Search Results (4)

Tetracyclines (TCs) pollution in vegetable fields is a widely recognized concern, yet the health and ecological risks of TCs residues in the soil–cabbage food chain remain unclear. This study used enzyme-linked immunosorbent assay (ELISA) to investigate the health risks associated with TCs contamination in soil–cabbage (Brassica campestris L. ssp. chinensis) systems to better understand TCs accumulation in soil–cabbage and its impact on human health. The human health risks of the edible parts of Chinese cabbage and the ecological risks of TCs-contaminated soils were assessed using the health risk quotient method (RQ) and risk quotient method, respectively. The results showed that after 65 days of tetracycline (TC), chlortetracycline (CTC), and oxytetracycline (OTC) treatments, the degradation rates of TCs in soil were higher in black soil than in purplish clay soil, following the order of OTC > CTC > TC. As the three types of TCs concentration increased (0–20 mg kg⁻¹), their accumulation in the leaves and roots of Chinese cabbage in purplish clay soil was generally higher than in black soil. The health risk values of the three types of TCs in Chinese cabbage were also higher in purplish clay soil than in black soil, following the order of TC > CTC > OTC. Under controlled pot experimental conditions, the TC content in Chinese cabbage grown in purplish clay soil posed moderate risks to children aged 1–6 years (0.1 < HQ < 1.0), while the CTC and OTC contents in Chinese cabbage leaves indicated low risks to both adults and children (HQ ≤ 0.1). Additionally, all three TCs in both soils posed high ecological risks (RQ ≥ 1.0), with risk values being higher in purplish clay soil than in black soil, following the order of TC > CTC > OTC. Consequently, more fertile soils can help mitigate the impact of TCs pollution on human health and ecological safety. Full article

Purple soil is a type of global soil that is referred to by various names in different countries, which makes it difficult to understand, utilize, and ameliorate purple soil internationally. Soil Taxonomy (ST) and the World Reference Base for Soil Resources (WRB) are the most widely used soil classification systems in the world. The aim of this study was to clarify the classification of purple soil in ST and the WRB and to establish a reference between different classification systems of purple soil. Therefore, based on the current principles and methods of the ST and WRB systems, 18 typical purple soil profiles in the eastern Sichuan Basin were identified, retrieved, and classified. Then, the soil units of the WRB were compared with those of ST and the Chinese Soil Taxonomy (CST). The results revealed that the 18 typical purple soil profiles could be classified into three soil orders, four soil group orders, and seven soil subgroups in ST and four reference soil groups (RSGs) in the WRB; each profile had its own unique principal and supplementary qualifier combinations within the soil units. It was found that when compared with the ST system, the WRB and CST systems had stronger abilities to distinguish purple soil. In addition, the WRB system was able to more comprehensively consider soil characteristics such as soil layer thickness, ferric horizon, soil color, texture mutations, and carbonate through qualifiers. However, the CST system added diagnostic characteristics, such as the lithologic characteristics of purplish sandstones and shales and the ferric properties and alic properties at the soil group and subgroup levels, which enhanced the differentiation ability of the purple soil at the subgroup level. Full article

During a study of biodiversity of cyanobacteria in Gorely volcano soils (Kamchatka Peninsula), a strain of heterocytous, a false branching cyanobacterium with gradually tapered filaments, was isolated. Prominent features of the strain were purplish-grey trichomes and firm, distinct multilayered sheaths. Based on the results obtained from the morphological, ecological, and phylogenetic analysis using the 16S rRNA and 16S–23S ITS region, 16S–23S ITS secondary structure analysis, comparison of flanking regions of BoxB and V3 helices, and the p-distance between the 16S–23S ITS region, we describe our strain K7 as a novel species of the genus Roholtiella with the name Roholtiella volcanica sp. nov., in accordance with the International Code of Nomenclature for algae, fungi, and plants. This work continues the rapid expansion of the description of new taxa of cyanobacteria, and particularly demonstrates a coming phase in cyanobacterial taxonomy in which the discovery of new species in recently described genera rapidly increases our understanding of the diversity in this phylum. Full article

With an increasing interest in closing the nutrient loop in agroecosystems, organic amendments are highly recommended as a reliable resource for soil nutrient recycling. However, from a carbon sequestration perspective, not much has been reported on the contribution of different organic amendments to soil organic carbon (SOC), crop carbon (C) uptake, and soil carbon dioxide (CO₂) emissions in wheat-maize cropping systems of sloppy upland soil. To fill the knowledge gap, a two-year lysimeter-field plots experiment was conducted in a sloppy upland purplish soil under wheat-maize cropping systems. The experiments were arranged in a complete random block design with five treatment plots, namely; fresh pig slurry as organic manure (OM), crop residues (CR), conventional mineral fertilizers (NPK) as the control, organic manure plus mineral fertilizers (OMNPK), and crop residues plus mineral fertilizers (CRNPK). Our results showed the leaf photosynthesis rate was not significantly increased by organic amendment application treatments compared to NPK treatment, and was within a range of 4.8 to 45.3 µmol m⁻² s⁻¹ for the wheat season and −20.1 to 40.4 µmol m⁻² s⁻¹ for the maize season across the five treatments and the measured growth stages. The soil CO₂ emissions for the maize season (in the range of 203 to 362 g C m⁻²) were higher than for the wheat season (in the range of 118 to 252 g C m⁻²) on average across the different experimental treatments over the two-year experiment. The organic amendment application increased annual cumulative CO₂ emissions from 30% to 51% compared to NPK treatment. Over the two years, the average crop C uptake ranged from 174 to 378 g C m⁻² and from 287 to 488 g C m⁻² for the wheat and maize seasons, respectively, and the organic amendment application increased the crop C uptake by 4% to 23% compared to NPK treatment. In the organic amendment treatments, the C balance ranged from −160 to 460 g C m⁻² and from −301 to 334 g C m⁻² for the wheat and the maize seasons, respectively, which were greater than those in the NPK treatment. Overall, the present study results suggest incorporation of organic amendments could be an effective strategy for increasing C sequestration and sustaining crop productivity in sloppy upland soil. Full article