Studies on organic acids in paddy field soils with reference to their inhibitory effects on the growth of rice plants     

Yasuo Takijima 《Soil Science and Plant Nutrition》2013,59(5):14-21

Many Studies (1) have been made on the physiological diseases of rice plants caused by root rot which develops during the plant growth. The view that organic acids; accumulatted in rice paddy soil may be one of the factors impeding the function of roots began only recently to be expressed concerning the low productive paddy fidds. However, studies on the metabolism of these organic acids, especially of saturated lower fatty acids, are mostly fragmental except for a series of studies made by Takai and others (2). To deal with the problem of root injuries and diseases of rice plants, we must establish the magnitude of the organic acid production in relation to the differences in character of soils.  相似文献   

Abstracts of nippon Dojyohiryogaku Zasshi     

Kazuo Sugahara  Yasuo Harada  Akio Inoko 《Soil Science and Plant Nutrition》2013,59(2):197-208

Color change of city refuse during composting process was investigated according to the methods of measurement for color of materials based on the CIE 1931 Standard Colorimetric System. Stimulus value Y (the degree of lightness) and chromaticity coordinates (x, y) were determined with Color Analyzer by measuring relative spectral reflectance. Stimulus value Y of city refuse decreased during composting process, but chromaticity coordinates (x, y) scarcely changed.

Color of various composts, which were produced from city refuse, straw, hog fecal wastes, tree bark, and tree bark mixed with activated sludge, were also investigated by measuring relative spectral reflectance. The shapes of the reflection spectra of city refuse were different from those of the other composts. Colors of the various composts were similar to each other when specified according to their three attributes: value, hue, and chroma (Munsell renotation).

While city refuse was rotting and maturing, stimulus value Yand C/N ratio equally decreased. A positive correlation was found between stimulus value Y and C/N ratio. It was concluded that stimulus value Y can be used as a criterion for determining the degree of maturity of city refuse compost.

The correlation between stimulus value Y and C/N ratio of various composts was also investigated. According to the position on the two coordinates having stimulus value Y and C/N ratio as axe s, various composts were classified into three groups: (i) city refuse compost group, (ii) straw compost group, and (iii) tree bark compost group.  相似文献   

Cadmium contamination of soils and rice plants caused by zinc mining IV. Use of soil amendment materials for the control of Cd uptake by plants     

Yasuo Takijima  Futoshi Katsumi 《Soil Science and Plant Nutrition》2013,59(4):235-244

In view of the difficulty in practicing water management as a measure to prevent the production of high Cd rice, alkaline or calcareous soil amendment materials were examined, concerning their pH effect on the availability of soil heavy metals.

1. In the experiment conducted on the contaminated paddy field, the essential Cd uptake by the plant occurred after the ear-forming stage and was reduced remarkably by a basal application of the amendment materials followed by top application, depending on the activity of raising the soil pH. Combined use of calcium silicate and fused magnesium phosphate for a basal dressing was most effective on Cd uptake, producing rice of the lowest Cd content, one fifth of the control.

2. The content of Cu in rice also decreased with the treatment to an extent second to Cd, while that of Zn and Pb decreased in straw but hardly changed in rice. Cu seemed fastest in the straw-to-grain movement which was also promoted by the treatments.

3. Soil Cd and Cu were less soluble in 0.1 N HCl solutions than were Zn and Pb, with the application of fused phosphate. Soil Cd became more insoluble in the incubated soil in a submerged condition and its solubility appeared to be depressed by the addition of ammonium sulfate.

4. Based on the good results for the control of high Cd rice obtained through three years' survey in the problem area, it was recommended that these materials be used in sufficient quantity to raise soil pH, taking care not to cause delay in the first growth.  相似文献   

Cadmium contamination of soils and rice plants caused by zinc mining V. Removal of soil cadmium by an HCl-leaching method for the control of high Cd rice     

Yasuo Takijima  Futoshi Katsumi  Satoshi Koizumi 《Soil Science and Plant Nutrition》2013,59(4):245-254

Abstract

A method of leaching polluted soil with diluted HCl solution was investigated for controlling high Cd in rice. Results obtained in the pot and field experiments are summarized as follows:

1. By leaching the soil in the pot with 0.05 or 0.1 N HCl solution followed by washing with water, soluble heavy metals were remarkably removed in the order of Cd>Cu>Zn?Pb; the Cd content decreased to half with 0.1 N HCI treatment.

2. Heavy metal contents of the plants decreased with the treatments. Especially, Cd content in straw and rice of the soil applied with CaCO₃ after the treatment was one-third and one-fifteenth of the control, respectively.

3. A contaminated paddy field was similarly treated using industrial cone. HCl. One-fourth of the soluble Cd in the surface soil was removed by this method, and the Cd content of the unpolished rice decreased from 0.33 ppm to 0.06 ppm in the plot treated with fused magnesium phosphate and calcium silicate after the treatment.

4. Cd concentration of the drained water from the treated field could soon be diluted far below the allowable limit with the abundant river current. A sufficient supply of calcareous materials was needed to compensate for the lost bases in the soil.  相似文献   

A short discussion on the chemical composition of allophane based on the data of Yoshinaga in 1966     

Yasuo Kitagawa 《Soil Science and Plant Nutrition》2013,59(4):321-324

Many scientists have attempted to discern the chemical composition and the structure of allophane (2, 4–6). Yoshinaga (7) presented the chemical composition of eighteen samples of pure allophane in detail, and concluded as follows: All samples consisted principally of silica, alumina, and water. The silica-alumina molecular ratio ranged from about 1.3 to 2. Molecular ratios of ignition loss (+H₂0) and total water (±H₂O) to alumina were nearly constant, with the averages about 2.5 and 5.7, respectively. The chemical composition of soil allophane fell into a relatively narrow range, and the change in the percentage composition of the three major elements had a regularity.  相似文献   

The oxidation products formed from: Soil organic matter by hydrogen peroxide treatment     

Yasuo Harada  Akio Inoko 《Soil Science and Plant Nutrition》2013,59(4):513-521

The oxidation products formed from soil organic matter during hydrogen peroxide digestion were studied by means of analyses of carbon and nitrogen, thin layer chromatography, infrared Spectroscopy, and redox titration.

The carbon remaining after hydrogen peroxide digestion, as expressed in percentage by WeIght of the original soil was 0.57 to 4.09, corresponding to 17.81 to 29.00 per cent of the carbon fOUnd in the original soil. The nitrogen remaining after the same treatment was 75 to 100 per cent of total nitrogen in the original soil. The greater part of the remaining water soluble nItrogen was NH₃-N. The thin layer chromatography showed the presence of oxalic acid and V.V. light-ahsorbing substances in the oxidation products. No organic matter other than oxalate Was indicated on the infrared spectra. The amount of water soluble oxalate formed from 100 g of soil determined by means of redox titration was 5.7 to 117.0 mmole. Assuming that the ratio of solution: soil is 5:1 at the final stage of per oxidation, the concentration of oxalate in the SUpernatant solution was in the range from 0.011 to 0.234 M.  相似文献   

Effect of Addition of Al Hydroxides on Changes in Dispersibility and Charge Characteristics of Soils     

Katsuhiko Itami  Yasuo Kitagawa  Kazutake Kyuma  Takashi Kosaki 《Soil Science and Plant Nutrition》2013,59(3):627-635

Using a soil from a newly reclaimed area where high dispersibility of fine particles had led to poor physical properties in the field, changes in dispersibility and charge characteristics after artificial precipitation of Al hydroxides onto the soil were investigated. Al hydroxides were precipitated by neutralization with NaOH of an acidic A1C1₃ solution in which the soil samples were placed.

When the titration rates were changed, no significant differences in dispersibility were observed in the resultant soils. In the systems with the addition of 2 g kg^-1 or less of A1(OH)₃, dispersion ratios of clays were almost identical with those of blank samples although the specific surface areas were reduced. In the systems with 5 g kg^-1 or more of A1(OH)₃, considerable effects of Al hydroxides on reduction of clay dispersibility were recognized (e.g. 10 g kg^-1 addition yielded less than one-third of the original ratio of the clay dispersion). A slightly larger decrease in dispersion was observed by the addition of 15 g kg^-1 or more. As the amount of added Al increased, the amount of negative charges of the soil decreased while that of positive charges increased. The charge characteristics of the system with the addition of 20 g kg^-1 of A1(OH)₃ were closer to those of the adjacent forest soil which was characterized by a very low dispersibility. It was inferred that added Al hydroxides polymerized to form Al polycation species that were not readily exchangeable, neutralizing negative charges of clays, and acting as interparticle bonding between the clays. On the other hand, forest soils were considered to have acquired a physical stability against the dispersion of fine particles as free Al oxides had been accumulated in the process of natural weathering. It was concluded that charge characteristics primarily determined the dispersion and flocculation behavior of soils and that Al hydroxides were important modifiers of charge characteristics of soils.  相似文献   

Selective determination and formation of elemental selenium in soils     

Hidekazu Yamada  Yasuo Kase  Manabu Usuki  Shin Kajiyama  Koyo Yonebayashi 《Soil Science and Plant Nutrition》2013,59(2):403-408

A selective method for the determination of elemental selenium in soil was developed and was applied to the study of elemental selenium in soil. (1) Elemental selenium extracted with carbon disulfide from soil was selectively transformed into selenocyanate ion by reacting with potassium cyanide in carbon disulfide. The selenocyanate ion formed was recovered into an aqueous solution and the amount of selenium in the aqueous solution was determined. This method was specific to elemental selenium and did not interfere with the other selenium compounds and soil components. The method was also highly sensitive and enable to determine more than 0.1 μg kg^-1 of elemental selenium in soil. (2) The formation of elemental selenium was confirmed, when a soil was submerged and the redox potential of the soil decreased. The amount of elemental selenium formed was proportional to the selenite content of the soil, indicating that elemental selenium is transformed from selenite upon its reduction.  相似文献   

Karyotype analysis of interspecific fusants of basidiomycetes by pulsed-field gel electrophoresis     

Takeshi Yokono  Yutaka Tamai  Tomonori Azuma  Yoh Sakuma  Kiyoshi Miura  Yasuo Kojima  Masahide Sunagawa  Masatake Ohmasa 《Journal of Wood Science》2000,46(6):480-484

The purpose of this research was to analyze the karyotype of the interspecific fusants of twoPleurotus species. Auxotrophic mutants derived from the cultivated strain ofP. ostreatus andP. cornucopiae were used. Protoplasts were fused electrically, and the fusants were selected under auxotrophic complementation. Esterase isozyme analysis showed that several fusants had isozyme bands originating from both parental strains, and others had unilateral isozyme bands. The fusant that had expressed isozyme bands of both parental strains showed chromosomal DNA bands of both of the parental strains in pulsedfield gel electrophoresis analysis. Despite the above results, the chromosomal composition of the fusants obtained by the pulsed-field gel electrophoresis did not exhibit all of the bands of both fusion parents.  相似文献   

Phylogenetic analysis of hindgut microbiota in Hokkaido native horses compared to light horses     

Hidehisa YAMANO  Satoshi KOIKE  Yasuo KOBAYASHI  Hiroshi HATA 《Animal Science Journal》2008,79(2):234-242

The analysis of 16S rDNA sequence of bacteria in feces of Hokkaido native horses and light horses were performed to compare the hindgut microbiota between the two breeds. One hundred and four bacterial 16S rDNA clones (57 clones from four native horses and 47 clones from two light horses) were obtained. Only four sequences (3.8% of total sequences) showed 97% or more similarity to known species. The sequences were mainly affiliated with Cytophaga–Flavobacter–Bacteroides and low GC Gram‐positive bacteria (LGCGP). Proportion of LGCGP was higher in light horses. Other phyla including Verrucomicrobia, Spirochaetes and Archaea were detected only for native horses, suggesting high diversity of microbiota in native horses. In LGCGP, clusters related to known cellulolytic species were found only for native horses, while a cluster related to soluble sugar‐utilizing species was detected only for light horses. The library composition‐comparing software LIBSHUFF showed significant (P < 0.05) difference of fecal microbiota between the horse breeds. The number of Fibrobacter succinogenes‐related sequence and the frequency of detection of novel groups were found to be higher in native horses by selective amplification analysis. The results suggest that genetic diversity and population size of the F. succinogenes group are higher in the hindgut of native horses.  相似文献