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We aimed to elucidate the effects of decreases in nitrogen (N) inputs on N budgets and soil acidity in N saturated forests in Tokyo, Japan using new analysis and comparison to sampling data collect...

We investigated the physicochemical properties of starches extracted from 8 lotus (Nelumbo nucifera Gaertn.) rhizomes harvested in different months (September 2012 to May 2013). The physicochemical properties of the lotus starches depended on the harvest date. The peak viscosity (PV) in the Rapid Visco-Analyser analysis, and the viscosity at 65 °C (V65) in the rotational viscometer analysis were significantly lower in SEP starch (extracted from the September-harvested sample) than in the other lotus starches. The Spearman’s rank correlation coefficients of potassium ion (K) content vs. V65 and of K content vs. PV were 0.905 and 0.714, respectively, indicating that potassium ions are important for expressing the pasting properties of lotus starch. Principal component analysis suggested that the potassium, magnesium, calcium, and phosphorus contents are important for displaying both the pasting and gelatinization properties of the lotus starches. Meanwhile, the cluster analysis revealed that physicochemical properties of the SEP starch were different from those of the starches harvested in other months.

Sago palm (Metroxylon sagu Rottb.) is the most promising starch producing palm species. Sago palm accumulates around 200 kg starch or more per plant or in the trunk. This palm species is recognized as one of the crops used by human beings since ancient times. The growing area of sago palm spreads across several land conditions such as upland, tidal, and submerged areas which do not have a proper water drainage system. It can grow in swamp, alluvial, and peat soils where almost no other major crops can grow without drainage or soil improvement. It is adaptive to an extremely wide range of environmental conditions from brackish water to fresh water. However, its growth performance and starch yield vary depending on the growth environment such as soil types and water conditions. Considering the recent social backgrounds, namely a new competition between biofuel production and food production as well as demand for food diversification, the efficient use of carbohydrates from the sago palm and related species as well as predicted increase in the sustainable development and utilization of land in swampy areas are currently anticipated. This chapter provides a brief review on future prospects of sago palm growth and production in different soil conditions mostly in accordance with the publications from the Society of Sago Palm Studies.

We investigated how temperature condition during ultra-high-pressure homogenization (UHPH) affects the colloidal, interfacial, and foaming properties of whey protein isolate (WPI) and micellar casein (MC) using the one of UHPH device, Star Burst (SB). While UHPH treatment generally induces both mechanical force and heating under high operating pressure, we differentiated the effects of “mechanical force (below denaturation point of whey proteins)” and “combination of mechanical force and heating (above denaturation point of whey proteins)” on the proteins by controlling the protein dispersion temperature prior to the SB treatment at 240 MPa. For WPI, the combined use of mechanical force and heating induced the exposure of protein hydrophobic regions leading to a more increase in foaming ability while the sole use of mechanical force caused a more decrease in foam stability due to less adsorption efficiency at the interface. For MC, the sole effect of mechanical force strongly increased foaming ability and foam stability due to the large particle size reduction, rather than the combined use. These results suggested that SB treatment can contribute to expand the possibilities of development of new materials possessing unique physicochemical and functional properties by controlling treatment conditions.

We investigated the physicochemical properties of starches from rhizomes of two lotus (Nelumbo nucifera Gaertn.) cultivars, Shinashirobana cultivar and Kanasumi-line No. 20, harvested at the same farm in Japan. A rapid visco analyser analysis indicated that pasting temperatures of the starches from Shinashirobana cultivar and Kanasumi-line No. 20 were 62.1 and 66.5 °C, respectively, and the peak viscosities of the starch of both lotuses were similar 244 and 240 RVU, respectively. The starch from the Kanasumi-line No. 20 at 60 °C had low viscosity, 16.2 mPa∙s, but the starch from Shinashirobana cultivar had higher viscosity, 2,720 mPa∙s, at 60 °C. The onset and peak temperatures of the differential scanning calorimetry (DSC) curve of the starch from Shinashirobana cultivar were 4–5 °C lower than those of the starch from Kanasumi-line No. 20, although both exhibited similar ΔH values (13.4 and 11.6 J/g). The distribution patterns of the branched chain lengths of amylopectin in the two starches indicated that the rate of low-degree of polymerization (DP 5–12) of all branched chains was higher for the starch from Shinashirobana cultivar than that for the starch from Kanasumi-line No. 20. These results suggest that the increased rate of DP 5−12 in the starch from Shinashirobana cultivar is related to the higher viscosity of the starch.

In Asian countries, paddy rice ( Oryza sativa ) has been cultivated as a main crop for many years, but cesium uptake by rice has only been studied recently. As a result, the effect of land use on cesium uptake by rice is not well understood, and there is little information about the interaction of cesium with alkali metals in the rice–soil system. The objective of this study was to elucidate the stable cesium (Cs), potassium (K), and rubidium (Rb) levels in rice cultivated under paddy and upland conditions and in the soil (a Hapludept). We cultivated 13 rice cultivars (temperate and tropical japonica ) under both conditions, and determined the concentrations of Cs, K, and Rb in brown rice and soil (total, exchangeable, and water-soluble fractions) by means of inductively coupled plasma mass spectrophotometry and atomic absorption spectrophotometry. We found that the soil concentrations of water-soluble Cs, K, and Rb were higher under upland conditions than paddy conditions, and Cs and Rb concentrations in brown rice were also higher under upland conditions. The upland conditions may increase soil ion concentrations by water evaporation, and the higher water-soluble Cs and Rb concentrations would increase their concentrations in brown rice. However, more K accumulated in brown rice under paddy conditions. This suggests that the roots absorbed K rather than Cs and Rb from the soil mainly by means of ion diffusion, because paddy conditions would increase ion diffusion but not the soil ion concentration. We conclude that the land use (here, paddy and upland conditions) changed the Cs, K, and Rb levels in the brown rice and soil by different mechanisms because root uptake of these elements would be different.

Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, (13)C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant.

Soils (acid sulfate soils, peat soils, gley soils, and others) distributed under sago forest and their productivity of sago palm are described in this chapter. Sago palm in tropical lowland areas is growing with the formation of the communities behind the mangrove forest. The main sources of water for sago palm are rivers, which are present in the eutrophic environment and more or less affected by sea tides. Sago palm equipped with the mechanism to eliminate salt effect or regulate salt uptake in several ways can grow in brackish water. Acid sulfate soils are derived from sulfate ion (SO42−) in seawater. Sulfate ion is reduced to form sulfide compounds by sulfate-reducing bacteria in soils (potential acid sulfate soils). Sulfide compounds are oxidized to sulfate ion and hydrogen ion is produced by sulfur- and iron-oxidizing bacteria in soils (actual acid sulfate soils). The sago starch yield is observed to be extremely high near the coast and lower in the inland places (soil pH 3.3–3.8). The tropical woody thick peat soils called Histosols in the tropical rainforest climate of Southeast Asian islands are formed to transport small amount of sediments by the shorter rivers compared to large rivers of continents. The constituent components in water flowing into tropical peat soils ensure the normal growth of sago palm. In Sarawak no effect of nitrogen (N) application on leaf production of sago palm was found, which was explained by the findings of endophytes’ activities on the nitrogen fixation. The sago palm growth in Inceptisols of the Philippines and Indonesia at the different stages was larger than those in Histosols of Malaysia from the long-term growth study.

The crystalline structure of sago starch related to the gelatinization characteristics is reported in this chapter, although the sago starch synthesis at the molecular biological level is still under discussion. Sago starch granules are oval with a temple bell-like shape, a mean diameter of 37.59 μm, and exhibit a Maltese cross, indicating the presence of some common internal ordering. Sago starch from its X-ray diffraction pattern shows a peak at around 5.6, 17, 18, and 23° (2θ for Cu Kα), which corresponds to 1.58, 0.521, 0.492, and 0.386 nm, respectively. Sago starch is classified as a C type (a mixture of A type and B type as an accessary), containing slightly higher content of B type in the basal portion of sago palm trunk. Low viscosity of sago starch amylopectin is explained by the presence of smaller molecule with a slightly higher number of long chains than the high-viscosity amylopectin. The gelatinization temperature and enthalpy of sago starch determined by a differential scanning calorimeter (DSC) are 69.4–70.1 °C and 15.1–16.6 J g−1, depending on the moisture content, degree of a crystallinity within the granule, granule size, and the amylose to amylopectin ratio. The observation of granular birefringence (Maltese cross) under polarized light is one of the useful tools to determine the gelatinization behavior of sago starch.

Humic substances are ubiquitous in the environment. The development of models for their chemical structure can be expected to improve our understanding of their environmental behavior. In this study, we used X-ray diffraction (XRD) to develop models for the stacking nanostructure of 12 humic acids (HAs) extracted from Japanese Andisols, Inceptisols and Entisols. In the XRD profiles of the HAs, the γ band, which was attributed to aliphatic side chains, and the 002 band were separated by means of curve fitting with the Voigt function. The interlayer spacing of the carbon (C) planes (d002) and the mean thickness of the stacking nanostructure along the c axis (Lc) were calculated from the position of the peak for the 002 band and the full width at half maximum by means of Bragg’s and Scherrer’s equations, respectively. The average number of C planes in the stacking nanostructure (Nc) was estimated from d002 and Lc. The Lc and Nc values ranged from 1.04 to 1.84 nm and from 3.01 to 5.40, respectively. T...

To relate the isotopic composition of soil humic acids (HAs) to their source plants and their degree of humification (as indicated by the degree of darkening), as well as to soil type, we determined the stable isotope ratios for carbon (δ13C) and nitrogen (δ15N) of HAs extracted from 26 virgin soil samples (14 Andisols and 12 non-Andisols) and from leaf samples from ten C3 plants and seven C4 plants. The high absorption coefficients (estimated at 600 nm for 1% solutions), low hydrogen and nitrogen contents, low H/C ratios, low alkyl C and O-alkyl C contents, high O/H and C/N ratios, high aryl C contents, and high aromaticity of the Andisol HAs indicated a high degree of humification. The δ13C and δ15N values of the non-Andisol HAs increased along with the progression of humification of C3 plant-derived HAs. A significant correlation was observed between the δ15N and δ13C values of the non-Andisol HAs, but not for the Andisol HAs. Most of the Andisol HA δ13C values were higher than the highest non-Andisol HA δ13C value, and δ13C values were distributed between the δ13C values for the C3 and C4 plants. The contributions of C4 plant-derived carbon to total Andisol HA carbon (CRC4) are usually calculated on the assumption that the δ13C values are not substantially altered during the decomposition of plant materials and the formation of soil organic matter. However, if 13C enrichment occurs during organic matter decomposition, CRC4 will be overestimated. Therefore, we suggest a new method to calculate CRC4 values of Andisol HAs with a correction for isotopic fractionation associated with microbial degradation; the corrected CRC4 values ranged from − 5% to 58% and were approximately 22% lower than the uncorrected values.

Evolved gas analysis-mass spectrometry (EGA-MS) provides a direct connection between the pyrolyzer and mass spectrometer through a deactivated capillary tube, and provides both a thermal profile relating to the differential thermogravimetric curve of the sample and a mass spectrum of evolved gas from the sample. In this study, EGA-MS was performed to obtain thermal profiles and identify the pyrolysis products of 12 humic acids (HAs) with different degrees of humification extracted from 5 Andisols, 3 Entisols, and 3 Inceptisols, as well as soil samples. All HAs were thermally decomposed gradually over a wide temperature range (100-700°C), and the EGA curves showed four peaks and shoulders at around 250, 350, 450, and 550°C. The peaks at around 550°C were observed for the Andisol HAs only. Carboxyl groups, carbohydrates, and short chain alkanes and alkenes of the HAs and bulk soil samples evolved at a relatively low-temperature region (200-300°C). On the other hand, aromatics including benzenes and lignin derivatives evolved at a relatively high-temperature region (300-600°C). While the shapes of the EGA curves were different between the soils and extracted HAs, the major components of the evolved gas and the pyrolysis behavior of the constituents in the HAs and soil samples were similar. The amount of evolved gas from the Andisol HAs, which mainly consisted of CO2, was very low in comparison to that from the Entisol and Inceptisol HAs. The amount of evolved gas and the molecular weight of the pyrolysis products decreased as humification progressed, but the proportion of CO2 in the total area of the EGA curves increased. The results demonstrated that humification reduces the proportion of volatile components and increases the amount of carboxyl groups. As a result, the molecular structure of HAs is found to be mainly composed of non-volatile components and carboxyl groups. Since EGA-MS can provide information about the chemical structure and pyrolysis characteristics of a small sample without pretreatment, it is a useful tool for soil organic matter research.

The effects of reclamation and land consolidation on organic matter sedimentation were studied in a small lagoon, Kiba-gata, which is one of the three Kaga lagoons (Shibayama-gata, Imae-gata, and Kiba-gata) located in central Japan. Reclamation work was conducted during 1954–1969 to increase the paddy field area and to improve the drainage system. Lake Kiba-gata was affected by changes in the drainage system and land consolidation around the lagoon. A sediment core was obtained in the central part of Lake Kiba-gata in June 2012. The organic matter flux recorded in the sediment core increased from 1.1 to 2.3 and from 3.9 to 7.5 g cm−2 year−1, respectively, during 1903–1974 and 1989–2012, although it was similar to the flux recorded for 1974–1989 following reclamation. The C/N ratio, δ13C, and δ15N values also changed during these time intervals. These results indicate that the primary productivity in the lagoon is increasing with time and that the recent contribution of phytoplankton to productivity has exceeded the level of past contributions because of changes in drainage and increase in human activity around the lake due to the reclamation and land consolidation.

Phosphate rocks (PRs) can be a source of cadmium pollution in soil and food chain. PRs are mainly used for the manufacturing of phosphate fertilizers. The characteristics of PRs with special reference to cadmium, which are important phosphate fertilizer source, were investigated. In my field of study, PR of USA (PR1: from Wyoming, PR2: from Florida PR3: from Idaho), Morocco (PR4: from Qued Zem), Russia (PR5 from Slyudanka), and Japan (PR6: from Okinawa) were selected and compared using X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray diffraction (XRD). Elemental analysis results of PR samples showed that they were mainly composed of Ca, P, Si, Al, S and Fe. Total phosphate concentration in all PRs was 6 to 38% on the average. The Cd concentration levels in all PR samples ranged from 0.15 to 507 mg kg − 1 . PR4 sample exhibited about two times higher Cd concentration than those of the literatures so far published. XRD analysis revealed that; fluorapatite ((Ca 5 (PO 4 ) 3 )F), hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ) and carbonate fluorapatite (Ca 5 (PO 4 ,CO 3 ) 3 F) were the dominant minerals. This study also confirmed that PR3 and PR4 exhibited higher Cd content and prominent mineral component was carbonate fluorapatite, suggesting that Cd might be exchanged to Ca and/or occluded in carbonate fluorapatite during its formation by sedimentation.

Cadmium (Cd) is a common impurity in phosphate fertilizers and application of phosphate fertilizer may contribute to soil Cd accumulation. Changes in Cd burdens to agricultural soils and the potential for plant Cd accumulation resulting from fertilizer input were investigated in this study. A field experiment was conducted on Haplaquept to investigate the influence of calcium superphosphate on extractable and total soil Cd and on growth and Cd uptake of different Komatsuna (Brassica rapa L. var. perviridis) cultivars. Four cultivars of Komatsuna were grown on the soil and harvested after 60 days. The superphosphate application increased total soil Cd from 2.51 to 2.75 mg kg−1, 0.1 mol L−1 hydrochloric acid (HCl) extractable Cd from 1.48 to 1.55 mg kg−1, 0.01 mol L−1 HCl extractable Cd from 0.043 to 0.046 mg kg−1 and water extractable Cd from 0.0057 to 0.0077 mg kg−1. Cd input reached 5.68 g ha–1 at a rate of 240 kg ha–1 superphosphate fertilizer application. Superphosphate affected dry-matter yield of lea...

Dieldrin, an insecticide that is considered a persistent organic pollutant, remains in the soil for a long time after application. In recent years, dieldrin has been detected in cucumber (Cucumis sativus L.) fruits produced in some areas at concentrations exceeding the tolerance limit in Japan. Thus, we compared dieldrin residues in 19 vegetable crops produced in a dieldrin-contaminated field. Since dieldrin concentrations in the soil of each crop plot differed about 2-fold, we used the bioconcentration factor to compare the degree of dieldrin residue contamination among crops. The bioconcentration factors of Cucurbitaceae crops were much higher than those of non-Cucurbitaceae crops. Among non-Cucurbitaceae crops, the bioconcentration factors of komatsunas (Brassica campestris var. perviridis), Japanese radishes (Raphanus sativus L.), carrots (Dancus carota L.), and potatoes (Solanum tuberosum L.) were relatively high. In these Cucurbitaceae plants, dieldrin was not accumulated in particular parts or orga...

The phosphorylated sago starch-extraction residue (P-SR) was produced for the removal of heavy metal from wastewater. The phosphoric ester in the phosphorylated residue was evaluated by means of infrared microspectrometry and solid-state NMR. In this study, the phosphorus contents of produced P-SR, phosphorylated cellulose (P-C), and phosphorylated sago starch were 31.7, 34.2, and 4.6 mg/g, respectively. The phosphorus contents of P-C and sago starch were clearly different because of the difference of each structure. The maximum sorption capacities of heavy metals (cadmium, lead, copper, and zinc) in single heavy metal sorption on P-SR were 0.20, 0.25, 0.36, and 0.24 mmol/g (Cu > Pb > Zn > Cd), respectively. On the other hand, the amount of sorbed heavy metals in coexisted heavy metal sorption on P-SR followed the order of Pb > Cu > Cd > Zn that was different from the relations of maximum sorption capacities for individual heavy metals. The heavy metal sorption behavior in single and coexisted heavy metal solution for P-SR were different and P-SR showed the intrinsic heavy metal sorption affinity, called as selective sorption. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Biodegradable plastics were synthesized for the effective use of sago starch-extraction residue, which has been discarded as a waste. Two types of esterified sago starch-extraction residue, P-SP and L-SP, were obtained. It had black color for P-SP160 (esterified by palm oil) to light yellow color for L-SP80 (esterified by lauric acid) and showed high carbon content, ranging from 399.3 to 537.1 g kg−1. Biodegradable plastics from the residue, which had high esterification degree showed thermoplasticity and slower decomposition in Andisols in Japan and Inceptisols in Philippines. The esterification degrees of P-SP160 and L-SP were 3.23 and 2.95 to 5.18 mmol g−1, respectively. In addition, L-SP80 exhibited the most appropriate thermal softening behavior by heating. The cumulative decomposition of P-SP160 in Andisols and Inceptisols showed 16.7 and 32.8% of total carbon during 31 day of the incubation. On the other hand, the decomposition rates of L-SP80 in Andisols and Inceptisols were less than 10% of total carbon during 31 day of the incubation. The addition of triacetin as plasticizer to P-SP160 and L-SP80 remarkably influenced the decomposition rate of both molded P-SP160 and L-SP80. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Amount of nitrogen (N) dry deposition on the leaf surface of oak and cedar was compared using throughfall method and foliar rinsing method. The study was conducted at FM Tamakyuryo, located at the northeast edge of the Tama Rolling Hills, Tokyo, Japan. The throughfall method showed that the total N deposition were 19.7, 19.1, and 50.6 kg N ha−1 year−1 for open bulk deposition and total deposition in oak forest and cedar forest, respectively. The deposition of ammonium nitrogen on leaf surface were 0.29 ± 0.38 (average ± standard deviation) and 0.75 ± 1.06 mg N m−2 for oak and cedar, respectively, and that of nitrate nitrogen were 0.15 ± 0.18 and 0.35 ± 0.28 mg N m−2, respectively. Dry deposition on leaf surface was influenced by the cumulative amount of rainfall before sampling and was found to be easily washed off with high amount of precipitation within a few days.

Previous trials have revealed variable responses of sago palm (Metroxylon sagu Rottb.) to fertilizer application, particularly nitrogen (N). In the present study, we quantified the fertilizer use efficiency (FUE) of sago palm for the first time using 15N-labeled fertilizer in pot and field experiments. The pot experiment was conducted in Japan using a 2:1 mixture of sand to Philippine soil. The field experiment was conducted in Leyte in the Philippines. Both experiments consisted of three replicates in each of three treatments: control, 15N urea at 50 kg N ha−1 and 15N urea at 100 kg N ha−1. The N uptake of sago palm increased significantly, but inconsistently with increasing N application. The few instances of a significant increase in N uptake did not translate into significant improvements in growth parameters, except for the number of leaflets in the pot experiment. The FUE values for sago seedlings (

This paper summarizes the characteristics of regional-scale nitrogen (N) flow models. The regional scale is generally considered to be an area that ranges from more than 10 km2 to the size of a continent. Parameterization is the key process in creating a regional-scale model. During parameterization, transfer functions that reflect the controlling factors must be created at the target scale because the influence of different factors will change with the size of the scale. Watersheds are the most useful unit for evaluating overall N discharge; however, regional activity data is most often available for municipal units. Thus, municipal units must be reaggregated into watershed units. A longer time period is desirable to normalize seasonal and annual variations at regional scales. Parameters that influence N flow must match the investigated spatial and temporal scales. Given the need to use a range of parameters that vary in terms of the quality of the data, models exhibit inevitable uncertainties. ...

It is shown that 2 wt% clay-reinforced nylon and 4 wt% clay-reinforced nylon have similar tensile strengths, which are increased by about 30% compared to those of nylon 6. With an increase in loading rate, the ultimate tensile strength increases for both nylon 6 and nanocomposites, and the ductility decreases for nylon 6 while it does not change obviously or even increase a little for nanocomposites. The fatigue strength of 2 wt% clay-reinforced nylon is also increased by about 30% compared to that of nylon 6, but the fatigue strength of 4 wt% clay-reinforced nylon is slightly increased or similar to that of nylon 6. The cyclic deformation has been examined using stress-strain hysteresis loops. The small cyclic deformation in 4 wt% clay-reinforced nylon is attributed to the no increase in fatigue strength. The strain incompatibility near the phase boundary leads to the relaxation of three dimensional stress field in 2 wt% nano-composite, while leads to the extraction of clay platelets in 4 wt% nano-composite. Furthermore, time-dependent behavior and microscopic damage mechanisms are discussed.

The objective of this study is to assess the applicability of a commercial magnesium oxide (MgO) and a composite material containing MgO and natural minerals ('MgO-SH-A') as the soil amendments for suppression of cadmium (Cd) uptake and accumulation into rice grains. Firstly, the mineralogical and physicochemical properties, soil neutralizing capacities and Cd sorption characteristics of these materials were investigated. Both materials were strongly alkaline and possessed large surface areas. The X-ray diffraction pattern of MgO-SH-A indicated the presence of MgO and a magnesium-silicate mineral (antigorite) as the main components. MgO-SH-A showed a milder soil neutralizing capacity as compared to commercial MgO. The sorptions of Cd on commercial MgO and MgO-SH-A both fitted Langmuir isotherm. The maximum Cd sorption capacity of commercial MgO (46.8 mmol g(-1) DW) was higher than that of MgO-SH-A (5.87 mmol g(-1) DW), although the latter material showed higher affinity to Cd as compared to the former one. The dominant reaction involved in the Cd sorptions was suggested to be precipitation of Cd(OH)2 on the material surface. About 40% of Cd sorbed on MgO-SH-A was resistant to desorption by 0.1 M HCl, implying that this portion was strongly retained on the material surface.

The objective of this study is to assess the applicability of a commercial magnesium oxide (MgO) and a composite material containing MgO and natural minerals (‘MgO-SH-A’) as the soil amendments for suppression of cadmium (Cd) uptake and accumulation into rice grains. A cultivation experiment of rice plants ( Oryza sativa L. cv. Kinuhikari) was conducted in an actual Cd-contaminated alluvial paddy field to evaluate the effectiveness of these materials. The ‘plant available’ fractions of Cd in the paddy soil significantly decreased by application of commercial MgO at 2250 kg ha −1 or MgO-SH-A at 4500 kg ha −1 . These decreases would be primarily attributed to the increase in soil pH due to applications of the MgO materials because these soil Cd fractions were significantly negatively correlated with the soil pH. Even under a suppressive condition for Cd uptake by rice plants, i.e., continuous flooding of the paddy field around the heading stage, applications of these materials further reduced Cd concentration in brown rice as compared to that from the control. It was concluded that the two MgO materials examined would be effective in preventing Cd contamination of rice grains grown in Cd-polluted paddy fields.

The effect of soil freeze–thaw cycles on the denitrification potential was examined based on the C2H2 inhibition method. The gross N2O production curve of the soil sample (incubation with C2H2) showed minor changes between the freeze–thaw treatment and the unfrozen control. However, kinetics analysis revealed that the initial production rate, an indicator of the population density of denitrifying communities, decreased (P = 0.043) and the specific growth rate constant, an indicator of the activity of denitrifying communities, increased (P = 0.039) as a result of the freeze–thaw cycles in five of six soil samples examined. The increase in the specific growth rate constant suggested the stimulation of the activity of denitrifying communities that survived after the freeze–thaw cycles and may explain the minor suppression on the gross N2O production in spite of decreasing the population density of denitrifying communities that was suggested by the initial production rate. The net N2O production curve of the soil sample (incubation without C2H2) showed a remarkable change in one out of six soil samples, and in that one soil sample, N2O release to the atmosphere was largely stimulated (7.6 times) by the freeze–thaw cycles. However, the stimulation of the N2O release by the freeze–thaw cycles was even observed in two other selected soil samples (4.6 and 1.8 times), suggesting that an imbalance in the N2O-producing and N2O-reducing activities of denitrifying communities might complementally explain the N2O release stimulated by the freeze–thaw cycles.

Laboratory experiments were conducted to examine the effect of charcoal addition on N2O emissions resulting from rewetting of air-dried soil. Rewetting the soil at 73% and 83% of the water-filled pore space (WFPS) caused a N2O emission peak 6 h after the rewetting, and the cumulative N2O emissions throughout the 120-h incubation period were 11 ± 1 and 13 ± 1 mg N m−2, respectively. However, rewetting at 64% WFPS did not cause detectable N2O emissions (−0.016 ± 0.082 mg N m−2), suggesting a severe sensitivity to soil moisture. When the soils were rewetted at 73% and 78% WFPS, the addition of charcoal to soil at 10 wt% supressed the N2O emissions by 89% . In contrast, the addition of the ash from the charcoal did not suppress the N2O emissions from soil rewetted at 73% WFPS. The addition of charcoal also significantly stimulated the N2O emissions from soil rewetted at 83% WFPS compared with the soil without charcoal addition (P

This study was done to determine microbial interactions between nitrogen-fixing bacteria (NFB) and different indigenous bacteria, both of which were isolated from the same samples of sago palm. Co-culture of NFB and indigenous bacteria, isolated using nutrient agar medium, into a nitrogen-free Rennie medium showed significantly higher nitrogen-fixing activity (NFA) than single inoculations of NFB did in almost all combinations. A reduced oxygen status also enhanced the NFA of NFB. All NFB preferred simple sugars as their substrates for NFA and showed extremely low levels of NFA in starch, hemicellulose, and pectin-containing media. NFA was markedly stimulated in the consortium of starch-degrading Bacillus sp. strain B1 and NFB, ranging from 0-1.5 to 150-270 nmol C2H4 culture-1 h-1. The consortium of hemicellulose-degrading Agrobacterium sp. strain HMC1 or Flexibacter sp. strain HMC2 and NFB also showed enhanced NFA, ranging from 0-0.1 to 16-38 nmol. In contrast, no enhanced NFA was detected in the consortium of pectin-degrading Burkholderia sp. strain BT1 or Paenibacillus sp. strain P1 and NFB. These results may indicate that beneficial microbial interactions occur in sago palm to enhance nitrogen-fixing activity through collaborative utilizations of starch, hemicellulose and their degradation products.

This study investigated the continuous record of eutrophication in Lake Onuma based on the geochemical properties of two lake sediment cores obtained from the deepest part of the lake in 2011. Based on a tuff layer deposited during the eruption of Mt. Komagatake, and on the correlation between fluctuations in δ13C and δ15N values, two sediment cores, ON11-2-2 and ON11-6, were dated to the 1920s and 1890s, respectively. The δ13C value and C/N ratio for the lake sediments show values within the ranges for planktonic material and river sediment, suggesting that the lake sediment is a mixture of these sources and that their mixture ratio was almost constant since the 1920s. On the other hand, the δ15N of two cores show a similar trend with increasing δ15N from the 1950s–1960s to the present time. It is attributed to the increase in the δ15N value of planktonic material reflecting anthropogenic nitrogen inflow to the lake.

Mechanisms controlling the activity of free aluminum (Al) in soil solutions and their implications for pedogenesis in two Japanese volcanic ash soils were investigated by means of acid-base titrations and kinetic studies of mineral dissolution. The A and AB horizons of both soils are rich in soil organic matter (SOM) and organically bound Al. In addition, short-range ordered aluminosilicates such as imogolite and proto-imogolite are abundant. Despite their abundance, the A horizons are undersaturated with respect to short-range ordered aluminosilicates, such as imogolite and proto-imogolite. This suggests low dissolution rate of these minerals, possibly due to alteration of the physico-chemical characteristics of their surfaces, caused by complexation with SOM. The AB horizons in both soils are close to equilibrium with short-range ordered aluminosilicates. The fast release of Al upon addition of strong acid to A horizons, combined with the reaction stoichiometry, observed in acid-base titrations suggests that the activity of Al3+ and H+ are controlled by complexation reactions with SOM. Furthermore, our data support previous studies indicating that SOM input in A horizon of volcanic ash soils dissolves short-range ordered aluminosilicates. Thus, simultaneous accumulation of SOM and depletion of short-range ordered aluminosilicates, due to leaching, are important long-term processes of the pedogenesis in soils developed from volcanic ash deposits.

Mechanisms controlling the activity of free aluminum (Al) in Bw1 horizons of soils developed from volcanic ash deposits in Japan were investigated by means of acid–base titrations and kinetic studies. In a Bw1 horizon, with a high content of acid-oxalate extractable Al, soil solution reached equilibrium with short-range ordered aluminosilicates in the order of days. Relatively fast kinetics of the release and precipitation of Al and Si indicate a high reactivity of short-range ordered aluminosilicates in the soil. In the Bw1 horizon of an adjacent soil, with a high content of crystalline clay minerals like halloysite and interlayered vermiculite, solution remained well undersaturated with respect to short-range ordered aluminosilicates and aluminum hydroxide. Apparent equilibrium with respect to halloysite occurred after more than 30 days. This halloysite ( log K so 0 = 3.74 ± 0.02 (25 °C)) has a solubility that is less than that reported in the literature ( log K so 0 = 4.36 (25°C)). Our findings suggest that different reactive aluminosilicates may control the activity of free Al in sub-surface horizons of volcanic ash soils with different mineralogy.

A plot with a high aluminum (Al) concentration in soil solution was found in Kumagaya, central Japan; the maximum was 4.0 mg L−1 as total dissolved Al (TD-Al) at a depth of 10 cm in August 2000. The soil type was Dystric Andosols with three horizons, A/Bw1/Bw2, which contained a considerable quantity of Al extracted by dithionite-citrate and acid-oxalate extractants. The upper two horizons were acidic with soil pH (H2O) of 4.4 and 4.6. The fundamental cause of the high TD-Al concentration was the low pH with a very low base saturation of less than 2%. The seasonal change in TD-Al concentrations in soil solution at a depth of 10 cm was significantly and positively correlated with the nitrate concentrations but weakly and rather negatively correlated with the sulfate concentrations. Nitrification functioned as the direct acid source to cause the TD-Al concentrations to fluctuate strongly, whereas sulfate adsorption onto the soil at the research plot functioned as a sink of proton.

This paper focuses on N balance in a paddy field planted with whole crop rice (Oryza sativa cv. Kusahonami). The experiment was conducted with two treatments during two rice-growing seasons: one was fertilized with N (160 kg N ha−1; 16N plot) and the other unfertilized (0N plot); both plots were fertilized with P and K. The N input from precipitation was 15 and 12 kg N ha−1 in 2002 and 2003, respectively. The N input from irrigation water reached as much as 123 and 69 kg N ha−1 in 2002 and 2003, respectively. This was because irrigation water contained higher NO3− concentrations ranging from 4 to 8 mg N l−1. The N uptake by rice plants was the major output: 118 and 240 kg N ha−1 in the 0N and 16N plots in 2002 and 103 and 238 kg N ha−1 in 2003, respectively. N losses by leaching were 4.8–5.3 and 6.5–7.3 kg N ha−1 in 2002 and in 2003, respectively. Laboratory experiments were carried out to estimate the amounts of N2 fixation and denitrification. Amount of N2 fixation was 43 and 0 kg N ha−1 in the 0N and 16N plots, respectively. Denitrification potential was quite high in both the plots, and 90% of the N input through irrigation water was lost through denitrification. Collectively, the total N inputs were relatively large due to irrigation water contaminated with NO3−, but N outflow loading, expressed as leaching−(irrigation water + precipitation + fertilizer), showed large negative values, suggesting that the whole crop rice field might serve as a constructed wetland for decreasing N.

Vasomotor function has often been evaluated with basal blood flow. Simultaneous measurement of skin blood flow and sweating using a single probe were provided as lesser basal blood flow on one side compared to the contralateral side in complex regional pain syndrome does not always indicate greater vasoconstrictor nerve activity.

In our previous report (Yanai et al. 2004: Soil Sci. Plant Nutr., 50, 821–829), we demonstrated that soil freeze-thaw cycles caused a partial sterilization of the soil microbial communities and exerted limited effects on the potential of organic matter decomposition of soils. In the present study, the effects of soil freeze-thaw cycles on the nitrification potential of soils were examined and the impacts of the freeze-thaw cycles on the nitrifying communities were analyzed. Samples of surface soils (0 to 10 cm depth) were collected, from tropical arable land sites, temperate forest, and arable land sites~ Nitrification potential was assayed by the incubation of soils with or without the addition of 200 fig N of ammonium sulfate per g soil to reach a moisture content adjusted to 60% of maximum water-holding capacity at 27~wC following four successive soil freeze-thaw cycles (-13 and 4°C at 12 h-intervals). Nitrification potential of the soils, in which the decrease in the microbial biomass followi...

The occurrence and current status of butyltin and phenyltin compounds were investigated in sediments collected from the Arakawa and Sumida Rivers and Tokyo Bay in 2000. A series of butyltin and phenyltin compounds, including monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monophenyltin (MPT), diphenyltin (DPT), and triphenyltin (TPT) was detected by gas chromatography-mass spectrometry (GC-MS). The total concentrations of the butyltin (MBT + DBT + TBT) and phenyltin (MPT + DPT + TPT) compounds ranged from 25.7 to 116 and from non-detectable levels to 22.4 ng g' (as Sn), respectively. The concentrations of the organotin (OT) compounds in sediments were relatively lower than those of the samples collected in 1984. OT compounds accounted for 124% (as Sn) of total Sn in the sediments. Among the OT compounds investigated, MBT was the most prevalent in the sediments.

The adsorption of Cr(VI) ion on synthetic hydrated oxides of iron (goethite (α-FeOOH) and lepidocrocite (γ-FeOOH)) with different crystallinities was studied in order to remove the Cr(VI) ion from polluted water. At pH 4.5, the amounts of the adsorbed Cr(V1) ion on goethite and lepidocrocite were 51.9 and 62.2 mmol g−, respectively. Probably, this is due to the fact that the structure of lepidocrocite is more open than that of goethite. Lepidocrocite, therefore, is more effective for the removal of Cr( V1) ion from Cr(Vl)-contaminated and acidic groundwater and sewage.

Effects of soil freeze-thaw cycles on soil microbial biomass were examined using 8 soil samples collected from various locations, including 4 arable land sites and 2 forest sites in temperate regions and 2 arable land sites in tropical regions. The amounts of soil microbial biomass C and N, determined by the chloroform fumigation and extraction method, significantly decreased by 6 to 40% following four successive soil freeze-thaw cycles (- 13 and 4°C at 12 h-intervals) compared with the unfrozen control (kept at 4°C during the same period of time as that of the freeze-thaw cycles). In other words, it was suggested that 60 to 94% of the soil microorganisms might survive following the successive freeze-thaw cycles. Canonical correlation analysis revealed a significantly positive correlation between the rate of microbial survival and organic matter content of soil (r = 0.948*). Correlation analysis showed that the microbial survival rate was also positively correlated with the pore-space whose size ...

Acidification is one of the important impact categories for life cycle impact assessment. Although its characterization has progressed during this decade through the employment of midpoint approaches, only limited studies of endpoint approaches have been performed. Objective. This study aimed at developing damage function of acidification for terrestrial ecosystems in Japan. Damage function expresses a quantitative relationship between the inventory and endpoint damage. The geographical boundary was limited in Japan both for emission and impact. In this study, sulfur dioxide (SO2), nitrogen monoxide (NO), nitrogen dioxide (NO2) (NO and NO2 collectively mean NOx), hydrogen chloride (HC1), and ammonia (NH3) were considered as major causative substances of acidification. Net primary production (NPP) of existing vegetation was adopted as an impact indicator of terrestrial ecosystems. The aluminum toxicity was adopted as the major factor of effect on terrestrial ecosystems due to acidification. The leachate concentration of monomeric inorganic aluminum ions was selected to express the plant toxicity of aluminum. The results of damage function gave utilizable factors both for a midpoint approach and an endpoint approach; Atmospheric Deposition Factor (ADF) and Damage Factor (DF) applicable to the former and the latter, respectively. The ADF indicates an increase of H+ deposition per unit area to an additional emission of causative sustance. The additional emission corresponds to some alternatives in industry, not the baseline emission. The DF indicates the total NPP damage in all of Japan due to the additional emission of causative substances. The derived NPP damage is on the order of one millionth of the NPP itself. HC1 and NH3 showed larger ADFs and DFs than that of SO2 and NOx. The reason was ascribed to the relatively large source-receptor relationships (SRR) of HC1 and NH3. However, since the method applied to determine the SRR of HC1 and NH3 has larger uncertainties than that of SO2 and NOx, attention is needed to handle the difference. The damage function easily defines the concrete NPP damage due to an additional emission. The impact indica tor, NPP, also has an advantage in its mass unit that is directly summable through the entire impact categories. Expansion of endpoints, such as in aquatic ecosystems, material degradation, human health, and biodiversity aspects of terrestrial ecosystems, is an important subject for future work. Further, uncertain analyses for major parameters will provide helpful information on the reliability of damage function.

Mt. Oyama, a volcano in Miyakejima Island, became active at the end of June 2000 and began emitting volcanic fumes with a high amount of sulfur dioxide (SO2) at the end of August 2000. Emission of volcanic fumes was still observed in August 2002. We aimed at analyzing the soil properties in Kumagaya in relation to the effect of the volcanic fumes from Mt. Oyama. A soil survey was conducted in a deciduous secondary forest in Kumagaya, Saitama Prefecture, Japan in September 2001, and the physical and chemical properties of the soil were analyzed. The soil in the research plot consisted of volcanic ash soil. However, the properties were markedly different between the topsoil and subsoil. For example, the base saturation values in the A and Bwl horizons were very low, 1.7 and 0.85%, respectively, while the value in the Bw2 horizon was 29%. The soils in the A and Bw1 horizons displayed a considerable anion exchange capacity (AEC) under the field conditions, and the amount of exchangeable sulfate (SO4 ...

With the popularity of cellular phones featuring built-in cameras, it is no surprise that content for information transfer using images taken from these phones is in great demand. Therefore, the need for correspondent image processing technology and a system to support content development is becoming much more urgent. A new method of image matching, which contains two approaches, is described. The first approach is to segment objects from images having a relatively simple background by applying a method for growing recursive regions and for the matching. The other is to do matching directly by using a presented GA algorithm in images with complex backgrounds to extract remarkable characters such as magazine titles and brand names on commodities, which are difficult to be segmented from their environment using existing methods. Experimental results show that the approaches work effectively in our system.

To analyze in greater detail the fate and behavior of toxic organotin compounds in the environment, total tin (Sn) concentrations were determined for sediments of the Arakawa River, the Sumida River, and Tokyo Bay by using a graphite furnace atomic absorption spectrophotometer (GFAAS). Sn concentrations in 2000 were compared with those of 1984 (8 years before the regulation on tributyltin-based antifouling paint) as well as with other heavy metals (Cu, Ni, Pb, and Zn). The Sn concentrations ranged from 1.04 to 4.43 mg kg−1 for sediments sampled in 2000. Although the average concentration of Sn in the sediments was low compared with that of 1984, the concentration tended to increase at several sites in 2000. Moreover, the Sn concentration showed significant correlations with the Cu, Ni, Pb, and Zn concentrations. These results suggest that a significant proportion of the overall Sn content in these sediments was probably introduced from the sources other than antifouling paint. The metals extracte...

Endophytic nitrogen-fixing organisms have been isolated from the aerial parts of field-grown sweet potato (Ipomoea batatas). The (15)N dilution method, which is based on the differences in stable nitrogen isotope ratios, is useful for measuring nitrogen fixation in the field. In this study, seedlings of two sweet potato cultivars, 'Beniazuma' and 'Benikomachi,' were transplanted into an alluvial soil that had been treated with organic improving material in advance. Whole plants were sampled every 2 or 3 weeks. After separating plants into tuberous roots and leaves, the fresh weights of the samples were measured, and the nitrogen content and natural (15)N content of leaves were determined with an elemental analyzer and an isotope ratio mass spectrometer linked to an elemental analyzer, respectively. The contribution of nitrogen fixation derived from atmospheric N2 in sweet potato was calculated by assuming that leaves at 2 weeks after transplanting were in a non-nitrogen-fixing state. The contribution ratios of nitrogen fixation by nitrogen-fixing endophytes in leaves of both sweet potato cultivars increased rapidly from 35 to 61 days after transplanting and then increased gradually to 55-57% at 90 days after transplanting. Over the course of the sweet potato growing season, the activity of nitrogen-fixing endophytes in leaves began to increase at about 47 days after transplanting, the weight of leaves increased rapidly, and then growth of tuberous roots began a few weeks later. Our findings indicate that nitrogen-fixing endophytes will be activated under inorganic nitrogen-free sweet potato cultivation, allowing for growth of the tuberous roots.