Carbon Phosphorus Research Articles

Mechanism harvesting of main crops straw returning effects on ratooning fragrant rice yield and 2-accetyl-1-pyrroline and their drivers to soil microbial communities

Straw return to the field is an important measure for increasing soil fertility to increase production. Recent studies have shown that straw return to fields can increase rice yield, but the effect of straw return to fields on ratooning rice is limited. To address this problem, this paper investigated the effect of straw return on a ratooning rice system by harvesting at different heights during the first season.A two-year field experiment was conducted by using a fragrant rice variety (Meixiangzhan 2) as the material. Three experimental treatments including i) the CK treatment: manual harvesting and straw harvested at a height of 20 cm was not returned to the field; ii) the MT1 treatment: mechanical harvesting and straw was returned to the field at a harvest height of 10 cm; iii) the MT2 treatment: mechanical harvesting and straw at a harvest height of 20 cm was returned to the field. The investigated parameters in the rice cropping system in this study were the agronomic traits, yield formation, soil properties, and root soil microorganisms.We found that compared with those in the CK treatment, the yield and 2AP content in the MT treatment significantly increased, the yields of MT1 and MT2 increased by 18.17-32.64% and 12.19-20.42%, respectively. The contents of available potassium, available phosphorus, ammonium nitrogen and active organic carbon in the soil were significantly increased by straw return to the field. The soil capacity increased, and rice production increased. In addition, the straw returned to the field produced a large amount of cellulose and anaerobic environment, which provided an explanation for the increase in some anaerobic bacteria, such as pseudxanthomonas, Rhodobacteriaceae and desulphurides in the MT treatment group. Specifically, straw return provides a large amount of organic material for rice cultivation systems and improves soil fertility under the action of microorganisms to increase production.Overall, the interaction between straw return and harvest height had different effects on yield and 2AP content, and the MT2 treatment was the most beneficial for harvesting ratooning fragrant rice.

Soil properties and environmental factors across different altitudes influence biodiversity of root endophytic fungi in the orchid Bletilla sinensis

Context Bletilla sinensis is a perennial orchid herb widely used in Chinese herbal medicine. The endophytic fungi associated with its roots significantly affect plant growth and secondary metabolite accumulation, whereas environmental factors crucially determine the community and diversity of these fungi. Aims This study investigated the impact of habitat environment on the symbiotic relationship between B. sinensis and its endophytic fungi by analysing the community composition and diversity of endophytic fungi in B. sinensis roots at various altitudes. Methods B. sinensis roots were sampled from three altitudes (HXJ1, HXJ2, HXJ3) in Jinjiang Town, Shangri-La County, Yunnan Province, China. Endophytic fungi were isolated and analysed using high-throughput sequencing technology. Key results The endophytic fungi were dominated by Ascomycota (85.4%) and Basidiomycota (14.6%). α-Diversity analysis showed that HXJ2 had the highest species richness (Chao1 = 34), while HXJ1 exhibited the highest diversity (Shannon = 2.25, Simpson = 0.84). β-Diversity analysis revealed moderate community similarities between sampling sites (Bray–Curtis indices: 0.433–0.597). Notably, fungal abundance showed strong positive correlations with soil total phosphorus (r = 1.000, P < 0.01) and total carbon (r = 0.998, P < 0.05) in HXJ1. Conclusions The study revealed a clear altitudinal pattern, where higher altitudes exhibited lower fungal diversity. However, the mid-altitude site (HXJ2) showed higher fungal diversity compared with both higher (HXJ3) and lower altitudes (HXJ1), suggesting that local environmental factors, such as soil nutrients and surrounding vegetation, may interact with temperature to influence fungal diversity. Implications This study sheds light on the symbiotic relationship between B. sinensis and its endophytic fungi, with implications for the cultivation and medicinal properties of this herb.

Applied machine learning for predicting the properties and carbon and phosphorus fate of pristine and engineered hydrochar

Application of advanced techniques and machine learning (ML) for designing and predicting the properties of engineered hydrochar/biochar is of great agro-environmental concern. Carbon (C) stability and phosphorus (P) availability in hydrochar (HC) are among the key limitations as they cannot be accurately predicted by traditional one-factor tests and might be overcome by engineering the pristine HC. Therefore, the aims of this study were (1) to determine the optimal production conditions of engineered swine manure HC with high C stability and P availability, and (2) to develop the best ML models to predict the properties of HC derived from different feedstocks. Pristine- (HC) and FeCl3 impregnated swine manure-derived HC (HC-Fe) were produced by hydrothermal carbonization under different pH (4, 7, and 10), reaction temperature (180, 220, and 260 ℃), and residence time (60, 120, and 180 min) and characterized using thermo-gravimetric, microscopic, and spectroscopic analyses. Also, different ML algorithms were used to model and predict the hydrochar solid yield, properties, and nutrients content. FeCl3 impregnation increased Fe-phosphate content, while it reduced H/C and O/C ratios and hydroxyapatite P content, and therefore improved C stability and P availability in the HC-Fe as compared to HC, particularly under lower pH (4), temperature of 220 ℃, and at 120 min. The generalized additive ML model outperformed the other models for predicting the HC properties with a correlation coefficient of 0.86. The ML analysis showed that the most influential features on the hydrochar C stability were the H and O contents in the biomass, while P availability in HC was more dependent on the C, N and O contents in biomass. These results provided optimal production conditions for Fe-engineered manure hydrochar and identified the best performing ML model for predicting hydrochar properties. The main implication of this study is that it offers a high potential to improve the utilization of biowastes and produce biowaste-derived engineered hydrochar with high C stability and P availability on a large scale.Graphical

Effects of Different Intertillage Practices on Soil Biochemical Properties and Soybean Yield in Soybean Fields

Heilongjiang Province, China, is a major soybean-producing area where low temperatures in early spring and poor soil moisture retention are the main limiting factors leading to low soybean yields. To improve land productivity, this study was conducted in Heilongjiang Province, China, from 2020–2021 via a field plot trial method, where four different intertillage treatments were set up in 2020: conventional intertillage (T1), early intertillage (T2), conventional subsoiling (T3), and early subsoiling (T4). In 2021, the effects of intertillage on soil biochemical characteristics and soybean yield formation were systematically analyzed under the T5 treatment (subsoiling at the stage of full development from the fourth to the fifth compound leaf) and the T6 treatment (soil culture at the stage of full development from the fourth to the fifth compound leaf). The results of the experiment revealed that deep loosening in advance improved the chemical properties of the soil. Compared with those of the T1 treatment, the contents of the organic carbon, total nitrogen, and available phosphorus and potassium in the early subsoiling treatments (T4, T5, and T6) were significantly increased. Intertillage time and depth had a strong influence on the soil microbial characteristics. Early medium intertillage could significantly increase the species abundance of bacteria and fungi in the soil, whereas subsoiling could increase the relative abundance ratio and uniformity of the dominant species. Compared with that in the T1 treatment, the yield of soybean in the T4 treatment was significantly greater, with yield increases ranging from 18.71% to 19.36%. In summary, the intertillage measures of one deep loosening and one medium soil cultivation at the stage of full development from the fourth to the fifth compound leaf and one large soil cultivation at the stage of full development from the sixth to the seventh compound leaf can be adopted on the basis of early deep loosening 4–5 d after soybean sowing to achieve high soybean yields. The results provide a theoretical basis for increasing the yield and efficiency of soybean fields under corn–soybean rotation, as well as innovation and development of cultivation systems

Impact of Organic Amendment on the Bacterial Community and Rice Yield in Paddy Soil

In this investigation, the influence of organic amendment on the structural and functional dynamics of soil microbial communities and its effect on rice productivity were examined. Five fertilization treatments from a 40-year field experiment were selected： no fertilizer （CK）, inorganic NPK fertilizer （NPK）, inorganic NPK combined with green manure （NG）, inorganic NPK combined with green manure and pig manure （NGM）, and inorganic NPK combined with green manure and rice straw （NGS）. The findings revealed that the organic amendment enhanced the soil organic carbon （SOC）, total nitrogen （TN）, and total phosphorus （TP） levels, alongside an increase in rice yield； notably, the most significant improvements were observed with the NGM treatment. High-throughput sequencing highlighted that within the bacterial community, Proteobacteria （22.57%） and Nitrospirota （18.56%） dominated in abundance. The organic amendment led to a substantial shift in microbial community composition, chiefly reflected by an increase in Proteobacteria alongside a decrease in Nitrospirota. Predictive functional analyses through PICRUSt2 revealed a rise in gene abundance linked to the decomposition of organic carbon, specifically genes encoding amylase （amyA）, cellulase （bglX, bglB, and endoglucanase）, and hemicellulose-decomposing enzymes （xylA and xynA）. Additionally, there was an observed increase in the abundance of genes facilitating organic nitrogen mineralization, such as those for urease （ureA, ureB, and ureC）, glutamate dehydrogenase （gdhA）, and glutamine synthetase （aspQ）. The random forest model determined that several soil property indicators, including TP, SOC, pH, TN, and dissolved organic nitrogen, along with the composition of the bacterial community and the abundance of functional genes involved in the decomposition of organic carbon and nitrogen, significantly influenced the rice yields. Furthermore, PLS-PM analysis elucidated that the organic amendment boosted soil SOC and TP levels, which, by modifying the bacterial community's composition, augmented the relative abundance of genes associated with the breakdown of organic carbon and nitrogen. This process facilitated nutrient cycling, culminating in elevated rice production.

Effect of biogas slurry on the nutrient cycling and micro-organisms community in two types of soil

The biogas slurry (BS) generated through the anaerobic fermentation of biogas in pig farms is extensively employed as an organic fertilizer in Northeast China. BS is often used in large amounts because of fragmented farmland ownership resulting from previous local policies. In this work, 20 m3 · 667m-2 of BS was applied to black soil twice and to aeolian sandy soil once to explore microbial-driven nutrient cycling. The results indicated that BS increased organic carbon, total nitrogen, and total phosphorus contents in black soil. The activities of C-cycling and P-cycling enzymes in black soil were enhanced, while the activities of P-cycling enzymes in aeolian sandy soil were reduced. The BS application increased the abundance ratio of fungi to bacteria in both soil types. Total carbon, total nitrogen, and total phosphorus primarily influenced the microbial community structure in black soil, while pH was the key factor in aeolian sandy soil. However, the excessive increase of heavy metals in black soil treated twice BS posed a potential risk to the environment. Utilizing BS as fertilizer is a viable strategy applicable for Northeastern China’s agriculture, and application dosages must be adjusted according to experimental results.

Soil macrofauna trophic structure and its relationship with soil factors in oases of contrasting cultivation ages

Transforming arid and semi-arid deserts into farmlands significantly alters soil moisture and fertility, affecting the trophic structure and functionality of soil fauna. Diversity and function of soil macrofaunal community can accurately reflect changes in soil quality and health during the succession of oasis farmlands. In this study, the assemblage of soil macrofauna and soil environmental factors in cultivated and abandoned croplands in the Zhangye Oasis of Gansu Province, were investigated using a hand-sorting method, and we analyzed the relationship between the trophic structure of soil macrofauna and the soil environment. Our results showed that: 1) Farmland cultivation increased the soil water content, soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP), while reducing pH. 2) The density, taxon richness, and Shannon-Wiener index of soil macrofauna in cultivated croplands were higher than in abandoned croplands, increasing with cultivation duration. The density of soil macrofauna in 100-year-old farmlands was 2.5, 1.5 and 1.4 times of that in 10-year-old, 30-year-old and 50-year-old farmlands; 3) the density and taxon richness of predatory, phytophagous, and other feeding types of soil macrofauna in cultivated croplands were higher than those of abandoned croplands. The observed increases in density and taxon richness are likely due to the improved soil conditions resulting from cultivation practices. The density-based ratio of predatory to phytophagous and other feeding types of soil macrofauna initially increases then decreases, inversely related to cultivation age. 4) changes in soil environment had little effect on the predatory soil macrofaunal community, and the explained variance by SOC, TP, and pH indicates the significant influence of these soil properties on the composition of the phytophagous soil macrofaunal community. SOC, TP, and pH explained 7.3 % of the variation in phytophagous soil macrofaunal community, while TN, TP, and pH explained 15.4 % of the variation in other feeding types of soil macrofauna. In conclusion, our findings highlight the positive impact of oasis farmland cultivation on soil quality and the enhancement of soil macrofauna diversity, which in turn could contribute to the resilience and productivity of these agricultural ecosystems.

Synergy and trade-off between plant functional traits enhance grassland multifunctionality under grazing exclusion in a semi-arid region.

Grazing exclusion is effective in restoring vegetation and ecological services in degraded grasslands within semi-arid regions. Variations in plant functional traits associated with the duration of grazing exclusion can indicate both ecological adaptability of plants and restoration processes of ecosystems. However, research on ecosystem multifunctionality (EMF) under grazing exclusion and restoration mechanisms mediated by plant functional traits is relatively limited. In this study, we calculated EMF based on plant species diversity, above-ground biomass (AGB), below-ground biomass (BGB), storages of soil organic carbon (TSOC), soil nitrogen (TSN), and soil phosphorus (TSP) in grasslands under varying durations of grazing exclusion in the semi-arid Songnen Plain, China, and investigated the trait-based pathways involved in forming EMF. The findings revealed irregular fluctuations in plant species diversity, while AGB, TSOC, TSN, and TSP exhibited a linear increase with grazing exclusion duration. Additionally, BGB initially increased but experienced a slight decline over the 17 years of grazing exclusion (GE17). Notably, EMF peaked at 0.778 in GE17 site. In particular, the proportions of AGB and TSOC in the EMF were higher in grazing exclusion sites than that in grazing site. Leaf area (LA) and leaf weight (LW) were lowest in grazing site and highest in GE17 site. Redundancy analysis indicated that the plant functional traits, including LA, leaf nitrogen content (LNC), and LW, collectively explained a substantial proportion of the variance (70.85%) in ecosystem function indicators. Structural equation modelling analysis revealed a direct impact of grazing exclusion on EMF (P<0.05). However, EMF was remarkably and directly affected by the AGB (P<0.01) that regulated by the trade-off between LW and LNC. In addition, the synergy between LW and LA had an impact on TSP (P<0.01), and further enhance EMF (P<0.05). These findings prominently emphasize the advantageous outcomes of proper grazing exclusion concerning the functional aspects of degraded grasslands. Moreover, they persuasively validate the crucial significance of plant functional traits in relation to the enhancement of EMF. Consequently, this study is capable of providing valuable information for revealing multiple driven mechanisms of grassland EMF in the semi-arid regions.

Optimization of Irrigation and Fertilization in Maize–Soybean System Based on Coupled Water–Carbon–Nitrogen Interactions

Effective water and nitrogen management plays a pivotal role in enhancing crop yields while simultaneously reducing greenhouse gas emissions. This study differs from previous research by investigating the effects of water–nitrogen co-regulation involving organic carbon on the yield increase and emission mitigation in a soybean–maize system. A dryland experiment was conducted, employing 20 distinct combinations of water and nitrogen treatments that were meticulously designed for the maize–soybean system. The DSSAT crop model was employed to quantitatively elucidate the intricate interactions between water and nitrogen. A multi-objective optimization model, integrating experimental data and mechanistic insights, was constructed and refined using the NSGA-III genetic algorithm to identify the optimal water and nitrogen application ratios. An analysis of maize and soybean data from Acheng in Heilongjiang, China, indicates that optimized irrigation and nitrogen application regimes—152.2 mm and 247.1 kg·ha−1 for maize and 91.7 mm and 106.2 kg·ha−1 for soybean—substantially enhanced the net economic returns within the dryland ecosystem. There is a significant positive correlation between the yield (Y), soil nitrogen content, and soil organic carbon (SOC). Nitrate nitrogen has a significant positive correlation with CO2 gas emissions. Organic carbon changes the soil’s carbon to nitrogen ratio by participating in the water and nitrogen cycles, thereby affecting nitrogen and phosphorus loss and carbon emissions. This study presents a sustainable method for regulating water and nitrogen in the maize–soybean system.

Vermicompost as Organic Amendment: Effects on Some Soil Physical, Biological Properties and Crops Performance on Acidic Soil: A Review

One of the most precious natural resources is soil, which provides ecological functions necessary for life&amp;apos;s survival and sustenance. Therefore, preserving and enhancing soil health is crucial for agricultural and ecological sustainability. However, careless application of mineral fertilizer lowers fertility and organic matter and has negative impacts on the environment, ground water quality, and soil health, whereas the use of organic amendments is essential for enhancing soil health. In order to improve the physical, biological, and crop productivity of acidic soil, this review emphasizes the potential of vermicompost as a soil conditioner. Thus, adding organic amendments to soil is a management tactic that can boost microbial populations, activity, and variety, enhances soil fertility and improve soil structure. Vermicompost (VC) is one type of organic amendment that is created when earthworms and soil microorganisms interact. The end product has a high degree of maturity, high porosity, aeration, drainage, water storage capacity, and microbial activity. As a result, applying this amendment encourages biological activity, which raises the soils&amp;apos; potential for production both directly through increased nutrient availability and indirectly through improved physical characteristics. Similarly, the addition of vermicompost (VC) to soil raised its pH levels, phosphorus, potassium, calcium, magnesium, and total organic carbon; it also enhanced the soil&amp;apos;s cation exchange capacity, microbial biomass carbon, micronutrient content, and nitrogen content, all of which increased crop yield. In addition to raising crop yield and improving soil quality and nutrient availability, vermicompost also strengthens crop resistance to pests and diseases. By adding essential nutrients, humic acids, growth-regulating hormones, and enzymes to the soil, it acts as an organic fertilizer that improves plant nutrition, photosynthesis, and overall crop quality.

A Study of the Effects of Wetland Degradation on Soil-Microbial-Extracellular Enzyme Carbon, Nitrogen, and Phosphorus and Their Ecological Stoichiometry

Due to the unique geographic location of A’er Xiang, there is a natural landscape where sandy land and lake-marsh wetlands coexist. However, the wetland degradation caused by the disturbance of anthropogenic activities has led to the change in land use. In this study, the spatial-temporal substitution method was used to select five sample plots: the original wetland converted to forest land for reuse area of five years and ten years; the original wetland converted to cropland for reuse area of five years and ten years; and the native wetland. It aims to investigate the variations in carbon, nitrogen, and phosphorus and their stoichiometric characteristics of soil-microorganisms-extracellular enzymes before and after reuse, and to analyze potential interactions among these elements. The results indicated that following wetlands degradation, changes in land use for five years did not significantly affect the content of soil organic carbon (TOC), total nitrogen (TN), or total phosphorus (TP). However, after ten years, both TOC and TN, except for TP, decreased significantly. Microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) contents in cropland were consistently higher than those in WL, showing a trend of first increasing and then decreasing with longer conversion periods. In contrast, forest land values were lower than in WL and increased as the conversion period lengthened. The microbial biomass phosphorus (MBP) content was ranked across the five sample sites as follows: 10 CL &gt; 5 CL &gt; 5 FL &gt; 10 FL &gt; WL. β-1,4-glucosidase (BG) activity was significantly increased after conversion to forest land and significantly decreased after conversion to cropland. β-1,4-N-glucosidase (NAG) and L-leucine aminopeptidase (LAP) activities were ranked as follows among the five sites: 5 FL &gt; WL &gt; 5 CL &gt; 10 FL &gt; 10 CL. Phosphatase (PHOS) activity showed no significant changes post-conversion, though it was consistently lower compared to WL.

2D Carbon Phosphide for Trapping Sulfur in Rechargeable Li-S Batteries: Structure Design and Interfacial Chemistry.

Rechargeable lithium-sulfur batteries (LiSBs) assembled with earth-abundant and safe Li anodes are less prone to form dendrites on the surface, and sulfur-containing cathodes offer considerable potential for achieving high energy densities. Nevertheless, suitable sulfur host materials and their interaction with electrolytes are at present key factors that retard the commercial introduction of these batteries. Here we propose a two-dimensional metallic carbon phosphorus framework, namely, 2D CP3, as a promising sulfur host material for inhibiting the shuttle effect and improving electronic conductivity in high-performance Li-S batteries. The good electrical conductivity of CP3 eliminates the insulating nature of most sulfur-based electrodes. The dissolution of lithium polysulfides (LiPSs) into the electrolyte is largely prevented by the strong interaction between CP3 and LiPSs. In addition, the deposition of Li2S on CP3 facilitates the kinetics of the LiPS redox reaction. Therefore, the use of CP3 for Li-S battery cathodes is expected to suppress the LiPS shuttle effect and to improve the overall performance, which is ideal for the practical application of Li-S batteries.

Evaluation of Soil Quality in Different Bletilla striata Agroforestry Systems in Eastern China

Agroforestry is being promoted as a feasible land use management to improve understory economic benefits. However, there are few studies on species selection and the comprehensive evaluation of soil quality change in rhizoma bletillae (Bletilla striata) agroforestry systems. The soil quality index (SQI) and minimum dataset (MDS) methods can reflect the overall condition and were effective tools for understanding different cultivation systems. In this study, we evaluated the soil quality of four cultivation models (including three agroforestry systems: PeB, moso bamboo (Phyllostachys edulis)–rhizoma bletillae; PoB, plane trees (Platanus orientali)–rhizoma bletillae; CcB, pecan trees (Carya cathayensis)–rhizoma bletillae; and CK, rhizoma bletillae monoculture. The total dataset (TDS) consisted of 15 soil parameters containing physical, chemical, and biological characteristics. The results showed that soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) were finally selected and established as the MDS. Agroforestry could significantly influence soil quality. Compared with CK, the SQI in CcB significantly increased and decreased in PeB and PoB. Soil water content (SWC), nitrate nitrogen (NO3−-N), dissolved organic carbon (DOC), SOC, TN, and TP contents were higher in CcB than in the other cultivation models. Based on various soil indicators and SQI analysis, the CcB was the best in improving soil quality. These findings showed that the soil quality index based on the MDS can be used as an effective indicator for agroforestry systems selection. It provides theoretical guidance for the practice of bionic cultivation and the sustainable management of rhizoma bletillae.

Response of Microbiological Properties to Short-term Nitrogen Addition in Perennial Alpine Cultivated Grassland

Removing nitrogen limitation is necessary to increase plant productivity in alpine grasslands. A short-term nitrogen addition experiment was conducted to understand the effects of nitrogen addition on the soil physicochemical properties and microbial community structure of perennial alpine cultivated grassland in the region around Qinghai Lake. From June to August 2022, four N application gradients （T0： 0 kg·hm-2·a-1, T1： 22.5 kg·hm-2·a-1, T2： 45 kg·hm-2·a-1, T3： 67.5 kg·hm-2·a-1） were set up in a four-age perennial cultivated grassland, and soil samples were collected from the 0-20 cm soil layer. The soil physical and chemical properties and microbial community structure were determined under the different treatments. The results showed that soil water content （SWC）, soil organic carbon （SOC）, ammonium nitrogen （NH4+-N）, nitrate nitrogen （NO3--N）, available nitrogen （AN）, available phosphorus （AP）, total phosphorus （TP）, total nitrogen （TN）, and total carbon （TC） tended to increase with the increase in nitrogen application level and the T3 treatment significantly decreased the soil pH. Nitrogen addition did not significantly alter the Alpha diversity of soil microbial communities and different levels of nitrogen application affected the structure of soil microbial communities to different degrees. The T1 and T2 treatments increased the number of soil bacteria and fungi and T3 treatment decreased the number of soil bacteria and fungi. Nitrogen addition increased the relative abundance of the dominant flora of Actinobacteriota, Zygomycota, Blastococcus, and Gibberella and decreased the relative abundance of the dominant flora of Proteobacteria, Bacteroidota, Sphingomonas, and Claroideoglomus. RDA analysis showed that SOC and soil electrical conductivity （EC） were the key soil physicochemical factors affecting changes in soil bacterial communities, and soil pH was the main factor affecting the distribution of soil fungal communities. Collectively, 67.5 kg·hm-2·a-1 may be the optimal level of N application to improve the soil environment of perennial alpine cultivated grasslands.

Effect of altitude on soil physico-chemical properties and microbial biomass carbon in the Eaglenest Wildlife Sanctuary of Arunachal Pradesh

ABSTRACT The present study focuses on the variation in soil properties and microbial biomass carbon along an elevation gradient in the Eaglenest Wildlife Sanctuary, Arunachal Pradesh. Soil was acidic in nature and pH value ranges from 4.37 ± 0.14 to 5.25 ± 0.29. Soil texture varied from sandy to loamy sand. Clay content and available potassium showed a significant negative correlation (p < 0.05) with altitude. Water holding capacity and available nitrogen showed a strongly significant positive correlation (p < 0.01). Soil bulk density, temperature, moisture content, pH, available phosphorus and microbial biomass carbon showed a strongly significant negative correlation (p < 0.01) with altitude. Soil organic carbon stock was highest (66.39 ± 9.36 t h−1) in tropical zone and lowest (44.33 ± 6.34 t h−1) in temperate zone. Higher soil organic carbon and organic matter (4.16 ± 0.58% and 7.17 ± 1.00%) were found in subtropical zone while lowest (2.57 ± 0.38% and 4.42 ± 0.64%) were found in tropical zone. Available nitrogen and available potassium were highest (604.10 ± 24.13 kg h−1 and 418.14 ± 26.53 kg h−1) in subtropical zone and lowest available potassium (282.82 kg h−1 ± 14.68 kg h−1) was recorded in the temperate zone. Higher available phosphorous (62.51 ± 6.96 kg h−1) was recorded in tropical zone while lowest (10.66 ± 1.49 kg h−1) was recorded in the subtropical zone. The first four main components of the principal component analysis jointly explained 78.51% of the overall variation. The results from the principal component analysis align closely with Pearson’s correlation analysis and analysis of variance, reinforcing the accuracy and reliability of the observed trends in data. The present study clearly indicates that altitudinal variation exerts a significant effect on the soil’s physico-chemical properties. It suggests that understanding the effects of altitudinal variation on soil properties is important for the establishment and restoration of the vegetation in diverse altitudinal zone.

ANALISIS SENYAWA FITOKIMIA DAUN Moringa oleifera DARI KAWASAN GEOTERMAL ACEH BESAR SEBAGAI KANDIDAT ANTIINFLAMASI

Indonesia is home to a diversity of herbal plants, particularly in Aceh. Moringa oleifera is traditional medicinal plant utilized by locals in the geothermal area Aceh Besar, recognized for its anti-inflammatory properties. However, the bioactive compounds in M. oleifera leaves sourced from Ie Seum have not been documented, making it challenging to explain the roles of the compounds scientifically to anti-inflammatory factors. This research aimed to identify the phytochemical compounds in the ethanol extract of M. oleifera leaves (referred to as EDM) and analyze the physicochemical characteristics of the soil in the geothermal area. This study used a qualitative design to identify EDM compounds with GC-MS and soil physicochemistry. The identification of EDM compounds is conducted through gas chromatography with mass spectrometry (GC-MS). The physicochemical properties of the soil are assessed by examining its texture, pH, organic carbon content, total nitrogen, exchangeable cations, and phosphorus. Sample collection on topsoil (0-20 cm) with an area of ​​100cmx100cm on one land where M. oleifera plants grow in Ie Seum area in September 2024. A soil sample of 500g was using several methods, namely the hydrometermethod, pH meter, Walkey and Black, ammonium acetate 1M pH 7, Kjeldahl, KCl 1N, Bray 1, HCl 25%, and DTPA extraction. The soil test result showed classified as silty clay. The results GC-MS indicated the presence 11 metabolites, including linolenic acid, phytol, 9,12,15-octadecatrienoic acid ethyl ester, hexadecanoic acid, neophytadiene, gamma-tocopherol, vitamin E, squalene, icosane, and beta-pinene. EDM from the Ie Seum contains compounds that are beneficial in anti-inflammatory.

Retrieval of carbon and inorganic phosphorus during hydrothermal carbonization: ANN and RSM modeling

Retrieval of carbon and inorganic phosphorus during hydrothermal carbonization: ANN and RSM modeling

Ground cover management enhances soil extracellular enzyme activities across Chinese orchards.

The impacts of ground cover management (GCM) on orchard soil properties have been extensively studied. However, the quantitative assessment of soil extracellular enzyme activities (EEAs) in mulch agriculture remains understudied. In this study, we investigated EEAs related to GCM to assess microbial metabolic activity, soil health, and nutrient status, based on 81 studies focusing on orchards in China. Our findings show that GCM significantly increases carbon acquisition (C-acq, 37%), nitrogen acquisition (N-acq, 34%), phosphorus acquisition (P-acq, 26%), and oxidative decomposition (OX, 14%) enzymes compared to continuous clean tillage. A subgroup analysis and a random forest model were conducted to further identify the effects and potential mechanisms through which soil EEAs respond to GCM in orchards under various moderators. The significant changes in EEAs induced by GCM vary with experimental and environmental factors. Tree age, climate conditions, and soil depth are the primary contributors to the variation in soil EEAs. Overall, our results suggest that the implementation of GCM positively affects EEAs, thereby enhancing microbe-mediated soil ecosystem functions and soil fertility. This meta-analysis provides comprehensive evidence of GCM-induced effects on hydrolase and oxidase activity, improving our understanding of the underlying mechanisms by which orchard mulching impacts soil nutrient cycling.

Cyanobacteria in winter: seasonal dynamics of harmful algal blooms and their driving factors in boreal lakes

Lake cyanobacteria can overgrow and form blooms, often releasing life-threatening toxins. Harmful algal blooms (HABs) are typically caused by excess nutrients and high temperatures, but recent observations of cyanobacteria beneath the ice in boreal lakes suggest that the dynamics are more complex. This study investigates the seasonal dynamics of HABs in boreal lakes and identifies their driving factors. We study cyanobacteria assemblages in two boreal lakes in Abitibi-Témiscamingue (Quebec, Canada): Lake Fortune, noted for its under-ice cyanobacteria, and Lake Beauchamp, which has experienced recurrent summer-only cyanobacterial blooms. From June 2021 to July 2022, we identified monthly cyanobacterial communities and estimated water nutrients, organic carbon, temperature, oxygen, and pH. Cyanobacterial communities were dominated by the genus Planktothrix in Lake Fortune, and this genus was in a bloom state for each month of the year. Cyanobacterial abundance was highest (210 000 cells/mL) in November and lowest (28 000 cells/mL) in March. The abundance of Planktothrix correlated with total nitrogen and phosphorus and dissolved organic carbon concentrations. Planktothrix dominated even under ice cover, because of its ability to thrive in low-light and low phosphorus conditions. In Lake Beauchamp, Aphanothece was found throughout the year, highest (27 800 cells/mL) in August and lowest (2100 cells/mL) in March. In Lake Beauchamp, cyanobacterial blooms correlated with total dissolved phosphorus, nitrogen and organic carbon concentrations during summer and fall. The dominance of Aphanothece was especially pronounced during the summer and fall. Our study provides new knowledge about the seasonal dynamics of cyanobacterial blooms to help guide the future management of HABs in boreal lakes.

Land-use change from native forest to avocado orchards: Effects on soil nutrient transformation and microbial communities

Land-use change is known to alter soil microbial communities and the processes they carry out. However, there is meager information about how conversion of natural forests to agricultural land for avocado production affects soil nutrient concentration and microbial activity and diversity. Total soil nutrients (C, N and P), microbial ecoenzymatic activity, and microbial diversity were studied in avocado orchards and contiguous forest fragments in Michoacán state, México. Within orchards, samples were taken from fertilized areas beneath avocado trees as well as from unfertilized areas. Results showed that (i) total phosphorus concentration was higher in avocado orchards compared to native forests soils; (ii) transformation of native forests to avocado orchards decreased the ecoenzymatic activity necessary for degradation of lignified compounds and phosphate monoesters; (iii) bacterial diversity was higher in avocado orchard soils compared to native forest soils while fungal diversity was higher in avocado unfertilized soils; (v) transformation of native forests to avocado orchards increased the evenness of bacterial and fungal communities; (vi) transformation of native forest to avocado orchards caused significant changes in the composition of soil microbial communities; however, this was clearer for fungal communities than for bacterial communities; (vii) abundance of ectomycorrhizal fungi and antagonists of plant pathogens decreased in avocado orchards while pathogenic and saprotrophic fungal guilds increased. Our results suggest that land use change from native forest to avocado orchards generates important changes in the dynamics of soil organic carbon and soil organic phosphorus in avocado orchard soils, probably due to the predominant conventional management model in the avocado belt. Furthermore, this type of land use change results in the increased abundance of important microbial groups identified as phytopathogens and the decrease of beneficial microbial groups. These changes should be taken into account to formulate forest and soil conservation polices and of more sustainable agricultural management models that consider soil microbial communities and their functions.