Shallow Furrows Research Articles

Experimental analysis of nanostructured PEEK, African giant snail shell, and sea snail shell powder for hydroxyapatite formation for bone implant applications

This experimental research focuses on the nanostructure analysis of three materials; polyether ether ketone (PEEK), African land giant snail shell (ALGSS), and sea snail shell (SSS) powder, for the formation of hydroxyapatite (HA) coatings in bone implant applications. The study aimed to evaluate these materials’ surface characteristics, furrow depth, density, and other relevant parameters to assess their suitability as bone implant materials. The nanostructure analysis revealed distinct characteristics for each material. PEEK exhibited shallow furrows and a high density of furrows, making it a favourable substrate for hydroxyapatite coating formation. The ISO 25178 roughness analysis further characterised surface roughness and topography. African land giant snail shell powder, displayed a high material ratio, indicating a potential for hydroxyapatite conversion for biomedical application. The sea snail shell powder demonstrated intermediate furrow depth and density, warranting further investigation for optimisation as a precursor for hydroxyapatite coatings. The findings emphasise the significance of nanostructure properties in bone implant materials. The tailored nanostructure of materials such as PEEK, the synthesized powder can influence their biocompatibility, osseointegration, and long-term performance. The novelty of this research lies in the comprehensive analysis of the nanostructure properties of these materials, contributing to the understanding of their potential for bone implant applications. Overall, this experimental research is significant and provides valuable insights into the nanostructure characteristics of PEEK, African land giant snail shell powder, and sea snail shell powder and they all demonstrated the potential of forming hydroxyapatite coatings. These findings contribute to advancements in bone implantology, paving enhancing innovative and improved bone implant materials

Furrows and, to a Lesser Extent, Seed Priming Improve Restoration Success in the Sagebrush Steppe

Seeding of native perennial species commonly fails in the presence of invasive annual weeds. The ability of weeds to deplete soil moisture through early germination and rapid growth gives them a competitive advantage. A possible solution to help native species compete with weeds is to enhance their germination rate and growth. We primed seeds of bluebunch wheatgrass (Pseudoroegneria spicata) and Lewis flax (Linum lewisii) in a matrix of compost, clay, and biostimulants for 4−7 d. We used an extrusion technique to incorporate the seed and priming matrix into pellets for the priming duration that had the quickest germination. We evaluated primed seeds in pellets at two field sites against seeds in pellets that were not primed and seeds left untreated (control). Seed treatments were planted in shallow (1-cm) and deep (15-cm) furrows, in a complete factorial design, with the expectation that the deep furrow treatment would provide an enhanced microsite to improve plant growth. Results indicated that deep furrows were the strongest driver in enhancing seedling establishment, while priming showed a smaller contribution. In the first month after planting, a combination of priming and furrowing increased seedling emergence by 128% and 303%, for bluebunch wheatgrass and Lewis flax, respectively, compared with control seed planted in shallow furrows. The following year, primed bluebunch wheatgrass and Lewis flax seeds in deep furrows increased plant biomass by 158% and 110%, respectively, compared with control seed in shallow furrows. Overall, this study generally indicates that the rapid germination of primed seeds and the use of deep furrows may assist seedlings in establishing, which may allow them to better compete with invasive weeds.

Unique pattern of histogenesis of the parakeratinized epithelium on lingual prominence in the domestic goose embryos (Anser anser f. domestica)

A triangular lingual prominence (LP) is a characteristic part of the tongue in Anseriformes containing adipose tissue. The parakeratinized epithelium (PEp) covers the LP. Studies aimed to describe the histogenesis of PEp during the process of the intensive formation of the LP in domestic goose during embryonic period and to determine the structural readiness to perform a protective function. The study were conducted by using LM, SEM and TEM technique. The results revealed that on day 16th the undifferentiated epithelium of LP transformed into the typical avian multilayered epithelium. Contrary to pattern of histogenesis of parakeratinized epithelium on the lingual body, on the medial and lateral areas of the elongating and bulging LP were formed epithelial furrows. Which around 20th day, on lateral areas of LP deepened up to half of epithelium, whereas on the medial area began to fade. The ultrastructure of cells lying in furrows indicated progressive apoptosis-like degeneration. On the 25th day, shallow furrows were only present on lateral areas, where bulging of LP was continued. Whereas the epithelium on medial area started cornification by the accumulation of cytokeratin fibers. Lack of the periderm during the development of the PEp of the LP indicated its endodermal origin.

Deciphering myriapoda population dynamics during Gondwana deglaciation cycles through neoichnology

In this work, we explore the biogenic structures generated by extant myriapods on the substrate surface to understand better the record of Diplichnites gouldi and other related traces in the topmost deposits of the Late Carboniferous Itararé Group (Paraná Basin, S Brazil) and the population dynamics of Myriapoda in an ancient glacial setting. Controlled neoichnological experiments involving substrate composition, plasticity, and moisture provided information about the morphometric traits and preservation potential of the crawling traces produced by Chilopoda and Diplopoda individuals. Morphometric (cluster) analysis using a sampling of 50 D. gouldi specimens provided information about size variability in these trackways in the studied deposits. The extant millipede and centipede individuals produced trackways like D. gouldi and trails similar to Diplopodichnus biformis. The millipedes also produced shallow furrows that fit in Cruziana problematica and traces that resemble a bass clef. These two morphologies are also present in the glacial trace fossil assemblage of the Itararé Group. A new ichnotaxon, Clavifasulcus jordii n. igen. et isp. was erected to characterize the trails that resemble a bass clef, and the neoichnological experiments allowed assuming them as a millipede's death march or pose. The morphometric analysis revealed seven different size classes among D. gouldi, coinciding with the number of myriapod's ontogenetic stages. Considering the very low diversity of myriapods in glacial settings, the population dynamics of extant myriapod in these environments, and the short colonization window represented by each rhythmite couplet, we consider that the different size classes found in D. gouldi in the topmost rhythmites of the Itararé Group rather represents ontogeny than a diversity of tracemakers.

Responses of soil nutrients and microbial activity to the mill-mud application in a compaction-affected sugarcane field

Context Compaction removal and organic amendment application are commonly used to mitigate the compaction-induced declines in crop yield, soil carbon (C) and soil health. However, the response of microbial activities and nutrient pools to the combination of mill-mud amendments and decompaction in the soil profile are not fully understood. Aims A field trial was conducted at Burdekin, Australia, to investigate the effects of different decompaction managements on soil nutrient cycling, associated biological activities and sugarcane yield. Methods This experiment included four treatments: control (CK, without mill-mud), mill-mud shallow furrow (MS), deep trenching without mill-mud (DT) and deep trenching mill-mud application (MD). Key results The MD treatment increased concentrations of hot water extractable organic C by 30–70% and hot water extractable total nitrogen (N) by 30–90% at the application depth. Soil microbial biomass C and N were also higher in mill-mud applied layers. Mill-mud applied treatments increased plant cane yield by 7% (MS treatment) and 14% (MD treatment) compared to CK. The DT treatment also increased plant cane yield by 11% compared to CK. Conclusion The MD treatment increased the supply of organic C and nutrients to the microbial community within the entire soil profile, enhanced nutrient cycling processes, improved soil environmental conditions and soil health for sugarcane growth and thus increased sugarcane productivity. Implications Further research should focus on microbial community composition shifts to further explore the mechanisms responsible for soil microorganism regulation of nutrient cycling in sugarcane farming systems.

Experimental neoichnology of post-autotomy arm movements of sea lilies and possible evidence of thrashing behaviour in Triassic holocrinids

Echinoderms exhibit remarkable powers of autotomy. For instance, crinoids can shed arm and stalk portions when attacked by predators. In some species, it has been reported that the autotomized arms display vigorous movements, which are thought to divert the attention of predators. This phenomenon, however, has not been well explored. Here we present results of experiments using the shallowest water species of living stalked crinoid (Metacrinus rotundus) collected at 140 m depth. A wide range of movements of detached arms, from sluggish writhing to violent flicks, was observed. Interestingly, autotomized arms produce distinct traces on the sediment surface. They are composed of straight or arched grooves usually arranged in radiating groups and shallow furrows. Similar traces were found associated with detached arms of the oldest (Early Triassic) stem-group isocrinid (Holocrinus). This finding may suggest that the origins of autotomy-related thrashing behaviour in crinoids could be traced back to at least the Early Triassic, underscoring the magnitude of anti-predatory traits that occurred during the Mesozoic Marine Revolution. A new ethological category, autotomichnia, is proposed for the traces produced by thrashing movements of shed appendages.

Lower Cretaceous (upper Albian) enigmatic plant-like columnar structures, marine Comanche Shelf, Texas

Multiple well-preserved molds of a fossil stalk-like structure are in erect positions in marine limestone beds in the upper part of the upper Albian Fort Lancaster Limestone exposed in West Texas. The Albian molds have a seven-sided cross section and seven vertical ribs that are separated by shallow furrows; the ribs bear closely spaced rings surrounding shallow depressions. The Fort Lancaster Limestone is the uppermost Albian cyclical carbonate unit deposited on the Barremian–early Cenomanian Comanche Shelf and is about 104 Ma to 100 Ma in age. These molds represent Coliculus septimus gen. et sp. nov., which, in cross section, is analogous to that of the horsetail Equisetum L., and occupies a shallow marine environment as do modern large rooted alga and marine grasses. Discovery of molds of a plant stem in strata at about 100 Ma extends the geologic range of marine plants other than algae. These molds are named and described so that they may be recognized in other Cretaceous strata.

Habitat divergence shapes the morphological diversity of larval insects: insights from scorpionflies

Insects are the most diverse group of organisms in the world, but how this diversity was achieved is still a disputable and unsatisfactorily resolved issue. In this paper, we investigated the correlations of habitat preferences and morphological traits in larval Panorpidae in the phylogenetic context to unravel the driving forces underlying the evolution of morphological traits. The results show that most anatomical features are shared by monophyletic groups and are synapomorphies. However, the phenotypes of body colorations are shared by paraphyletic assemblages, implying that they are adaptive characters. The larvae of Dicerapanorpa and Cerapanorpa are epedaphic and are darkish dorsally as camouflage, and possess well-developed locomotory appendages as adaptations likely to avoid potential predators. On the contrary, the larvae of Neopanorpa are euedaphic and are pale on their trunks, with shallow furrows, reduced antennae, shortened setae, flattened compound eyes on the head capsules, and short dorsal processes on the trunk. All these characters appear to be adaptations for the larvae to inhabit the soil. We suggest that habitat divergence has driven the morphological diversity between the epedaphic and euedaphic larvae, and may be partly responsible for the divergence of major clades within the Panorpidae.

Porcupine gnaw marks on a Late Pliocene bone from the Upper Siwaliks exposed near Village Khetpurali (Haryana, India).

Bone accumulation by porcupines at archaeological sites is well known. However, in paleontological sites such a taphonomical occurrence is rather rare. We here report porcupine (Hystrix sp.) gnaw marks on an unidentified bone fragment, dated to ~2.6 Ma from the Upper Siwalik deposits exposed near Khetpurali (Haryana), India. The present gnaw marks are very distinct and are characterized by visible edges and grooves making clear broad and shallow furrows. The present find adds to our knowledge of Siwalik vertebrate taphonomy where most of the accumulations reported earlier were either fluvial or made by carnivores.

Two new species of the family Nippobodidae (Acari, Oribatida), including a description of the leg-folding process.

Nippobodespanemorfissp. n. and Leobodestrypasissp. n. are described by means of optical and Scanning Electron Microscopy (SEM) and compared to other congeners. The leg-folding process is described and illustrated.Nippobodespanemorfissp. n. is characterised by interlocking, double hook-shaped, posterior prodorsal condyle and anterior zone humeral apophysis; posterior prodorsal depression present. Tutorium a large lamina defining a pocket-shaped structure; bothridial opening ovoid, situated at the bottom of a U-shaped structure; deep, rounded-ovoid anterior notogastral depression present; ten pairs of notogastral setae; c setae looped, dentate, sharply tipped. Marginal setae h3, p3 on large promontories, followed by deep V-shaped incision; notogaster completely surrounded by circumgastric depression; lateral genital zone with locking structure constituted by longitudinal cuticular elevation, with promontories and a parallel furrow involved in the leg-folding process; genital plate smaller than anal plate.Leobodestrypasissp. n. is characterised by: the presence of posterior prodorsal depression and anterior notogastral depression; bridge-shaped anterior prodorsal condyles; heart-shaped frontal prodorsal orifice; ten pairs of notogastral setae; posterior prodorsal condyle and humeral condyle interlocked, forming double hook-like structure; circumgastric furrow surrounding entire notogaster; setae lp, h2, h1 situated on shallow medial furrow; notogastral setae lm, lp, h1, h2 medially aligned; p1, p2, p3, h3 marginally situated. Legs I-IV, tutorium, pedotectum I, and pedotectum II involved in leg folding which is inferred to be a protection mechanism.

Tribological properties of surface topography in ultrasonic vibration-assisted grinding of zirconia ceramics

In order to clarify the friction phenomenon of zirconia ceramics in the dental prosthodontics, tribological properties of surface topography in ultrasonic vibration-assisted grinding (UVAG) are studied in this work. The mechanism of material removal is researched to introduce the discontinuous grooves in UVAG theoretically. The UVAG experiments are conducted on zirconia ceramics. Through investigating and comparing experimental results, it is found that UVAG surface has better tribological properties compared with diamond grinding surface. 3D surface roughnesses of UVAG surface are improved when suitable spindle speed, large feed, small cutting depth, and large vibration amplitude are adopted. Surface topography in UVAG changes from thorn scaly to discontinuous shallow furrow when feed increases and spindle speed decreases. The discontinuous grooves are most apparent when vibration amplitude is maximum. Furthermore, the friction coefficient is experimentally studied. The results indicate that there is no significant difference among all the friction coefficients in UVAG. Proper cutting and vibration parameters can improve the average friction coefficient.

Effects of quenching temperature on tempering microstructure and mechanical properties of 30MnB steel

This article presents the effects of quenching temperature on tempering microstructure, mechanical properties and wear resistance of 30MnB steel were studied. The results showed that: The microstructure of 30MnB steel was the tempered martensite and retained austenite after quenching at 840°c-900°c and then tempering at 200°c. the carbide precipitation did not occur when 30MnB steel was tempered at 200°c, only the carbon segregation occurred. Meanwhile, the tensile strength of 30MnB was all above 1350MPa after quenching at 840°c-900°c and then tempering at 200°c, the -40°c ballistic work was above 20J, indicating that it had good low temperature impact toughness. 30MnB had minimum abrasion loss after quenching at 880°c and then tempering at 200°c, the wear morphology was fine wear mark, shallow furrow and ridge augmentation.

Tribological properties of nanometer cerium oxide as additives in lithium grease

This paper presents a comparative study of the influence of nanometer-CeO2 (nano-CeO2) and temperature on tribological and lubricating properties of lithium grease. The morphology and structure of nanocrystals were characterized by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. Friction and wear tests were conducted on the friction and wear tester. Results show that the lithium grease with addition of nanometer-CeO2 has much better friction-reducing and anti-wear performance than that of base grease. When the additive in grease is 0.6 wt%, the friction coefficient (COF) and wear scar diameter (WSD) decrease by 28% and 13% comparing with base grease, respectively. The base grease and grease with 0.6 wt% nanometer-CeO2 both possess the lowest average COF and wear width at 50 °C. The worn surface morphology after friction test was analyzed by scanning electron microscopy (SEM) and NANOVEA three-dimensional profilometer. Under the lubrication of the lithium grease containing 0.6 wt% nano-CeO2, few shallow furrows can be observed on the quite smoothed surface and the WSD decreased. Moreover, It was found that the nano-CeO2 has been incorporated into the surface protective and lubricious layer by energy dispersive spectrometer (EDS) analysis.

EFFECT OF IRRIGATION METHODS ON WATER CONTENT DISTRIBUTION, WATER AND CORN PRODUCTIVITY

Field experiment was carried out during spring seasons of 2015 in AL-Rasheed township southern of Baghdad, Iraq to study the effects of irrigation methods on water content distribution, water use efficiency and yield of corn. Four surface irrigation treatments were used: 100% conventional basin (control), 70% of control treatment basin irrigation, Conventional furrow and shallow furrow. Water content distribution results showed that shallow furrow irrigation decreased moisture content to 14.7, 18.3 % for 0-10 and 10-20 cm depth respectively, compared to conventional basin irrigation. The result showed that treatments of conventional furrow, shallow furrow and 70% basin irrigation reduced the depth of added water in rate of 33, 28 and 30%, respectively comperd to control treatment (884mm season-1). Conventional furrow irrigation significantly increased corn grain yield to all treatments except conventional basin. In the mean while, other treatment did not differ from the conventional irrigation method. Water use efficiency of conventional furrow irrigation was significantly higher than all other treatments with 80% increment than others. Thus the 70% basin irrigation and shallow furrow irrigation is more productive yield when compared with traditional irrigation.

Morphological study of the European hedgehog (Erinaceus europaeus) tongue by SEM and LM.

The hedgehog tongue is a tactile and taste organ which carries out various functions. Detailed functional and morphological studies are required to clearly define the relationship of the hedgehog tongue with taste, food palatability, mastication and swallowing of food, as well as the production of sounds. The aim of this study was to determine the relationship between the morphological characteristics of the European hedgehog tongue and the lifestyle of this animal, as well as to compare findings with the results of studies on other vertebrates. Gross and micro-anatomical light and scanning electron microscopy studies revealed that the hedgehog tongue could be divided in three areas, namely the apex, body and root. A keratinized stratified squamous epithelium, which was smooth on the ventral surface but bore four types of papillae on the dorsal surface, lined the tongue. Three types of these papillae were found to have gustatory functions and to express their activity in close relation with the salivary glands. These simple conical filiform papillae were situated caudally and distributed one after the other without a break. The dome-shaped fungiform papillae on the apex, with the highest distribution rate on the apex edge, were small, but those on the body and root were large. The three circular vallate papillae were arranged in a triangular shape. The foliate papillae with a few tiny projections, found in a shallow furrow, were situated between the root and the body. Most of the nerve fibers observed in different sections of the tongue tissue were of the unmyelinated type, confirming that the main task of the hedgehog tongue was its gustatory function.

Effect of nanometer silicon dioxide on the frictional behavior of lubricating grease

Nanometer-silicon dioxide encapsulated in lithium grease is prepared, and the frictional behavior of the lithium grease and nanometer-silicon dioxide–contained lithium grease is compared with respect to the additive content, load, and frictional temperature in this article. The structure and morphology of nanometer-silicon dioxide is characterized by X-ray diffraction and scanning electron microscopy, respectively. Friction and wear tests were conducted on a four-ball friction and wear tester. The morphology of worn steel surface is analyzed by scanning electron microscopy and three-dimensional surface profiler. Results show that the addition of nanometer-silicon dioxide in grease can markedly improve the friction-reducing performance and anti-wear ability of base grease. When the nanometer-silicon dioxide in grease is 0.3 wt%, the friction coefficient and wear scar diameter decrease by 26% and 7% compared with base grease, respectively. The nanometer-silicon dioxide (0.3 wt%)–contained grease exhibits the lowest average friction coefficient at the load of 342 N, which decreases by 39% as compared with that of base grease. The worn surface is quite smooth with few shallow furrows and the wear scar diameter decreases under the lubrication of the grease containing 0.3 wt% nanometer-silicon dioxide. Moreover, it was found that the nanometer-silicon dioxide have been incorporated into the surface protective and lubricious layer by energy dispersive spectrometer analysis.

Revision of the family Carabodidae (Acari: Oribatida) X. Bovicarabodes jacquelinae sp. nov., redefinition of the genus Tuberocepheus Balogh & Mahunka, 1969 and redescription of Tuberocepheus longus (Balogh, 1962)

ABSTRACTBovicarabodes jacquelinae sp. nov. is easily differentiated from other congeners by paired rounded to ovate prodorsal cavity with internal ovoid incision; presence of medial eye pillar; two cuticular ridges anterior to interlamellar setae; and incomplete bothridial ring with bothridial tooth. Notogastral anterior depression ovoid, with two posterior semicircular zones delimited by prominent furrow; notogastral anterior depression extending to beyond c2 and da setae. Tutorium a strongly curving cuticular thickening; humeral apophysis elongate; small triangular discidium. Genital opening smaller than anal opening; aggenital and ad3 setae in close proximity. B. jacquelinae is similar to B. deharvengi, differentiated principally by shape and position of elevated interlamellar process; position of interlamellar setal insertion; notogastral anterior depression; and shape of humeral process. Tuberocepheus longus (Balogh, 1962) is redescribed, with clarification being obtained by the use of optical and scanning electron microscopy. The genus is characterized by the combination of the following characters: Prodorsum divided into two ear-like processes; shallow lamellar furrow not clearly delimited; smooth narrow bothridal ring; bothridial tooth a finger-like projection; and conspicuous polyhedral posterior prodorsal depression. Notogaster 12 pairs of setae; seta c absent; medium-sized elevated zone situated between notogastral anterior depression and notogastral posterior depression; two pairs lateral paired elevations; three pairs central paired elevations; pedotectum I larger than tutorium. Epimeres poorly delimited; anterior genital furrow simple, lacking lateral depression; well-developed depression surrounding genital opening; depressions surrounding genital opening and anterior genital furrow connected by a narrow channel; anal opening larger than genital opening.

Morphological characterization and in vitro germination of heat-treated pollen in Eucommia ulmoides

AbstractPolyploid breeding has the potential to increase the economic secondary metabolites of Eucommia ulmoides. However, pollination with induced ploidy-mixed pollen has failed to produce polyploids (GAO, 2006). In this investigation, the morphological characterization and in vitro germination of heat-induced ploidy-mixed pollen of E. ulmoides were analysed to determine why there is no polyploid production. Heat-treated pollen grains were easily distinguished as large and small according to their length. The large pollen grains were significantly longer than both untreated and heat-treated small samples, suggesting that they were probably 2n pollen. Rather than the three germinal pores in small pollen, the large grains typically had four pores and, in some cases, shallow furrows, which might affect their germination. Although the maximal germination rates of the treated small and large pollen were not significantly different, the large pollen germinated tardily during the early stages of incubation. The small pollen maintained its growth during the incubation, but the tube growth of large pollen almost stopped after 24 h incubation. Both vegetative and generative nuclei in the large pollen moved into tubes later than in small pollen and the frequency of mitosis in generative nuclei of large pollen was low. Therefore, the tardy germination, poor tube growth, and weak activity of both vegetative and generative nuclei probably caused the poor competition of large pollen in certation. Finally, techniques to increase the competition of highploidy pollen and the prospect of 2n female gamete induction in the polyploid breeding program of E. ulmoides are discussed.

Morphological comparison of the larvae of Panorpa obtusa Cheng and Neopanorpa lui Chou & Ran (Mecoptera: Panorpidae)

Holometabolous larvae are often diverse morphologically, and the driving forces for this diversity are often not well elucidated. In this study, the larvae of two species of Panorpidae (Mecoptera) living in different habitats (epedaphic in Panorpa obtusa Cheng, 1949 and euedaphic in Neopanorpa lui Chou and Ran, 1981) are studied using light and scanning electron microscopy. The larvae of Neopanorpa Weele have shallow furrows and short setae on the head capsule, and their first four abdominal prolegs are short. By contrast, the larvae of Panorpa Linnaeus have long setae but lack furrows on the head capsule, and the prolegs are medium-sized. These morphological differences may reflect their adaptations to distinct living habits.

EFFECT OF CONTROLLED DRAINAGE IN THE WHEAT SEASON ON SOIL CH4 AND N2O EMISSIONS DURING THE RICE SEASON

The effect of draining crop fields during the wheat season on the soil CH4 and N2O emissions during the rice season in this article. There were four treatments: traditional cultivation during the wheat season + cultivation without fertilization during the rice season (CK1 field), traditional cultivation during the wheat season + traditional cultivation during the rice season (CK2 field), draining the fields through shallow furrows + traditional cultivation during the rice season (CQ field) and draining the fields through deep furrows + traditional cultivation during the rice season (CS field). The results are listed as follows. (1) Draining the field through furrows during the wheat season significantly reduced the CH4 and N2O emissions during the rice season. Compared with the CK1 field, the total CH4 emissions from the CQ and CS fields decreased by 43.1% and 39.9%, respectively; compared with the CK2 field, the total CH4 emissions from the CQ and CS fields decreased by 58.1% and 55.7%, respectively; compared with the CK2 field, the total N2O emissions from the CQ and CS fields decreased by 33.6% and 32.7%, respectively. N2O emissions from the CQ and CS fields caused by fertilization declined by 44.0% and 42.9% compared with that from the CK2 field. (2) Draining the wheat field in winter changed the CH4 emission pattern during the following rice season. The daily average CH4 emission flux from the winter flooded CK1 and CK2 fields were comparable before the field sunning and after the re-flooding and the fluxes from the drained CQ and CS fields before the field sunning were close to that from the CK1 and CK2 fields but were significantly greater than that from the drained CQ and CS fields after the field re-flooding. (3) The soil CH4 emission flux was