Current issue

• 2021 Vol.37 No.25 Published:05 September 2021

  Study on the Migration, Transformation and Prediction Model of Cadmium in the Whole Growth Stage of Late Rice Yang Guohang, Li Qiong, He Lizhao, Gu Jing, Niu Jing, Zhang Haiou, Zheng Zijian, Zhao Zhen 2021, 37 (25):  1-10.  DOI: 10.11924/j.issn.1000-6850.casb2020-0680 Abstract + ( 338 )   HTML ( 7 )   PDF ( 1548KB )   ( 73 ) To better understand the migration, transformation and prediction model of cadmium (Cd) in the whole growth stage of late rice, we used soil-rice point-to-point data of Cd in field test in Wangcheng Changsha to study the differences of absorption, accumulation and distribution of Cd in different parts (root, stem and leaf, grain) of rice and its four typical growth stages (seedling stage, tillering stage, filling stage and mature stage). The results indicate that the Cd content and enrichment ability of each part in the same growth stage are all the roots> stems and leaves> grains, and the Cd content in roots are significantly higher than that in other parts, and there are significant differences in different growth stages, namely mature stage> filling stage> tillering stage> seedling stage. The transport capacity of Cd is soil root> root-stem and leaf> stem and leaf-grain> root-grain, most of the Cd in grain is from the transfer of the stem and leaf, and the transport capacity of Cd in tillering stage is significantly higher than that in other stages. The accumulation and distribution differences of Cd are stem and leaf> root> grain, and the tillering stage and mature stage are much higher than seedling stage and filling stage. The main factors affecting the Cd absorption are soil pH and available cadmium (ACd) content, pH has a negative effect and available cadmium has a positive effect, and the Cd content in stems and leaves of tillering stage is most affected by them, therefore it is the key stage to control Cd into grain. The pH and available cadmium in tillering stage could be used to predict Cd content of grains in mature stage, and the optimal prediction model is lgCdthe grain in maturity stage= 0.158- 0.099pHtillering stage+ 0.261lgACdtillering stage. The research results could provide a theoretical basis and data support for the risk assessment and controlling of soil Cd pollution in rice fields in Changzhutan area of China.

  Yield Response of Common Vetch and Maize to Intercropping and N-fertilizer Rate Han Zhongying, Zhao Cai, Hu Falong 2021, 37 (25):  11-16.  DOI: 10.11924/j.issn.1000-6850.casb2020-0708 Abstract + ( 191 )   HTML ( 9 )   PDF ( 1365KB )   ( 58 ) Investigating the yield response of common vetch and maize in single culture and intercropping to different N-fertilizer rates is important to optimize farming practices and improve crop yield. This field experiment was conducted in 2017, which focused on exploring the dry matter accumulation, yield components and yield response of maize and common vetch in single culture and intercropping system in Gansu Hexi oasis irrigation area under different N-fertilizer rates. The results showed that dry matter accumulation of common vetch in intercropping was increased by 44.0%, 36.7% and 37.2% compared with that of N0 (zero N), N1 (reduced N) and N2 (traditional N). Among various N-fertilizer treatments, N1 had the highest dry matter accumulation, which increased by 9.1% and 25.5% compared with N2 and N0 under intercropping, and by 9.4% and 32.1% under single culture. Dry matter accumulation of maize in intercropping increased by 23.3%, 22.5% and 23.0% compared with that of single culture under N0, N1 and N2. Also, N1 had the highest dry matter accumulation, which increased by 9.3% and 19.8% compared with that of N2 and N0 under intercropping, and by 9.9% and 20.7% under single culture. Compared with single culture, the pods number of common vetch and ears number of maize under intercropping were improved by 7.6% and 14.5%, and grain yield of the two crops increased by 34.9% and 27.0%. The path analysis revealed that the yield of common vetch was determined by pods number > grain weight > grain number, and that of maize was ears number > grain number > grain weight. Intercropping combined with N-fertilizer rate at 240 kg/hm2 could achieve relatively high grain yield, and it should be used as a suitable practice for maize-common vetch intercropping in Hexi irrigation area.

  Effects of Phosphorus on Nitrogen Absorption, Translocation and Utilization in Dryland Flax Xie Yaping, Niu Junyi, Wang Limin, Dang Zhao, Zhao Wei, Li Wenjuan, Qi Yanni, Wang Ping, Li Yue, Zhang Jianping 2021, 37 (25):  17-26.  DOI: 10.11924/j.issn.1000-6850.casb2020-0711 Abstract + ( 192 )   HTML ( 6 )   PDF ( 1357KB )   ( 40 ) This field study was conducted to assess the effects of phosphorus on nitrogen absorption, translocation as well as utilization in dryland flax. We set four phosphorus (P2O5) levels of 0, 45, 90 and 135 kg/hm2, planted two flax varieties (‘Lunxuan 2’ and ‘Dingya 22’) in 2017 and 2018 at Dingxi, and adopted a completely random block group design. The results showed that phosphorus had an influence on nitrogen absorption and translocation of the above ground parts and the physiological utilization efficiency of nitrogen in dryland flax, and the difference between the years was significant. Year, variety and phosphorus interaction showed significant impact on nitrogen absorption in the above ground parts at anthesis and maturity, nitrogen absorption and distribution rate in seeds at maturity, and total nitrogen translocation amount, translocation efficiency, rate of contribution and physiological utilization efficiency of stems, leaves and other parts. The application of phosphorus averagely increased nitrogen absorption in the above ground parts at anthesis and maturity by 76% and 82% respectively, nitrogen absorption and distribution rate in seeds at maturity by 127% and 25% respectively, and nitrogen translocation and translocation efficiency in stems and leaves and other parts by 556%, 102%, 237%, and 16% respectively compared with no application of phosphorus. The physiological utilization efficiency of nitrogen significantly increased with increased phosphorus rate of ‘Lunxuan 2’, however, physiological utilization efficiency of nitrogen of ‘Dingya 22’ showed no difference between 90 kg/hm2 and 135 kg/hm2. The correlation analysis indicated that the phosphorus application amount had significantly positive correlation with nitrogen absorption translation and utilization in dryland flax.

  Bibliometrics Analysis of Studies on Constructed Wetland Based on Web of Science Xu Yang, Wu Zhi, Liu Xiaorong, Chen Jinfeng, Han Qingbin, Liu Ping, Wang Jiayou, Wang Dairong 2021, 37 (25):  20-21.  DOI: 10.11924/j.issn.1000-6850.casb2021-0386 Abstract + ( 354 )   HTML ( 7 )   PDF ( 1521KB )   ( 59 ) The paper aims to understand the latest research progress, hot spots and development trends in the field of constructed wetlands at home and abroad, and to provide data basis and reference for relevant researchers. The literature related to constructed wetlands from 2000 to 2019 in the core database of Web of Science was used as the data source, we conducted a bibliometrics analysis with the package ‘bibliometrix’ in R. The results showed that the number of literature related to constructed wetlands generally increased during 2000 to 2019. The journal Ecological Engineering had the most publications in this study field. The most frequently cited article was published by Vymazal in Science of the Total Environment in 2007. China, USA and Spain were the top three countries in the world for the number of publications, and the Helmholtz Center for Environmental Research in Germany was the most prolific research institute. The removal of pollutants such as nitrogen and phosphorus and the performance of constructed wetlands have always been the hotspots of research in this field. The field of constructed wetland research is still in a rapid development stage.

  The Influence of Spatial Structure of Cyclobalanopsis glauca Forest on Understorey Regeneration Yi Xuan, Zhu Guangyu, Wang Zhuoyu, Zhou Genmiao, Bian Gengzhan, Zhang Yani, Huang Liang, Liu Wenjian 2021, 37 (25):  27-34.  DOI: 10.11924/j.issn.1000-6850.casb2021-0197 Abstract + ( 263 )   HTML ( 5 )   PDF ( 1679KB )   ( 47 ) Forest spatial structure has a significant influence on the regeneration of saplings. To clarify the key factors affecting the regeneration of saplings, the natural secondary forest of Cyclobalanopsis glauca forest was taken as the research object in Hunan Qingyang Lake State-owned Forest Farm. The density, tree height, ground diameter and crown width of saplings were measured, and the mixing degree, size ratio, opening index and aggregation index were calculated to represent forest spatial structure. The regeneration of saplings under the forest was evaluated and the correlation between them was explored by using the grey relational analysis method. The results show that there are 6 species of undergrowth regeneration saplings in 13 sample plots of C. glauca forest in Hunan Qingyang Lake State-owned Forest Farm, belonging to 4 families and 5 genera, which are C. glauca, Castanopsis sclerophylla, C. multinervis, Choerospondias axillaris, Dalbergia hupeana and Pinus massoniana. C. glauca is the dominant species in regeneration saplings, and the importance value of saplings is 63.09%. The spatial structure index and undergrowth regeneration index of each forest spatial structure of C. glauca are greater than 0.5, indicating a high correlation degree. Based on the mean correlation degree of all forest spatial structure indexes to undergrowth regeneration index, the order of influence on undergrowth regeneration is size ratio> openness> aggregation index> mixing degree, and size ratio has the most significant influence on undergrowth regeneration of C. glauca. Therefore, to promote undergrowth regeneration of natural secondary forests of C. glauca, we should adjust the size differentiation degree of trees, and consider the spatial distribution pattern of trees comprehensively.

  Optimization of Fertilizing Scheme for Fast-growing Plantation of Black Locust Clones Yu Zhenxu, Li Yifan, Qin Guanghua, Song Yumin, Qiao Yuling, Ma Ling 2021, 37 (25):  35-40.  DOI: 10.11924/j.issn.1000-6850.casb2020-0365 Abstract + ( 269 )   HTML ( 4 )   PDF ( 1283KB )   ( 42 ) Control test was used to optimize fertilizing scheme and to improve fertilizer utilization efficiency in the management of black locust plantation forest. Through three-factor quadratic orthogonal regression test, fertilizer was applied to the juvenile narrow-crown black locust fast-growing and high-yield plantation forest for three consecutive years in Minquan forest farm of Henan Province. The results showed that fertilization could significantly promote diameter growth, and increasing range of the two consecutive years could reach 186.67% and 47.30% respectively, the diameter growth of 3 years could reach 7.6 cm. Regression test showed that after three years, quadratic model and total model reached significant levels, and lack of fit test was being invalid, and fitting equation was becoming significant. Converting mode to treat data was failed, which proved the attempt completely impossible. Conclusion is drawn that it is effective to fit regression equation by three factors quadratic orthogonal regression test, and it is possible to find the optimal fertilization scheme of black locust plantations forest.

  Effects of Wood Vinegar on the Growth and Development of Acer truncatum Seedlings Wang Yaqian, Zhang Shangkun, Li Dongbing 2021, 37 (25):  41-46.  DOI: 10.11924/j.issn.1000-6850.casb2020-0703 Abstract + ( 236 )   HTML ( 5 )   PDF ( 1320KB )   ( 57 ) This study aims to elucidate the effect of wood vinegar on the growth and development of Acer truncatum seedlings, to determine the optimum concentration of wood vinegar for soil application and provide reference information for the efficient cultivation of A. truncatum. A. truncatum seedlings were cultivated in a light incubator, with wood vinegar diluted by water at 200, 400, 600, or 800 times being applied to the soil. Ultrapure water was applied for the control group. Seed germination and seedling growth were carefully recorded. The results showed that when wood vinegar was diluted 800 times, it had the most significant effects on the germination rate, fresh weight of seedlings, dry weight of seedlings, total chlorophyll content in leaves, POD activity, and CAT activity, giving a relative increase of 19.0%, 46.6%, 47.7%, 9.7%, 33.8%, 51.9%, respectively. The plant height was increased by 11.1% (41.5% under the condition of 200-fold dilution of wood vinegar). The MDA content in the leaves was very similar to the control group, but the SOD vitality dropped significantly by 46.8%. This study confirms that soil application of wood vinegar promotes seed germination and seedling growth of A. truncatum. After being properly diluted the wood vinegar is beneficial to seed germination, seedling growth and stress resistance.

  Effects of Container Nursery Substrates on the Growth of Phyllostachys bissetii Liu Xinghong, Zhang Wenxin, Huang Wenjiang, Ma Hailin, Pan Yadong, Liu Fangchun, Liu Cuilan, Yan Liping, Wu Dejun 2021, 37 (25):  47-51.  DOI: 10.11924/j.issn.1000-6850.casb2020-0310 Abstract + ( 182 )   HTML ( 4 )   PDF ( 1342KB )   ( 34 ) This study aims to screen out the high-qualified substrate for bamboo seedling. Taking Phyllostachys bissetii as trial material, a pot experiment was conducted with five different container nursery substrates composed of different proportions of peat, perlite and wormcast (CK, peat: perlite: wormcast=10:5:0; Q1, peat: perlite: wormcast=7:5:3; Q2, peat: perlite: wormcast=5:5:5; Q3, peat: perlite: wormcast=3:5:7; Q4, peat: perlite: wormcast=0:5:10), to determine the effects of different container nursery substrates on root length, biomass, and the contents of nitrogen, phosphorus and potassium, as well as the growth of ground diameter and plant height of P. bissetii. The results indicated that the indexes of the root length, the biomass and nitrogen content of aboveground and belowground, and root shoot ratio of P. bissetii cultivated with Q1 substrate all reached the maximum, which had statistically significant difference with other substrates. In the meantime, the number of branches and leaves of P. bissetii in the Q1 substrate was also the most. Furthermore, the ground diameter increased by 14.51%, 14.96%, 5.80% and 11.03% compared with that of CK, Q2, Q3 and Q4 respectively, and the plant height increased by 19.34%, 18.91%, 10.16% and 11.38% respectively. As a result, the container nursery substrate with the proportion of peat: perlite: wormcast of 7:5:3 is the most suitable for the growth of P. bissetii.

  The Forest Health Models in Guangxi Maoershan National Nature Reserve Tian Hongdeng, Gan Guojuan, Shen Wenhui, Tan Yibo, Zhu Hui, Tang Zhongxiang, Ye Jianping 2021, 37 (25):  52-57.  DOI: 10.11924/j.issn.1000-6850.casb2020-0516 Abstract + ( 277 )   HTML ( 6 )   PDF ( 2960KB )   ( 73 ) The purpose of the study is to analyze the current situation of forest health development in Maoershan National Nature Reserve and clarify its advantages, thus to put forward relevant development strategies on promoting the sustainable and healthy development of forest health. Combined with regional resource advantages, the establishment of diversified forest health models which have local characteristics was explored through literature retrieval method and field research method. The results show that there is a unique potential for forest health in this study area, including superior location and geographical condition, pleasant climate-environmental condition, abundant forest resource storage, unique national cultural resource, and huge potential forest health market. According to its resource characteristics, six typical models of forest health are established, including low mountain-bamboo forest health model, high mountain-forest health model, forest-oxygen bar health model, forest-flower health model, forest-river health model and forest-wetland health model. Forest health products comprise specialty food, ethnic medicine products, sports products, cultural products, health science popularization education and so on. It is suggested that biodiversity and ethnic cultural characteristics should be the key development elements of forest health in Maoershan National Nature Reserve in the future．

  Genetic Research of Pericarp Color Traits of Luffa cylindrica Huang Shuping, Tan Jie, Chen Xia, Zhang Hongyuan, Zhang Min 2021, 37 (25):  58-63.  DOI: 10.11924/j.issn.1000-6850.casb2020-0689 Abstract + ( 233 )   HTML ( 5 )   PDF ( 1732KB )   ( 59 ) This study conducted the genetic analysis of the pericarp color of Luffa cylindrica, aiming to provide a theoretical basis for controlling gene discovery of pericarp color traits of L. cylindrica and improving exterior quality of L. cylindrica. The genetic population including P1, P2, F1, F2, B1 and B2 were generated by using green-pericarp line YX014 and white-pericarp line LJ-01 as the parents. The research adopted visual means to classify the pericarp color traits of L. cylindrica on each individual plant in six genetic populations. The mixed major gene plus poly-gene inheritance model was used to analyze the inheredity of L. cylindrica pericarp color traits. The results showed the inheritance of pericarp color traits of L. cylindrica were controlled by two major genes and accorded with the model of additive-dominant-epistasis (model B-1). The heritability of major gene had higher value in B1, B2 and F2 population, which reached 96.4%, 99.1% and 99.4%, respectively. In addition, the additive effects of the two major genes were -2.50 and 0.00, and the dominance effects of the two major genes were 0.50 and 0.48 respectively. It indicated that the additive effect of the first pair gene was dominant and negative, and the dominance effects of the two major genes were relatively equal. The heritability of major genes controlling the pericarp color of L. cylindrica was relatively high. It showed that the genetic improvement of L. cylindrica fruit pericarp color should be carried out in earlier generation of separation.

  Effects of Simulated Acid Rain Stress on the Germination Characteristics of Lycium ruthenicum Seeds Nie Bilin, Lv Haiying, Rumanam Nigmat, Sabrinisa Merzat 2021, 37 (25):  64-70.  DOI: 10.11924/j.issn.1000-6850.casb2020-0706 Abstract + ( 205 )   HTML ( 4 )   PDF ( 1375KB )   ( 43 ) To understand the influence of acid rain stress on the germination characteristics of Lycium ruthenicum seeds, we used to the paper germination experiment to study the germination percentage (GP), relative germination percentage (RGP), germination rate (GR), relative germination rate (RGR), germination index (GI), relative germination index (RGI), vitality index (VI), relative vitality index (RVI), length of radicle (LR), length of germ (LG), radicle to germ ratio (RTGR), average germination time (AGT), heteromorphic germination percentage (HGP), and relative acid damage rate (RADR) of L. ruthenicum seeds under different degrees of simulated acid rain stress. The results showed that the simulated acid rain stress had no obvious influence on the germination indexes of L. ruthenicum seeds at pH 5, and shortened the seed AGT to a certain extent; pH 4 had no significant effect on the indexes of L. ruthenicum seeds’ GP, RGP, GR, RGR, GI, RGI, VI, RVI, but HGP and RADR increased significantly; pH 3 and pH 2 suppressed the seeds of L. ruthenicum germination obviously. The study indicates that a moderately acidic environment is more suitable for the germination of L. ruthenicum. In the actual planting practice, this feature can be used to shorten the seedling time of L. ruthenicum.

  The Aroma Components Analysis of Rosa odorata var. erubescens and Its Application in Urban Gardens Wang Hui, Zhu Jijun, Feng Shucheng 2021, 37 (25):  71-75.  DOI: 10.11924/j.issn.1000-6850.casb2021-0210 Abstract + ( 341 )   HTML ( 4 )   PDF ( 1323KB )   ( 38 ) Rosa odorata var. erubescens is the famous ancient climbing rose. It is found that R. odorata var. erubescens in Shanghai has good adaptability through early introduction. For further development and utilization, the aromaticity is mainly studied in this research. Stir Bar Sorptive Extraction-Thermal Desorption (SBSE-TD) combined with Gas Chromatography-Mass Spectrometer(GC-MS) was used to extract and analyze the aroma components of fresh flower. It is concluded through components analysis that the main aroma component is 3,5-dimethoxytoluene, and then 3-hexenyl acetate, caryophyllene, geraniol. The aroma type is tea scent type represented by 3,5-dimethoxytoluene, with faint scent note. Meanwhile, 3,5-dimethoxytoluene has unique calming effect. R. odorata var. erubescens has a broad application prospect in the construction of ornamental garden and health care garden.

  Effects of Water and Fertilizer Coupling on Growth and Quality of Glehnia littoralis in Rapid Growth Period Guo Yandong, Fang Hailing, Tang Xingli, Zhou Yifeng, Zhang Mingxia 2021, 37 (25):  76-84.  DOI: 10.11924/j.issn.1000-6850.casb2020-0660 Abstract + ( 255 )   HTML ( 3 )   PDF ( 1367KB )   ( 47 ) The paper aims to select the appropriate amount of fertilizer and irrigation of Glehnia littoralis in coastal saline alkali land, reduce the loss of nitrogen and improve the efficiency of water and fertilizer utilization and standardize the planting of G. littoralis. The effects of water and fertilizer coupling on plant height, antioxidant enzyme activity index, osmoregulation substances and active components of G. littoralis in rapid growth period were studied, and the best combination of water and fertilizer coupling application was selected and verified by field experiment. The results show that in the whole growth process of G. littoralis, the plant height increased the fastest from the middle of June to early August; water and fertilizer coupling had a significant effect on plant growth of G. littoralis; under the condition of sufficient water, the plant height of G. littoralis could be significantly increased by applying fertilizer. Under the condition of water stress, the activities of SOD, CAT and POD in the leaves of G. littoralis increased with the appropriate application of nitrogen fertilizer, while those in the leaves of G. littoralis decreased with the increase of soil water content at the same fertilization amount; the activities of SOD, CAT and POD were the highest on 40 d (W2F3), 40 d (W2F3), and 60 d (W3F2), which were 38.246, 89.761 and 85.222 U/(g·FW), respectively. Under the same water condition, the contents of soluble sugar, soluble protein and free proline in leaves increased with the increase of fertilizer application amount; under the same fertilization condition, those in leaves decreased with the increase of soil water content; the soluble sugar content of W2F3 (relative soil water content of 60%-70%, and fertilizer amount of 240-360 kg/hm2) treatment group was 26.6% higher than that of W2F1 (relative soil water content of 60%-70%, and fertilizer amount of 120-180 kg/hm2) treatment group, soluble protein content of W2F2 (relative soil water content of 60%-70%, and fertilizer amount of 180-270 kg/hm2) treatment group was 47.11%-90.47% higher than that of W2F1 treatment group, and free proline content of W2F3 treatment group was 11.93%-36.95% higher than that of W2F1 treatment group. Moderate and mild water stress coupled with appropriate nitrogen and potassium nutrition could greatly stimulate the synthesis of coumarins in G. littoralis, in which, the total content of coumarins in W2F2 treatment group was the highest (0.011%). The comprehensive study shows that under mild and moderate water stress condition, the application of N/K fertilizer is beneficial to improving antioxidant enzyme activity and accumulating osmoregulation substances and coumarins, which is very important for plant growth under abiotic stress.

  Evaluation of Water Environmental Characteristics and Eutrophication of Songya Lake Wetland Li Qiaoyun, Liao Juyang, Xu Wen, Liu Yan, Liao Peng, Wu Linshi, Song Yin, Wang Ling, Zhang Juan, Huang Yaqi, Tan Zhihu 2021, 37 (25):  85-91.  DOI: 10.11924/j.issn.1000-6850.casb2020-0696 Abstract + ( 438 )   HTML ( 8 )   PDF ( 1438KB )   ( 58 ) Based on the monthly monitoring data of five samples of water quality in Songya Lake National Wetland Park from June 2018 to May 2019, the spatial and temporal distribution characteristics of water quality in Songya Lake Wetland were analyzed, and the eutrophication status of water quality in this area was evaluated by the modified Carlson trophic state index (TSI). The results showed that: (1) the average content of dissolved oxygen in Songya Lake Wetland was 8.93 mg/L, which was in the oxygen-rich state, and the average pH was 8.2, which was basically weakly alkaline; (2) the average concentration of total nitrogen and total phosphorus was 0.98 mg/L and 0.062 mg/L, respectively, the variation trend of total nitrogen was basically the same as that of ammonia nitrogen, presenting a seasonal variation trend of higher in summer and lower in winter, and there was a large difference in chlorophyll-a concentration among the sampling points; (3) there were differences of the eutrophication status of water quality in the five sampling sites of Songya Lake, the degree of eutrophication from light to heavy was: 2# water management area B< 3# water management area C< 1# wetland water outlet < 4# Reed Square< 5# lake central island, sample 2# showed middle nutrition, while the rest were eutrophication; (4) the seasonal change characteristics of eutrophication status of wetland water quality in Songya Lake were: summer> autumn> winter> spring, and the difference of comprehensive nutritional status index in four seasons was not obvious (P<0.05); (5) the comprehensive nutritional status index of Songya Lake wetland was significantly and positively correlated with DO, pH and TP (P<0.01), and significantly and negatively correlated with Chla (P<0.05), but not with TP and NH3-N.

  The Combination of Salt Water Treatment and Precision Irrigation: Advantage Analysis Ren Yujie, Li Junlin, Wang Xiangyu, Zhou Xinguo, Guo Hong’en 2021, 37 (25):  92-96.  DOI: 10.11924/j.issn.1000-6850.casb2020-0723 Abstract + ( 230 )   HTML ( 5 )   PDF ( 1222KB )   ( 59 ) Salt water desalination technology is the most reasonable way to develop and utilize marine resources. This article describes the harm of soil salinization caused by direct irrigation with saline water. It outlines the significance of salt water treatment and precision irrigation, and introduces the brackish water desalination process and precision irrigation process. Meanwhile, this paper proposes a combination of brackish water treatment and precision irrigation and discusses the development trend of salt water desalination and precision irrigation. The study analyzes the two major factors of energy and technology that restrict the development of salt water desalination technology, and concludes that water-saving irrigation technology will integrate remote irrigation management and comprehensive control analysis in the future, which can truly achieve intelligent irrigation management. The combination of solar technology and nanofiltration technology will have broad market prospects, and materials such as nanoparticle membranes and photothermal conversion carbon fibers will be the hot spots of seawater desalination research. Therefore, the combination of salt water desalination technology and precision irrigation will greatly improve the resource utilization efficiency and the soil environment, which will be more in line with the future development trend of ecological technology.

  The Recycling and Reutilization Capacity of Landscaping Waste in Xi’an: Current Situation and Countermeasures Wang Ruiying 2021, 37 (25):  97-102.  DOI: 10.11924/j.issn.1000-6850.casb2020-0722 Abstract + ( 192 )   HTML ( 3 )   PDF ( 1147KB )   ( 40 ) At present, lack of landscaping waste recycling capacity in Xi’an is not only a waste of resources, but also the disadvantage over the protection on urban ecological environment. The purpose of this study is to understand the current situation on the reuse of landscaping waste in Xi’an, and put forward countermeasures for improving the recycling capacity of landscaping waste. This paper summarizes the experience of landscaping waste recycling at home and abroad, as well as the current situation of Xi’an through collecting the information and practice. In some developed countries and first-tier cities of China, the reutilization rate of greening waste is high and the development is mature, which has the support from policy, management, economy and propaganda. There are two ways to deal with landscaping waste in Xi’an: landfill and transfer and clearing. At present, only the small scale of reutilization practice has been carried out in two pilot areas, and the utilization of resource is still in the trial period. It has not been carried out in the whole city. According to the current situation of landscaping waste reutilization in Xi’an, this paper proposes suggestions to promote the reutilization capacity of landscaping waste from four aspects: policy guarantee, implementation of publicity, clearly defined authority and economic support. This study also puts forward measures to further promote the reutilization capacity of landscaping waste for the construction of ecological civilization in Xi’an.

  The Difference of Soil Nutrient Content in the Middle and Upper Reaches of Niyang River Basin of Tibet Ma Heping, Qu Xingle, Wang Jianke, Song Xiaoguang 2021, 37 (25):  103-108.  DOI: 10.11924/j.issn.1000-6850.casb2020-0685 Abstract + ( 250 )   HTML ( 7 )   PDF ( 1240KB )   ( 52 ) To study the soil nutrients in the middle and upper reaches of the Niyang river basin of Tibet and explore the spatial variability and distribution characteristics of soil nutrients, 216 soil samples (0-10, 10-20 and 20-30 cm) were taken by standard sampling method in the cultivated land, grass land and forest land, and the content of total nitrogen, alkali-hydrolyzed nitrogen, total potassium, available potassium, total phosphorus, available phosphorus and soil organic matter were determined. The results show that the content of soil organic matter, total nitrogen and alkaline hydrolysis nitrogen in the study area have an order of forest land> grass land>cultivated land, and there are significant differences among the three (P<0.05). There is no significant difference in total potassium content between grass land and forest land, and the available potassium content is forest land> grass land>cultivated land. Under different land use types, the distribution of total nutrients and available nutrients in the soil show certain surface clustering, the content of total nutrients and available nutrients in the soil at the depth of 0-10 cm is significantly higher than that of 10-20 cm and 20-30 cm and the three have significant differences (P<0.05). The average content of alkaly-hydrolyzed nitrogen in the forestland is the highest and that of cultivated land is the lowest in the study area. The average content of available phosphorus in cultivated land (19.47 mg/kg) is significantly higher than that in grass land (5.73 mg/kg) and forest land (5.19 mg/kg). In conclusion, long-term vegetation restoration can improve soil quality in the upper and middle reaches of Niyang river basin, and the study could provide basic support for improving the soil effect in the area.

  Climate Suitability Model of Citrus in Guangxi Liu Wu, Mo Jiayao, Li Zheng, Wang Jiandong, Zheng Chuanwei, Zhang Lei 2021, 37 (25):  109-114.  DOI: 10.11924/j.issn.1000-6850.casb2020-0634 Abstract + ( 278 )   HTML ( 11 )   PDF ( 3152KB )   ( 88 ) To establish a daily scale suitability model of temperature, precipitation, sunshine and comprehensive elements in Guangxi, and apply it to the classification of Citrus climate suitability grade and the analysis of the temporal and spatial distribution characteristics of climate suitability over the years. Based on the daily meteorological data of 87 national automatic weather stations in Guangxi from 1961 to 2018 and the climate habit of Citrus growth, the fuzzy mathematical method was used to establish the model, and the model was verified by using the abnormal weather in typical years and stages. The results show that: the regression fitting effect of daily meteorological elements of the model is good, and the determination coefficient is above 0.89; the classification method of suitability index of each element is reasonable, and most areas of Guangxi are suitable for Citrus planting, which is in line with the actual situation. The scale of the model is fine, and the quantitative evaluation has good effect; it could better describe the abnormal weather changes of Citrus climate suitability with seasons and stages, such as extreme high temperature, low temperature, drought, rainstorm, etc.; the spatial distribution characteristics of meteorological elements’ suitability of Citrus in Guangxi are obviously affected by regional climate, the heat condition is sufficient or even too much, while precipitation and sunshine are insufficient in some areas. Therefore, more consideration should be given to precipitation and sunshine in choosing Citrus planting areas in Guangxi.

  Green Control Measures of Weeds in Wheat Field in the Yellow River Irrigation Area of Hetao Wen Aiqing, Zhang Jiancheng, Yang Lei, Liu Jing 2021, 37 (25):  115-120.  DOI: 10.11924/j.issn.1000-6850.casb2020-0712 Abstract + ( 218 )   HTML ( 4 )   PDF ( 1693KB )   ( 37 ) To solve the problem of green prevention and control of weeds in wheat field, based on the observation of the competition between wheat and weeds in the wheat field of the Yellow River irrigation area of Hetao, an experiment was conducted to determine the effects of green control measures and wheat yields of different wheat varieties under different planting densities, organic fertilizers, tillage times and mulching methods. The results showed that the weeds unearthed more than 10 days later than wheat in wheat fields damaged by Chenopodium album, Amaranthus hypochondriacus and Echinochloa crusgalli. Weeds were mainly distributed between rows (holes), and the number of plants accounted for 66.6% (planting in drill) and 97.6% (hole seeding) respectively. The growth of weeds in rows (holes) was relatively weak, and the fresh weight of individual plant was lower than that between rows (holes) by 39.3% to 41.9%, the effect of ecological weed control was obvious in the early stage of wheat growth. Among the green weed control measures, except the insignificant difference in the effect of varieties and planting densities on weed control, the other measures had obvious weed control effects. Comprehensive comparison showed that black mulching full film mulching hole seeding, conventional film mulching hole seeding, increasing the number of tillage and organic fertilizer without weed seed pollution had the control effects of the plants’ number of 82.3%, 71.7%, 22.0%, 8.6%, respectively, and their fresh weight control effects were 98.0%, 97.1%, 23.9%, 9.6%, respectively. Black mulching full film mulching hole seeding, conventional film mulching hole seeding, and increasing the number of tillage increased wheat yield by 69.4%, 56.4%, and 21.1% respectively, which could realize the purpose of mechanized green grass control of organic wheat production and low-cost, high-yield and large-scale production.

  Control Effect and Safety of Pendimethalin-pyroxasulfone 27% EC Against Annual Weeds in Cotton Field Li Qi, Guo Wenlei, Meng Qi, Yu Jinping, Liu Yixue, Zhang Wei 2021, 37 (25):  121-124.  DOI: 10.11924/j.issn.1000-6850.casb2020-0716 Abstract + ( 320 )   HTML ( 4 )   PDF ( 1262KB )   ( 55 ) The study aims to determine the control effect and safety of pendimethalin-pyroxasulfone 27% EC soil sealing treatment on annual weeds in cotton field. Random group test design was conducted in the field pharmacodynamic experiment. The results showed that: pendimethalin-pyroxasulfone 27% EC had excellent control effect on main weeds of cotton such as Digitaria sanguinalis, Eleusine indica, Porbulaea oleracea and Amaranthus refroflexus. 40 days after treatments, the average fresh weight control effects were 86.1%, 91.7%, 96.7% and 99.3% under the effective ingredient dosage of 607.5, 810, 1012.5 and 1620 g a.i./hm2 respectively, and the yield increase rate of cotton was 26.04%-28.87%. Thus, pendimethalin-pyroxasulfone 27% EC could be sprayed to control weeds in cotton field, which is safe to cotton, and the recommended dosage is 607.5-1012.5 g a.i./hm2.

  Biological Characteristics of Pseudomonas argentinensis Causing Fruit Streak Disease on Pepper and Screening of Bactericides Zhang Luhui, Zhao Zhiqiang, Zhao Quanxin, Guo Qingyuan 2021, 37 (25):  125-131.  DOI: 10.11924/j.issn.1000-6850.casb2021-0314 Abstract + ( 257 )   HTML ( 4 )   PDF ( 1346KB )   ( 69 ) The biological characteristics of the bacterial fruit streak pathogens of pepper were studied and the pathogens were screened for indoor agents with the aim of providing a basis for research on disease patterns and disease control in field. The growth rate of the pathogenic bacteria at different temperature, pH and NaCl concentrations were determined by UV spectrophotometer assay. The indoor pharmaceutical screening test for the pathogenic bacteria was conducted using the filter paper sheet inhibition circle method. The results showed that the optimum growth temperature for the bacterial fruit spot of pepper was 28℃, the optimum pH was 7.0 and the salt tolerance of the pathogen was 12%. 18 test agents were used in the recommended dosage range, and four agents, namely tetramycin, ethyl alliin, 77% Shishin and chlorobromoisocyanuric acid, were effective against the pathogen. The EC50 value of tetramycin was 11.75 mg/L, which was stronger than the other three agents, so tetramycin could be used as the first choice of field control agents.

  Report on Population Dynamics of Aphis gossypii and Pesticide Efficacy Trial in Watermelon and Muskmelon Greenhouses in Liaoning Zhong Tao, Fan Weiyan, Sun Baixin, Xu Guoqing 2021, 37 (25):  132-137.  DOI: 10.11924/j.issn.1000-6850.casb2020-0787 Abstract + ( 231 )   HTML ( 2 )   PDF ( 1359KB )   ( 37 ) To understand the occurrence dynamics of Aphis gossypii, and improve a pesticide-reduction technology against aphids, we carried out monitoring, investigation and trials in the watermelon and muskmelon greenhouses of Liaoning Province. Yellow sticky boards were applied to monitor the occurrence dynamics of A. gossypii in the greenhouses, and systematic investigations and pesticide efficacy trials with two reagents mixed were implemented. The results showed that the peak of winged aphids occurred in early-March in muskmelon cultivar ‘Cuibao’ greenhouses of Datun town, Beizhen City, and the peak of total aphids was in the end of February; the winged aphids reached peak in mid-May in watermelon cultivar ‘Tianwang’ greenhouses of Xiongyue town, Yingkou City, and the peak of total aphids was in early-May; the peak of winged aphids occurred in late-May in watermelon cultivar ‘Tianwang’ greenhouses of Dapu Mongolian town, Fengcheng City, and the peak of total aphids was in mid-May. Compared with the control, the new type high-fat membrane powder could significantly improve the control effect of 25% thiamethoxam water dispersible granule (WG) against A. gossypii, and the control effect after 14 days’ treatment could reach 97.0%. The critical period for the control and prevention of A. gossypii in muskmelon cultivar ‘Cuibao’ greenhouses and watermelon cultivar ‘Tianwang’ greenhouses is late-February and early and mid-May respectively, which could achieve good efficacy and have low cost.

  Status Quo and Development Trend of Agriculture Remote Sensing Technology Application in China Wang Limin, Liu Jia, Ji Fuhua 2021, 37 (25):  138-143.  DOI: 10.11924/j.issn.1000-6850.casb20190700361 Abstract + ( 631 )   HTML ( 26 )   PDF ( 1094KB )   ( 139 ) The paper reviews the status quo of the agriculture remote sensing technology application in China, and explores its development trends and deficiencies, aiming to provide a reference frame for decision-making on agricultural policies of China. By reviewing and summarizing literatures and policies of the past and by comparing the experiences at home and abroad, the paper sums up the significance, application level, development trends of agriculture remote sensing technology application, and makes related proposals. Under the technical support of remote sensing (RS), geographic information system (GIS), global positioning system (GPS), China shows urgent demand on agriculture remote sensing technologies, which are widely applied in the country. Meanwhile, the country has made significant progress in agriculture remote sensing technology application, whose development is featured with fundamentality, integrity, and systematicness. Compared with the advanced level in the world, agriculture remote sensing technology application in China still lags behind, it is necessary to focus on basic studies, intensify the application universality of key technologies, reinforce macro-planning at national level, so as to further improve the application of agriculture remote sensing technologies and the agricultural digitization of China.

  Status Quo of Digitalization Development of University Journals Concerning Agriculture in China Li Juan 2021, 37 (25):  150-156.  DOI: 10.11924/j.issn.1000-6850.casb2021-0226 Abstract + ( 166 )   HTML ( 4 )   PDF ( 1296KB )   ( 105 ) This study was conducted to discover the status quo of the digitalization development of university journals concerning agriculture in China, and to find out their differences and deficiencies of the digitalization development by comparison, aiming to analyze their overall development level and existing problems as well as put forward suggestions. Altogether 33 university journals concerning agriculture in China were investigated, which were also included in Chinese S&T Journal Citaton Reports (Natural Science) (2018 Edition) based on Wanfang database. Statistical methods of network survey were adopted on their digitalization construction. Results show as follows: under the trend of digital publishing development, the construction of value-added services of 33 university journals concerning agriculture in China has made some progress. The websites of the journals and their online editing systems have been basically popularized. The online publication, back publication browsing and online first of the journals have achieved some results. Their WeChat official accounts, RSS subscriptions, and E-mail alerts are under construction. However, there are still existing problems, such as the uneven construction of the websites, less service content, poor service level and insufficient talent team construction. It is suggested that the digitalization development of university journals concerning agriculture could be improved by increasing the capital investment, strengthening the journal website construction, integrating the journal resources and enhancing the digitalization development, as well as reinforcing the construction of digital publishing talent teams, and assisting the construction of university journals concerning agriculture through the first-class discipline development.

  Credit Risk Assessment of Farmer Loans: Based on CFPS2018 Data Liang Weisen, Fang Wei 2021, 37 (25):  157-164.  DOI: 10.11924/j.issn.1000-6850.casb2020-0572 Abstract + ( 308 )   HTML ( 4 )   PDF ( 1267KB )   ( 51 ) The aim of the study is to improve the accuracy of credit risk measurement of farmer loans, reduce the non-performing rate of banks’ agricultural loans and promote the bank's credit coverage to farmers. We selected default indicators from the four aspects of householder characteristics, assets and liabilities, income and expenditure, and willingness to repay, and used a combination of factor analysis and Logistic regression to build the credit risk assessment model for farmer loans. The empirical analysis took CFPS2018 data as a sample. The asset status of farmers was the most important factor affecting loan default, and the asset-liability ratio was positively correlated with the credit risk of loans. The more households spend on consumption, the more likely their loans will default. Recognition of trust is an important factor, the higher the trust of farmers in cooperation with others, the lower the risk of default. Moreover, the prediction accuracy of the constructed model exceeded 90%, which was universally applicable. We encourage qualified rural small and medium-sized banks to implement internal credit risk rating to improve the credit coverage of farmers. At the same time, banks should strengthen related supporting constructions, such as optimizing the risk organization structure, improving the risk management system, and building the risk control talent team.