Table of Content

Volume 39 Issue 9
25 September 2023
Spatiotemporal Evolution Characteristics and Pattern Optimization of Production-living-ecological Functions of Territorial Space in Chongqing Section of the Three Gorges Reservoir Area
GAO Peng-fei, YANG Chao-xian, XIN Gui-xin, LÜ Zhao-qun
2023, 39(9):  1103-1113.  doi:10.19741/j.issn.1673-4831.2022.1162
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Rapid urbanization and industrialization have driven the evolution of the functional pattern of territorial space. Exploring the spatiotemporal evolution rules of the "production-living-ecological" functions can provide a scientific basis for optimizing the functional layout of territorial space. Taking Chongqing section of the Three Gorges Reservoir Area as a case study, this study used geographic data, land use data and social-economic data to investigate the evolution process of the "production-living-ecological" function of the territorial space. The model methods were employed, including spatio-temporal difference, obstacle degree and comparative advantage index. The results show that:(1) From 2010 to 2020, the evolution of "production-living-ecological" functions generally exhibited the varying spatial and temporal patterns, such as declined production functions, improved living functions and slightly increased ecological functions. The low-value areas of production function were mainly concentrated in 8 districts and counties within the central urban area, while the high value areas were distributed in 14 districts and counties outside the central urban area. The gap between the high and low extreme values showed a decreasing trend. The high and low values of living function showed the opposite spatial change trend compared with those of production function. The agglomeration trend of ecological function was not apparent, and the spatial distribution trend of high and low values was similar to that of production function. (2) Based on the spatiotemporal differences in evolving "production-living-ecological" functions and the diagnosis and identification of development obstacles and dominant functions, the measurement for optimizing and constructing of the future territorial spatial pattern was proposed. It is necessary to build a modern living and producing core agglomeration area in the 8 core urban districts dominated by mountainous and hilly landforms. In 7 outer districts and counties like Fuling District dominated by parallel ridges, valleys, and hills, it is imperative to establish a production-ecological mixed zone for coordinating modern industrial and agricultural development and ecological protection. Peripheral 7 districts and counties, like Wulong District featured mountainous landforms, it is to establish policy piloting areas for integrated conservation of ecological production for integrating ecological restoration and construction and agricultural and tourism development.
Spatial and Temporal Variation of Habitat Quality in Zhangjiajie Giant Salamander National Nature Reserve and Zhangjiajie City
WANG Cheng, LIU Yi, XIE Yi-xing, ZHOU Shao-hui, CHEN Jia-fa
2023, 39(9):  1114-1122.  doi:10.19741/j.issn.1673-4831.2022.0313
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Habitat quality assessment is an important regional tool for land use policy and integrated management, and highly significant for ecological environmental protection and sustainable development. Based on land use transfer matrix, landscape pattern indices and the InVEST model, the spatial and temporal variations in habitat quality caused by the changes of land use and landscape fragmentation of Zhangjiajie Giant Salamander National Nature Reserve and Zhangjiajie City were quantitatively assessed. The results show that:from 2000 to 2020, the land use of both the City and the Reserve was generally stable, although minor changes were caused by the mutual transformation among grassland, cultivated land and forest land. However, landscape fragmentation occurred, patch connectivity decreased, and average patch area became smaller, all of which were significantly disturbed by human activities. The habitat quality of both the City and the Reserve declined with different extents, mainly in areas with previously excellent and good habitats turned into medium and poor level. The habitat quality of Zhangjiajie City declined significantly with a decrease of 1.86%. The habitat quality of the Giant Salamander Nature Reserve declined slightly, but in the core and experimental zones of the Reserve it decreased significantly by 1.69% and 1.57%, respectively. Along topographic gradients, habitat quality of the Giant Salamander Nature Reserve increased with slope and elevation, but along a population density gradient it decreased with the increasing of population density. These results could have certain theoretical and practical value for habitat protection and functional regulation of these ecosystems.
Effects of Land Use Change on Tradeoff-synergy Relationship of Ecosystem Services in New Area of Megacity: The Case of Nanjing Jiangbei New Area
QIAN Hong-yun, CHEN Shuang
2023, 39(9):  1123-1132.  doi:10.19741/j.issn.1673-4831.2022.0580
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Quantitative description of ecosystem services (ES) interactions is of great significance for rational allocation of resources and sustainable development in the new urban areas. In this study multiple ESs were calculated, including carbon storage (CS), habitat quality (HQ) and water yield (WY) in Nanjing Jiangbei New Area. The ESs' tradeoff-synergy relationships were assessed at different scales using InVEST model, GIS technology and the land use/land cover data respectively in 2000, 2010 and 2020. The results show that:(1) From 2000 to 2020, in Nanjing Jiangbei New Area, the HQ and CS decreased from 0.490 5 and 2.502×107 t to 0.461 3 and 2.460×107 t, respectively. The high values of CS and HQ were mainly distributed in forestland, while the low values were located in urban construction land such as Luhe Development Zone. The WY increased by 6.65×108 m3, with the high value area mainly falling in the construction land, and the low value area located in the water bodies along the Yangtze River. (2) At the regional scale, the WY-CS interaction and WY-HQ interaction presented mainly trade-offs, while the HQ-CS interaction presented mainly synergistic, accounting for 11% of the total area. At the district scale, the ES tradeoff-synergy degree kept relatively high in the districts directly managed under Jiangbei New Area, while the ES tradeoff-synergy degree was relatively low in other districts. The change of construction land and water surface area has been identified as an important driving mechanism affecting the tradeoff or synergy of ESs.
Trend Analysis of Atmospheric Particulate Matter over the Beijing-Tianjin-Hebei Region During 2015-2021 Using the KZ Filtering Approach
ZHAN Qing, ZHANG Yun-jiang, CHEN Hong, ZHANG Ke-xin, GE Xin-lei
2023, 39(9):  1133-1143.  doi:10.19741/j.issn.1673-4831.2022.0875
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The Beijing-Tianjin-Hebei Region has become a key focus area for addressing atmospheric particulate matter pollution in recent years in China. In this study, Kolmogorov-Zurbenko (KZ) filtering analysis was applied to analyze the time series of fine particulate matter (PM2.5), inhalable particulate matter (PM10), and coarse particulate matter (PM2.5-10) in 13 cities in the Beijing-Tianjin-Hebei Region from 2015 to 2021. The results show that the annual average concentrations of PM2.5 and PM10 had generally decreased, with a decline rate of 5.07 and 8.10 μg·m-3·a-1, respectively. The KZ filtering analysis also revealed that the short-term, seasonal, and long-term components of PM2.5, PM10, and PM2.5-10 are independent of each other. The highest contribution to the fluctuations in the original time series was found to be from the short-term component (over 50%), followed by the seasonal component, indicating that the fluctuations are mainly influenced by short-term and seasonal variations in pollutant emissions and meteorological conditions. Using the KZ-filtered concentration series, a stepwise multiple regression linear model was established to quantitatively evaluate the contributions of meteorological factors and emission reduction measures to the trends observed. The city-by-city analysis results show that the impact of meteorological conditions on PM2.5 concentrations was highest in Qinhuangdao (14.86%), while emission reduction measures had the greatest impact on PM2.5 concentrations in Hengshui (96.77%). The impact of meteorological conditions on PM10 concentrations was highest in Qinhuangdao (13.69%), while emission reduction measures had the greatest impact on PM10 concentrations in Langfang (93.96%). The impact of meteorological conditions on PM2.5-10 concentrations was highest in Cangzhou (26.23%), while emission reduction measures had the greatest impact on PM2.5-10 concentrations in Langfang (91.80%). Overall, the analysis results suggest that emission reduction measures plays a crucial role in improving particulate matter pollution in the Beijing-Tianjin-Hebei Region from 2015 to 2021.
Temporal and Spatial Differences and Influencing Factors of Green Total Factor Productivity of Animal Husbandry in China
LIN Zi-teng, ZHANG Yan-rong
2023, 39(9):  1144-1157.  doi:10.19741/j.issn.1673-4831.2022.0907
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In this study, by constructing an input-output system, we used a super-efficiency epsilon-based measure (EBM) model based on non-oriented scores and variable returns to scale, and a global Malmquist-Luenberger (GML) index to measure and analyze the green total factor productivity (GTFP) of animal husbandry in 31 provinces in China from 2011 to 2020. On this basis, Dagum's Gini coefficient decomposition and kernel density estimation methods were used to explore the regional differences and dynamic evolution of the GTFP of animal husbandry, and the fixed-effect model and Driscoll-Kraay standard error estimators were used to test its influencing factors. The results show that the overall level of the GTFP of animal husbandry in China from 2011 to 2020 was low, and it showed a decreasing gradient pattern of 'northeast-east-central-west'. Sustainable technological progress was the main driving force of regional and national GTFP of animal husbandry in China; the regional difference showed a continuous upward trend with a polarization phenomenon and gradient effect. Interregional difference was the main source of regional differences in the GTFP of animal husbandry; the difference between eastern and western regions was the largest, and the difference between northeast and central regions was the smallest. In terms of influencing factors, industrial agglomeration, financial support for agriculture, and per capita GDP had significant negative effect on China's animal husbandry GTFP, and transport accessibility had a significant positive effect. The results of this study provide a basis for the promotion of sustainable development of animal husbandry in China.
Analysis of Temporal and Spatial Evolution Characteristics and Terrain Effect of Vegetation in Hengduan Mountains Region Based on MODIS
BAI Ma-qu-xi, PU Bu-duo-ji, ZHUO Yong, CI Zhen, BIAN Qiong, HUANG Peng, XI Rao-zhuo-ma, YU Luo
2023, 39(9):  1158-1169.  doi:10.19741/j.issn.1673-4831.2022.0743
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Proper evaluation of the topographic effects of vegetation change could provide scientific basis for the benefit assessment of ecological stability sustainable development, ecological protection and ecological construction in the Hengduan Mountains Region. Based on MODIS vegetation remote sensing products and DEM data, Sen+M-K trend analysis was used combined with the terrain difference correction method to analyze the relationship between vegetation and terrain factors in the Hengduan Mountains Region from 2000 to 2020. The results show that:(1) Within the 21 years, the distribution pattern of NDVI was higher in the south and lower in the north, higher in low altitudes and lower in high altitudes. NDVI varies significantly with elevation change, and there are obvious differences between ridge and valley. The area of vegetation in stable accounted for 64.13%, and the areas with extremely significant increase and significant increase accounted for 12.54% and 11.77%, respectively. The average annual change rate was 0.013 (10 a)-1. (2) The distribution and change of NDVI have obvious topographic effects in Hengduan Mountains Region. NDVI fluctuates slightly in the area with elevation less than 3 845 m, and decreases in a stepwise manner above 3 845 m. Although the difference of NDVI is small in different slope directions, the north slope is greater than the south slope, the west slope is greater than the east slope, and the northwest slope is the largest. NDVI increases in steps with the slope increasing from 0 to 38.9°, but decreases sharply when the slope is higher than 38.9°. (3) In the flat land with the elevation less than 1 919 m and the slope less than 3.8°, the interannual increase rate of NDVI is small, and the significant degradation distribution is obvious. At elevations of 1 919-3 162 m, slope of 3.8°-25.1°, and aspects of northwest, west and north slope, NDVI is mainly stable and increasing, with high interannual variation rate. The vegetation transition area with elevation of 2 739-3 534 m, slope of 22.2°-28.0°, and slope aspect of east and west, where NDVI is prone to fluctuation, so it is necessary to pay attention and to strengthen ecological governance.
Effects of Vegetation Types on the Potential and Pathway of Microbial Carbon Sequestration in Reclaimed Soil of Open-pit Mine
YOU Yun-nan, ZHU Yan-feng, CHEN Fu, CHENG Yan-jun, DONG Wen-xue, MA Jing
2023, 39(9):  1170-1179.  doi:10.19741/j.issn.1673-4831.2022.0927
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Since the semi-arid open-pit mining activities have seriously damaged the local ecological environment, it is urgent to clarify the interaction mechanisms among vegetation, soil and microorganism. Meanwhile, it is of great significance for large-scale ecological restoration of damaged mines to explore the potential and pathway of microbial carbon sequestration, and stimulate the self-recovery ability of degraded ecosystems, as well as achieve the nature-based solutions. For this purpose, 18 topsoil samples of three typical replanting types, namely Pinus tabulaeformis (YS), Pinus tabulaeformis + poplar (DYS), and Pinus tabulaeformis + poplar + alfalfa (DYX), were collected from the waste dump of Heidaigou open pit mine in Zhungeer Banner, Inner Mongolia. High-throughput sequencing and real-time fluorescence quantitative PCR were used to determine the abundance of soil microbial carbon fixation genes and the community structural variation. The results indicate that:(1) The vegetation types presented a significant impact on the physiochemical characteristics of the reclaimed soil (P<0.05). The more complex vegetation types, the more significant the decrease in soil pH and water content, as well as the more significant increases in organic carbon, total nitrogen, and nitrate nitrogen. (2) The vegetation types had no significant effect on the bacterial community structure in the reclaimed soil, but showed a significant effect on the abundance of carbon sequestration genes, i. e. the abundances of rbcL, korA, acsA, acsE, pccA, smt, and frda were significantly increased with the increasing of varieties in the vegetation types (P<0.05). (3) Soil water content, organic carbon, total nitrogen, and nitrate nitrogen are the dominant factors for bacterial community structure changes, while different vegetation combinations altered the environmental factors to manipulate carbon sequestration potential and pathways. This study could help to understand the impact of diversified vegetation combination on the carbon cycle of reclaimed soil in mining areas, and provide the theoretical basis for ecological restoration, carbon sequestration and sink enhancement in the Loess Plateau.
Effects of Restoration Succession Years of Abandoned Paddy Fields on Plant Community Diversity in Jingxin Wetland
TANG Yu-qi, SHANG Yi-jun, ZHU Wei-hong, CAO Guang-lan
2023, 39(9):  1180-1187.  doi:10.19741/j.issn.1673-4831.2022.1101
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The Jingxin Wetland, located in the lower reaches of the Tumen River, plays a vital role in maintaining regional ecological balance as the only offshore wetland in Jilin Province. In recent years, many paddy fields in the Jingxin Wetland area have been abandoned, and the area has increased year by year. As a semi-natural wetland formed by natural succession, abandoned paddy fields have a significant impact on regional biodiversity, but the mechanism behind the transition of plant communities through natural succession remains unclear. In this study, we focused on the Jingxin Wetland, and identified its site and biological habitat characteristics by performing a site survey and literature survey. To determine the changes of plant diversity in the process of natural succession, we compared the plant species and communities of natural wetland with semi-natural wetland of different abandoned times by using space series analysis instead of time series analysis. A total of 99 plant species belonging to 64 genera of 33 families were identified in natural wetland and abandoned paddy fields. The species primarily consist wetland hydrophyte herbaceous, and aquatic plants. Based on the community characteristics, Cyperaceae, Polygonaceae, and Poaceae were the dominant species in the Jingxin Wetland. As the time of abandonment increased, the dominant species of the semi-natural wetland plant community shifted towards the dominant species of the natural wetland plant community. The plant diversity of the abandoned paddy fields was much higher than that of the natural wetland; however, the diversity decreased as succession time progressed and began to resemble the natural wetland community. Nevertheless, compared with wetlands at the same latitude, the succession rate of the abandoned paddy fields was slower, thereby highlighting the influence of soil, water, and organic matter in the subsequent restoration of abandoned paddy fields and the need to continuously strengthen wetland management and protection.
Effects of Amaranthus palmeri on Soil Seed Bank Community Characteristics in Abandoned Cultivated Land
LI Mei-yang, LI Long-qin, HAO Guang, KANG Bin-yue, GAO Yue, LI Hong-yuan
2023, 39(9):  1188-1195.  doi:10.19741/j.issn.1673-4831.2022.0601
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To explore the effects of the alien invasive plant Amaranthus palmeri on the characteristics of soil seed bank community, this study selected abandoned soil seed bank under different invasion pressures of Amaranthus palmeri as the research subject, and revealed the response of abandoned soil seed bank community to Amaranthus palmeri invasion through field investigation and germination experiment, so as to provide the basis for the scientific control of invasive plants. The results show that:(1) A total of 30 species of plants belonging to 17 families and 30 genera, mainly annual herbs, were found in the soil seed bank. The species diversity index and seed density of soil seed bank were significantly lower in the area being severely invaded than in the area being lightly invaded. The species diversity index of the soil seed bank had no obvious response to soil depth, and the invasion pressure has no interaction with soil depth. (2) The analyses of soil seed banks by using the non-metric multidimensional scaling (NMDS) further show that there were significant differences in community structure between the two groups under different invasion pressures. (3) The invasion at moderate and high degrees both exerted negative effects on soybean (Glycine max), Setaria viridis and Suaeda glauca.
Comparing the Effectiveness of Birdwatching to Line Transect for Biodiversity Surveys: A Case Study of Laoshan, Nanjing
LIU Meng-meng, ZHANG Man-yu, HAN Qian, WU Da-wei, WANG Si-lu, LU Chang-hu
2023, 39(9):  1196-1204.  doi:10.19741/j.issn.1673-4831.2022.0570
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Long-term and systematic biodiversity monitoring data is the basis for achieving goals of biodiversity conservation. The development of citizen science has promoted the large-scale data collection on birds with less resource investment. In this study, six years birdwatching data and a one-year formalized bird monitoring data were used to compare the similarities and differences between the traditional line transect method and birdwatching method, and the advantages and disadvantages of the two survey methods were explored for further promoting the application of public science birdwatching in bird diversity research and protection. To do this, birdwatching data were collected from July 2015 to June 2021 from public birdwatching data platforms, and the comprehensive survey of bird species and their distribution by fixed-distance line transects was conducted from July 2020 to June 2021 in Laoshan, Nanjing. List length was used as an indicator of the professionalism of the investigators. Mann-Whitney test was used to assess the differences in the counted number of bird species per survey trip by using the two different methods. By resampling the data within each group of observers, two hundred bootstrap samples were produced for each group and 95% confidence intervals were calculated for the detection rates. The results show that 214 bird species were recorded by the two methods, of which 83 species were only recorded by birdwatching activities. From July 2020 to June 2021, 125 species were recorded by birdwatching and 131 species were recorded by the line transect method. Comparing the detection rates of species between the two methods, the largest differences in detection rates were for breeding birds, uncommon raptors, and rare bird species in the study area. The monitoring intensity of transect method was 11, and the birdwatching was between 2.4 and 8. The peak of birdwatching activity was concentrated in May-June. The average number of bird species surveyed by birdwatchers per trip (23.57±20.04) was greater than that monitored by the line transect method (19.81±6.84). In the short term, neither of the two survey methods can completely record all bird species in the study area. In the long term, birdwatching data can fill the gap of traditional bird monitoring to a certain extent. However, spontaneous birdwatching activities are easily influenced by birdwatchers' preferences, with biases in time, space, and species identification, and by problems such as insufficient monitoring intensity and inaccurate data recording. Therefore, the design and specification need to be strengthened to reduce the biases in citizen science data sets and then provide a proper data base for bird research and conservation in a broader field.
Changes and Coupling of DOM, Fe, and Phosphorus Fractions in Paddy Soil Driven by the Decomposition of Periphytic Biofilm Biomass
WU Li-rong, GONG Li-na, LIU Jun-zhuo, WU Yong-hong
2023, 39(9):  1205-1212.  doi:10.19741/j.issn.1673-4831.2022.0992
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Periphytic biofilms are ubiquitous at the soil-water interface in paddy fields with great impact on soil nutrient transformation through various pathways. However, the effects of phototrophic biofilm biomass decomposition on the coupling of dissolved organic matter (DOM), Fe, and phosphorus in paddy soil remains unclear. In this study, a microcosm experiment was carried out by adding different amounts of periphytic biofilms to paddy soil; and the effects of phototrophic biofilm biomass decomposition on paddy soil DOM components, Fe2+ content, activity of iron oxide (Feo/Fed), and phosphorus fractions were investigated. Fourier-transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) was used to elucidate the molecular characteristics of DOM. The results show that the decomposition of periphytic biofilms increased DOM content and changed the proportion of different DOM components, of which the relative abundance of tannin-like compounds increased by 1.97%-9.74%. Also, we observed a significant increase in soil Fe2+ content and Feo/Fed ratio as well as enhanced soil reducibility. The content of inorganic phosphorus and especially the Fe-bound P in soil increased, which translated to increased P availability. Phototrophic biofilm biomass decomposition changed soil DOM components and Fe forms, while recalcitrant tannin-like components affected the bioavailability of P by reducing its adsorption to minerals. Principal component analysis (PCA) show that there were great differences in DOC content, the relative abundance of tannin-like compounds, Al-bound P content, Fe2+ content, and Feo/Fed ratio between the phototrophic biofilm decomposition treatments and the control. The correlation results show that there were significantly positive correlations between Fe2+ content and Fe-bound P content, Feo/Fed ratio, and Al-bound P content, and the relative abundance of tannin-like compounds was positively correlated with Feo/Fed and Al-bound P content. In a word, soil DOM components, Fe forms, and P forms interacted with each other, and both the increase of tannin-like DOM and the transformation of Fe forms had positive effects on the increase in P bioavailability. The results have revealed the effects of periphytic biofilm biomass decomposition on the coupling of DOM, Fe, and P in paddy soil. It also provides theoretical support for the future use of periphytic biofilm to regulate the coupling process of carbon, Fe, and P, and to improve the bioavailability of P in paddy soil.
Assessment of Energy Efficiency of In-situ Thermal Desorption: Creation and Application
FAN Ting-ting, JIN De-cheng, LIU Peng, WANG Xiang, ZHAO Yuan-chao, DENG Shao-po, ZHANG Sheng-tian, LIU Ze-quan, WAN Jin-zhong
2023, 39(9):  1213-1220.  doi:10.19741/j.issn.1673-4831.2022.0671
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With the development of industrialization, soil environmental safety has become a serious matter in China. In-situ thermal desorption technology (ISTD) is one of the technologies with high remediation efficiency in short-term period. However, the high energy consumption and high cost become the "bottleneck" for its wide application. Currently, there is no unified quantitative method for evaluating the energy efficiency of in-situ thermal desorption, both home and abroad. To address this issue, energy efficiency evaluation method based on pollutants and energy efficiency evaluation method based on polluted soil/water volume were developed on the bases of the principle of in-situ thermal desorption and energy consumption calculation model of in-situ thermal desorption, as well as the characteristics of organic pollution sites in China. The applicability of these methods was explored through an engineering project involving in-situ thermal desorption and coupled chemical oxidation technology in North China. Based on the energy consumption analysis of the technology receptors (including coupled chemical oxidation technology), it was found that the energy consumption of in-situ thermal desorption applied to soil and water heating accounted for 61.80% to 74.43% of the total energy consumption, while the energy consumption applied to pollutants only accounted for 2.11% to 17.57%. To account for the uncertainty in the energy consumption analysis of thermal desorption technology and the calculation of pollutant amount, it is believed that using the volume energy efficiency evaluation method is more meaningful for in-situ thermal desorption technology. The results of the pollutant soil-water volume energy efficiency evaluation indicate that the energy efficiency of the coupled zone is 7.91×10-6 m3·kJ-1, while that of the thermal desorption zone is 1.06×10-6 m3·kJ-1. After coupling chemical oxidation technology, the energy efficiency of in-situ thermal desorption technology is increased by about 6.5 times.
Effects of Superphosphate Addition on Nitrogen Retention in Solar-assisted Aerobic Composting of Rural Organic Wastes
LI Nan, LU Yong-ze, ZHU Guang-can, LI Shu-ping
2023, 39(9):  1221-1230.  doi:10.19741/j.issn.1673-4831.2022.0405
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Better humification can be achieved by solar-assisted aerobic composting. However, nitrogen loss is a simple consequence of the high composting temperature. This experiment designed two piles with pig manure and weeds as the composting raw materials and rice straw as the conditioner, and added 2.5% superphosphate to Pile 1 and 5% superphosphate to Pile 2 for 20 days in order to achieve the nitrogen retention effect of solar-assisted aerobic composting of pig manure. Physical and chemical characteristics as well as changes in the microbial population were examined to better understand the impact of nitrogen retention. The results show that the ammonium nitrogen content of Pile 1 decreased from 1.40 mg·g-1 to 1.34 mg·g-1, while the range of Pile 2 increased from 1.13 mg·g-1 to 1.27 mg·g-1. At the end of composting, the nitrate-nitrogen contents of the two piles were 0.29 and 0.33 mg·g-1 with the nitrogen loss ratios of 22.64% and 17.44%, respectively, indicating improved nitrogen retention in Pile 2 and better ammonia retention with the addition of 5% superphosphate. The total phosphorus of the two piles increased by 26.9% and 9.3%, and the available phosphorus content decreased by 2.3% and 18.3%, respectively with increased addition of superphosphate. The two piles' seed germination index (GI) exceeded 100%, and the C/N value also complied with the criteria for decomposition. The abundance of pathogenic species (Staphylococcus sciuri, Enterobacter cloacae, and Enterococcus casseliflavus) decreased to zero as the response developed. Pile 2 had a lower pH, a more diverse and abundant bacterial community, and less ammonia volatilization. Denitrifying bacteria (Pseudoxanthomonas, Pusillimonas, Flavobacterium) in Pile 2 was lower than that in Pile 1. At the same time, the abundances of nitrogen-preserving bacteria such as Bacillus thermolactis, Ammoniibacillus agariperforans and Bacillus licheniformis were increased, which was beneficial to nitrogen retention.
Optimization of Fermentation Process for Producing Amino Acid Water-soluble Fertilizer by Mixing Rapeseed Meal and Soybean Meal
LU Shu-shan, LIU Hao, ZHAO Yan-zhou, TU Ji-jun, CAO Hui
2023, 39(9):  1231-1238.  doi:10.19741/j.issn.1673-4831.2022.0839
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Amino acid water-soluble fertilizer boasts advantages such as full water solubility, high activity, and rich nutritional content. It serves to enhance crop yield and quality, while also contributing to soil pH balance and soil improvement. As a novel and functional fertilizer, it employs a mixture of rapeseed meal and soybean meal as raw materials. Utilizing laboratory-preserved Lactobacillus plantarum G71, commercial yeast, and Bacillus subtilis, the fermentation process is optimized through methodologies like orthogonal testing, Plackett-Burman experiments, climbing response surface methodology, and Box-Behnken Design. The optimal fermentation conditions were found to be a fermentation time of 217.68 hours, initial pH of 9.12, material-to-water ratio of 1:7.008, inoculation rate of 3%, and turning interval of 24 hours. Verified results indicate a yield of free amino acids reaching 76.8 g·kg-1 within the fermentation solution. Therefore, employing mixed bacterial fermentation effectively enhances the amino acid content of fermentation solutions derived from agricultural residues like rapeseed meal and soybean meal, subsequently elevating resource utilization efficiency. This approach holds significant implications for the advancement of ecologically sustainable, high-value agriculture.