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The effect of organic matter (OM) on soil phosphorus (P) sorption is controversial, as there is still no clear answer whether organic matter inhibits or increases P sorption. Despite the great need for renewable sources of available P and OM in agricultural soils, little is known about the interaction between P and dissolved organic matter (DOM) in natural soil systems. The aim of this research was to uncover if and how soil saturation with DOM derived from different types of abundant agricultural wastes (cattle manure, horse manure, biogas digestate, compost) affects the phosphate sorption. We examined the P sorption process in control and DOM-saturated sandy soils. The results indicated that OM introduced with agricultural waste did not always reduce P sorption, but certainly had an effect on impairing P fixation, and thus, may result in potentially greater P mobility in the soil, including P availability. Among these waste materials, DOM from horse manure had the most positive effect on P mobilization; thus, horse manure—if available—is recommended for spreading on soils with low P mobility. [ABSTRACT FROM AUTHOR]

Abundant and functionally diverse earthworm communities in perennials deliver ecosystem services like increasing nutrient availability by incorporating organic matter. This study aimed to analyse the decomposition of annual and perennial energy crop residues, and the subsequent nutrient release, depending on earthworm functional diversity. In a laboratory experiment, two ecological earthworm groups—anecics (detritivorous Lumbricus terrestris (L.)) and endogeics (geophagous Aporrectodea caliginosa and A. rosea)—were incubated with wilted cup plant (Silphium perfoliatum) and maize (Zea mays) litter for 4 or 8 weeks. Decomposition and consumption rates were calculated. The C, N and P in litter and casts were analysed. Mineralisation was a function of earthworm biomass and the number of individuals. Functional diversity had no beneficial effect. Decomposition was found to be highest in treatments with detritivorous earthworms, i.e., higher earthworm biomass, yet consumption and nutrient turnover in relation to earthworm biomass were higher in treatments with geophages indicating enhanced competition. N limitation became apparent in both litter treatments and was predominant with cup plant litter. N limitation and recalcitrant cell wall compounds affected consumption rates and the egestion of total C and P. While N in casts was lower than expected, P was increased. We observed that the effects manifested at different stages of decomposition of maize and cup plant, highlighting differences in temporal development of decomposition and nutrient turnover between litter types. Our results indicate that earthworms promote decomposition of recalcitrant litter and nutrient turnover, but N limitation may hamper nutrient release. Cup plant systems offer a suitable habitat for soil-dwelling organisms, but management approaches must consider the adequate input of organic matter as an energy and nutrient source to enhance ecosystem service provision. [ABSTRACT FROM AUTHOR]

Rock-Eval pyrolysis and the biomarker composition of organic matter were systematically studied in hydrate-bearing sediments from the Shenhu area, South China Sea. The n-alkane distribution patterns revealed that the organic matter in the sediments appeared to originate from mixed sources of marine autochthonous input, terrestrial higher plants, and ancient reworked organic matter. The low total organic carbon contents (average < 0.5%) and the low hydrogen index (HI, <80 mg HC/g TOC) suggested the poor hydrocarbon-generation potential of the deposited organic matter at a surrounding temperature of <20 °C in unconsolidated sediments. The abnormally high production index and the fossil-originated unresolved complex mixture (UCM) accompanied by sterane and hopane of high maturity indicated the contribution of deep hydrocarbon reservoirs. Preliminary oil-to-source correlation for the extracts implied that the allochthonous hydrocarbons in the W01B and W02B sediments might have originated from the terrestrial source rocks of mature Enping and Wenchang formations, while those of W03B seem to be derived from more reduced and immature marine source rocks such as the Zhuhai formation. The results of the organic extracts supported the previous identification of source rocks based on the isotopic composition of C2+ hydrate-bound gases. The biomarker of methanogens, squalane, was recognized in the sediments of this study, possibly suggesting the generation of secondary microbial gases which are coupled with the biodegradation of the deep allochthonous hydrocarbons. [ABSTRACT FROM AUTHOR]

The synrift Mayo Oulo‐Léré Basin in Northern Cameroon is located in the transition zone between the West and Central African Rift Systems. Structural and stratigraphic elements of the basin resemble those of the Yola Basin in NE Nigeria, an extension of the Upper Benue Trough. The Lower Cretaceous lacustrine shales with source rock potential which occur in nearby rift basins are also present in the Mayo Oulo‐Léré Basin. These shales were investigated at two outcrop locations (Badesi and Tchontchi), and samples collected (n = 60) were subjected to palynofacies and bulk geochemical analyses to evaluate their petroleum generation potential and to interpret their depositional environment. At the studied locations, shales were divided into two lithofacies: grey to black laminated shales containing algal‐bacterial OM together with common woody (phytoclast) debris ("facies Fml"); and cm‐bedded shales which had a higher content of algal‐bacterial OM but a lower phytoclast content ("facies Fmlc"). Palynological and bulk geochemical data indicate that the shales contain well‐preserved organic matter (OM) and locally display good to excellent oil generation potential. Average TOC contents are 2.7% and 1.4% for samples of the Fmlc and Fml facies shales respectively. HI values (94‐889 mg HC/g TOC and 131‐638 mg HC/g TOC respectively) suggest that the shales contain Types I to III kerogen. Organic material in the Fmlc facies shales is dominated by amorphous organic matter (AOM: 90% on average) with a low phytoclast content (6% on average); whereas samples of the Fml facies shales contain less AOM (74% on average) and have a higher phytoclast content (23% on average). AOM in the Fmlc shales is highly fluorescent; these shales are interpreted to have been deposited in dysoxic to anoxic conditions. The AOM in the Fml shales is weakly fluorescent and the shales were deposited under more oxic conditions. The kerogen in the shales ranges from immature to early oil window mature. Average values of the pyrolysis S2 yield are 15.5 mg HC/g of rock and 7 mg HC/g of rock for samples from Fmlc and Fml facies shales respectively. The shales increase in thickness northwards towards the Logone Birni Basin where they may have reached the oil window, as in neighbouring basins. The results of this study of lacustrine shales from the Mayo Oulo‐Léré Basin suggests that there may be potential for oil exploration in northern Cameroon. [ABSTRACT FROM AUTHOR]

Polyprenols separated from lipids are promising new components from Ginkgo biloba L. leaves (GBL). In this paper, ginkgo lipids were isolated by extraction with petroleum ether, saponification, and molecular distillation. Eight known compounds: isophytol (1), nerolidol (2), linalool (3), β-sitosterol acetate (4), β-sitosterol (5), stigmasterol (6), ergosterol (7), β-sitosterol-3-O-β-D-glucopyranoside (8) and Ginkgo biloba polyprenols (GBP) were separated from GBL by chromatography and identified mainly by NMR. The separated and identified compounds 1, 2 and 3 are reported here for the first time in GBL. The 3D-DAD-HPLC-chromatogram (190-232 nm) of GBP was recorded. This study provides new evidence as there are no previous reports on antibacterial/antifungal activities and synergistic interactions between GBP and the compounds separated from GBL lipids against Salmonella enterica, Staphylocococus aureus and Aspergillus niger. Nerolidol (2) showed the highest activity among all the tested samples and of all mixture groups tested the GBP with isophytol (1) mixture had the strongest synergistic effect against Salmonella enterica among the three tested strains. A proportion of isophytol and GBP of 38.19%:61.81% (wt/wt) was determined by mixture design as the optimal proportion for the synergistic effect of GBP with isophytol against Salmonella enterica. [ABSTRACT FROM AUTHOR]

Trapped organic compounds (lipids) have been analysed in tubular carbonate concretions and their host sediments in Miocene deep water mudrocks from coastal outcrops in East Coast Basin and Taranaki Basin of North Island, New Zealand. The concretions, including calcitic, dolomitic and mixed mineralogies, have varied morphologies in many cases suggestive of conduits or pipes that channelled the escape of subsurface fluids and/or hydrocarbon gases. The extracted lipids include water column and/or diagenetically-derived alkanes, fatty acids and alcohols as well as specific marker compounds (including archaeal pentamethylicosane (PMI) and archaeol) associated with subsurface anaerobic oxidation of upwardly seeping methane gas (AOM). Strong carbon-13 isotopic depletions (δ13C –75 to –120‰) measured for PMI, archaeol and other AOM-specific marker compounds on three concretion samples support involvement of AOM in generating bicarbonate-rich fluid that was at least partly responsible for cementing the pipe-like concretions and central conduits. Other morphological types appear not to be AOM-related. Sterane and n-alkane parameters indicate low thermal maturity of the extracted organic matter. The molecular and compound specific isotopic organic geochemical evidence that some tubular concretions functioned as methane conduits thus supports an assertion that the tubular concretions represent ‘fossilised’ parts of the subsurface plumbing of biogenic or thermogenic hydrocarbon-fed cold seep systems. [ABSTRACT FROM AUTHOR]

It has been widely assumed that for a given BMI, Asians have higher percent body fat (PBF) than whites, and that the BMI threshold for defining obesity in Asians should be lower than the threshold for whites. This study sought to test this assumption by comparing the PBF between US white and Vietnamese women. The study was designed as a comparative cross-sectional investigation. In the first study, 210 Vietnamese women ages between 50 and 85 were randomly selected from various districts in Ho Chi Minh City (Vietnam). In the second study, 419 women of the same age range were randomly selected from the Rancho Bernardo Study (San Diego, CA). In both studies, lean mass (LM) and fat mass (FM) were measured by dual-energy X-ray absorptiometry (DXA) (QDR 4500; Hologic). PBF was derived as FM over body weight. Compared with Vietnamese women, white women had much more FM (24.8 ± 8.1 kg vs. 18.8 ± 4.9 kg; P < 0.0001) and greater PBF (36.4 ± 6.5% vs. 35.0 ± 6.2%; P = 0.012). However, there was no significant difference in PBF between the two groups after matching for BMI (35.1 ± 6.2% vs. 35.0 ± 5.7%; P = 0.87) or for age and BMI (35.6 ± 5.1% vs. 35.8 ± 5.9%; P = 0.79). Using the criteria of BMI ≥30, 19% of US white women and 5% of Vietnamese women were classified as obese. Approximately 54% of US white women and 53% of Vietnamese women had their PBF >35% (P = 0.80). Although white women had greater BMI, body weight, and FM than Vietnamese women, their PBF was virtually identical. Further research is required to derive a more appropriate BMI threshold for defining obesity for Asian women. [ABSTRACT FROM AUTHOR]

Lithostratigraphic and organic chemostratigraphic studies of fluvial/lacustrine sediments in the Late Cretaceous Fort Crittenden Formation in south-eastern Arizona USA, reveal changes in palaeoclimate and tectonics as well as associated fluctuations in lake level. The lower Fort Crittenden is dominated by marginal wetland to deep-water lake deposits, whereas the upper Fort Crittenden is characterized by wetland to deltaic deposits. Abundance of polycyclic aromatic hydrocarbons (PAH) and reflectance of fusinite substantiate the impact of wildfires within the watershed. Organic geochemical evidence of wildfires is linked with sedimentological indicators of seasonal aridity suggesting that wildfires were common occurrences. Sedimentological evidence for seasonal aridity includes mottles and pseudoslickensides on ped structures within wetland mudstones. Distinct variations in PAH assemblages, characterized by the number of aromatic rings, indicate that there were variations in the intensities of wildfires, assuming no variations in the types of fuel. Fusinite reflectance values are consistent with combustion temperatures from 470 to 550 °C observed in modern wildfires. [ABSTRACT FROM AUTHOR]

The geological record of mangrove plants is based on comparable morphological characteristics of pollen, fruits and wood, of fossil and modern species. But this record relies on the assumption that the ecological and habitat preferences of ancestral taxa have remained similar through ages. A reexamination of fossil evidence of Avicennia, Pelliciera, Sonneratia, Rhizophora, Bruguiera, Ceriops, etc. reveals that the modern mangrove flora was pantropic by the Eocene, and appears to have originated during Paleocene times. Earlier Paleozoic and Mesozoic candidates for a mangrove ecology lack conclusive evidence of their exclusive association with tidal environments. It is therefore clear that continental drift had a limited role in the dispersal and development of modern mangrove floras. The Eocene/Oligocene boundary crisis appears to herald a beginning of the biogeographic split between the current-day eastern and western provinces of mangrove plants. But, while the climatic origins of this major disjunction is not clearly understood, our reassessment of Tertiary paleoclimates suggests that the major cooling events of the middle Paleocene, the end of the Eocene and the middle Pliocene were the most likely influences on the evolution of mangrove floras. The associated invertebrates, especially molluscs, further support our assertion that a modern mangrove ecosystem was established only during the earliest Eocene times. We summarize our interpretation in a set of 9 palinspastic maps of fossil mangrove genera through their evolution ending with the current, bipartite distribution of present day taxa. [ABSTRACT FROM AUTHOR]

Background: Increasing population and food consumption are placing unprecedented demands on crop production. Maize is one of the most important food crops in the world, the improvement of its yield primarily depends on the application of chemical fertilizer. Methods: Earthworm activity is an essential factor in promoting soil fertility and stimulating plant growth. Inspired by amino acids composition of earthworm (Eisenia fetida) epidermal mucus, the liquid fertilizer was developed and prepared by utilizing a bionic approach. The influence of earthworm epidermal mucus (mucus), the mucus-mimicked mixture of amino acids (bionic fertilizer) and urea fertilizer (urea) on maize emergence and growth were studied and compared with the control group (distilled water). Experimental cultivation tests were conducted. The aforementioned three types of liquid fertilizer effects on maize seed vigor index, seedling emergence rate and plant quality were quantitatively evaluated. Results: Based on the conducted research, it was found that the beneficial effects of different fertilizers for maize emergence rate were ranked as follows: mucus > bionic fertilizer > urea. The low concentration treatments were beneficial to the maize emergence, while the high concentration treatments were helpful to the maize growth and root development. Besides, the lower concentration of mucus was the most effective fertilizer treatment for improving seedling quality. In addition, the test results of three types of liquid fertilizer effects on maize growth indicated that the higher concentration treatments provided more nitrogen nutrition than lower concentration treatments. Furthermore, the maize stem height and diameter were significantly promoted (p < 0.05) by the three types of liquid fertilizer. The beneficial influences of liquid fertilizer treatments for plant height, stem diameter, relative chlorophyll content and photosynthetic characteristic of leaves were ranked as follows: bionic fertilizer > urea > mucus. Conclusions: Bionic fertilizer demonstrated significant beneficial fertilizing effects (p < 0.05), which increased soil nutrients, improved maize physiological parameters, promote its growth and improved dry matter accumulation. The tested results verified the effectiveness of bionic fertilizer on stimulating maize growth. [ABSTRACT FROM AUTHOR]

Besides the importance of dissolved organic matter (DOM) in soil biogeochemical processes, there is still a debate on how agricultural intensification affects the leaching of terrestrial DOM into adjacent aquatic ecosystems. In order to close this linkage, we conducted a short-term (45 day) lysimeter experiment with silt loam and sandy loam undisturbed/intact soil cores. Mineral (calcium ammonium nitrate) or organic (pig slurry) fertilizer was applied on the soil surface with a concentration equivalent to 130 kg N ha−1. On average, amounts of leached DOC over 45 days ranged between 20.4 mg (silt loam, mineral fertilizer) and 34.4 mg (sandy loam, organic fertilizer). Both, mineral and organic fertilization of a silt loam reduced concentration of dissolved organic carbon (DOC) in the leachate and shifted its composition towards a microbial-like signature (BIX) with a higher aromaticity (Fi) and a lower molecular size (E2:E3). However, in sandy loam only mineral fertilization affected organic matter leaching. There, lowered DOC concentrations with a smaller molecular size (E2:E3) could be detected. The overall effect of fertilization on DOC leaching and DOM composition was interrelated with soil texture and limited to first 12 days. Our results highlight the need for management measures, which prevent or reduce fast flow paths leading soil water directly into aquatic systems, such as surface flow, fast subsurface flow, or drainage water. [ABSTRACT FROM AUTHOR]

Earthworms are commonly known as essential modifiers of soil carbon (C) and nitrogen (N) cycles, but the effects of their species on nutrient cycles and interaction with soil microbial activities during the decomposition of organic materials remain unclear. We conducted an incubation experiment to investigate the effect of two different epigeic earthworms (M. hilgendorfi and E. fetida) on C and N concentrations and related enzyme activities in agricultural soils with added barley residues (ground barley powder). To achieve this, four treatments were included; (1) M. hilgendorfi and barley, (2) E. fetida and barley, (3) barley without earthworms, and (4) without earthworms and without barley. After 32 days incubation, we measured soil pH, inorganic N, microbial biomass C (MBC), water or hot-water soluble C, and soil enzyme activities. We also measured CO2 emissions during the incubation. Our results indicated the earthworm activity in soils had no effect on the cumulative CO2 emissions. However, M. hilgendorfi had a potential to accumulate MBC (2.9 g kg−1 soil) and nitrate-N (39 mg kg−1 soil), compared to E. fetida (2.5 g kg−1 soil and 14 mg kg−1 soil, respectively). In conclusion, the interaction between soil microbes and earthworm is influenced by earthworm species, consequently influencing the soil C and N dynamics. [ABSTRACT FROM AUTHOR]

In deciduous trees, the 13C values of leaves are known to diverge during growth from those of woody organs. The main purpose of this study is to determine whether the divergence in 13C between leaves and current-year twigs of Fagus sylvatica (L.) is influenced by changes (i) in the relative contents of organic matter fractions and (ii) in the 13C of respired CO2. The 13C values of bulk matter, extractive-free matter, lignin, holocellulose, starch, soluble sugars, water-soluble fraction and respired CO2, as well as their relative contents in bulk matter were determined. The 13C values of biochemical fractions and respired CO2 showed very similar temporal variations for both leaves and twigs. Variations in bulk matter 13C during growth were, therefore, poorly explained by changes in biochemical composition or in respiratory fractionation and were attributed to the transition from 13C-enriched reserves (mainly starch) to 13C-depleted new photoassimilates. The divergence between leaves and twigs was related to higher values of soluble sugar 13C in twigs. However, the difference between lignin and holocellulose 13C varied during growth. This phenomenon was attributed to the delay between holocellulose and lignin deposition. These results may have implications for analysis of organic matter 13C in trees and forest ecosystems. [ABSTRACT FROM AUTHOR]

The Late Cretaceous Grassy Lake and Cedar Lake amber deposits of western Canada are among North America's most famous amber-producing localities. Although it has been suggested for over a century that Cedar Lake amber from western Manitoba may be a secondary deposit having originated from strata in Alberta, this hypothesis has not been tested explicitly using geochemical fingerprinting coupled to comparative analyses of arthropod faunal content. Although there are many amber-containing horizons associated with Cretaceous coals throughout Alberta, most are thermally mature and brittle, thus lacking the resilience to survive long distance transport while preserving intact biotic inclusions. One of the few exceptions is the amber found in situ at Grassy Lake. We present a suite of new analyses from these and other Late Cretaceous ambers from western Canada, including stable isotopes (H and C), Fourier transform infrared (FTIR) spectra, and an updated faunal compendium for the Grassy and Cedar lakes arthropod assemblages. When combined with amber's physical properties and stratigraphic constraints, the results of these analyses confirm that Cedar Lake amber is derived directly from the Grassy Lake amber deposit or an immediate correlative equivalent. This enables the palaeoenvironmental context of Grassy Lake amber to be extended to the Cedar Lake deposit, making possible a more inclusive survey of Cretaceous arthropod faunas. Les gisements ambriferes du Cretace superieur de Grassy Lake et Cedar Lake, dans l'Ouest canadien, figurent parmi les sites de production d'ambre les plus celebres d'Amerique du Nord. Bien que, pendant plus d'un siecle, on ait soutenu que le gisement de Cedar Lake, de l'Ouest du Manitoba, pourrait etre un depot secondaire ayant son origine dans des strates albertaines, cette hypothese n'a pas ete mise explicitement a l'epreuve a l'aide de methodes geochimiques combinees a des analyses comparatives de la faune d'arthropodes qu'il contient. S'il existe, dans toute l'Alberta, de nombreux horizons ambriferes associes aux charbons cretaces, dans la plupart des cas, l'ambre qu'ils renferment est thermiquement mature et cassant, ne pouvant donc pas resister a un transport sur de longues distances tout en preservant des inclusions biotiques intactes. Une des rares exceptions est l'ambre trouve en place a Grassy Lake. Nous presentons une serie de nouvelles analyses de specimens provenant de ces gisements et d'autres gisements ambriferes du Cretace tardif de l'Ouest canadien, dont des analyses des isotopes stables (H et C) et des spectres infrarouges par transformee de Fourier (IRTF), ainsi qu'un compendium faunique a jour des assemblages d'arthropodes de Grassy Lake et Cedar Lake. Jumeles aux donnees sur les proprietes physiques et aux contraintes stratigraphiques des ambres, les resultats de ces analyses confirment que l'ambre de Cedar Lake est directement derive du gisement ambrifere de Grassy Lake ou d'un equivalent correlatif immediat. Ceci permet d'elargir le contexte paleoenvironnemental de Grassy Lake au gisement de Cedar Lake, rendant ainsi possible un recensement plus complet des faunes d'arthropodes cretacees. [Traduit par la Redaction], Historical background The Canadian amber deposits at Grassy Lake (southern Alberta) and Cedar Lake (western Manitoba) are renowned internationally because of the richness of their arthropod inclusions (Pike 1994). These [...]