential to meet food demands for the increased population while minimizing the environmental impact. Considering rice as staple food for most of the world's population, it requires innovative approaches to ensure sustainable production. In this paper, we create a hypothesis that integrated nutrient management (INM) acts as a source of energy for microbes and improves the physical, chemical and biological properties of soils, but the current understanding of how soil microbiomes interact in integrated nutrient management toward mediating climate stress to support sustainable rice crop production is limited.
View Article and Find Full Text PDFAmmonia oxidation plays a vital role in regulating soil nitrogen (N) cycle in agricultural soil, which is significantly influenced by different fertilizer regimes. However, there is still need to further investigate the effects of different fertilizer managements on rhizosphere soil ammonia-oxidizing archaea (AOA) and bacteria (AOB) community in the double-cropping rice field. Therefore, the effects of different long-term (37 years) fertilizer managements on rhizosphere soil potential nitrification activity (PNA), AOA and AOB community structure, and its relationship under the double-cropping rice system in southern of China were studied in the present paper.
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