Current issue

• 2023 Vol.39 No.25 Published:05 September 2023

  Effects of Different Nitrogen Application Levels on Dry Matter Accumulation and Distribution in Maize with Density Tolerance and Suitable Machine Harvesting LAN Huiqing, ZHANG Xiangqian, CHENG Yuchen, SHI Jingjing, CHEN Xuanyi, BU Hengtong, BAI Dongxing, LU Zhanyuan, LIU Yajie, CHEN Lirong 2023, 39 (25):  1-10.  DOI: 10.11924/j.issn.1000-6850.casb2023-0126 Abstract + ( 169 )   HTML ( 12 )   PDF ( 1246KB )   ( 76 ) The study of the effect of nitrogen application level on the dry matter accumulation in maize with high density tolerance and suitable machine harvesting is of great significance for the selection of suitable nitrogen application level and yield formation of maize. Based on the long-term localization experiment of nitrogen fertilizer conducted by the Academy of Agriculture and Animal Husbandry Sciences of Inner Mongolia Autonomous Region in 2018, maize ‘Guangde 5’ was used as the test material, and six nitrogen application levels were set, including 0 kg/hm2 (N0), 120 kg/hm2 (N8), 180 kg/hm2 (N12), 240 kg/hm2 (N16), 300 kg/hm2 (N20) and 360 kg/hm2 (N24). Dry matter accumulation and distribution ratio of different organs at seedling stage, jointing stage, trumpet stage, tasseling to spinning stage, grout stage and mature stage were analyzed, and the dry matter transport rule after flowering (tasseling to spinning stage to mature stage) was clarified. The results showed that: (1) dry matter accumulation and yield increased with the increase of N application rate between 0-240 kg/hm2, but decreased with the increase of N application rate when N application rate exceeded 240 kg/hm2, especially after the large flare stage. (2) The dry matter accumulation of different treatments conformed to the Logistic equation, the application rate of nitrogen fertilizer had significant effect on dry matter accumulation rate and promoted the dry matter accumulation peak earlier. (3) The distribution of maize dry matter in various organs changed with the development of the growth period, nitrogen application was beneficial to the transfer of dry matter from vegetative organs to grains in late growth period and promoted the development and formation of grains. (4) A comprehensive comparison of the 2-year data showed that the yield of N20 (2020) and N16 (2021) treated with nitrogen was higher than that of other nitrogen applications. They were 4.35%-45.50% and 0.57%-57.19%, respectively. Based on the analysis of yield, dry matter accumulation, distribution and transport of organs, the optimal nitrogen application rate of maize is 240 kg/hm2.

  Effects of Different Nitrogen Rates and Organic Fertilizers on Growth, Yield and Quality of Flue-cured Tobacco in Low Fertility Soil ZHAO Fang, ZHA Hongbo, CHEN Hua, YANG Junzhang, GAO Shunbo, GUI Longfeng, XIAO Jiafan, ZHAO Shengchun, XIA Lei, XU Bin, LI Wenlu, HU Guangjun 2023, 39 (25):  11-15.  DOI: 10.11924/j.issn.1000-6850.casb2022-0754 Abstract + ( 120 )   HTML ( 8 )   PDF ( 1325KB )   ( 47 ) To study the effects of different nitrogen rates and organic fertilizers on the growth, yield and quality of flue-cured tobacco in low-fertility soil, the field experiment was conducted with ‘Yunyan 87’. The results showed that the growth and development of flue-cured tobacco plants were promoted with the increase of nitrogen application rate in a certain range, and the yield and quality of flue-cured tobacco were formed. However, the disease was aggravated and the quality of flue-cured tobacco tended to decrease when the amount of pure nitrogen increased to 126 kg/hm2. The agronomic and economic characters of the treatment of adding decomposed farm manure were better than that of adding commercial organic fertilizer. In summary, according to the comprehensive analysis of field performance, agronomic traits, stress resistance and economic indicators, T4 (treatment 1 fertilization + decomposed farm manure 16500 kg/hm2) treatment was the best, followed by T5 (treatment 1 fertilization + commercial organic fertilizer 1500 kg/hm2) treatment, and T2 (increasing 10% of local conventional fertilizer, applying 115.5 kg/hm2 of nitrogen) treatment, T3 (increasing 20% of local conventional fertilizer, applying 126 kg/hm2 of nitrogen) and T1 (conventional control, applying 105 kg/hm2 of nitrogen) treatments were worse, and T6 (no fertilizer control) treatment was the worst.

  Correlation Analysis of Camellia oleifera Yield and Main Fruit Economic Character JIANG Zepeng, CAI Ya, ZHANG Xing, LIANG Bin, WANG Dongxue 2023, 39 (25):  16-20.  DOI: 10.11924/j.issn.1000-6850.casb2022-0752 Abstract + ( 126 )   HTML ( 7 )   PDF ( 1171KB )   ( 39 ) In this study, the relationship between the yield of Camellia oleifera and the main economic characters of the fruit was researched, as well as the correlation among the main economic characters, to provide scientific basis for the breeding of improved varieties of C. oleifera. As experimental objects, the yield and main economic characters of 35 clones’ fruit were measured for three consecutive years, to evaluate the relationship between the trait indicators by correlation analysis and regression analysis. The results showed that: in addition to single fruit weight, major economic traits such as single seed weight, rate of fresh seed, oil rate of kernel and fruit had significant differences in different years. The variation degree of major economic traits of fruits from high to low was in the order of oil rate of kernel> rate of fresh seed> single seed weight= oil rate of fruit> single fruit weight. There was an antagonistic relationship between yield and main economic traits of fruit. The fruit yield per plant had an extremely significant negative correlation with single seed weight, rate of fresh seed, and oil rate of fruit, a significant negative correlation with oil rate of kernel, and a negative correlation with single fruit weight, but not significant; the multiple regression equation was y=23.798-2.920x2-0.249x4, with single seed weight (x2) and oil rate of kernel (x4) as independent variables, fruit yield per plant (y) as dependent variables. In summary, single seed weight and oil rate of kernel had the greatest inhibitory effect on yield under the same conditions. The maximization of a single trait should not be pursued when selecting improved varieties of C. oleifera, but a comprehensive consideration should be made based on the relationship between target traits.

  Study on Crown Grafting Technology of Purple-leaf Lagerstroemia indica LI Maojuan, CUI Qiang, XU Yuze, ZHANG Haixia, LIAO Zhenni, HE Caisheng 2023, 39 (25):  21-26.  DOI: 10.11924/j.issn.1000-6850.casb2022-0683 Abstract + ( 90 )   HTML ( 4 )   PDF ( 1259KB )   ( 24 ) The purpose of this study is to provide theoretical basis and technical support for the crown grafting of purple-leaf Lagerstroemia indica, so as to meet the demand for the large-scale L. indica varieties of the landscape market. The survival rate and increment of three cultivars of purple-leaf L. indica (‘Ebony Fire’, ‘Ebony Flame’ and ‘Ebony Embers’) were studied by different rootstock diameter, scion diameter, grafting method and grafting period. The result showed that the crown grafting technology was applied to different cultivars of purple-leaf L. indica, which could carry out in spring, summer and autumn, and the best time was in spring. The survival rates were more than 90% by the crown grafting from late February to early March in southern China. The diameter of branches above 2 cm was better selected as rootstocks for grafting, and the best diameter of scion was 0.8-1.2 cm. The best grafting method was three knife cutting, and the grafting survival rate was 91.6%. Grafting bagging treatment in spring could significantly accelerate the healing of graft union, and the grafting survival rate could be nearly doubled. The study can provide grafting technical support for the large-scale production of elite purple-leaf L. indica varieties.

  Study on the Correlation Between Leaf Yellowing of Chinese Yam and Physiological Indexes, Mineral Elements Content LI Ju, CHANG Wei, GONG Xuefeng, LI Zhi, YANG Liang, SONG Zhanfeng, MIAO Mingjun 2023, 39 (25):  27-32.  DOI: 10.11924/j.issn.1000-6850.casb2022-0727 Abstract + ( 87 )   HTML ( 4 )   PDF ( 1279KB )   ( 31 ) To explore the correlation between leaf physiological indexes as well as mineral elements content and leaf yellowing of Chinese yam, the yam variety ‘Ya Yam No.1’ was taken as experimental materials, the fresh weight, dry weight, chlorophyll content, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activity and mineral elements content of yam leaves with different yellowing degree were measured, respectively. The results showed that: with the leaf yellowing degree deepening, leaves fresh weight, dry weight, dry matter content, and POD activity decreased obviously, chlorophyll a (Chla) and chlorophyll b (Chlb) content decreased dramatically, but Chla/Chlb showed a rising trend. SOD activity firstly increased and then decreased, and finally increased again. CAT activity showed bimodal curve variation tendency. The contents of N, S and B increased, while the contents of Ca, Mg, Fe and Mn decreased obviously. Correlation analysis showed that Chla and Chlb were very significantly positively correlated with Ca, Mg, Fe, Mn and POD activity, and significantly or very significantly negatively correlated with N, S and B. The results preliminarily confirmed that the decrease of chlorophyll and Ca, Mg, Fe, Mn contents in Chinese yam leaves was closely related to leaf yellowing.

  Impacts of Calcium Supply on the Vegetative and Reproductive Growth of Aloe saponaria ZHOU Jueding, LIU Xianbin, GAO Di, PENG Xinxin 2023, 39 (25):  33-41.  DOI: 10.11924/j.issn.1000-6850.casb2022-0649 Abstract + ( 103 )   HTML ( 2 )   PDF ( 1260KB )   ( 27 ) The paper aims to study the impacts of calcium supply with varying concentrations on the vegetative and reproductive growth of aloe plants and explore the possibility of increasing the artificially cultivated varieties of aloe plants to meet the market demand of raw materials. This study took the multifunctional plant Aloe saponaria as the research object, adopted the planting method of mixed substances + nutrient solution, set up 13 different experimental treatments with calcium supply with varying concentrations in collaboration with the modified Hoagland nutrient solution, artificially cultivated A. saponaria for 4 months, and determined the external morphological growth data, plant production data and reproductive production data. The study results showed that except the data of root length, leaf number, tiller number and pedicel number, other determined data including plant height, leaf thickness, maximum leaf area, total biomass, aboveground biomass, underground biomass, reproductive organ biomass, pedicel height, capsule number and seed number all reached the maximum value in the 110% calcium experimental treatment; the secondary maximum values appeared in the experimental treatment of 100% and 120% calcium concentrations; and in the two calcium concentration experimental treatments of 0% and 500%, all the above measured data were the smallest. The experimental biomass data showed that the biomass of aboveground organs accounted for the largest proportion, followed by reproductive organs, and the biomass of underground organs was the smallest. This study has fully demonstrated that A. saponaria belongs to calcicolous plants, the formula of Hoagland nutrient solution with Ca2+ concentration at 11 mmol/L is the most suitable for its plant growth and development.

  Effects of Low Temperature and Low Light Intensity on Labellum Color of Hedychium ‘Hanyue’ TAN Jiachuan, HU Xiu, ZHONG Yucheng 2023, 39 (25):  42-47.  DOI: 10.11924/j.issn.1000-6850.casb2022-0723 Abstract + ( 84 )   HTML ( 3 )   PDF ( 2155KB )   ( 17 ) The influence of environmental conditions on floral color of Hedychium ‘Hanyue’ was analyzed，so as to provide the basis for the species selection, cultivation, storage and preservation of cut flowers. H. ‘Hanyue’ bud period branches were used as the experimental materials which were treated under different temperature, light intensity. The change of floral color phenotype, chroma value and the pigment content were observed. Under low temperature condition of 10℃, the content of carotenoids and total flavonoids decreased while anthocyanin increased; the values of red-green degree a*, yellow-blue degree b* and color saturation degree C* decreased, while luminance value L* increased; the phenotype showed that the color of the labellum was lighter and the brightness increased. Under the condition of 10000 lx, the color of the heart of the labrum was weakened, the accumulation of carotenoid decreased, but the accumulation of total flavonoids increased, anthocyanin accumulation had no significant change, and the values of a*, b*, C* decreased. Under the combination of low temperature and light treatment, the decreasing range of H. ‘Hanyue’ labellum color and carotenoid content were greater than that under single factor treatment. It is concluded that carotenoids play a decisive role in the flower color phenotype of H. ‘Hanyue’. According to the results of this study, a sunny and warm environment should be selected for the cultivation of H. ‘Hanyue’, and the indoor temperature as well as light intensity can be properly increased to encourage normal flower color when using cut flowers.

  Response of Root Morphology and Physiological Characteristics of Atractylodes chinensis to Water Regulation WANG Zicheng, ZHANG Ruifu, WANG Lingfei, JIA Junying, GUO Yuan, LI Zhijun, SUN Dezhi 2023, 39 (25):  48-53.  DOI: 10.11924/j.issn.1000-6850.casb2023-0241 Abstract + ( 121 )   HTML ( 2 )   PDF ( 1426KB )   ( 30 ) To investigate the effect of moisture on root growth and physiological characteristics of seedlings of Atractylodes chinensis, moisture regulation was carried out on 2-year-old A. chinensis. The results showed that root length, root surface area, root diameter and root volume of A. chinensis increased significantly when the relative soil moisture content was 60%, and the specific root length and specific surface area increased when the soil moisture content was lower than 60%. Root vigor increased and then decreased with the decrease of soil water content. Malondialdehyde content decreased and then increased with decreasing soil water content. The osmoregulatory substances proline, soluble sugar and soluble protein content showed higher accumulation at 50% and 60% of soil water content in each sampling period, and the peroxidase (POD) and superoxide dismutase (SOD) activities showed a trend of increasing and then decreasing in each treatment. Its soil water content of 50%-60% at the time of water management during the seedling stage of A. chinensis is conducive to promoting the root growth of A. chinensis and enhancing its water adaptation ability.

  Effect of Microbial Fungicide Application on the Quality of Forest Panax notoginseng ZHANG Ao, LI Biao, HE Shu, XIONG Bingjie, YAN Xingru, HUANG Youguo, WANG Shu, SHI Rui 2023, 39 (25):  54-63.  DOI: 10.11924/j.issn.1000-6850.casb2022-0831 Abstract + ( 77 )   HTML ( 3 )   PDF ( 2635KB )   ( 34 ) To further improve the quality of forest Panax notoginseng in Yunnan Province, liquid chromatography-mass spectrometry (LC-MS) technique combined with multivariate statistical analysis was used for the screening and KEGG annotation of sugar alcohols, vitamins and other classes of differential metabolites in the roots of forest P. notoginseng applied with microbial fungicides. A total of 82 metabolites were detected in the 2 groups of P. notoginseng roots. There were 26 different metabolites, 11 up-regulated, including 9 sugar alcohols and 2 vitamins; 15 down-regulated, including 11 sugar alcohols, 2 vitamins and 2 others. Some sugar alcohols and vitamin metabolites, such as D-threitol, ribulose-5-phosphate and vitamin C (ascorbic acid), were increased in P. notoginseng roots with microbial fungicide application, which showed that microbial fungicide application had some promotion effect on the quality improvement of P. notoginseng under the forest. However, microbial fungicide application also led to a decrease in the content of some metabolites in P. notoginseng, such as sodium ferulate, piscidionl A and D-glucosamine.

  Analysis of Quality and Safety of Dendrobium officinale in Different Bionic Cultivation Modes YAN Peipei, YE Wei, JIANG Jinlan, WANG Peiyu, JIANG Jianfang, HONG Zengchun 2023, 39 (25):  64-68.  DOI: 10.11924/j.issn.1000-6850.casb2022-0749 Abstract + ( 87 )   HTML ( 1 )   PDF ( 1270KB )   ( 32 ) The difference of quality of Dendrobium officinale ‘Minghu No.1’ in different bionic cultivation modes was investigated, so as to screen out a green and high-yield bionic cultivation mode suitable for D. officinale. D. officinale ‘Minghu No.1’ was cultivated on cliffs, pear trees and bionic frames, respectively. The agronomic characters, yield, polysaccharide content, conventional pesticide residues and heavy metal residues of the three kinds of ‘Minghu No.1’ were detected after two years cultivation, and their differences were compared and analyzed. The plant height, leaf number, leaf length, leaf width, fresh weight, dry weight and polysaccharide content were in the order of bionic frames> pear trees> cliffs; the leaf thickness, one-year buds number and moisture content were in the order of pear trees> cliffs> bionic frames; only the stem thickness was pear trees> bionic frames> cliffs, while chlorophyll was cliffs> pear trees> bionic frames. None of the 38 conventional pesticide residue items were detected, and none of the 8 conventional heavy metal residue items exceeded the standard limit value. Bionic frame cultivation is the most suitable cultivation mode for ‘Minghu No.1’, with the highest yield and the highest polysaccharide content; all three kinds of ‘Minghu No.1’ cultivated in different bionic cultivation modes have no risk to human health and are safe to eat.

  Evaluation of Plant Landscape Scenic Beauty of Changdao Park in Huzhou City Based on SBE Method WANG Yongli, XU Xinquan, ZHANG Jianguo 2023, 39 (25):  69-76.  DOI: 10.11924/j.issn.1000-6850.casb2022-0677 Abstract + ( 87 )   HTML ( 3 )   PDF ( 2114KB )   ( 30 ) This paper aims to study the botanical landscape characteristics of urban parks, and provides scientific basis for the optimal improvement and conservation management of botanical landscapes. Using the Scenic Beauty Estimation Procedures (SBE) combined with on-the-spot investigation, 28 typical plant community landscapes in 5 different functional areas of Changdao Park in Huzhou city are evaluated for their beauty. The results are as follow. (1) From the perspective of functional divisions, the evaluation results of the beauty degree are: plant viewing area (area B)> cultural and leisure activity area (area C)> citizen outdoor activity area (area D)> theme restaurant area (area A)> urban exhibition area (area E). (2) From the evaluation results of specific plots, the SBE score of C3, B2, B1 and D5 ranks in the top four, and the SBE score of E2, C1, E1 and D2 ranks in the bottom four. (3) Judging from the evaluation results of evaluators from different majors, the aesthetic results of evaluators with different professional backgrounds tend to be consistent. In the plant community landscapes of Changdao Park, the landscape plots with diverse plant species, reasonable hierarchical structure, rich colors and good growth are generally more popular; while the evaluation results of landscape plots with simple community structure without hierarchical changes, relatively single plant species and inadequate conservation and management are poor. In the future improvement and transformation of the plant landscapes of Changdao Park, it should be carried out from the aspects of improving the rationality of the hierarchical structure of the plant community, highlighting the characteristics of the plant community in different functional zones, and improving the maintenance and management of the plant landscape.

  Effects of Combined Application of Organic Substituting Fertilizer and Slow Controlled Fertilizer on Soil Fertility in Paddy Field LIU Xiaoting, WANG Jingwen, YANG Wenye, ZHANG Qichun 2023, 39 (25):  77-83.  DOI: 10.11924/j.issn.1000-6850.casb2022-0764 Abstract + ( 100 )   HTML ( 2 )   PDF ( 1232KB )   ( 43 ) To explore the effects of organic alternative fertilizer and slow controlled fertilizer on soil physical and chemical properties, enzyme activity, microbial biomass and rice yield, the field experiment consisting of eight treatments were conducted: control (CK1), formula fertilization (CK2), organic alternative fertilizer (C1), Yangfeng coated slow controlled fertilizer (C2), Jinda chelated slow controlled fertilizer (C3), Wanli Shennong organic slow controlled fertilizer (C4), Xinlianxin slow controlled fertilizer (C5) and Yantai Longdeng slow controlled fertilizer (C6). The effects of different fertilizers combined with formulated fertilizers on paddy soil fertility were evaluated through chemical properties, soil enzyme activity and microbial biomass analysis. The results showed that the contents of soil organic matter, alkali hydrolysable nitrogen, available phosphorus, available potassium, enzyme activity and microbial biomass of C1-C6 treatments were increased compared with CK1 treatment after two years of continuous fertilization. The rice yields of C1-C6 treatments were significantly higher (19.07%-46.58%) than that of CK1 treatment. The principal component analysis and cluster analysis showed that the highest soil fertility was found in C1 treatment, followed by C5, C3, C4, C2, C6, CK2, CK1 treatment. The soil fertility of organic substitute fertilizer treatment and slow controlled fertilizer treatment was higher than that of control and formula fertilization treatments, and the soil fertility of organic alternative fertilizer treatment was the highest. The organic fertilizer plays a significant role in reducing fertilizer application, increasing crop yield and improving soil fertility. And the results of this study can provide a reference for the optimization of formula fertilizer.

  Influence of Rice-duck Integrated Farming Systems on Soil pH and Nutrients GUO Yujiao, LUO Xuan, JING Haoqi, WENG Kaiqi, CAO Zhengfeng, ZHANG Yang, WANG Xiaozhi, CHEN Guohong, XU Qi 2023, 39 (25):  84-88.  DOI: 10.11924/j.issn.1000-6850.casb2022-0756 Abstract + ( 101 )   HTML ( 5 )   PDF ( 1133KB )   ( 34 ) To explore the effects of different rice-duck integrated farming systems on soil pH and nutrients, this experiment selected fields such as conventional rice-duck co-cropping, green fertilizer and rice-duck integrated farming and multi-year rice-duck integrated farming to study the changes of soil pH and nutrient levels in different plots. The results showed that compared with the control group of conventional rice cultivation method, the decrease of pH and nutrient level in the rice-duck integrated farming group was smaller than that in the control group. Even the level of alkaline nitrogen of the rice-duck integrated farming group increased by 8.6 mg/kg after harvesting compared to before ducking, while in the control group, the alkaline nitrogen level after harvesting ducks decreased by 4.98 mg/kg compared to before ducking. For green fertilizer and rice-duck integrated farming, the alkaline nitrogen level increased significantly (P<0.05) from the planting green fertilizer to the flowering stage, the levels of quick-acting phosphorus and quick-acting potassium decreased by 21.95% and 33.49%, respectively, and the soil pH decreased by 14.05%. In addition, through the monitoring of rice-duck integrated farming fields for many years, it was found that with the increase of the number of rice-duck integrated stubble, soil fertility, especially alkaline nitrogen level, could be improved, and the pH of the soil could also be better maintained at a stable level. The above results showed that the rice-duck integrated farming model could enhance soil fertility by improving soil alkaline nitrogen level, and the effect became more obvious with the increase of planting years. Planting green fertilizer in this model could also further improve soil alkaline nitrogen level. Therefore, the rice-duck integrated farming model was a planting model that could effectively maintain and improve soil fertility, which was worth popularizing and applying.

  Study on Fertilization System of Nutrient Critical Value for High Yield of Asparagus Lettuce in Yunnan CHEN Jianfeng, YIN Mei, CHEN Hua, WANG Zhiyuan, WANG Wei, WANG Yingxue, YANG Yanxian, FU Libo 2023, 39 (25):  89-93.  DOI: 10.11924/j.issn.1000-6850.casb2022-0704 Abstract + ( 90 )   HTML ( 3 )   PDF ( 1167KB )   ( 26 ) To explicit the precision fertilization amount of asparagus lettuce in Yunnan, field experiments of asparagus lettuce were arranged to investigate the relationships between the nutrients data of plough layer, fertilization of current season, and the lettuce yield and net output. It was found that the highest yield of lettuce was obtained by treatment with N2P2K2 in different experiment sites. In different sites, soil nutrients (alkaline hydrolyze nitrogen, available phosphorus and available potassium) and lettuce yield had positive relationships. The Pearson coefficients between lettuce yield of treatment with N, P, K lacking and soil alkali-hydrolyze nitrogen, available phosphorus and available potassium content were 0.91, 0.98 and 0.99, respectively. Soil correction coefficient could reflect the soil fertility potential to some extent. The nutrient critical value for high yield of lettuce in Yunnan was calculated according to optimum fertilizer application rate and the levels of available nutrients in the soil. The regression equations between soil nutrient correlation coefficient and soil nutrient contents could be expressed as follows: yN=0.123-0.0144lnxN, yP=0.2446-0.0474lnxP, yK=0.806-0.118lnxK. The nutrient critical values for high yield of asparagus lettuce could be calculated as follows: N was (286.8±45.6) kg/hm2, P2O5 was (135.7±4.9) kg/hm2, K2O was (346.3±126.1) kg/hm2. The soil nutrient supply capacity was estimated by measuring soil nutrient content before lettuce planting, and the fertilization amount of lettuce in the current season was calculated by subtracting the soil supply from the nutrient critical value for high yield.

  Spatial Distribution Characteristics and Fertility Evaluation of Soil Nutrients Based on GIS LI Jiaxin, GAI Weiling, SUN Xianmin, ZHAO Xin, ZHANG Xiaoguang, CUI Dejie 2023, 39 (25):  94-101.  DOI: 10.11924/j.issn.1000-6850.casb2022-0730 Abstract + ( 102 )   HTML ( 2 )   PDF ( 1960KB )   ( 41 ) To understand the soil nutrient status of 18 villages in the north of Ligezhuang Town of Jiaozhou City, so as to provide reference for scientific setting of fertilization methods and soil improvement in the construction of high-standard farmland. Soil nutrient content was detected in the study area. A total of 43 sampling points were set up to determine soil pH, organic matter, total nitrogen, alkali-hydrolyzed nitrogen, available phosphorus and available potassium. The general Kriging interpolation method of ArcGIS was applied to analyze the spatial distribution characteristics of soil nutrients in the study area. The index weights were determined by principal component analysis, and the soil fertility grades were divided by index sum method and the results were visualized. The results showed that: (1) the soil in the study area was mainly acidic and neutral. The content of organic matter, total nitrogen and alkali-hydrolyzed nitrogen was insufficient, and the content of available phosphorus was rich with medium available potassium. (2) Generally, pH values were low in the north and south, high in the middle, while low in the east but high in the west. The contents of organic matter, total nitrogen and alkali-hydrolyzed nitrogen were higher in the east but lower in the west, indicating that they were significantly correlated. The distribution of available phosphorus was low in the east while high in the west, and that of available potassium was high in the east but low in the west. (3) The land areas of class Ⅰ-Ⅴ were 365.11, 545.80, 803.71, 547.93 and 390.85 hm2, respectively, accounting for 13.76%, 20.57%, 30.29%, 20.65% and 14.73% of the total studied area. The overall soil fertility of the 18 villages in the north of Ligezhuang Town in Jiaozhou City was at a medium level, and it was abundant in the east but poor in the west. To control soil acidification and increase contents of organic matter, total nitrogen and alkali-hydrolyzed nitrogen were of great significance for the next step of building high standard farmland.

  Research Progress of Humic Acid Fertilizer ZHANG Peng, E Shengzhe, YUAN Jinhua, WANG Yuxuan, ZHAO Tianxin, LIU Yana, LU Gangbin, YE Gengkang, CAO Kun, CHEN Zhenyu 2023, 39 (25):  102-108.  DOI: 10.11924/j.issn.1000-6850.casb2022-0758 Abstract + ( 128 )   HTML ( 6 )   PDF ( 1448KB )   ( 50 ) Humic acid has the ability to improve soil, increase fertilizer efficiency and provide nutrients for plants. It plays an important role in the ecological environment. Humic acid is a complex aromatic macromolecule formed by amino acids, amino sugars, peptides and aliphatic compounds. The extraction of humic acid includes microbial dissolution method, alkali-acid precipitation method and acid extractant method. Based on this, the basic concept, properties, mechanism of humic acid and the preparation principle and function of humic acid fertilizer were summarized, and some shortcomings were discussed. It was pointed out that the research focus of humic acid fertilizer in the future would be the main components of humic acid raw materials. More cost-saving method should be studied for the production of humic acid, and a unified quality inspection standard should be established.

  Study on Predicting Models of Grass Yield in North Shore of Qinghai Lake ZHU Shengcui, LI Guoting, WEI Yonglin, MA Fulin, JIN Xianling, CAO Yingmin 2023, 39 (25):  109-115.  DOI: 10.11924/j.issn.1000-6850.casb2022-0857 Abstract + ( 107 )   HTML ( 1 )   PDF ( 1224KB )   ( 36 ) The objective is to realize the dynamic prediction of grass yield, grasp the change of grass yield in time, and provide scientific basis for animal husbandry production efficiency and structural adjustment in alpine region. Taking the north bank of Qinghai Lake as the research area, the grass yield prediction models for different grassland types (alpine meadow, alpine steppe and temperate steppe) were established by grass yield data, meteorological data and NDVI data from 2003 to 2020. The effect of fencing and grazing on the grass yield prediction models were analyzed. The results showed that alpine meadow had the best prediction effect among the three different grassland types. The regression effect between grass yield data and meteorological elements was better than that between NDVI and meteorological elements. The regression correlation coefficients between grass yield data and meteorological data in Haiyan were above 0.8, which passed the significant test of 0.001. Five models of Haiyan, four models of Qilian, two models of Yanglong and two models of Gangcha were screened with high prediction accuracy, which had good estimation ability and could meet the needs of grass yield prediction application in or outside the fence in these four areas.

  Discriminant Analysis and Prediction of Rice Blast Epidemic Based on Virulence of Magnaporthe oryzae and Meteorological Factors LAN Bo, YIN Changfa, CHEN Jian, SHI Weitao, YANG Aiping, ZHANG Xiaoyang, KUANG Hongmin, XIAO Hui, LI Xiangmin, YANG Yingqing 2023, 39 (25):  116-121.  DOI: 10.11924/j.issn.1000-6850.casb2022-0769 Abstract + ( 97 )   HTML ( 3 )   PDF ( 1335KB )   ( 36 ) Rice blast is a destructive disease of rice. Forecasting the epidemics of rice blast by using scientific model function is an effective way to prevent and control rice blast. Using the rainfall days, rainfall amount, temperature, pathogenicity of Magnaporthe oryzae, and avirulence gene as variables and the occurrence index of rice blast disease as the dependent variable, a model function for discriminating the epidemic of rice blast disease in Jiangxi Province was established. The results showed that the occurrence index of rice blast was positively correlated with the rainfall days, rainfall amount and the pathogenicity of M. oryzae, while the avirulence gene frequency and temperature were negatively correlated. The prediction function model had a high correct discrimination rate (above 80%) for the occurrence grade of rice blast, and the discrimination result did not show the exponential sliding. Therefore, this model function could be used as a method for the prediction of rice blast disease to guide the safe production of rice.

  Screening and Field Application Evaluation of Chemicals for Zizania latifolia Diseases Prevention and Control LI Fang, ZHANG Juefeng, ZHONG Haiying, CHEN Jianming 2023, 39 (25):  122-129.  DOI: 10.11924/j.issn.1000-6850.casb2022-0734 Abstract + ( 97 )   HTML ( 5 )   PDF ( 1370KB )   ( 40 ) To effectively control the disease of Zizania latifolia and screen out the safe and efficient fungicides, the effects of 7 fungicides on the microspores of Ustilago esculenta were tested in laboratory for evaluating the safety about gall formation of Zizania latifolia. At the same time, the drug resistance experiment of Bipolaris zizaniae and the field efficacy monitoring were used to screen the high-efficiency fungicides. The results showed that among the seven fungicides, pyraclostrobin had the best efficacy with 79.3% on Uromyces coronatus in Tongxiang area and 41.44% on Bipolaris zizaniae in Huangyan area, respectively. However, pyraclostrobin had the greatest effect on the microspores of Ustilago esculenta, and the concentration of 0.01 g/L completely inhibited the growth. Mineral oil had the least effect on the growth of Ustilago esculenta microspores, but the control effects of Zizania latifolia diseases were poor. The mixture of mineral oil and 25% pyraclostrobin suspension could reduce the use concentration while maintaining the high efficacy of the fungicide. In addition, epoxiconazole and picoxystrobin, which had little effect on the growth of Ustilago esculenta microspores, also had a field control effect of more than 40% on Uromyces coronatus. Therefore, when screening high-efficiency fungicides for Zizania latifolia, we should fully detect their safety to Ustilago esculenta, carefully screen the use time of fungicides, so as to avoid seriously affecting gall formation and thus limiting the yield and quality of Zizania latifolia.

  Extraction Process of Iridoid Glycosides Based on Response Surface Methodology HE Zhipeng, WANG Shibao, HU Benxiang, ZHANG Hui, CHEN Yuan, TANG Wenqiang, HU Yagang 2023, 39 (25):  130-138.  DOI: 10.11924/j.issn.1000-6850.casb2022-0759 Abstract + ( 88 )   HTML ( 1 )   PDF ( 2849KB )   ( 31 ) The extraction process of iridoid glycosides from Gentianae macrophyllae radix was optimized by response surface methodology. On the basis of single factor test, according to the design of response surface method, the total content of loganic acid, swertiamarin and gentiopicroside was used as the index to optimize the extraction conditions. The optimum extraction conditions were as follows: 80% methanol was solvent, extraction temperature was 50℃, ultrasonic power was 720 W, liquid-solid ratio was 40 mL: 1 g, extraction time was 30 minutes and extracted 2 times. According to this condition, the actual measured value and predicted value were 15.562% and 15.904%, with the relative deviation of 2.20%, and the results were basically the same. The operation process is relatively simple and the test results are ideal, which provides a reference for the extraction process of iridoid glycosides in Gentianae macrophyllae radix.

  Analysis of Volatile Components in Dendrobium officinale, Dendrobium nobile and Lily Flowers YANG Yuan, YANG Qiuyue, WANG Dachang, RUAN Baoli, YANG Yang, LUO Yingzi, HUANG Mingjin 2023, 39 (25):  139-146.  DOI: 10.11924/j.issn.1000-6850.casb2022-0671 Abstract + ( 90 )   HTML ( 2 )   PDF ( 1392KB )   ( 31 ) To identify the volatile oil components in Dendrobium officinale, D. nobile and lily flowers, N-hexan-water distillation method was used to extract volatile oil from D. officinale, D. nobile and lily flowers, analysis of their chemical components were conducted by gas chromatography-mass spectrometry (GC-MS). A total of 83 chemical components were identified from the three flowers. 50, 68 and 22 chemical components were isolated from D. officinale, D. nobile and lily flowers, respectively, and 47, 57 and 16 chemical components were identified. Their relative contents accounted for 91.72%, 70.79% and 83.94% of the total volatile oil, respectively. Among the aroma components, 17, 25 and 5 were identified, accounting for 11.34%, 27.61% and 24.37%, respectively. The main aroma components in D. officinale flowers were ethyl palmitate, ethyl linoleate, cetyl aldehyde and chlorophyl alcohol. The main aroma components of D. nobile flowers were palmitic acid, ethyl palmitate, ethyl linoleate, caryophyllene, α-terpinol, 4-ethyl-2-methoxyphenol. The main aroma components of lily flowers were ethyl palmitate, ethyl linoleate and ethyl oleate.

  Wheat Disease Recognition Model Integrating Attention Mechanism and Multi-scale Convolution LU Xiaowei, MENG Zhiqing 2023, 39 (25):  147-154.  DOI: 10.11924/j.issn.1000-6850.casb2023-0216 Abstract + ( 84 )   HTML ( 3 )   PDF ( 2290KB )   ( 34 ) Classification and recognition techniques based on deep convolutional neural networks are proposed to solve the wheat disease identification problem. In this paper, the proposed method is compared and analyzed against existing wheat disease recognition models, and the promising results of applying deep learning technology in agricultural disease identification and monitoring are discussed. The experimental results show that the method based on the deep convolutional neural network is 3%, 4%, 5%, and 5% higher than the traditional EfficientNet network in terms of accuracy, precision, recall, and F1, and can effectively identify wheat disease. We verified the effectiveness of the proposed components by ablation experiments, and the convergence speed of the model was significantly better than the existing models. The proposed identification model provides strong support for agricultural production and is expected to become one of the main technical tools in the field of agricultural disease identification and monitoring in the future.

  Knowledge Map Construction and Analysis of Pork Price Research Based on CiteSpace LING Liwen, HUANG Rongxi, HUANG Chuxin 2023, 39 (25):  155-164.  DOI: 10.11924/j.issn.1000-6850.casb2022-0686 Abstract + ( 119 )   HTML ( 3 )   PDF ( 4318KB )   ( 76 ) Using CiteSpace bibliometric visual analysis software, CNKI Chinese core journals were selected as data resources to analyze 805 research papers related to pork prices between 2001 and 2021, and to sort out and summarize the characteristics and development trends of domestic pork price research. The study reveals that: (1) the pork price research in China can be divided into four stages, namely: the initial stage (2001-2006), the rapid development stage (2007-2011), the short-term decline stage (2011-2015) and the stable development stage (2016- present). (2)The research community shows a characteristic of ‘small aggregation and general distribution’, and the cooperation between researchers is not strong. (3)There are few collaborative links between research institutions, and research is mostly conducted within internal institutions. (4)‘pork price’, ‘livestock products’ and ‘feed price’ are high-frequency keywords for pork price research, and ‘pork price’, ‘pig prices’ and ‘price fluctuations’ are high-frequency central words. The research on pork price fluctuations analysis, pork prices influencing factors analysis and pork price forecasting models is concluded according to the keywords. (5)The strongest emergent term is ‘year-on-year increase’, and the most persistent emergent terms are ‘central region’, ‘southern China’ and ‘grain and oil prices’. It demonstrates that pork price volatility is a hot topic of research in this area, and the research has a typical regional characteristic.