Maximum Rate Of Accumulation Research Articles

Accumulation and exportation of nutrients by yellow Passion fruit cv. IAC 275

Abstract The mineral nutrition is essential to increase yield and fruit quality of passion fruit. There is no information of nutrient accumulation throughout the production cycle. Thus, in order to assist in the correct nutrients supply and update the recommendations, studies involving cultivars and cultivation techniques are necessary. The aim of this study was to evaluate the plant growth, the nutrient accumulation and the exportation in plants of yellow passion fruit cv. IAC 275. The experimental design was a randomized block, with three replications, where the treatments were evaluation times. Stem length, dry mass matter and nutrient accumulation in aerial part (leaves and stems), fruits and roots were evaluated. The maximum daily accumulation rate and periods of maximum nutritional requirement were calculated, in addition to the nutrient extraction and exportation. The nutrient accumulation at the end of the cycle, at 450 days after sowing, were in g plant-1: N (178.5) > K (162.4) > Ca (70.8) > Mg (14.8) > S (13.3) > P (11.0) and mg plant-1: Fe (827.6) > Mn (130.7) > Zn (69.8) > B (56.7) > Cu (17.8).

Variability in iodine in temperate seaweeds and iodine accumulation kinetics of Fucus vesiculosus and Laminaria digitata (Phaeophyceae, Ochrophyta).

The biogeochemistry of iodine in temperate coastal ecosystems is largely mediated by macroalgae, which act as a major biological sink and source of iodine. Their capacity to accumulate, retain and release iodine has been associated with abiotic and biotic stressors, but quantitative information is limited. We evaluated the seasonal iodine retention capacity of eleven macroalgal species belonging to different systematic groups, collected from two sites in Ireland. Iodine accumulation and retention were then further quantified in Fucus vesiculosus and Laminaria digitata in relation to I- concentrations in seawater and temperature. In general, iodine contents were ~101 -102 μmol·(g dw)-1 for Laminariales, 100 -101 μmol·(g dw)-1 for Fucales, 10-1 -100 μmol·(g dw)-1 for Rhodophyta, and 10-1 μmol·(g dw)-1 for Chlorophyta. Typically, algal iodine contents were above average in winter and below average in summer. Iodine accumulation in F.vesiculosus and L.digitata depended on I- availability and followed the Michaelis-Menten kinetic. The ratio of maximum accumulation rate to half accumulation coefficient (ρmax : Kt ) was 2.4 times higher for F.vesiculosus than for L.digitata, suggesting that F.vesiculosus was more efficient in iodine accumulation. Both species exhibited a temperature-dependent net loss of iodine, and only an exposure to sufficient external I- concentrations compensated for this loss. This study revealed that both environmental (e.g., I- in seawater, temperature) and organismal (e.g., the status of the iodine storage pool) variables determine retention and variability in iodine in temperate seaweeds.

Environmental Status of Kam’yanske Reservoir (Ukraine)

Abstract Environmental status of Kam’yanske reservoir (47°55′51.6″N 33°46′08.4″E) as one of the small water bodies belonging to southeast Ukraine was investigated. The integrated environmental assessment based on the quality indices of salt content, trophic–saprobiological indicators and specific toxic water indicators of Kam’yanske reservoir are characterised as ‘satisfactory’ and ‘slightly polluted’. Defined bottom accumulation coefficient (BAC) shows continuing heavy metals enlargement in the upper layer of the bottom sediments and chronic pollution in ecosystem. The content of heavy metals in the muscles of industrial fish in the researched pond did not exceed maximal allowed concentration (MAC) for fish as food according to Ukrainian standards. Accumulation of heavy metals in fish was due to the peculiarities of their ways of nutrition and existing. The total contents of heavy metals in common carp was almost twice as large compared to other fish. The maximum accumulation rates set for fish muscles of essential elements – zinc and iron.

1 g Model Tests on the Displacement Accumulation of Large-Diameter Piles Under Cyclic Lateral Loading

Abstract Large-diameter monopiles are an established foundation type for offshore wind energy converters. A crucial aspect in the design of such piles is the bearing behavior under cyclically acting wind and wave loads, namely the accumulation of deflections and rotations under these loads. Regarding the prediction of the behavior under cyclic one-way load, some empirical approaches and also numerical simulation methods exist. In contrast, the behavior under cyclic two-way loading is widely unclear and must be investigated by pile tests. This paper presents the results of 1 g model tests with large-diameter piles in sand under arbitrary cyclic loading types. It was found that for almost rigid large-diameter piles, the effect of the loading type on the rate of displacement accumulation could be accounted for by a function which is almost independent on the system parameters, e.g., pile stiffness or relative density of the sand, but dependent on load eccentricity. The maximum accumulation rate occurs for asymmetric two-way loading. Using the functions found in the tests, a prediction of displacement accumulation for load spectra consisting of packages of arbitrary loads becomes possible. For flexible piles, a different effect of the loading type on the rate of displacement accumulation was observed. Here, asymmetric two-way loading was obviously not more unfavorable than one-way load.

Growth Pattern and Copper Accumulation in Callus of Datura metel

<p>This experiment was aimed to evaluate the copper accumulation using callus culture of <em>Datura metel</em> L. The culture was established from leaves onto MS contained NAA 2.5 mg/L and Kinetin 0.5 mg/L as the control. The exposure of the culture was carried out by 2 copper compounds as treatment, i.e. CuCl<sub>2</sub>.2H<sub>2</sub>O and Na<sub>2</sub>CuEDTA at level concentration 0.; 0.1; 5; 10; 15; and 20 µM. The growth pattern of callus in control showed increasing growth rate in 36 days, whereas exponential stage was reached at 12-20<sup>th</sup> doi*. Whilst, after 10 doi, the treatment showed constant growth pattern. The absorption rate of the culture was increased by the addition of the CuCl<sub>2</sub>.2H<sub>2</sub>O at 5 – 15 µM of level concentration but declined at 20µM. The maximum rate of accumulation of Cu (0,1519 mg g<sup>-1</sup>) was obtained at 15 µM. Instead, the addition of Na<sub>2</sub>CuEDTA at 5 – 20µM of level concentration showed the significant increment while the maximum accumulation was obtained at 20µM (0,1420 mg g<sup>-1</sup>). The existence of chelator in copper compound reduced the rate of toxicity while all tolerance index values were between 66,24 and 97,28 %.The results suggested the role of callus of <em>D. metel</em> as that fairly absorbed and accumulated Cu<sup>2+</sup>. Exposure with CuCl<sub>2</sub>.2H<sub>2</sub>O indicated higher accumulation than Na<sub>2</sub>CuEDTA.</p><p><strong>How to Cite</strong></p><p>Nurchayati, Y., Santosa, S., Nugroho, L. H., & Indrianto, A. (2016). Growth Pattern and Copper Accumulation in Callus of Datura metel. <em>Biosaintifika: Journal of Biology & Biology Education</em>, 8(2), 135-140. </p>

Responses of dry matter, nitrogen accumulation and distribution and nitrogen utilization of pepper to new-type fertilizers in Guizhou yellow soil.

In order to explore the pepper yield responses to new-type fertilizers in yellow soil in Guizhou Province, a pot experiment, with the variety of "Bola 5", was conducted to estimate the effects of four new-type fertilizers, including water retaining fertilizer (BSX), stable slow release fertilizer (WDX), coated slow release fertilizer (BMX) and long-lasting nitrogen fertilizer (CXDF), on the accumulation and distribution of dry matter and nitrogen (N) uptake and N use efficiency. The results showed that the application of new-type fertilizers could significantly influence the accumulation and distribution of dry matter and shoot N uptake. Compared with dry matter accumulation, the start time and the end time of N accumulation during fast-growing period were advanced by 17-26 d and 28-45 d, respectively, and the duration of N accumulation in fast-growing period was shorter by 7-23 d, which indicated that the occurrence time of N accumulation was prior to the accumulation of dry matter. In contrast to the common compound fertilizer (FHF) treatment, the occurrence time of dry matter and nitrogen accumulation in the treatments with new-type fertili-zers (BSX, WDX, BMX and CXDF) were obviously lagged, and the lag time was longest in the BMX treatment. However, it had a shorter duration of fast-growing stage and a maximum accumulation rate for the WDX treatment, revealing that WDX could realize the high nutrient use efficiency in a short time. The post-anthesis dry matter and N accumulation accounted for 63.0%, 20.1% and 73.3%, 20.5% for the BSX and BMX treatments, respectively, while these proportions for the WDX were 59.3% and 11.6%, respectively. This indicated that BSX and BMX were beneficial to promote dry matter and N assimilation after flowering, while WDX was conducive to dry matter and nutrients accumulation before flowering. Compared with the FHF treatment, new-type fertilizers (BSX, WDX and BMX) application could significantly improve N use efficiency. Nitrogen partial productivity, nitrogen agronomic efficiency and nitrogen apparent utilization rate of the WDX treatment were the highest, with the average of 66.74 kg·kg-1, 44.28 kg·kg-1 and 54.7%, respectively. Consequently, these four new-type fertilizers were sui-table for pepper cultivation in Guizhou, in which the yield response to the WDX was the best.

Geodynamic background of the 2008 Wenchuan earthquake based on 3D visco-elastic numerical modelling

The 2008 Wenchuan earthquake (Mw7.9) occurred in the Longmen Shan fault zone. The stress change and crustal deformation during the accumulation period is computed using 3D finite element modelling assuming visco-elastic rheology. Our results support that the eastward movement of the Tibetan Plateau resulting from the India-Eurasia collision is obstructed at the Longmen Shan fault zone by the strong Yangtze craton. In response, the Tibetan ductile crust thickens and accumulates at the contact between the Tibetan Plateau and the Sichuan Basin. This process implies a strong uplift with the rate of about 1.8mm/a of the upper crust and induces a stress concentration nearly at the bottom of the Longmen Shan fault zone. We believe that the stress concentration in the Longmen Shan fault zone provides a very important geodynamic background of the 2008 Wenchuan earthquake. Using numerical experiments we find that the key factor controlling this stress concentration process is the large viscosity contrast in the middle and lower crusts between the Tibetan Plateau and the Sichuan Basin. The results show that large viscosity contrast in the middle and lower crusts accelerates the stress concentration in the Longmen Shan fault zone. Fast moving lower crustal flow accelerates this stress accumulation process. During the inter-seismic period, spatially the maximum stress accumulation rate of the eastern margin of the Tibetan Plateau is located nearly at the bottom of the brittle upper crust of the Longmen Shan fault zone. The spatial distribution of the stress accumulation along the strike of the Longmen Shan fault zone is as follows: the normal stress decreases while the shear stress increases from southwest to northeast along the Longmen Shan fault zone. This stress distribution explains the thrust motion in the SW and strike-slip motion in the NE during the 2008 Wenchuan earthquake.

Assessment of the irrigation feasibility of low-cost filtered municipal wastewater for red amaranth (Amaranthus tricolor L cv. Surma)

Because of the scarcity of clean water, treated wastewater potentially provides an alternative source for irrigation. In the present experiment, the feasibility of using low-cost filtered municipal wastewater in the irrigation of red amaranth (Amaranthus tricolor L cv. Surma) cultivation was assessed. The collected municipal wastewater from fish markets, hospitals, clinics, sewage, and kitchens of households in Sylhet City, Bangladesh were mixed and filtered with nylon mesh. Six filtration methods were applied using the following materials: sand (T1); sand and wood charcoal consecutively (T2); sand, wood charcoal and rice husks consecutively (T3); sand, wood charcoal, rice husks and sawdust consecutively (T4); sand, wood charcoal, rice husks, sawdust and brick chips consecutively (T5); and sand, wood charcoal, rice husks, sawdust, brick chips and gravel consecutively (T6). The water from ponds and rivers was considered as the control treatment (To). The chemical properties and heavy metals content of the water were determined before and after the low cost filtering, and the effects of the wastewater on seed germination, plant growth and the accumulation rate of heavy metals by plants were assessed. After filtration, the pH, EC and TDS ranged from 5.87 to 9.17, 292 to 691µScm−1 and 267 to 729mgL−1, respectively. The EC and TDS were in an acceptable level for use in irrigation, satisfying the recommendations of the FAO. However, select pH values were unsuitable for irrigation. The metal concentrations decreased after applying each treatment. The reduction of Fe, Mn, Pb, Cu, As and Zn were 73.23%, 92.69%, 45.51%, 69.57%, 75.47% and 95.06%, respectively. When we considered the individual filtering material, the maximum amount of As and Pb was absorbed by sawdust; Cu and Zn by wood charcoal; Mn and Cu by sand and Fe by gravel. Among the six filtration treatments, T5 showed the highest seed germination (67.14%), similar to the control T0 (77.14%). The healthy plants/pot ratio (93.62%) was significantly higher for T5, even higher than the control (85.19%). Additionally, the average plant height for T5 (8.097in.) was statistically identical to the control (8.633in.). The average number of leaves for T5 (10) was near to the control (12). Finally, the minimum amount of heavy metals accumulated in the plants of T5, whereas the maximum accumulation rate varied among treatments. The accumulated levels of Fe, Mn, Cu, and Zn were within the safe limit; however, the concentrations of Pb and As exceeded their safe limits. The results showed that the low-cost filtration method potentially allows municipal wastewater to be used in irrigation for agricultural production.

Changes in Carbohydrate Accumulation and Activities of Enzymes Involved in Starch Synthesis in Maize Kernels at Different Positions on an Ear during Grain Filling

Kernels at the upper position of a maize ear usually show slower filling rate and lower weight than those at the basal and middle positions. The mechanism is little understood. The objective of this study was to understand if changes in carbohydrate accumulation and activities of the enzymes involved in starch synthesis in the kernels at different positions on a maize ear were associated with grain filling. A maize cultivar Denghai 11 was planted in spring and summer. Contents of the soluble sugar,sucrose and starch and the activities of the adenosine diphosphoglucose pyrophosphorylase(AGPase),starch synthase(St S),and starch branching enzyme(SBE) in kernels at different positions on an ear and their relationships with grain filling rate were determined. The results showed that kernel number per ear,100-kernel weight,and grain yield were more or higher for the spring maize than for the summer maize. Although the grain yield was different between the spring maize and the summer maize,the maximum kernel filling rate,mean kernel filling rate,100-kernel weight,the contents of both soluble sugar and sucrose in kernels,the maximum starch accumulation rate and mean starch accumulation rate in kernels all exhibited an order of basal position middle position upper position. The activities of AGPase,St S,and SBE in kernels at different positions on an ear showed the changes of single peak curves,and the peak and mean enzymatic activities in kernels at the upper position were significantly lower than those at both middle and basal positions. The starch accumulation rate and kernel filling rate were very significantly and positively correlated with activities of AGPase,St S,and SBE in kernels. The results suggested that a smaller starch accumulation rate and lower weight for the kernels at the upper position on a maize ear are mainly attributed to lower activities of the enzymes involved in starch synthesis in these kernels. A higher kernel weight for the spring maize is closely associated with its stronger ability of starch synthesis in the kernels.

Effect of Drought Stress During Flowering Stage on Starch Accumulation and Starch Synthesis Enzymes in Sorghum Grains

Starch content is a key factor affecting sorghum grain quality. The research of sorghum grain starch accumulation and the related synthesis enzyme activities has great significance for understanding the mechanisms of starch metabolisms. The differences between a high and a low starch content sorghum hybrids (Tieza 17 and Liaoza 11, respectively) in grain starch accumulation and the related synthesis enzyme activities were assessed following imposition of water stress during flowering stage. The total starch, amylase and amylopectin accumulation all decreased at the mid-late stage of grain filling under drought stress during flowering stage. The maximum and mean accumulation rates also decreased. During grain filling, soluble starch synthase (SSS), granule-bound starch synthase (GBSS), starch branching enzyme (SBE), and starch debranching enzymes (DBE) activities were all affected, though differently. Drought stress reduced starch accumulation in a larger extent for Tieza 17 than Liaoza 11. Drought stress during flowing stage reduced starch synthesis enzyme activities, thus reducing starch accumulation in grains, and the differences between starch components were also demonstrated under drought stress.

Growth and production of irrigated vitória pineapple grown in semi-arid conditions

This study aimed to evaluate the growth characteristics of irrigated Vitória pineapple plants grown in semi-arid conditions and determine its developmental stages based on those characteristics. It was used a randomized block design with four replicates. The experimental treatments were: plant harvest at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The following variables were determined: plant height, stem diameter, D-leaf length, D-leaf fresh and dry mass, biomass production of plants and plant parts (organs), and vegetative biomass. Five phenological stages are proposed based on vegetative biomass production: < 20% biomass production (V1); 21-40% (V2); 41-60% (V3); 61-80% (V4); and > 80% (V5). The maximum growth rate for plant height, D-leaf length, and stem diameter was observed at the end of the phenological stage V1 (390-411 DAP), and at the end of stage V5 these plant traits had average values of 106, 82, and 7 cm, respectively. The maximum biomass accumulation rates were observed at stages V4 and V5, resulting in a final fruit yield and total fresh biomass of 72 t ha-1 and 326 t ha-1, respectively. Finally, we estimated that 80% of the accumulated biomass may remain in the field after fruit and slip harvest, and could be incorporated as plant residue into the soil.

Accumulation of terrestrial organic carbon on an active continental margin offshore southwestern Taiwan: Source-to-sink pathways of river-borne organic particles

Sediment samples (213 sites) collected from the tectonic-active continental margin, offshore southwestern Taiwan were analyzed for grain sizes, organic carbon, nitrogen and carbon isotopic composition to obtain mass accumulation rate of terrestrial organic carbon and carbon budget to evaluate fate of terrestrial organic carbon from small mountainous rivers on the continental margin offshore southwestern Taiwan. Terrestrial organic carbon accumulation rates range from 0.29 to 45.6gCm−2yr−1 with a total accumulation budget of 0.063Mtyr−1, which accounts for less than 13% of total river particulate organic carbon loads exported from the adjacent rivers, the Gaoping (a.k.a., Kaoping), Erhjen and Tsengwen rivers. This low burial efficiency of terrestrial organic carbon demonstrated that a majority of river-borne particles together with organic materials was moved away from the study area.For the river-borne particles from the Gaoping river, a pair of depocenters in the upper slope flanking the Gaoping submarine canyon are the locations where the maximum TCorg accumulation rate were observed which hold up to 45% (0.016Mtyr−1) of the calculated accumulation found in the study region. On the other hand, the occurrence of higher-fraction terrestrial organic carbon in the upper and middle Gaoping submarine canyon suggests that a majority of particulate organic carbon of the Gaoping river was transported directly into the deep-sea basin through the Gaoping submarine canyon. Our results demonstrated that active margin with narrow shelf and slope is not an efficient sink for the large amount of terrigenous organic carbon supplied by the small rivers, but, a transient environment for these river derived particles.

Biogeochemical variability during the past 3.6 million years recorded by FTIR spectroscopy in the sediment record of Lake El'gygytgyn, Far East Russian Arctic

Abstract. A number of studies have shown that Fourier transform infrared spectroscopy (FTIRS) can be applied to quantitatively assess lacustrine sediment constituents. In this study, we developed calibration models based on FTIRS for the quantitative determination of biogenic silica (BSi; n = 420; gradient: 0.9–56.5%), total organic carbon (TOC; n = 309; gradient: 0–2.9%), and total inorganic carbon (TIC; n= 152; gradient: 0–0.4%) in a 318 m-long sediment record with a basal age of 3.6 million years from Lake El'gygytgyn, Far East Russian Arctic. The developed partial least squares (PLS) regression models yield high cross-validated (CV) R2CV = 0.86–0.91 and low root mean square error of cross-validation (RMSECV) (3.1–7.0% of the gradient for the different properties). By applying these models to 6771 samples from the entire sediment record, we obtained detailed insight into bioproductivity variations in Lake El'gygytgyn throughout the middle to late Pliocene and Quaternary. High accumulation rates of BSi indicate a productivity maximum during the middle Pliocene (3.6–3.3 Ma), followed by gradually decreasing rates during the late Pliocene and Quaternary. The average BSi accumulation during the middle Pliocene was ~3 times higher than maximum accumulation rates during the past 1.5 million years. The indicated progressive deterioration of environmental and climatic conditions in the Siberian Arctic starting at ca. 3.3 Ma is consistent with the first occurrence of glacial periods and the finally complete establishment of glacial–interglacial cycles during the Quaternary.

Periprosthetic wear particle migration and distribution modelling and the implication for osteolysis in cementless total hip replacement

In total hip replacement (THR), wear particles play a significant role in osteolysis and have been observed in locations as remote as the tip of femoral stem. However, there is no clear understanding of the factors and mechanisms causing, or contributing to particle migration to the periprosthetic tissue. Interfacial gaps provide a route for particle laden joint fluid to transport wear particles to the periprosthetic tissue and cause osteolysis. It is likely that capsular pressure, gap dimensions and micromotion of the gap during cyclic loading of an implant, play defining roles to facilitate particle migration. In order to obtain a better understanding of the above mechanisms and factors, transient two-dimensional computational fluid dynamic simulations have been performed for the flow in the lateral side of a cementless stem-femur system including the joint capsule, a gap in communication with the capsule and the surrounding bone. A discrete phase model to describe particle motion has been employed. Key findings from these simulations include: (1) Particles were shown to enter the periprosthetic tissue along the entire length of the gap but with higher concentrations at both proximal and distal ends of the gap and a maximum rate of particle accumulation in the distal regions. (2) High capsular pressure, rather than gap micromotion, has been shown to be the main driving force for particle migration to periprosthetic tissue. (3) Implant micromotion was shown to pump out rather than draw in particles to the interfacial gaps. (4) Particle concentrations are consistent with known distributions of (i) focal osteolysis at the distal end of the gap and (ii) linear osteolysis along the entire gap length.

Effects of fertilization and row spacing on microenvironment within population canopy and dry matter accumulation of waxy maize

在田间试验条件下, 以糯玉米"凤糯6号"为试验材料, 研究了相同密度下, 不同施肥量(600 kg·hm^-2、750 kg·hm^-2、900 kg·hm^-2, 基肥、追肥等量)和不同行距配置(50 cm、60 cm、70 cm和80 cm)对糯玉米群体冠层内温度、光照强度、相对湿度、CO₂浓度、光温分布以及群体水分利用率、群体干物质积累和蒸煮品质的影响。结果表明: 糯玉米群体冠层内微环境除了受灌浆时期、一天中不同时间段影响, 还受行距和施肥量影响。行距70 cm时, 糯玉米群体冠层内平均温度最小; 行距为70 cm、施肥量600 kg·hm^-2时, 灌浆初期、中期和后期的光照强度都表现出最大值, 分别为236.2 μmol·m²·s^-1、275.3 μmol·m^-2·s^-1和285.4 μmol·m^-2·s^-1; 冠层相对湿度在行距70 cm、施肥量900 kg·hm^-2时最大, 在灌浆3个时期最高相对湿度分别比最低值高41.99%、33.98%和36.11%; 灌浆初期CO₂浓度最大值发生在行距80 cm、施肥量为600 kg·hm^-2时, 为362.4 mg·m^-3, 灌浆中期和后期最大值发生在行距70 cm、施肥量为600 kg·hm^-2时, 为363.4 mg·m^-3和385.7 mg·m^-3。在行距70 cm、施肥量为900 kg·hm^-2时, 灌浆3个时期水分利用效率最高, 分别比最低值高14.75%、15.18%、14.46%; 干物质积累量和生长率最大, 分别为5 066.4 kg·hm^-2和14.3 kg·hm^-2·d^-1、383.2 kg·hm^-2和15.3 kg·hm^-2·d^-1以及 13 213.4 kg·hm^-2和19.7 kg·hm^-2·d^-1。糯玉米蒸煮品质即感官品质、气味、风味、色泽、糯性、柔嫩性、皮厚薄等在行距70 cm、施肥量为900 kg·hm^-2时最佳。

The study of zinc bioaccumulation in internal organs of swan mussel, Anodonta cygnea (Linea, 1876)

Heavy metals as importantpollutants in aquatic ecosystems can cause adverse biological effects on liveorganisms of these environments. This research was conducted to study the bioaccumulationof zinc (Zn) in internal organs (mantle, gill, hepatopancreas and foot) of thefreshwater bivalve, Anodonta cygnea during 27 days in vitro exposureperiod. Results showed that this species has a high potency of metalaccumulation. There was no significant difference between basal Zn levels instudied organs. Maximum accumulation rate were recorded in gill andhepatopancreas and their Zn content was significantly (α=0.05; P < 0.02) higher than mantle and foot. The minimumZn accumulation occurred in mantle. Zn levels in gill, hepatopancreas and footwere increased during exposure period, but a decreasing trend was observed inZn level of mantle between days 18 and 27. The results of this study indicatedthat accumulation potential of different organs and their sensitivity andimpressibility are different and gill and hepatopancreas are appropriate organsto study heavy metal bioaccumulation and their pollution in freshwaters.

Sedimentary facies of the subaqueous Changjiang River delta since the late Pleistocene

The sedimentary facies of the subaqueous Changjiang (Yangtze) River delta since the late Pleistocene was studied based on lithology and foraminifera analysis for two boreholes, CJK07 and CJK11, along with C-14 dating. Four sedimentary facies were identified, namely fluvial, tidal flat, offshore, and prodelta facies. The fluvial sedimentary facies is comprised of fluvial channel lag deposits, fluvial point bar deposits, and floodplain deposits, showing a fining-upward sequence in general with no benthic foraminifera. A layer of stiff clay overlies the fluvial deposits in core CJK07, indicating a long-term exposure environment during the Last Glacial Maximum (LGM). During the postglacial sea-level rise around 13-7.5 cal ka BP, the tidal flat facies was deposited in core CJK11, characterized by abundant silt-clay couplets. Euryhaline species dominate the subtidal flat foraminiferal assemblages, while almost no foraminifera was found in the intertidal flat. The offshore environment was the major sedimentary environment when the sea level reached its highest level around 7.5 cal ka BP, with a maximum accumulation rate of 10 mm/a found in core CJK11. Prodelta sediments have been deposited in core CJK11 since similar to 3 cal ka BP, after the formation of the Changjiang River delta. The difference in sedimentary facies between core CJK07 and CJK11 is due to their location: core CJK07 was in an interfluve while core CJK11 was in an incised valley during the LGM. Furthermore, AMS 14 C dating of core CJK07 shows poor chronological order, indicating that the sediments were reworked by strong tidal currents and that sediment deposited since similar to 7.7 cal ka BP in core CJK07 was eroded away by modern hydrodynamic forces caused by the southward shift of the Changjiang River delta depocenter.

Canopy Physiology and Characteristics of Yield Components during Reproductive Stage in Soybean Hybrids

Utilization of soybean hybrid is an effective way to increase soybean yield. We used two soybean hybrids(HybSoy-1and HybSoy-2) and two conventional varieties(CV) with the same maturity(Jiyu 72 and Jilin 30) as materials to explore physiological characters of canopy, traits of yield and yield components, and the physiological mechanism of increasing yield in soybean hybrid at reproductive stage. The result showed that, from 2010 to 2011, compared with CV, the yields of soybean hybrids were increased by 13.9% and 16.7%. Leaf chlorophyll contents at late growth stages, photosynthetic rates at R2(full bloom)–R7(beginning maturity) and leaf area indices(LAI) at R2–R4(full pod) were all significantly higher than those of CV; the maximum LAI of HybSoy-1 and HybSoy-2 in 2010 were 8.09 and 8.30, far more than those of CV, and LAI at late growth stages were not decreased sharply. Biomasses of all varieties reached a peak at R6 stage, while those of soybean hybrids at R2–R7 were higher than those of conventional varieties with significant difference between them at P0.05 and P0.01; the means and maximum accumulation rates of biomasses were 0.06 g d–1and 0.20 g d–1more than those of conventional varieties, respectively; and the days of speeding up or slowing down dry matter accumulation rate were ahead of 3.09 days and 5.85 days than those of CV, respectively, so premature advantage of dry matter accumulation was also obvious. As for yield components, there was no significant difference between hybrids and conventional soybean varieties on 100-seed weight, grain weight and pod weight of main stem, but grain weight and pod weight of branch in soybean hybrids were significantly higher than those in conventional varieties.There was no significant difference in the ratio of grain weight to biomass and the ratio of grain weight to stem weight between soybean hybrids and conventional soybean varieties. All results showed that the yields of soybean hybrids mainly depend on the strong canopy, high speed of dry matter accumulation, and higher biomass.

A strategy for reducing pollutants at source in order to obtain sustainable agricultural recycling of wastewater sludge

The Swedish licensing system for wastewater sludge use in agriculture, REVAQ, sets challenges. These include a maximum nominal accumulation rate of 0.2%/year on farmland, for specified metals, to be reached by 2025. Here a model is suggested, and applied for the Gothenburg regional wastewater treatment plant, Gryaab, to quantify historic sludge quality improvements and necessary future development. Local sampling campaigns covering two decades show a substantial reduction of heavy metals and ecologically harmful organic substances (such as adsorbable organic halogens, nonylphenols, phthalates, naphthalenes and polycyclic aromatic hydrocarbons) from households and society at large. For the metals studied the historic mass flow reduction to sludge varies from 1 to 2%/year for mercury, zinc and copper to 15%/year for silver. Copper needs further reduction, involving water pipes and copper roofing. Silver is rare in soil, and significant reduction from already low levels is needed to reach the accumulation goal. Further reduction of other metals involves addressing storm- and drainage water entering the sewers and the sediments already in the sewers. Fulfilling the goals of REVAQ implies national and local measures affecting public and private stakeholders including property owners, the wastewater collection system, commercial businesses and legislating authorities.

Mercury accumulation in peatbogs at Czech sites with contrasting pollution histories

Mercury (Hg) concentrations and accumulation patterns were studied in 210Pb-dated peat cores from three ombrotrophic sites in the Czech Republic with contrasting emission histories (Novodomské rašeliniště, ND, and Bílá Smědá, BS, in the polluted northern parts of the country, and Jezerní slať, JS, in a relatively pristine southern part of the Czech Republic). The Hg concentration varied significantly between sites. Whereas the sites in the northern part of the Czech Republic yielded a range of higher Hg concentrations (50–750μgkg−1 for ND and 30–600μgkg−1 for BS), a Hg concentration range of 40–220μgkg−1 was reported at JS. At the northern localities, the highest Hg concentrations were detected at depths of 5–10cm, corresponding to the period between the early 1960s until the late 1980s. In contrast, the highest Hg values at JS were observed at a depth of 10–15cm, corresponding to the period between the early 1950s and the early 1970s. The maximum Hg accumulation rates were approximately 2× higher at the northern localities (ND: 106μgm−2yr−1, BS: 90μgm−2yr−1, JS: 43μgm−2yr−1). Although a decrease in the Hg concentration can be observed in the youngest segments of all the peat cores, a slight increase in Hg accumulation rates in the most recent peat segments (living Sphagnum moss) has been reported for all three sites (40–44μgm−2yr−1), which is approximately 2× higher than in peat bogs in western and northern Europe. This observation may either be related to a real recent increase in Hg emissions in Central Europe (active coal mining and burning and limited Hg pollution control in thermal power plants) or could indicate a preferential Hg binding mechanism in the living moss at the surface of the peat.