Abstracts of nippon Dozyohiryogaku Zasshi     

Nobuhiko Fueki  Masayuki Tani  Shuji Higashida  Satoshi Nakatsu 《Soil Science and Plant Nutrition》2013,59(3):321-331

The present study was carried out to analyze the factors that affected the growth of sugar beet in four different soil types by using concrete-framed plots as follows: soil acidity (soil pH, exchange acidity y ₁) and nitrification of fertilizer introduced by row application. Comparison of the value of the exchange acidity y ₁ of the four soil types with the pH value adjusted to the same level (pH 5.1) revealed that the Humic Gray Upland soil displayed the highest y ₁ value (y ₁: 18.0), followed by the Humic Volcanogenous Regosol (y ₁: 6.9), Haplic Brown Lowland soil (y ₁: 5.3), and Low-humic Andosol (y ₁: 2.2). Al release to the soil solution was considered to occur at soil pH values of 4.8 and lower except in the Low-humic Andosol. Al concentration in the soil solution of the Low-humic Andosol was substantially lower than that of the other soils. On the other hand, the soil pH value decreased temporarily by nitrification of the fertilizer introduced by row application, especially in the Humic Gray Upland soil. In this case, the soil pH value became lower than 4.8 for a time. At this pH level, Al release to the soil solution was assumed to occur. As described above, the soils displayed different properties in terms of soil acidity. In the four soils, although the growth of sugar beet was significantly related to both soil pH and exchange acidity y ₁ values before sowing, these relations were not strictly valid. On the other hand, the linear correlation coefficients of the relationships between the growth of sugar beet (leaf length) and NO₃-N content in rows were higher than those of the soil pH and exchange acidity y ₁. No appreciable variation associated with the differences in the soil types was observed in this relation. Furthermore, the values of both soil pH and exchange acidity y ₁ were closely related to the NO₃-N content in rows and the relationship between the NO₃-N content and y ₁ value appeared to be somewhat closer than that with the soil pH. These closer relations had two important implications. Firstly, NO₃-N content reflected the nitrogen nutrient conditions. NO₃-N promoted the growth of sugar beet directly. Secondly, the NO₃-N content was affected by the soil acidity, which is expressed by the value of the exchange acidity y ₁. Low NO₃-N content indicated indirectly the toxicity of soil acidity to sugar beet growth. It was thus suggested that in the present study, nitrification of the fertilizer expressed by the NO₃-N content was a beneficial factor for the growth of sugar beet regardless of the soil types. Finally, to promote the nitrification of fertilizer and to minimize the Al toxicity enhanced by the decrease of the soil pH associated with nitrification, it is important to avoid low values for the soil pH.  相似文献   

Factors Affecting Microbial Biomass and Dehydrogenasc Activity in Apple Orchard Soils with Heavy Metal Accumulation     

Masakazu Aoyama  Toshiyuki Nagumo 《Soil Science and Plant Nutrition》2013,59(4):821-831

The size of the microbial biomass and dehydrogenase activity were measured in air-dried and rewetted apple orchard surface soils with accumulation of Cu, Pb, and As due to the application of Bordeaux mixtures and lead arsenate. The largest amounts of total Cu, Pb, and As found in the soils used were 1,108, 1,271, and 209 mg kg^-1 soil, respectively. The amounts of 0.1 M HCl-extractable heavy metals were strongly correlated with the total amounts, while those of 0.1 M CaCl₂-extractable heavy metals, except for As, increased significantly with decreasing soil pH. The amounts of microbial biomass C and N, expressed on a soil organic C and total N basis, respectively, were each negatively correlated with the amounts of total and 0.1 M HCl-extractable Cu. On the other hand, the dehydrogenase activity was not affected by the amounts of total and 0.1 M HCl-extractable heavy metals, and was negatively correlated with the amount of 0.1 M CaCl₂-extractable Cu and positively with the soil pH. Higher significant correlations were observed when the dehydrogenase activity was calculated per unit of soil organic C. Thus the microbial biomass was adversely affected by the slightly soluble fractions of Cu accumulated in apple orchard soils, whereas the dehydrogenase activity was affected by the water-soluble and exchangeable Cu of which amount depended on the soil pH. It is suggested that the microbial biomass and dehydrogenase activity expressed on a soil organic matter basis could become useful indicators for assessing the effects of heavy metals on the size and activity of the microbial biomass in soils differing in organic matter contents.  相似文献   

Quantitative and qualitative changes of organic matter in an Ando soil induced by mineral fertilizer and cattle manure applications for 20 years     

Masakazu Aoyama  Naonori Kumakura 《Soil Science and Plant Nutrition》2013,59(2):241-252

The effects of continuous application of cattle manure on the quantity and quality of soil organic matter (OM) were investigated in an Ando soil (Melanudand). Surface soil samples were periodically taken from NPK and NPK+ manure (80, 160, and 320 Mg ha^-1 y^-1) plots over a period of 20 y. Particulate (>53 µm) and mineral-associated <53 µm) OM fractions were separated from the soil samples by sieving after:mechanical dispersion. For the NPK treatment, both the organic C and total N concentrations of the whole soil continued to decrease, the reduction reaching about 10% after 20 y. Manure application at the rate of 80 Mg ha^-1 y^-1 did not lead to an increase in the amounts of organic C and total N in the whole soil. In contrast, both the organic C and total N concentrations increased by the application of 160 and 320 Mg ha^-1 y^-1 manure. Manure application at the rate of 320 Mg ha^-1 y^-1 increased the organic C concentration by 30% and total N concentration by 48% after 20 y. The decrease in the organic C and total N concentrations in soil with NPK fertilization was attributed to a decrease in the amount of mineralassociated OM. Manure application increased significantly the amount of particulate OM, while it did not affect the amount of mineral-associated OM. It also resulted in a decrease in the C/N ratio of soil OM, especially of the particulate OM. The analysis of humic acids showed that manure application induced a decrease in the degree of humification and an accumulation of high molecular weight components. The quantitative'and qualitative changes of OM in the Ando soil upon manure application were mainly due to the accumulation of manure-derived particulate OM.  相似文献   

Reproductive cycle,age, and body size at maturity and fecundity of female willowy flounder <Emphasis Type="Italic">Tanakius kitaharai</Emphasis>     

Yoji Narimatsu  Akibumi Yamanobe  Masakazu Takahashi 《Fisheries Science》2007,73(1):55-62

Annual reproductive cycle, age and body size at maturity, and potential and relative fecundity were examined in female willowy flounder in the North Pacific off Japan. Vitellogenesis became active from September, followed by the beginning of spawning in December. The spawning season continued until May with its peak in January. Estimated maturation rate was 50% at a standard length of 16 cm, 30% in 2-year-olds, and almost 100% in ≥3-year-old fish. Potential fecundity increased with age, while relative fecundity decreased in older fish. The results clarify some aspects of the detailed reproductive biology of female willowy flounder and emphasize the importance of age-composition data in estimating reproductive potential within a population.  相似文献   

A mesoscale iron enrichment in the western subarctic Pacific induces a large centric diatom bloom   总被引：2，自引：0，他引：2  

Tsuda A  Takeda S  Saito H  Nishioka J  Nojiri Y  Kudo I  Kiyosawa H  Shiomoto A  Imai K  Ono T  Shimamoto A  Tsumune D  Yoshimura T  Aono T  Hinuma A  Kinugasa M  Suzuki K  Sohrin Y  Noiri Y  Tani H  Deguchi Y  Tsurushima N  Ogawa H  Fukami K  Kuma K  Saino T 《Science (New York, N.Y.)》2003,300(5621):958-961

We have performed an in situ test of the iron limitation hypothesis in the subarctic North Pacific Ocean. A single enrichment of dissolved iron caused a large increase in phytoplankton standing stock and decreases in macronutrients and dissolved carbon dioxide. The dominant phytoplankton species shifted after the iron addition from pennate diatoms to a centric diatom, Chaetoceros debilis, that showed a very high growth rate, 2.6 doublings per day. We conclude that the bioavailability of iron regulates the magnitude of the phytoplankton biomass and the key phytoplankton species that determine the biogeochemical sensitivity to iron supply of high-nitrate, low-chlorophyll waters.  相似文献   

Characterization of neuron-like cells derived from canine bone marrow stromal cells     

Yasutaka Oda  Kenji Tani  Toshitaka Kanei  Tomoya Haraguchi  Kazuhito Itamoto  Hiroshi Nakazawa  Yasuho Taura 《Veterinary research communications》2013,37(2):133-138

Regenerative therapy using bone marrow stromal cells (BMSCs) has begun to be clinically applied in humans and dogs for neurological disorders such as spinal cord injury. Under appropriate conditions in vitro, BMSCs differentiate into neuronal cells, which may improve the effects of regenerative therapy. In this study, we evaluated canine neuron-like cells (NLCs) derived from BMSCs. We speculated on their suitability for neuro-transplantation from the point of view of their morphological features, long-term viability, abundant availability, and ability to be subcultured. Canine NLCs were differentiated as follows: third-passage BMSCs were maintained in pre-induction medium containing 2-mercaptoethanol and dimethylsulfoxide for 5 h, and then cells were transferred to neuronal induction medium containing fetal bovine serum, basic fibroblast growth factor, epidermal growth factor, dibutyryl cyclic AMP, and isobutylmethylxanthine for 7 or 14 days. Canine NLCs fulfilled the transplantation criteria and expressed markers of both immature neurons (nestin, 84.7 %) and mature neuronal cells (microtubule-associated protein-2, 95.7 %; βIII-tubulin protein, 12.9 %; glial fibrillary acidic protein, 9.2 %). These results suggest that canine BMSCs can be induced to differentiate into neuronal cells and may be suitable for neuro-transplantation. This study may provide information for improving cellular therapy for neurological diseases.  相似文献   

Nocturnal isoprene emission from mature trees and diurnal acceleration of isoprene oxidation rates near Quercus serrata Thunb. leaves     

Takafumi Miyama  Motonori Okumura  Yuji Kominami  Kennichi Yoshimura  Mioko Ataka  Akira Tani 《Journal of Forest Research》2013,18(1):4-12

Quercus serrata Thunb. ex Murray is a widespread deciduous oak in China, the Korean Peninsula, and Japan, and a strong isoprene emitter. Establishing accurate inventories of this species and estimating net carbon budgets, including biogenic volatile organic compounds (BVOC), necessitates detailed evaluation of BVOC emission and oxidation characteristics. Emissions of isoprene, the most abundant BVOC, presumably contribute to atmospheric chemistry through the formation of photochemical oxidants and secondary organic aerosols. We built an isoprene flux monitoring system to simultaneously reveal characteristics of the flux and fate of isoprene at multiple locations in Q. serrata forests. We used proton transfer reaction mass spectrometry (PTR-MS) and an automated closed chamber to measure isoprene emissions from soil and leaves in a warm-temperate Q. serrata forest. We used a relaxed eddy accumulation system with PTR-MS to simultaneously measure the canopy flux. In continuous foliage chamber measurements, we observed daily variations of isoprene emissions and continuous nocturnal emissions from leaves. Nocturnal emissions exceeded 25 % of total daily leaf emissions and were relatively high at sunset and low at sunrise. These results suggest that nocturnal emissions from mature trees may not be negligible. When leaf emissions were high in the daytime, the canopy isoprene flux tended to plateau at an upper limit. Observations of isoprene concentrations and gradients suggest that the plateau was caused by acceleration of isoprene oxidation, and sequential formation of secondary organic aerosols may occur near the leaf just after emission. Elucidation of these linkages may require continuous field measurements with a simultaneous multi-flux monitoring system.  相似文献   

Morphological analysis on comparison of organic and chemical fertilizers on grain quality of rice at different planting densities     

Kifayatullah Kakar  Naomi Asagi  Masakazu Komatsuzaki  Fumitaka Shiotsu  Toshiaki Kokubo 《Plant Production Science》2013,16(4):510-518

ABSTRACT

Effects of organic (Italian ryegrass and Bokashi) and chemical fertilizer on growth, yield, and grain quality of rice (Oryza sativa L.) were compared under different planting densities in 2013/2014 and 2014/2015. Italian ryegrass was incorporated into the soil as green manure. Bokashi (a mixture of organic materials) was applied as basal dressing. To measure yield and its components, 30 hills were chosen for each treatment. Rice grains were harvested from each treatment to assess the grain quality and to evaluate accumulation structures using a scanning electron microscope. Bokashi treatment increased panicle number per hill, ripened grain percentage, panicle number per m², and grain yield compared to no fertilizer treatment at normal planting density. Chemical fertilizer treatment increased plant length at high planting density. Italian ryegrass and Bokashi treatments promoted the taste point (taste score as reference) by reduction of amylose and protein contents at normal planting density in contrast to chemical fertilizer. 1000-grain weight, panicle number per m², and grain yield were higher at high planting density than at normal planting density. However, high planting density decreased panicle number per hill and spikelet number per panicle. It also enhanced the amylose content of rice grain. Scanning electron microscopic observation revealed that chemical fertilizer treatment marked up protein bodies and their traces on amyloplasts. However, Bokashi treatment produced large amyloplasts, which included many starch granules. These results show that Italian ryegrass and Bokashi can offset reductions of chemical fertilizer and can lead to sufficient starch accumulation structures in rice grains.  相似文献   

Purification and functional characterization of complement C3 and a novel zymosan-binding protein in tilapia serum     

Soha G. R. Abdel-Salam  Masakazu Tsujikura  Masakazu Kondo  Tomonori Somamoto  Miki Nakao 《Fisheries Science》2014,80(2):301-310

Zymosan, a yeast cell wall preparation that binds activated forms of complement C3, is a useful model target to activate the complement system. In our trial to analyze C3 diversity in Nile tilapia at the protein level using zymosan, we found that a novel 240-kDa serum protein (ZBP-240) also bound to zymosan in addition to C3-derived fragments. In the present study, we aimed to characterize tilapia C3 and ZBP-240, focusing on their immune-related functions. Four distinct C3 isoforms were purified from tilapia serum and shown to possess an intrachain thioester bond. ZBP-240 was also isolated from tilapia serum and examined for its binding properties to various microbial targets. As a result, ZBP-240 showed a wide spectrum of binding to Gram-positive and Gram-negative bacteria and yeasts. Amino acid sequence analysis of CNBr fragments of ZBP-240 suggested that this is a novel protein with no homologous sequence in protein databases. It was also suggested that the binding of ZBP-240 to microbes largely depends on hydrophobic interactions in a divalent-cation-independent manner, and that there may be a divalent-cation-dependent factor that enhances the binding of ZBP-240 in tilapia serum. Interestingly, ZBP-240 showed opsonic activity for tilapia kidney phagocytes at a level comparable to that of C3, implying that ZBP-240 is a novel teleost opsonic serum protein.  相似文献   

Effects of deep percolation on dissolved inorganic nitrogen exports from forested headwater catchments     

Kenta Iwasaki  Masanori Katsuyama  Makoto Tani 《Journal of Forest Research》2016,21(2):57-66

We examined the effects of deep percolation on dissolved inorganic nitrogen (DIN) exports from two adjacent weathered granite headwater catchments with different deep percolations of water in the Kiryu Experimental Watershed (KEW), Japan. The DIN output in streamflow was estimated from a regression equation between stream discharge and the DIN load, determined from both monthly sampling data and event-based sampling data. The range of deep percolation of DIN was estimated by multiplying observed DIN concentrations in bedrock groundwater by the deep percolation of water estimated from an annual water budget analysis. We found that the deep percolation of DIN corresponded to 34–76 % and ?18 to 8 % of the total DIN output in catchments where the deep percolation of water was 37–45 % and ?6 to 3 % of annual precipitation, respectively. This means that the deep percolation of DIN is not negligible when estimating the total output of DIN in the former catchment. Moreover, the fact that deep percolating water from upper catchments discharged into a lower catchment in KEW suggests that deep percolation of DIN affects downstream N budgets. Therefore, it is important to account for the deep percolation of DIN when evaluating N budgets in forested headwater catchments as well as downstream catchments.  相似文献