Environmental Control in Biology
Online ISSN : 1883-0986
Print ISSN : 1880-554X
ISSN-L : 1880-554X
Volume 51 , Issue 3
Environmental Control in Biology
Showing 1-6 articles out of 6 articles from the selected issue
Original Paper
  • Noriko TAKAHASHI, Hiroshige NISHINA, Kotaro TAKAYAMA, Saori FUTAGAMI, ...
    2013 Volume 51 Issue 3 Pages 99-103
    Published: 2013
    Released: October 04, 2013
    JOURNALS FREE ACCESS
    Roof greening in warehouse is expected not only to improve the environment but also to reduce the heat island effects by evapotranspiration from the soil and plants. Effects of roof greening on room air temperature in warehouse and cooling load in summer were investigated using simulation model. In this study, two types of roof greening were assumed, roof greening with soil (greening type 1) and without soil (greening type 2). Our results showed that room air temperature in warehouse was decreased by 18.1°C for greening type 1 and 9.5°C for greening type 2 compared with no roof greening. In greening type 1, the room air temperature was decreased with increasing the coefficient of transpiration from the plants. The maximum room air temperature was decreased with increasing the light interception ratio and decrease in room air temperature with increasing light interception ratio in greening type 2 was larger than that in greening type 1. Daily cooling load with greening type 1 was lower than that with greening type 2. Electricity cost for air-conditioning in summer was reduced by 135 yen for greening type 1 and 63 yen for greening type 2 compared with that for no greening when set temperature for cooling was 26°C. These results suggested that roof greening with soil can maintain lower air temperature in warehouse and save more cooling load than that without soil due to the latent heat with evaporative cooling from the soil.
    Download PDF (395K)
  • Vali RASOOLI SHARABIAN, Noboru NOGUCHI, Kazunobu ISHI
    2013 Volume 51 Issue 3 Pages 105-112
    Published: 2013
    Released: October 04, 2013
    JOURNALS FREE ACCESS
    In order to select appropriate vegetation indices for winter wheat, field experiments with four levels of N-fertilizer (0, 30, 60, and 90 kg ha−1) in two repetitions were conducted for three years. Hyper-spectral reflectance data using a portable field spectroradiometer (351 to 2,500 nm) were recorded from 10 am to 2 pm under cloudless conditions at two different growth stages of winter wheat. All two-band and three-band combinations of several vegetation indices were subsequently calculated in an algorithm for determining linear regression analysis against SPAD value, protein content, and grain yield. R square matrices were used to make contour plots and 3-D scatters. Using overlaying in analysis tools of ArcMap the between first and second year results, a number of common hot spots with strong correlations were revealed. The selected hot spots were validated with the dataset of the third year to choose the best vegetation indices for crop variable estimations.
    Download PDF (798K)
  • Ken-ichi YOSHII, Mika FUKUOKA, Takuya KAWAMURA, Takashi IKEDA
    2013 Volume 51 Issue 3 Pages 113-120
    Published: 2013
    Released: October 04, 2013
    JOURNALS FREE ACCESS
    A gradient in sugar levels in watermelon (Citrullus lanatus (Thunb.) Matsum. et Nakai) fruits implies an osmotic pressure imbalance. The implied osmotic pressure gradient runs opposite to the direction of physical growth, which suggests counterintuitive water movement within the fruit. We conducted experiments to identify the factors that cause and maintain this pressure gradient by psychrometry and 1H nuclear magnetic resonance (NMR) imaging. We made simultaneous psychrometer and 1H NMR measurements of hydroponically grown watermelon fruits immediately after harvesting, and made microscopic observations at the center of the fruits. Psychrometry showed a large water potential gradient from the skin to the center. 1H NMR measurements of blocks of tissue showed no effect of cutting on measurements. The water status showed the same trend by both psychrometry and 1H NMR imaging. In support of this trend, NMR imaging and microscopic examination revealed the disappearance of xylem at the center of the fruits. 1H NMR images of segments of tissue could be combined into continuous detailed images. There is a clear water status gradient within watermelon fruits. NMR and microscope observations revealed possible mechanisms for this gradient in the form of septa and the disappearance of xylem tissue in watermelon fruits.
    Download PDF (763K)
  • Asafor Henry CHOTANGUI, Koji SUGAHARA, Yoichi TORIGOE
    2013 Volume 51 Issue 3 Pages 121-129
    Published: 2013
    Released: October 04, 2013
    JOURNALS FREE ACCESS
    The purpose of this study was to investigate the performance of a simple empirical model that was previously developed to support rational fertilizer management in upland farms in Japan. Statistical criteria and graphical displays were used to evaluate the capability of the soil nitrogen (N) balance estimation system to estimate nitrate-N (NO3-N) leaching. Long-term lysimeter experimental data of three Andosol-based cropping systems in Abashiri, Mito and Miyakonojo were used in this study. Input data included soil characteristics, crop properties, climatic data and evaluation period. Results showed good fitness (low relative root mean square error) and precision (R2=0.57, 0.93) in Abashiri and Mito, respectively. Simulated NO3-N leaching agreed with observed trends for all N management schemes at the three locations. Overestimations followed by underestimations in Miyakonojo affected the system's precision (R2=0.30), thereby exposing its weakness. Simulated soil residual N strongly correlated to crop uptake and simulated and observed leached nitrate-nitrogen in Abashiri and Mito. Monthly leaching estimates showed peaks in March to April, June to July and September to October demonstrating the system's usefulness as a tool for rational fertilizer management. A sensitivity analysis demonstrated the system's ability to respond to N input and output data. RRMSE and R2 for high nutrient-input treatments indicated the system's ability to estimate NO3-N leaching.
    Download PDF (411K)
  • Yuta SAITO, Hiroshi SHIMIZU, Hiroshi NAKASHIMA, Juro MIYASAKA, Katsuak ...
    2013 Volume 51 Issue 3 Pages 131-137
    Published: 2013
    Released: October 04, 2013
    JOURNALS FREE ACCESS
    Plant factories have been receiving attention recently as a new vegetable production system. However, the high cost of producing vegetables in plant factories is a problem. An effective irradiation method was investigated to reduce the use of electric energy for light. A combination of LEDs and condenser lenses was constructed with the goal of having most of the light absorbed by a plant. Fresh weight, stem length, and number of leaves of leaf lettuce were measured under 12 different distributions of photosynthetic photon flux density (PPFD) created by the combination of three types of condenser lenses with the Full Width Half Maximum (FWHM) angles of 7°, 13°, and 35° and four LED driving currents of 0.2, 0.3, 0.4, and 0.5 amperes (A). Growth of lettuce was influenced by the distribution of PPFD using the same electric current. The choice of lens increased the fresh weight by 18% under the relatively strong light intensities of 0.4 A and 0.5 A. The combination of an electric current of 0.4 A with a lens of FWHM angle 13° produced the most efficient growth from a growth efficiency point of view.
    Download PDF (360K)
  • Hiroki KOBAYAKAWA, Katsu IMAI
    2013 Volume 51 Issue 3 Pages 139-147
    Published: 2013
    Released: October 04, 2013
    JOURNALS FREE ACCESS
    This study was conducted to evaluate the role of salicylic acid (SA) on acute ozone (O3: 0, 0.1, and 0.3 cm3 m−3; O0, O0.1 and O0.3, respectively)-induced photosynthetic inhibition of paddy rice leaves given different atmospheric carbon dioxide concentrations (CO2: 400 and 800 cm3 m−3; C400 and C800, respectively). Salicylic acid solutions (0, 0.1, and 1 mM; S0, S0.1, and S1, respectively) were applied as a pretreatment one day before O3 exposure. Gas exchange, chlorophyll fluorescence, and ascorbic acid were measured immediately before (BE), immediately after (AE-0), and 1 d and 3 d after (AE-1, AE-3) 5-h O3 exposure. The photosynthesis-related parameters, total ascorbic acid, and redox state of ascorbic acid (RDS) were decreased by O3 exposure. The O3-induced reduction of PN, ascorbic acid content, and its RDS were ameliorated by C800. Salicylic acid ameliorated the O3-inhibition of net photosynthetic rate (PN) slightly, and O3-induced depletion of total ascorbic acid and RDS substantially. SA did not increase PN in non-treated leaves (O0 plants). However, O3 exposure elevated the level of endogenous SA. These results show that SA plays a vital role in the defense response to acute O3 exposure in paddy rice. Effects of SA on O3-inhibition of PSII and ascorbic acid content were unaffected by elevated CO2 (C800).
    Download PDF (312K)
feedback
Top