Search Results (11)

The high-input production mode of rice monoculture (RM) has caused severe soil degradation and biodiversity loss, necessitating a transition toward more sustainable practices. The traditional rice-fish co-culture (RF) may provide valuable insights for this situation. However, it remains elusive how long-term RF system influences soil microbial community structure, enzyme activities, and carbon (C) sequestration. Here, a study was conducted at two representative RF areas in Lianshan Zhuang and Yao Autonomous County. At Shatian (P1), three treatments included rice monoculture (RM1) and 2-year and 5-year RF (RF2, RF5). At Gaoliao (P2), the experimental treatments included rice monoculture (RM2) and 15 and 30 years of RF (RF15, RF30). We collected the surface layer (0–20 cm) soils. Then, we analyzed the chemical properties, phospholipid fatty acids (PLFA), and enzyme activities to investigate the effects of their variation on soil C sequestration. The results showed that RF treatments significantly increased soil organic C (SOC) content. Specifically, RF2 and RF5 treatments promoted the SOC content by 4.82% and 13.60% compared with RM1 treatment at P1, respectively; RF15 and RF30 treatments increased the SOC content by 23.41% and 31.93% compared with RM2 treatment at P2, respectively. Additionally, RF5 treatment significantly increased the biomass of the soil microbial community in comparison with RM1 treatment, as did RF15 treatment and RF30 treatment compared with RM2 treatment, including the contents of total PLFA and the PLFA of gram-positive bacteria (G+), gram-negative bacteria (G−), actinomycetes, fungi, and bacteria. Activities of β-glucosidase, cellobiohydrolase, β-1,4-N-acetylglucosaminidase, and urease significantly increased in RF5 and RF30 treatments. The piecewise SEM results indicated that the changes of total PLFA content and the PLFA content ratio of fungi to bacteria were related to contents of dissolved organic C (DOC) and total N (TN) under different RF durations, which are key indicators affecting SOC content. Overall, SOC storage increases with the RF durations, and soil microbial community structure may drive soil C sequestration under long-term RF, which provides a scientific significance and practical value in promoting the sustainability of agricultural ecosystems, enhancing the potential of soil as a carbon sink, and addressing global climate change. Full article

Microplastic (MP) pollution has raised global concerns, and biodegradable plastics have been recommended to replace conventional ones. The “plastisphere” has been considered a hotspot for the interactions among organisms and environments, but the differences in the properties of soil microbial communities in the plastisphere of conventional and biodegradable MPs remain unclear. This in situ experiment was conducted to compare the diversity and structure of the bacterial community in the plastisphere of conventional MPs (polyethylene [PE]) and biodegradable MPs (polylactic acid [PLA]) in vegetable fields, orchards, paddy fields, and woodlands. It was discovered that the bacterial α-diversity within the plastisphere was significantly lower than that in the soil across all land use. Significant differences between plastic types were only found in the vegetable field. Regarding the community composition, the relative abundances of Actinobacteriota (43.2%) and Proteobacteria (70.9%) in the plastisphere were found to exceed those in the soil, while the relative abundances of Acidobacteriota (45.5%) and Chloroflexi (27.8%) in the soil were significantly higher. The complexity of the microbial network within the plastisphere was lower than that of the soil. Compared with the soil, the proportion of dispersal limitation in the PLA plastisphere significantly decreased, with the greatest reduction observed in the vegetable field treatment, where it dropped from 57.72% to 3.81%. These findings indicate that different land use types have a greater impact on bacterial community diversity and structure than plastics themselves, and that biodegradable MPs may pose a greater challenge to the ecological function and health of soil ecosystems than conventional MPs. Full article

The incorporation of organic amendments is widely acknowledged for its capacity to enhance soil fertility and boost crop productivity. However, whether the addition of organic amendments can improve soil quality and crop production, simultaneously causing methane emissions in paddy fields, deserves further investigation. In this meta-analysis, the effects of different organic amendments on soil nutrient levels, rice yield and CH₄ emissions were evaluated in paddy fields based on 328 observations from 77 field trial studies. Our results revealed that the addition of organic amendments significantly increased soil organic carbon (9.47%), microbial biomass carbon (21.13%), microbial biomass nitrogen (28.91%), urease (25.07%) and β-glucosidase (24.41%). Moreover, straw addition significantly increased the CH₄ emissions by 152.68% and rice yield by 7.16%; green manure addition significantly increased CH₄ emissions by 71.62% and rice yield by 10.09%, respectively. Although both increased the CH₄ emissions, green manure had the ability to improve the availability of N, which could improve rice uptake. The regression results showed that the variation in crop yield, soil nutrients and CH₄ emissions are influenced through the types and quality of organic amendments. Overall, this study suggests that organic amendments are beneficial in maintaining soil quality and improving rice yield, whereas it also increased the CH₄ emissions. These meta-analysis results may provide some references for optimizing organic amendments incorporated into the soil to sustain soil fertility and crop production while mitigating soil constraints and methane emissions. Full article

Pomacea canaliculata, as an invasive exotic species in Asia, can adversely affect crop yields, eco-environment, and human health. Application of molluscicides containing metaldehyde is one effective method for controlling P. canaliculata. In order to investigate the effects of metaldehyde on adult snails, we conducted acute toxicological experiments to investigate the changes in enzyme activities and histopathology after 24 h and 48 h of metaldehyde action. The results showed that the median lethal concentrations (LC) of metaldehyde on P. canaliculata were 3.792, 2.195, 1.833, and 1.706 mg/L at exposure times of 24, 48, 72, and 96 h, respectively. Treatment and time significantly affected acetylcholinesterase (AChE), glutathione S-transferase (GST), and total antioxidant capacity (TAC) activity, with sex significantly affecting AChE, GST, and TAC activity and time significantly affecting carboxylesterase (CarE). In addition, the interaction of treatment and time significantly affected the activity of GST, CarE and TAC. In addition, histopathological changes occurred in the digestive glands, gills and gastropods of apple snail exposed to metaldehyde. Histological examination of the digestive glands included atrophy of the digestive cells, widening of the hemolymph gap, and an increase in basophils. In treated snails, the hemolymph gap in the gills was widely dilated, the columnar cells were disorganized or even necrotic, and the columnar muscle cells in the ventral foot were loosely arranged and the muscle fibers reduced. The findings of this study can provide some references for controlling the toxicity mechanism of invasive species. Full article

Recent studies have indicated that the invasive apple snail (Pomacea canaliculata) exhibits tolerance to the salinity levels present in coastal agricultural soils, suggesting that apple snails could potentially invade salt-affected coastal agricultural areas. However, the effects of the alien snail Pomacea canaliculata invasion on coastal saline soils, such as in terms of soil properties, microbial diversity, and abundance, remain poorly understood. To fill this gap, we conducted experiments involving three salinity levels (0, 2‰, and 5‰, w/w), coupled with varying snail densities (0, 5, and 10 snails per box), applied to agricultural soil. We analyzed soil chemical properties, enzyme activities, and bacterial communities. The findings revealed that heightened soil salinity increased soil electrical conductivity (EC) (exceeding 1312.67 μS cm⁻¹). Under saline conditions, snail treatments significantly increased the soil organic matter (SOM) content from 15.82 mg kg⁻¹ to 18.69 mg kg⁻¹, and concurrently diminished the dissolved organic carbon (DOC) from 47.45 mg kg⁻¹ to 34.60 mg kg⁻¹. Both snail and salinity treatments resulted in ammonia nitrogen (NH₄⁺-N) accumulation, while nitrate nitrogen (NO₃⁻-N) concentrations remained low in salt-affected soils. A notable positive correlation existed between the EC and the activities of hydroxylamine reductase (HR) and peroxidase (POD), where HR exhibited a positive correlation with NH₄⁺-N, and POD displayed a negative correlation with NO₃⁻-N. Salinity substantially decreased the diversity and altered the composition of soil bacterial community, with the phyla Bacteroidota, Proteobacteria, and Firmicutes adapting to salt-affected soil environment and proliferating. Structural equation modeling (SEM) analysis indicated that snails exerted a direct influence on soil-available nitrogen (including NO₃⁻-N and NH₄⁺-N), while salinity impacted available nitrogen by modulating soil enzyme activities and bacterial communities. Our findings provide insights into how soil responds to the concurrent impacts of snail invasion and soil salinization, establishing some references for future research. Full article

Apple snails (ASs), the freshwater snails of the family Ampullariidae, are widely spread in tropical and subtropical regions. Owing to their strong invasiveness and harmful effects on agricultural production and ecosystems, they have attracted considerable attention. However, less research has been conducted on the whole picture of the current research status and development trends in the ASs field. For this purpose, we conducted a bibliometric analysis based on a total of 1028 publications regarding ASs published between 1900 and 2021 using VOSviewer 1.6.18 and CiteSpace 6.1.R3 software. The results suggest that ASs research has received increasing attention in recent years. The most productive country has been the USA, while the institution with the most publications was Consejo Nacional de Investigaciones Científicas y Técnicas Conicet. “Zoology” was the category of the most popular subject, Journal of Molluscan Studies was the primary journal, and P.R. Martin was the most outstanding author in ASs field. Invasive alien species, alarm response, copper (Cu) exposure, taxonomy and phylogenetic analysis, Angiostrongylus cantonensis (parasite), control (including molluscicidal activity), growth and reproduction, and feeding preferences were the main research hotspots. Further, “Pomacea maculata”, “Evolution”, “Biology”, “Digestive gland”, “Phylogeny”, “Identification”, “Pomacea canaliculata caenogastropoda”, “Diversity”, and “Nonnative apple snail” have been emerging active topics in recent years. These findings can help researchers in this area to better understand the direction and advances of ASs research and are valuable for future research and agricultural practice of apple snail control. Full article

As the frequency of droughts increases with climate change, the tolerance of aquatic organisms to abiotic stressors will become critical determinants of survival. Pomacea canaliculata has become a widely distributed agricultural and environmental pest in southern China. To evaluate their tolerance and adaptation under the drought condition, the survival, feeding, behavior, and antioxidant system changes in female and male P. canaliculata were investigated during drought stress and rewatering process through an indoor simulation experiment. The results showed that female snails laid eggs before burrowing into the soil to ensure offspring reproduction. Female P. canaliculata had higher survival rates than males under drought stress, and their recovery ability of activity after rewatering was also superior to those of males. The antioxidant system of P. canaliculata showed obvious activation with gender differences after rewatering. Overall, the survival rate of female P. canaliculata was higher after drought stress, and the resilience ability of female snails after rewatering was stronger, including in their behavior, feeding, and antioxidant system recovery. The P. canaliculata tolerance to drought and the ability to recover quickly after drought may contribute to their long-term survival and facilitate continuous invasion. Full article

Pomacea canaliculata is native to South America and has become a widely distributed agricultural and environmental pest in southern China. Previous studies have primarily focused on the tolerance of P. canaliculata to various environmental factors, and compared non-native invasive P. canaliculata with natives or non-invasive congeners. However, there has been no research concentrated on variation in innate growth and reproductive characteristics between P. canaliculata in its native and invaded areas. To address this gap, we conducted the first comparison experiment between P. canaliculata from their native area (Argentina) and from an invaded area (China). We recorded the temporal dynamics of shell height of male and female P. canaliculata, and investigated the sexual maturation and egg-related indicators in two populations from each country, rearing them under homogeneous temperature, photoperiod and food conditions. Our results showed that the shell growth rate of P. canaliculata in Argentina was significantly lower than that of P. canaliculata in China. Moreover, P. canaliculata exhibited stronger reproductive characteristics in populations from China, mainly reflected in the earlier sexual maturity, larger egg masses, higher hatching success, and a trend of shorter incubation period. These differences probably arose due to contemporary evolution in invaded areas under strong selective pressures in rice fields, and, together with more favorable climates, enable the snail populations to rapidly grow and expand in southern China. Full article

Soil acidification is a severe environmental problem around the world. Soil pH buffering capacity (pHBC) is the intrinsic factor affecting the soil acidification rate and is intensively impacted by anthropogenic and natural conditions. However, composite assessments of the effects of land use and soil type on soil pHBC are still limited. Therefore, we collected samples of five soil types (red soil, lateritic red soil, latosol, paddy soil and acid sulphate soil) from two land use patterns of agricultural and adjacent forest fields at different depths (0–10 cm, 10–20 cm and 20–30 cm) in South China, aiming to investigate the effects of land use and soil type on soil pHBC in this region. The results show that land use, soil type and their interactions greatly influence soil pHBC and physico-chemical properties. Forest soils have a significantly higher pHBC (11.40–49.50 mmol·kg⁻¹ soil·unit⁻¹ pH), cation exchange capacity (CEC), exchangeable Al³⁺ (EAl³⁺) and clay content than agricultural soils. Acid sulphate soil has the highest pHBC (49.27–117.83 mmol·kg⁻¹ soil·unit⁻¹ pH) values and exchangeable acid (EA) content among all investigated soil types, whereas lateritic red soil has the lowest pHBC (10.56–31.71 mmol·kg⁻¹ soil·unit⁻¹ pH). In agricultural fields, soil pHBC is positively related to CEC, soil organic carbon (SOC) and EA, indicating that agricultural soils may be in a cation exchange buffering stage. The soil pHBC of forest fields is positively correlated with SOC and EAl³⁺, implying that forest soils may be in the Al buffering stage. In conclusion, soil pHBC would vary with different land use forms and soil types, in which a series of key complex physico-chemical processes and interactions would occur to regulate soil pH buffering capacity. Full article

The soil seed bank (SSB) is a natural bank of viable seeds in the soil or on its surface. Researches on SSB have accumulated extensively worldwide, but have seldom been visualized and quantitatively analyzed. In this paper, publications related to SSB from 1900 to 2019 were collected from the Web of Science Core Collection database, and reviewed and analyzed using CiteSpace. Annual publications distribution, co-occurrence analysis, collaboration network analysis, co-citation analysis and burst detection were all conducted. The results showed that (1) the number of SSB publications had increased rapidly and is still a hotspot; (2) SSB study is an interdisciplinary field mainly concentrated in ecology, environmental science, and plant science; (3) close research cooperation occurred among European countries which were more influential, whereas the USA was the most active country; (4) soil seed genetic diversity, seed persistence, seed trait, restoration potential and restoration projects, and spatial and temporal variation were the main research areas. (5) R language and linear mixed effects models are currently popular in SSB research. Invasive species, weed control, restoration potential and restoration projects, seed traits (especially seed longevity and dormancy), and SSB responses to environment changes (especially climate change and fire) are newly emerging trends in the research. Full article

Potyviruses represent the largest group of known plant RNA viruses and include many agriculturally important viruses, such as Plum pox virus, Soybean mosaic virus, Turnip mosaic virus, and Potato virus Y. Potyviruses adopt polyprotein processing as their genome expression strategy. Among the 11 known viral proteins, the nuclear inclusion protein b (NIb) is the RNA-dependent RNA polymerase responsible for viral genome replication. Beyond its principal role as an RNA replicase, NIb has been shown to play key roles in diverse virus–host interactions. NIb recruits several host proteins into the viral replication complexes (VRCs), which are essential for the formation of functional VRCs for virus multiplication, and interacts with the sumoylation pathway proteins to suppress NPR1-mediated immunity response. On the other hand, NIb serves as a target of selective autophagy as well as an elicitor of effector-triggered immunity, resulting in attenuated virus infection. These contrasting roles of NIb provide an excellent example of the complex co-evolutionary arms race between plant hosts and potyviruses. This review highlights the current knowledge about the multifunctional roles of NIb in potyvirus infection, and discusses future research directions. Full article