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91.
Satoko Watanabe Kimihito Nakamura Chan Seok Ryu Michihisa Iida Shigeto Kawashima 《Soil Science and Plant Nutrition》2013,59(2):224-237
Treatment of animal and food wastes using a methane fermentation technique is drawing considerable public attention as a suitable option for the utilization of biomass resources. The application of a fermentation byproduct (methane fermentation digested liquid) as an agricultural fertilizer has been investigated. Determining the appropriate timing required for applying digested liquid on a rice (Oryza sativa L.) paddy plot is important. The concentrations of soil nitrogen (N) components and rice yield should be considered because digested liquid contains both inorganic and organic N. This study compares the N transformation and the rice yield and growth at different application times over a period of 3 y. The effects of the timing of basal application on soil N were different and the timing that maximized the rice yield was different in each year. Days before ponding (DBP) affected soil N before mid-summer drainage, and rice growth rates at the panicle formation stage and the ear emergence stage. The effects of DBP disappeared before harvest. The results indicated that sufficient potentially mineralizable N existed regardless of DBP, and the effect of DBP lessened after the mid-summer drainage, which coincides with the period when N uptake is most active. 相似文献
92.
Taiki Mori Nobuo Imai Daiki Yokoyama Kanehiro Kitayama 《Soil Science and Plant Nutrition》2013,59(5):554-557
ABSTRACTPrevious meta-analyses revealed that the ratio of activities of carbon (C)-acquiring enzyme to nitrogen (N)-acquiring enzymes in tropical forest ecosystems was nearly identical to those in other ecosystems, despite of the N-rich condition in tropical forests. This could be explained by microbes in tropical forest soils, which require a large amount of N to produce N-rich acid phosphatase (AP) for catalyzation of the organic form of phosphorus (P) and compensation for poor P availability in soils. Based on this idea, we hypothesized that experimental P fertilization would reduce the allocation to N-acquiring enzymes compared with that of C-acquiring enzymes, i.e. that it would increase the ratios of activities of β-1,4-glucosidase (BG) to β-1,4-acetylglucosaminidase (NAG) and leucine aminopeptidase (LAP). We tested this hypothesis using an experimental fertilization site with factorial N (100 kg ha?1 yr?1) and P (50 kg ha?1 yr?1) addition in a primary tropical lowland forest in Bornean Malaysia, where our earlier work demonstrated that P fertilization reduced AP activity. Contrary to our hypothesis, the BG:NAG and BG:(NAG + LAP) ratios were not altered by either N or P fertilizations. This result indicated that AP production was not a reason for the maintenance of a relatively high investment in N-acquiring enzyme at our study site. Rather, NAG and LAP production was likely driven by C acquisition, rather than N acquisition, as the target substrates contained C as well as N. This idea was supported by the fact that neither the BG:NAG ratio nor the BG:(NAG + LAP) ratio was elevated by N addition. We propose that the ratios of activities of BG to NAG and LAP do not necessarily indicate the ratio of C:N acquisition, at least in our N-rich tropical forest ecosystem. 相似文献
93.
Ahmed Al-Busaidi Tahei Yamamoto Mitsuhiro Inoue A. Egrinya Eneji Yasushi Mori Muhammad Irshad 《Journal of plant nutrition》2013,36(7):1159-1173
ABSTRACT Soil salinity is a major abiotic factor limiting crop production but an amendment with synthetic zeolite may mitigate effects of salinity stress on plants. The objective of the study was to determine the effects of zeolite on soil properties and growth of barley irrigated with diluted seawater. Barley was raised on a sand dune soil treated with calcium type zeolite at the rate of 1 and 5% and irrigated every alternate day with seawater diluted to electrical conductivity (EC) levels of 3 and 16 dS m?1. Irrigation with 16 dS m?1 saline water significantly suppressed plant height by 25%, leaf area by 44% and dry weight by 60%. However, a substantial increase in plant biomass of salt stressed barley was observed in zeolite-amended treatments. The application of zeolite also enhanced water and salt holding capacity of soil. Post-harvest soil analysis showed high concentrations of calcium (Ca2 +), magnesium (Mg2 +), sodium (Na+), and potassium (K+) due to saline water especially in the upper soil layer but concentrations were lower in soils treated with zeolite. Zeolite application at 5% increased Ca2 + concentration in salt stressed plants; concentrations of trace elements were also increased by 19% for iron (Fe2 +) and 10% for manganese (Mn2 +). The overall results indicated that soil amendment with zeolite could effectively ameliorate salinity stress and improve nutrient balance in a sandy soil. 相似文献
94.
Kenji Kanazawa Kyoko Higuchi Hiromi Nakanishi Naoko Kishi-Nishizawa Satoshi Mori 《Soil Science and Plant Nutrition》2013,59(4):717-721
Under iron deficient conditions, graminaceous plants secrete mugineic acid family phytosiderophores (MAs) from their roots to dissolve sparingly soluble iron compounds in the rhizosphere, and take up iron in the form of an Fe3+-MAs complex (Takagi 1976). A good correlation has been reported between the tolerance of Fe-deficiency and the amount of secreted MAs (Takagi 1993). Therefore, by using the genes involved in MAs biosynthesis, molecular breeding might produce transgenic plants tolerant to Fe-deficiency with a high level of MAs secretion. The biosynthetic pathway of MAs from L-methionine has been clarified (Fig. 1) and the enzymes participating in this process are now being investigated to isolate the genes responsible. Nicotianamine aminotransferase (NAAT) catalyzes the amino group transfer between nicotianamine (NA) and 2-oxoglutaric acid (Fig. 1). In order to purify NAAT, enzyme assay methods for NAAT have been developed and modified (Shojima et al. 1990; Ohata et al. 1993; Kanazawa et al. 1994). Some characteristics of NAAT have been reported using these enzyme assay methods (Kanazawa et al. 1994, 1995). Here, we further investigate some characteristics of this enzyme to improve the enzyme assay method, namely 1) the effect of K+ and Mg2+ on NAAT activity in vitro, and 2) the direct influence of MAs, Fe3+, and Fe2+ on NAAT activity. In addition, based on these results, the induction of enzyme activity by Fe-deficiency and suppression of the activity by Fe-resupply was investigated, by applying the new enzyme assay method. 相似文献
95.
Maiko Kaneko Etsuro Yoshimura Naoko K. Nishizawa Satoshi Mori 《Soil Science and Plant Nutrition》2013,59(3):701-712
To clarify the mechanism(s) involved in the short-term inhibition of root elongation by AI, we monitored the morphological changes of barley roots by digital microscopy. Within 30 min after exposure to 37 µM AI, the surface of the root epidermis in the region of a distance of 1.5 mm from the root tip became rough and began to show signs of damage. After 38 min, callose was rapidly excreted from the junction between the root cap and the root epidermis, and formed a spherical lump approximately 60 µm in diameter. The fine structure of the callose deposits on the root surface was analyzed by low-vacuum scanning electron microscopy. After 50 min, there was a significant increase in the callose contents in the distal 0.6 mm part. At the same time, root elongation stopped completely. Fluorescence staining indicated that callose was localized on the surface of the cell elongation area (the elongation zone of primary roots and root hairs), but not on the surface of the meristem. The root growth reduction associated with AI treatment may be due to the use of sugar substrates for callose formation instead of cellulose formation. 相似文献
96.
Le Van Chinh Kazuaki Hiramatsu Masayoshi Harada Makito Mori 《Paddy and Water Environment》2008,6(4):405-414
Chiyoda basin is located in Saga Prefecture in Kyushu Island, Japan, and lies next to the tidal compartment of the Chikugo
River to which the excess water in the basin is drained away. Chiyoda basin has a total area of about 1,100 ha and is a typical
flat and low-lying paddy-cultivated area. The main environmental issue in this basin is total nitrogen (TN) and total phosphorus
(TP) load management because TN and TP, which loaded from farmlands, degrade surface water as a result of anthropogenic eutrophication.
This paper presents a mathematical model of TN and TP runoff during an irrigation period in Chiyoda basin in order to elucidate
the pollutant fluxes that accompany water transportation in paddy fields and drainage canals, and to evaluate pollutant removal
from the study area to the Chikugo River. First, the water flow and the algorithm of gate operation were simulated by a continuous
tank model and the accuracy of the model was then evaluated by comparing the simulated water levels with observed ones during
an irrigation period. The observed and simulated water levels were in good agreement, indicating that the proposed model is
applicable for drainage and water supply analyses in flat, low-lying paddy-cultivated areas. Second, the TN and TP runoff
during an irrigation period was simulated based on the TN and TP loads that were determined by observed data in paddy fields.
For TN runoff, the simulated results and observed data were in good agreement whereas for TP runoff, the simulated results
were higher than the observed data. However, if the settled TP within the paddy tank was calculated as 6%, then the simulated
results and the observed data were in good agreement. We concluded that TN runoff from paddy field to the drainage canal system
was not affected much by the sediment related process. The present study could provide farmers and managers with a useful
tool for controlling the water distribution in an irrigation period, and the TN and TP loads in the downstream area as well
as the Chikugo River. 相似文献
97.
Increase in Iron and Zinc Concentrations in Rice Grains Via the Introduction of Barley Genes Involved in Phytosiderophore Synthesis 总被引:1,自引:1,他引:0
Hiroshi Masuda Motofumi Suzuki Kendi Claudio Morikawa Takanori Kobayashi Hiromi Nakanishi Michiko Takahashi Masahiko Saigusa Satoshi Mori Naoko K. Nishizawa 《Rice》2008,1(1):100-108
Increasing the iron (Fe) and zinc (Zn) concentrations of staple foods, such as rice, could solve Fe and Zn deficiencies, which are two of the most serious nutritional problems affecting humans. Mugineic acid family phytosiderophores (MAs) play a very important role in the uptake of Fe from the soil and Fe transport within the plant in graminaceous plants. To explore the possibility of MAs increasing the Fe concentration in grains, we cultivated three transgenic rice lines possessing barley genome fragments containing genes for MAs synthesis (i.e., HvNAS1, HvNAS1, and HvNAAT-A and HvNAAT-B or IDS3) in a paddy field with Andosol soils. Polished rice seeds with IDS3 inserts had up to 1.40 and 1.35 times higher Fe and Zn concentrations, respectively, compared to non-transgenic rice seeds. Enhanced MAs production due to the introduced barley genes is suggested to be effective for increasing Fe and Zn concentrations in rice grains. 相似文献
98.
Kunihiko Hamagami Bui Quoc Lap Ken Mori Yasumaru Hirai 《Paddy and Water Environment》2009,7(3):187-195
The attenuation of heat flux at the water surface with aquatic plants was examined by hydraulic experiments to consider the
influence of aquatic plants on the magnitude of thermal disturbance in the closed water body. First of all, the experiment
measuring temperatures on surface of leaf revealed the thermal conductivity of the leaf which is peculiar physicality of each
aquatic plant. Then, the hydraulic experiment examined attenuation of the underwater illuminance and the heat flux in the
covered part which depending on the kind and the luxuriant density of the aquatic plants. As the result, it is clarified that
the attenuation rate of the illuminance is large in the plant with a thick leaf, and that the heat flux at the water surface
and the developmental velocity of the mixed layer decreased when the luxuriant density of the aquatic plants increased. 相似文献
99.
Light-related plasticity in a variety of crown morphology and within-tree characteristics was examined in sun and shade saplings of Abies amabilis Dougl. ex J. Forbes growing in two late-successional forests with different snow regimes in the Cascade Mountains of Washington, USA. Compared with sun saplings, shade saplings typically had broad flat crowns as a result of acclimation at several scales (needle, shoot, branch, crown and whole sapling). Shoots of shade saplings had a smaller needle mass per unit of stem length than shoots of sun saplings, a feature that enhances light-interception efficiency by reducing among-needle shading. The low annual rate of needle production by shade saplings was associated with a longer needle lifespan and slower needle turnover. Reduced needle production within a shoot was reflected at the branch level, with lateral branches of shade saplings having a smaller needle mass than branches of the same length of sun saplings. Reduced allocation to needles permits greater investment in branches and stems, which is necessary to support the horizontally expanding branch system characteristic of shade saplings. Mean branch age of shade saplings was significantly higher than that of sun saplings. Shade saplings had lower needle mass per unit of trunk biomass or total biomass, reflecting greater investment in the trunk as a support organ. Increased investment in support organs in shade was more evident in the snowier habitat. The observed morphological acclimation makes A. amabilis highly shade and snow-tolerant and thus able to dominate in many late-successional forests in snowy coastal mountain regions. 相似文献
100.
Different leaching media composed of watersoluble extracts from Sakhalin fi r, Japanese cedar, and Japanese larch heartwoods
and of taxifolin were used to characterize leaching of the C12 and C14 homologues of benzalkonium chloride from treated wood.
The leaching medium of Sakhalin fi r extract moderately accelerated the leaching rates of the two homologues. Japanese cedar
extract accelerated the leaching of the C12 homologue at a similar rate and that of the C14 homologue at a higher rate. Japanese
larch extract remarkably accelerated the leaching rates of both homologues, particularly that of the C14 homologue. Thus,
the leaching rate of the C14 homologue was higher than that of the C12 homologue with the Japanese cedar and larch extracts.
The media of taxifolin, a major phenolic extractive of Japanese larch, preferentially accelerated the leaching rate of the
C14 homologue. The amounts of phenolic compounds in the different leaching media were in the following order: Japanese larch
> Japanese cedar > Sakhalin fi r. These results indicate a relationship between the amount of phenolic compounds and the leaching
rates of the two homologues. 相似文献