All issues
Volume 48, Issue 1
Displaying 1-16 of 16 articles from this issue
- |<
- <
- 1
- >
- >|
-
Masatoshi AOKI, Tatsuo HOSONO, Hiroshi TANI, Shinji MATSUMURA1992 Volume 48 Issue 1 Pages 1-10
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn basins, information on long-term air temperature is useful for farming. In the present study, air temperatures at 1.5m were measured every 10 minutes at various elevations on the slopes of a caldera basin (Akaigawa Basin, Hokkaido) during 2 periods (July to October 1987 and May to October 1988).
The relationships between elevation and daily minimum and maximum air temperatures at 1.5m were analyzed. Since the relationships had small regional differences, and were approximately linear relationship, the daily minimum and maximum air temperatures at any elevation in the basin could be estimated using gradients of air temperature to elevation (air temperature gradient) and the daily minimum and maximum air temperatures at a particular site.
In order to estimate the gradients, multiple regression models were tested which include various meteorological elements as independent variables. The best model for the minimum air temperature gradient (An, °C/100m) is as follows, where the independent variables are daily minimum air temperature (Tn, °C) and mean water vapor pressure (VPn mb), accumulated radiation heat loss (Rn, kWh/m2) and wind speed (Wn, m/s) during night time, as measured at the bottom of the basin.
An=-0.198Tn+0.107VPn+2.11Rn-0.298Wn-0.116
This regression model explains 77% of the variation in the daily minimum air temperature gradient, and its standard estimate error (0.5°C/100m) is equivalent to 10% of the gradient range. For the daily maximum air temperature gradient, an adequate regression model was not found by the independent variables tested.
Other results suggested that the daily minimum air temperature gradient at the Akaigawa Basin can also be predicted from the air temperature gradient of the lower atmosphere in Sap poro (about 70km distance from Akaigawa Basin) which is calculated by the aerological data reported at 21:00 (observed at about 20:30) of the previous night.View full abstractDownload PDF (3733K) -
Takuya KOBAYASHI, Yoshihisa KOHNO, Keiichi NAKAYAMA1992 Volume 48 Issue 1 Pages 11-18
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSAdverse effects of acid rain on the growth of plants include acidification of soils and the subsequent leaching of basic cations and release of certain elements in potentially toxic concentrations from soil. The present study describes changes in the elemental conditions of cultivated soil and soybean plants exposed to simulated acid rain.
The cultivated soil pH (soil: H2O=1:2.5) at the upper layer (0-5cm) was significantly decreased with increasing acidity of simulated acid rain. At pH 2.0, the contents of soluble basic cations, Mn and Zn in water (soil: H2O=1:5) were significantly increased in the upper soil layer (0-5cm) compared with pH 5.6. As a result of these changes on soil conditions, the uptake rate of basic cations, Cu, Mn and Zn by the soybean plants were increased by exposing the simulated acid rain at pH 2.0. These results suggested that the concentration of Mn and Cu in plant are available to estimate the acidification of soil with acid rain.
On the other hand, despite the contents of soluble Al in 1N CH3COONH4 was increased and of soluble P in water was decreased with decreasing pH of soil in the upper soil layer, P uptake rate by soybean plants was increased at pH 2.0. Any effects of toxic element were not observed at all pH treatments.
These results suggested that soil chamistry may change significantly in upper layer by simulated acid rain treatment at pH 3.0 or below, but the effects of such changes were not important on the growth and yield of soybean plants under the normal manuring practice.View full abstractDownload PDF (1028K) -
Yoichi YAMATO, Susumu MAEKAWA, Noboru INAGAKI, Motoichi TERABUN1992 Volume 48 Issue 1 Pages 19-28
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSWe tried modeling on the influence of shade with a structure on the growth of turnip (Brassica campestris L. rapa group), and discussed on the results obtained from the model.
1. The changes of four characters (total dry weight (DW), top DW, root DW and leaf area) with growth were fitted quadratic equations, when the observed values were transformed to logarithmic ones.
2. The relationships between relative values of total photon flux density and each of four characters were shown with linear regression.
3. Time courses of coefficients and constants in the linear regression equations obtained were fitted for polynomial equation.
4. Estimated values of every character by model were very close to the observed ones.
5. The results obtained from the model suggested that in the early developmental stage, the growth of foliage (top) being photosynthetic organ was depressed by the shade of structure, whereas in the later stage, the top was not affected but root being the non-photosynthetic organ markedly by shading. The degree of shading effect on the total DW was not almost changed through the developmental stage.View full abstractDownload PDF (1289K) -
Masatoshi AOKI, Ikuo HORIGUCHI, Chiharu ITOH, Gui-Qing YANG, Takashi H ...1992 Volume 48 Issue 1 Pages 29-37
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe authors developed an aseptic plant tissue culture vessel system which enabled ventilation, air composition control, and the addition of nutrient solutions (see Fig. 1). One feature of the system is that two kinds of germ filters are attached directly to the culture vessel (see Fig. 1, Fig. 2, and Fig. 3). One filter is for forced ventilation and the other is for the addition of nutrient solutions.
The merits of the system we developed are as follows: (1) Number of air changes is maintained at a desired value without sterilization of the ventilated air and without risk of contamination. It is therefor possible to increase the number of air changes much more than in present aseptic culture vessels wherein ventilation is induced by diffusion. (2) Accordingly, air composition control is very easily achieved. For example, air humidity in vessels is easily kept at the desired value by regulating the water temperature in the bottle of humidity regulator, as shown in Fig. 1. Furthermore, CO2 enrichment is easily practicable. (3) The addition of nutrient solutions during cultivation is achieved easily and quickly (about one minute for addition of 5cm3 solution into a vessel) without opening the vessel cap, and no sterilization of the solution is needed. (4) No advance autoclave procedure is needed except for the culture vessel unit (see Fig. 1). No contamination was observed for 10 weeks even if the cultivation was conducted in an un-clean room. (5) When open air (CO2 concentration: ca. 400ppm) was introduced into the developed vessels, the growth of edible lily plantlets was better than those of two controlled plots (Control-P and Control-T plots) (see Table 2). When the CO2 concentration in developed vessels was maintained at 5, 000ppm, the growth of plantlets was about 20 times greater than those of Control-P and Control-T plots (see Table 2).View full abstractDownload PDF (3190K) -
Hiroshi SEINO, Zenbei UCHIJIMA1992 Volume 48 Issue 1 Pages 39-48
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe productivity of terrestrial vegetation is a determinate element of the carrying capacity of the Earth for all living things including human being. In this study, the Chikugo model for evaluating the net primary productivity (NPP) from weather data was used to elucidate the global distribution and the latitudinal variation of NPP. Predicted NPP varied from below 1t dry-matter ha-1yr-1 in high latitude zone and dry regions to 29t dry-matter ha-1yr-1 in topical wet regions, depending on climatic conditions. The land area with the NPP above 10t dry-matter ha-1yr-1 was only 36.6% of the entire land area. The latitudinal change in NPP was characterized by a curve with a clear peak in the equatorial zone and two weak troughs in the subtropical high-pressure belts on both hemispheres. The potential global net production by terrestrial plants was estimated to be 136×109t dry-matter yr-1, agreeing well with those reported by other researchers.View full abstractDownload PDF (1192K) -
Kazuhiro FUJIWARA, Shuji KIRA, Toyoki KOZAI1992 Volume 48 Issue 1 Pages 49-56
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSShort single node cuttings of tissue-cultured potato plantlets (Solanum tuberosum L. cv. Benimaru) were placed onto the culture media with three different sucrose concentrations (5g·l-1 (S5), 15g·l-1(S15) and 25g·l-1(S25)) to follow the time course of CO2 exchange of potato cultures for 30 days. Moreover, how the CO2 balance of the cultures changes during the growth and development phases from short single node cuttings (length: 5mm; dry weight: 1mg) to plantlets (dry weight: >10mg) large enough to transfer to ex vitro conditions was investigated. The CO2 exchange was calculated from the time course of the difference (ΔC) between CO2 concentrations of inflow and outflow air (flow rate: 2.1l·h-1) through the culture vessel.
On day 3 ΔC for all sucrose concentrations showed tendencies to decrease by photosynthesis after the beginning of photoperiod. Cyclic changes in ΔC for all sucrose concentrations according to 8 hours-dark/16 hours-photoperiod cycles were clearly observed after day 5. The difference between maximum and minimum ΔC on the same day in each sucrose concentration increased as the day proceeded, and the difference on day 30 was in the order: S15>S25>S5. The CO2 exchange during photoperiod and daily CO2 exchange for all sucrose concentrations continuously increased as the day proceeded. The daily CO2 exchange was found to turn to positive values from negative ones around day 16 for S5, and day 10 for S15 and S25: the cultures turned into positive CO2 balances. These results indicate that the cultures have grown and developed dominantly depending on sucrose in the culture medium before the CO2 balance turned to positive, even having contained chlorophyll and been under appropriate CO2 (880±50μmol·mol-1 for inflow air) and light (120μmol·m-2·s-1 during photoperiod) conditions for photosynthesis. The dry weight increase and net production by photosynthesis for 30 days were in the order: S15>S25>S5.View full abstractDownload PDF (1140K) -
Yousey HAYASHI1992 Volume 48 Issue 1 Pages 57-64
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSTo investigate dependencies in the magnitudes of a waving ear on mean wind speed, field observations were carried out over a barley filed in the ripe stage. Fluctuating displacements derived from HONAMI were measured using a newly designed 2-dimension strain sensor. The velocity fields were measured by a sonic anemometer-thermometer.
A coherently waving phenomena of HONAMI appeared and was evaluated by the fluctuating displacements of a single ear of the stand. Dividing a time series of the fluctuating displacement into five typical bands of frequency by use of an analog filter, it was shown that there are two dominants of 0.5-Hz and below 0.1-Hz in the original. The bands were from a natural frequency and a gustness of wind respectively. Comparing the amplitudes, the natural frequency contributed remakably to the original fluctuation of HONAMI.
Magnitudes of an instantaneous ear-displacement, which represents 0.5-0.6-Hz of frequency, varied with increments of the mean wind speed within a range of 2.6-4.4-m/s. Except for this range, the dependency between the amplitude and the wind speed was not clear.
Instantaneous changes in lateral displacements and velocity fluctuations were quite similar except for the component of higher frequencies. Under such circumstances, an ear-displacement will appear to infulence strongly the aero-dynamical properties of the canopy boundary layer.
The force per unit length acts on a waving ear generates by a relative velocity of u-dx/dt. Here, u is the mean wind speed, and dx is the displacement of an ear from its mean position during dt. Using this concept, drug force was evaluated under two criteria for leeward ear-moving and ear-standing. Under the windy conditions, the force loaded on an waving ear reduced by 10% against the standing criterion with dx=0. On the other hand, the reduction rate became small down to 4% of the standing criterion under the condition of weak wind.View full abstractDownload PDF (928K) -
Masatoshi AOKI, Tatsuo HOSONO, Hiroshi TANI1992 Volume 48 Issue 1 Pages 65-68
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe authors measured air temperatures at 1.5m above the ground every 10 minutes at various elevations 135m-345m) on the slope of a caldera basin (Akaigawa Basin, Hokkaido) during two periods (July to October 1987 and May to October 1988). The relationships between elevation and effective accumulated temperature (base temperature=5°C), average diurnal range of air temperature are analyzed by these data (see Fig. 1 and Fig. 2). The relationships in 1987 and 1988 had small differences.
The dates when certain low temperatures occured at any elevation for the first time are shown (see Fig. 3). The finding suggests that the dates can be estimated using the daily minimum air temperature gradients calculated by the equation (see Eq. (1)) presented by the former article (Aoki et al., 1992).View full abstractDownload PDF (513K) -
Osamu KITAMURA1992 Volume 48 Issue 1 Pages 69-75
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (1866K) -
[in Japanese]1992 Volume 48 Issue 1 Pages 76
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (157K) -
Haruhiko YAMAMOTO1992 Volume 48 Issue 1 Pages 77-83
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (3003K) -
Kazuyoshi KIMURA1992 Volume 48 Issue 1 Pages 85-88
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (650K) -
Kenji KURATA1992 Volume 48 Issue 1 Pages 89-92
Published: June 10, 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (659K) -
1992 Volume 48 Issue 1 Pages 128a
Published: 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (47K) -
1992 Volume 48 Issue 1 Pages 128b
Published: 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (47K) -
1992 Volume 48 Issue 1 Pages 128c
Published: 1992
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (47K)
- |<
- <
- 1
- >
- >|