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    20 November 2018, Volume 39 Issue 11
    Estimating Surface Direct Radiation Effect of Aerosol Based on MODIS and AERONET Data
    ZHAO Jun-fang, XU Hui, KONG Xiang-na, GUO Jian-ping, XU Jing-wen, YU Wei-guo
    2018, 39(11):  693-701.  doi:10.3969/j.issn.1000-6362.2018.11.001
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    Under climate change, the research on the direct radiation effect of aerosol in high polluted areas is of great significance for atmospheric environment monitoring, climate change assessment and agricultural production distribution in these areas. In this paper, the direct radiation effects of aerosol from January 2001 to December 2016 were quantitatively evaluated in Beijing, Xianghe and Taihu three typical global aerosol monitoring network (AERONET) sites of China based on the observation data of AERONET and the surface albedo data of MODIS. 6S (Second Simulation of a Satellite Signal in the Solar) radiative transmission model was used. The results showed: (1) the PM2.5 mass concentration in three typical high pollution sites showed obvious seasonal variations, and the pollution was more serious in the autumn and in the winter than other season. In especial, the high values of PM2.5 mass concentration were mainly concentrated in January, February, November and December. (2)Compared with no aerosol, the interannual change of surface direct radiation caused by aerosol was obvious in each site. Affected by aerosol, the interannual change in daily average surface direct radiation in Beijing, Xianghe and Taihu stations was obviously increasing from 2001 to 2016. In especial, the maximum daily direct radiation was found in the Xianghe station (621.14W·m−2),followed by the Taihu station (743.29W·m−2) and the Beijing station (488.14W·m−2). (3) Affected by aerosol, the surface direct radiation in each station was reduced. Moreover, the effects of aerosol on the surface direct radiation in different stations were different. During the time of 2001−2016, the average surface direct radiation in Beijing, Taihu and Xianghe stations decreased by 32.29%, 24.01% and 15.07%, respectively. Among them, the aerosol had the greatest impact on the direct surface radiation of Beijing Station, followed by Taihu station and Xianghe station. (4) Over the recent 15 years, the aerosol surface radiation effect in Beijing,Xianghe and Taihu stations all increased.

    Coupling Effects of Water-Saving Irrigation and Shading Intensity on Growth and Development for Rice
    LI Rui, LOU Yun-sheng, ZHANG Zhen, MA Li, LI Jun
    2018, 39(11):  702-714.  doi:10.3969/j.issn.1000-6362.2018.11.002
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    A field experiment was conducted to reveal the coupling effects of water-saving irrigation and shading intensity on rice growth and phenological period. Irrigation was designed with 2 levels, conventional irrigation (F, flooding with 5cm water depth layer) and water-saving irrigation (W, wetting without water layer); shading intensity was set at 3 levels, control (CK, natural light source without shading), light shading (S1, single layer shading, photosynthetically active radiation decreased by 60%) and heavy shading (S2, double layer shading, photosynthetically active radiation decreased by 90%). Rice growth parameters were measured in main stages, tillering, jointing, heading, filling and maturing, which included plant height, leaf area index (LAI), chlorophyll content (SPAD value), and water content in single ear as well as canopy hyperspectral data. Using canopy hyperspectral data to extract the enhanced vegetation index (EVI) time series, heading date was predicted by denoising through spline interpolation and wavelet filtering. The results showed that with higher shading intensity, leaf area index and SPAD value decreased, and phenological periods delayed. Water-saving irrigation inhibited plant height and SPAD value of rice, promoted leaf area index under shading conditions. Water-saving irrigation advanced phenophase and shortened phenological periods of rice under shading conditions. Under the same shading conditions, the spectral reflectance on rice canopy was higher in water-saving irrigation (W) than that in conventional irrigation (F) at jointing stage and heading stage, but higher in conventional irrigation (F) than in water-saving irrigation (W) at filling stage and maturity stage. The denoised EVI time series were used to predict heading date in rice, with prediction accuracy being 97%, and extremely significant correlation (P < 0.01).

    Changes of Growth Stage for Spring Soybean in Jilin Province and Its Response to Climate Warming
    QIU Yi-xuan, MA Shu-qing, LI Xiu-fen
    2018, 39(11):  715-724.  doi:10.3969/j.issn.1000-6362.2018.11.003
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    Based on the soybean growth stages and climate data in 4 representative stations from 1981 to 2014 in Jilin Province, the change trends of main soybean growth stages and its relationship with climate warming were analyzed, the influence pattern of temperature on soybean growth rate was established. The results showed that the temporal and spatial variation of soybean growth in Jilin Province was obvious, the average sowing date of soybean was May 4, and the maturing date was September 24, the whole growth season of soybean was 143 days and the active accumulated temperature was 2640.8℃?d. The growth season of soybean delayed in eastern region of Jilin Province, the mean temperature and active accumulated temperature were both lower. The abrupt change of the mean temperature appeared in the 1990s in soybean production area of Jilin Province, the mean temperature during main growth season of soybean fluctuated at upward trend significantly (P<0.01), the mean temperature from May to September increased by 0.34℃•10y−1, and the mean temperature from seedling emergence to maturity increased by 0.43℃•10y−1. In the latest 34 years, the date of soybean sowing, emergence and third leaf was delayed significantly (P<0.05), but there was no significant change for soybean maturity date. The vegetative growth phase of soybean showed a more significant response to climate warming. The whole growth season decreased gradually (P<0.01). The soybean growth rate was positively correlated with mean temperature significantly (P<0.01), the soybean growth was accelerated with climate warming. During the whole growth season of spring soybean, if the mean temperature rose by 1℃, the soybean growth rate increased by 2.8%, and growth season decreased approximately 5.4 days.

    A Comparative Study on Forecast Model for Soybean Yield by Using Different Statistic Methods in Liaoning Province
    WANG He-ran, ZHANG Hui, WANG Ying, LI Jing, MI Na, WANG Ruo-nan, LI Lin-lin, DONG Wei, ZHANG Qi, SU Hang
    2018, 39(11):  725-738.  doi:10.3969/j.issn.1000-6362.2018.11.004
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    Two different dynamic forecast methods for soybean yield based on key meteorological factors and climatic suitability were established in this study. The key meteorological factors and climatic suitable index were calculated by daily meteorological data from 56 meteorological stations, soybean growth stage records of 5 key agrometeorological stations and yield data in Liaoning province from 1992 to 2016. The results showed that the key meteorological factors-based forecast model was suitable to forecast soybean yield on June 16, July 21, July 26, August 1, August 26 and September 16 (P<0.05), and the climatic suitability-based forecast model could be used for every 5 or 6 days from August 16 to October 1 (P<0.05) in Liaoning province. The average accuracies of return test of both models were higher than 83.0%. Compared with the key meteorological factors-based model, the climatic suitability-based model was stable, which indicated by smaller variation of average verified accuracy and average forecast test accuracy. From 1997 to 2016, both models could be applied in soybean yield tendency forecast, according to scoring criteria, core above zero reach up to 60% by the two models. In conclusion, the yield forecast models based on key meteorological factors and climatic suitability could meet the basic needs for agrometeorological services in Liaoning province. For soybean yield tendency forecasting, the method based on key meteorological factors should be preferred. In the normal years without severe meteorological disaster, the method on climatic suitability could be given priority to yield quantitative forecasting to reduce forecast times.

    Photosynthetic Responses of Different Grape Cultivars to Drought Stress and Their Recovery after Drought
    ZHU Yu-qing, YANG Zai-qiang
    2018, 39(11):  739-750.  doi:10.3969/j.issn.1000-6362.2018.11.005
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    In order to clarify the change of photosynthesis fluorescent parameters of grape leaves under drought stress, and their recovery under water treatment processing after different degree of drought stresses, taking the facility grape varieties “Kyoho” and “Summer Black” as test materials, authors conducted 5 different drought stress groups: T1 (drought stress 3d), T2 (drought stress 6d), T3 (drought stress 9d), T4 (drought stress 12d) and T5 (drought stress 15d), and taking the normal water treatment group as CK (relative moisture content of soil 70%? 80%). The results showed that the drought stress reduced photosynthetic parameters and fluorescence of grape leaf blades, and the amplitude of variation of Kyoho was larger than that of Summer Black. With 15d drought stress, photosynthetic parameter of Kyoho declined by 70%?90%, and Summer Black declined by 60%?80%. As for the fluorescence parameters in grape leaf blades, F0 increased significantly as the aggravation of drought stress, while qP, Fv/Fm, ETR, ΦPSⅡ decreased. Wherein, the ΦPSⅡ, qP, and ETR of Kyoho declined by 40.63%, 43.24%, and 57.71% respectively, while F0 increased by 48.27% under 15d drought stress. The ΦPSⅡ, qP and ETR of Summer Black declined by 26.38%, 40.00% and 59.69% respectively, while F0 increased by 50.19% under 15d drought stress. In terms of the recovery procedure after drought stress, the photosynthetic parameter recovery capability of Summer Black was greater than that of Kyoho under the comparatively low degree of stress (T1-T4), and the situation was opposite when the stress degree was high (T5). The difference of recovery level of fluorescence parameter in the two varieties was not significant.
    Effect of Low Temperature Treatment in Booting and Filling Stage on Yield Components and Quality of Main Rice Cultivars in Sanjiang Plain
    CHU Chun-yan,WANG Jin-dong,CHENG Yuan, ZHANG Yu, SUN Gui-yu
    2018, 39(11):  751-761.  doi:10.3969/j.issn.1000-6362.2018.11.006
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    Three main rice cultivars in Sanjiang Plain Longjing 29, Longjing31 and Longjing46 were selected and simulated low temperature stress at 16℃ by manual climatic box for 5 days to investigate the effect of rice cold tolerance at the booting, heading and filling stages on the yield components, milling quality, nutritional quality and RVA profile characteristics. The results showed that the seed setting rate, 1000-grain weight, brown rice rate, polished rice rate, whole milled rice rate and taste score of rice decreased and there was a significant difference compared with the control treatment after being treated by low temperature treatment during the booting stage, heading stage and filling stage (P < 0.05). The protein content increased significantly, and the amylose content decreased significantly at the booting and heading stage, and gradually increased during the filling stage. The final stage of filling was higher than the control treatment.The RVA profile characteristics increased or decreased compared with the control treatment due to the differences in varieties, but they both presented significant differences (P < 0.05). The low temperature stress had the greatest impact on rice yield, grinding quality and nutrient quality at booting stage, while the impact of low temperature stress to RVA profile characteristics was the greatest at filling stage, and there were significant differences among the three varieties (P < 0.05). Under low temperature stress, compared with the yield component of Longjing 46 were no significant difference except the 1000-grain weight compared with the CK at booting stage. Longjing 46 showed strong tolerance to low temperature. Low temperature had the least impact on the grinding quality and nutrient quality of Longjing 29 and RVA profile characteristics of Longjing 46. Rice production and cultivation, resistance breeding and certification of climate quality of rice in Sanjiang plain should comprehensively consider the quality indexes of main varieties, adopt appropriate measures of rice quality optimization cultivation during the period of booting-filling stage, and conduct climatic quality certification for rice according to the science of climate change.