Carbon To Nitrogen Ratio Research Articles

Implication of land use shifting on land degradation and restoration potential of conservation agriculture in India's North-West Himalayan region

The soil organic matter is a crucial factor in determining soil characteristics and productivity; however various land management practices degrade or aggrade the soil health. The objective of this study was to look at the influence of land-use conversion on soil health by using the concept of stratification ratio (SR) of soil organic carbon (SOC) and total nitrogen (TN) and appraise SR as a predictor of SOC and TN stock and soil health for India's North-West Himalayan region. The research is oriented toward assessing the consequences of various land use regimes' impacts on SOC and TN depth distribution, storage, and stratification and, hence, identifying appropriate sustainable tillage techniques for the region. The research was accomplished in 2020–21 in the long-term experimental plot with four land uses, namely control [natural sal forest (Shorea robusta L.), conventional tillage (CT), reduced tillage (RT), and zero tillage (ZT)] in a rainfed system of north-western Indian Himalayas. A decrease of 79% in the mean weighted diameter of CT was observed after conversion from forest land to CT; however, the decrease was only 50% in the case of the adoption of ZT. Further, the surface soil (0–5 cm) SOC was significantly different from each other, with forest soil having the highest SOC (27.5 ± 0.21 g kg−1) and CT having the lowest SOC (11.0 ± 0.09 g kg−1). The stock of SOC and TN increased significantly with increment in soil depth, and among landuses, the highest SOM was observed with forest and the lowest with CT. Among the treatments, forest (56.56 ± 1.90 Mg ha−1) had significantly higher SOC storage than conservation agriculture (CA) (42.84 ± 0.27 Mg ha−1, ZT, and 41.41 ± 1.84 Mg ha−1, RT) and CT (41.33 ± 1.19 Mg ha−1) based on equivalent soil mass approach. For forest land use, except the surface layer (0–5:5–10), all the soil layers had SR >2, whereas, for ZT, the bottom two layers (0–5:20–25 and 0–5:25–30) had SR >2 and for RT, only the bottom layer (0–5:25–30) was having SR > 2. It was observed that the conversion of land use to CT reduced the SR of SOM drastically; however, by adopting CA, the SR had been restored to near normal in forest land use. The carbon pool index (CPI) was used to determine the effects of soil tillage and residue incorporation on soil quality improvement with respect to a sal forest. The CPI value increased significantly with an increase in soil depth for three land uses, and also, at each soil depth, the CPI followed the ZT > RT > CT trend. Thus, CA may be considered a viable alternative to CT for improving soil physicochemical parameters.

Biochar Addition in Membrane Bioreactor Enables Membrane Fouling Alleviation and Nitrogen Removal Improvement for Low C/N Municipal Wastewater Treatment

Membrane bioreactors (MBRs) are frequently used to treat municipal wastewater, but membrane fouling is still the main weakness of this technology. Additionally, the low carbon-nitrogen (C/N) ratio influent has been shown to not only increase the membrane fouling, but also introduce challenges to meet the effluent discharge standard for nitrogen removal. Herein, the authors addressed the challenges by adding cost-effective biochar. The results suggested that the biochar addition can enable membrane fouling alleviation and nitrogen removal improvement. The reduced membrane fouling can be ascribed to the biochar adsorption capacity, which facilitates to form bigger flocs with carbon skeleton in biochar as a core. As a result, the biochar addition significantly altered the mixed liquor suspension with soluble microbial product (SMP) concentration reduction of approximately 14%, lower SMP protein/polysaccharide ratio from 0.28 ± 0.02 to 0.22 ± 0.03, smaller SMP molecular weight and bigger sludge particle size from 67.68 ± 6.9 μm to 113.47 ± 4.8 μm. The nitrogen removal is also dramatically improved after biochar addition, which can be due to the initial carbon source release from biochar, and formation of aerobic-anaerobic microstructures. Microbial diversity analysis results suggested more accumulation of denitrification microbes including norank_f__JG30-KF-CM45 and Plasticicumulans. Less relative abundance of Aeromonas after biochar addition suggested less extracellular polymer substance (EPS) secretion and lower membrane fouling rate.

Patterns and controlling factors of soil carbon sequestration in nitrogen-limited and -rich forests in China-a meta-analysis.

Soil organic carbon (SOC) management has the potential to contribute to climate change mitigation by reducing atmospheric carbon dioxide (CO2). Understanding the changes in forest nitrogen (N) deposition rates has important implications for C sequestration. We explored the effects of N enrichment on soil carbon sequestration in nitrogen-limited and nitrogen-rich Chinese forests and their controlling factors. Our findings reveal that N inputs enhanced net soil C sequestration by 5.52-18.46 kg C kg-1 N, with greater impacts in temperate forests (8.37-13.68 kg C kg-1 N), the use of NH4NO3 fertilizer (7.78 kg Ckg-1 N) at low N levels (<30 kg Ckg-1 N; 9.14 kg Ckg-1 N), and in a short period (<3 years; 12.95 kg C kg-1 N). The nitrogen use efficiency (NUE) varied between 0.24 and 13.3 (kg C kg-1 N) depending on the forest type and was significantly controlled by rainfall, fertilizer, and carbon-nitrogen ratio rates. Besides, N enrichment increased SOC concentration by an average of 7% and 2% for tropical and subtropical forests, respectively. Although soil carbon sequestration was higher in the topsoil compared to the subsoil, the relative influence indicated that nitrogen availability strongly impacts the SOC, followed by dissolved organic carbon concentration and mean annual precipitation. This study highlights the critical role of soil NUE processes in promoting soil C accumulation in a forest ecosystem.

Designing of Integrated Solid Waste Management at City Amanganj Dist. Panna Madhya Pradesh, India

The growth of cities might evidently manage the essential water supply and wastewater treatment services. It maintainsthe population to accelerate on amount of municipal solid waste generation. The revenues of SWM have managed around28% of total spending. The study has revealed that 4MT per day has been obtained from Amanganj District Panna, MadhyaPradesh. It has quantity and properties that measure the market with the product to meet with the vermicompostingmethod. The waste consists of decomposable organic matter through high carbon-nitrogen ratio by bio-composting.The study show has added on an efficient process with a stabilized way to manage and solve the problems arising on theadverse effects of household waste. This can improve the current solid waste management services offered by the Municipalgovernment of Amanganj to explore the constraints with the issues arriving on a suitable solution. Therefore, the sitesuitability has carried out through governmental records with the SWM system. It has derived on the different thematiclayers with solid waste dumping. A solid waste management system design with the waste segregation and treatment ofdisposal as well as capacity of engineered with the composting yard with the multiple chamber and layout of the facility

Acclimation by diverse phytoplankton species determines oceanic carbon to nitrogen ratios

AbstractThe carbon to nitrogen (CN) ratio of phytoplankton connects the carbon and nitrogen cycles in the ocean. Any variation in this ratio under climate change will alter the amount of carbon fixed by photosynthesis, and ultimately the amount sequestered in the ocean. However, a consistent mechanistic explanation remains lacking for observed species‐specific variations in phytoplankton CN ratios. We show that acclimation to ambient environmental conditions explains the observed variation of phytoplankton CN ratios by incorporating phytoplankton acclimation theory based on a resource allocation trade‐off between carbon vs. nitrogen acquisition capacity into a three‐dimensional marine ecosystem model. Inter‐specific differences in CN ratio and its sensitivity are caused by inter‐specific differences in Droop's minimum nitrogen cell quota. Our model, constrained by observed phytoplankton parameters, shows that the global mean phytoplankton CN ratio is greater than the canonical Redfield ratio, as suggested previously based on regional in situ observations.

Physico-chemical assessment of on-farm bioconversion of organic waste in dairy farms in context to sustainability and circular bioeconomy

ABSTRACT On a milk-producing dairy farm, milk production is correlated with manure production and the number of cattle, and manure is widely used as a soil fertilizer. However, excessive dairy manure production is linked with greenhouse gas emissions and water quality issues. On-farm planning of manure storage and application to enhance soil nutrients are essential in a circular economy to reduce environmental impact, where manure is not landfilled and incinerated. Instead, it creates a nutrient resource for crops and soil. Dairy manure, which is rich in nutrients, is a valuable fertilizer that contains many nutrients such as nitrogen (N), organic matter (OM), phosphorous (P), Potassium (K) and micronutrients. In this work, a pilot field research was conducted between 2016 and 2018 in various parts of California, USA (San Joaquin Valley, Sacramento Valley, Shasta Cascade, and the North Coast of California) to assess physio-chemical characteristics of solid fractions of dairy manure among various dairy farms. A total of 156 samples were collected from the gut (n = 107) and toe (n = 49) of the manure piles across California for determining total solid (TS), volatile solid (VS), temperature, moisture content and carbon-nitrogen ratio (C: N). Here, using the observations of field study and analysis, we show that C: N, OM and MC of solid fractions of dairy manure vary significantly among dairy farms. The average C: N ratio of manure (26–32) among various regions was close to an ideal C: N value of 24:1 for soil microbes to stimulate nutrient release to crops. Manure pH ranged between 7.0 and 8.0, which was close to an optimal pH range for common crops (6.0–8.0). Moreover, considering less cost and surplus availability, manure will likely continue providing a cost-effective organic fertilizer resource compared to commercial chemical fertilizers.

Study on the Technology of River Sediment Used as Planting Soil

This article conducted on-site experiments on improving river sediment to produce planting soil, using aerobic composting technology. The main composting parameters include carbon nitrogen ratio, moisture content, pH value, and temperature. In order to adjust the carbon nitrogen ratio of the sediment, auxiliary materials such as chicken manure, pig manure, rice straw, and wheat straw can be added according to the carbon nitrogen ratio of the sediment itself and relevant specifications. In this article, rice straw and rice husk are added. In the on-site test, a group of piles were maintained above 60 ℃for 3 days, achieving harmless treatment of the sediment. However, when the carbon nitrogen ratio of the pile is less than 20, it is difficult for the sediment temperature to reach 60 ℃, and it cannot be guaranteed that the sediment can achieve harmless treatment. After the improvement, the obstacle factors of the sediment have been reduced, meeting the standard requirements. Nutrients increased, and among the 36 indicators after sediment improvement, only nitrogen was below the standard limit, while potassium and magnesium exceeded the standard limit. All other indicators met the standard requirements.

Biodiversity dynamics in primary mid-taiga spruce forests after total windthrow in the Vodlozersky National Park, Russia

In windthrow-affected areas, the research of biota is of high relevance taking into account the lack of knowledge about the dynamics of their flora, soil properties, and tree stand regeneration. An important task is to study the mechanisms of the natural dynamics of plant communities after major disturbances in large boreal forests. This paper was aimed to investigate the effects of a total windthrow event on the dynamics of biodiversity in pristine mid-boreal spruce (Picea abies) forests. The study was carried out in the Vodlozersky National Park (Northwest Russia: Arkhangelsk Region and Republic of Karelia), situated in the northern and middle taiga subzones. A series of permanent sample plots was established in an area affected by massive windthrow in 2000. The windthrow consequences of the forest communities have been studied, starting from the year of the event (2000) at 2–5-year intervals. A soil survey has been conducted in 2016. Windthrown trees, situated in the sample plots, were counted by species and diameter classes. Natural regeneration was estimated in subplots with a division to height cohorts and vitality status. Geobotanical relevé sampling of the ground vegetation has been conducted in 1 × 1-m permanent plots. Aphyllophoroid fungi (Basidiomycota) were counted by fruit bodies. Main soil pits and partial pits were dug. The morphological description of soils was produced in both undisturbed and disturbed sites in the study area. Obtained data, covering 20 years of surveys of various components of the forest plant communities (tree stand, advance regeneration, ground vegetation, wood-destroying fungi, soils), were analysed. We found that 16–20 years after the windthrow event the species and age structure of the tree stand has been considerably changed due to the forest stand rejuvenation. Post-windthrow regeneration of coniferous species in the true-moss group of forests has been successfully going on. By the end of the second decade after the windthrow event, cowberry spruce forests contained 4300 individuals/0.01 km2 of viable spruce regeneration, including 1500 individuals/0.01 km2 belonging to the large size category of spruce trees. In the bilberry-Sphagnum-type forest, spruce regeneration amounted to 8700 individuals/0.01 km2, including 2200 individuals/0.01 km2 belonging to the large size category of spruce trees. This amount is sufficient to ensure the development of spruce-dominated communities in the future. Since the forest ecosystems were recovering after the windthrow, the biodiversity of changed, that was reflected in an increase in the species composition of the ground vegetation and fungal communities. Over the study period (2001–2021), surveys of the sample plots demonstrated 83 aphyllophoroid fungi species, including five species included in the Red Data Book of the Republic of Karelia, as well as 22 taxa, considered old-growth forest indicator- and specialist species. The number of wood-destroying fungi species was the highest in the period from the 12th to the 19th post-windthrow years. The changes in soil properties on windthrow-affected sites were more explicit in the upper horizons: soil acidity decreased; both potassium and carbon content increased; nitrogen distribution across horizons became more even. An increase in the carbon-nitrogen ratio was detected in the Е and BF horizons. The obtained data can be used for predicting the regeneration of pristine mid-boreal spruce forests affected by catastrophic disturbances.

土壤碳氮特征沿干旱梯度时空格局及对气候变化的响应——基于中国生态系统研究网络(CERN)长期定位监测数据

PDF HTML阅读 XML下载 导出引用 引用提醒 土壤碳氮特征沿干旱梯度时空格局及对气候变化的响应——基于中国生态系统研究网络(CERN)长期定位监测数据 DOI: 10.5846/stxb202205311527 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中国科学院国际合作局对外合作重点项目(121311KYSB20170004);中国科学院战略性先导科技专项(XDA19020305);中国博士后科学基金面上资助项目(2020M670439) Spatio-temporal patterns of soil carbon and nitrogen characteristics along aridity gradients and their responses to climate change: Based on long-term field observation data of Chinese Ecosystem Research Network Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤碳氮含量及其化学计量特征是表征生态系统碳汇能力和土壤质量的重要指标,在支撑生态系统结构功能以及缓解气候变化中起着关键作用。利用中国生态系统研究网络(CERN)长期定位监测数据,分析了土壤碳氮特征沿干旱梯度的时空规律及其对气候变化的响应。结果表明:空间上,典型荒漠草原生态系统随着干旱加剧,土壤有机碳和全氮含量减少,土壤有机碳对干旱响应的敏感性降低,而土壤全氮对干旱响应的敏感性增加,土壤有机碳随土壤全氮含量的增加而增加。时间上,2005-2018年,荒漠草原生态系统土壤有机碳和全氮含量变化速率沿干旱梯度表现出由负转正的增加趋势,其中,干旱区呈减少趋势,半干旱和半湿润地区呈增加趋势,鄂尔多斯站和沙坡头站呈显著增加趋势。从影响因素来看,土壤碳氮特征对降水量增加的敏感性沿干旱梯度呈现出先增强后减弱的"上凸"抛物线趋势,温度变化对土壤碳氮特征的调控没有表现出明显的干旱梯度效应。土壤碳氮比、土壤有机碳含量、土壤全氮含量对降水量和平均温度变化响应的敏感性均依次降低。不同干旱梯度土壤碳氮特征的变化规律为未来气候变化下生态系统结构与功能预测提供科学依据。 Abstract:Soil organic carbon content (SOC), soil total nitrogen content (TN) and its ecological stoichiometric characteristics indicate the carbon sink efficiency and soil quality of ecosystem, and play the critical role in supporting ecosystem structure and function and mitigating climate change. Using long-term field observation data of ecological stations of the Chinese Ecosystem Research Network (CERN), this study analyzed the spatio-temporal patterns of the SOC, TN and its stoichiometric characteristics of soil, and their responses to climate change along aridity gradient. Results showed that with the aridity intensifying spatially, the SOC and TN decreased, the response sensitivity of SOC to aridity decreased and that of the TN increased. The SOC was increased along the TN increasing. Temporally, the rate of SOC and TN changes with aridity gradient showed increased with the aridity mitigating, which were negative in the aridity region and positive in semi-arid region from 2005 to 2018. The SOC and TN of Shapotou station and Erdos station were significant increased with aridity change in past more than one decade. Additionally, the response sensitivity of the SOC, TN and stoichiometric characteristics to precipitation increasing showed an "upwardly convex" pattern, which firstly increased and then decreased with the aridity gradient, but none for temperature. The response sensitivity of the SOC, TN and carbon-nitrogen ratio to changes in precipitation and temperature were as follows: the sensitivity of soil carbon-nitrogen ratio > the sensitivity of SOC > the sensitivity of TN. It is implied that the rule of the SOC, TN and its ecological stoichiometric characteristics changes in different aridity gradient region provide the scientific basis for the of ecosystem structure and function prediction under future climate change. 参考文献 相似文献 引证文献

Dynamics of elemental composition in the sediments of Can Gio mangrove Biosphere reserve period of 13 years after Durian typhoon 2006

Corg levels, Ntot level, and CN ratio are indicators for nitrogen limitation of plants and other organisms in the recovery process of storm-damaged forests. Here we compare between the 2 sections by multifactor-ANOVA analysis sediment characteristics along with the succession of a monoculture of Rhizophora in the South Vietnam with data from from 2007 to 2019 to know the initial state of the sediment after the disturbance and change during the self-recovery of the ecosystem. In the first stage, the Corg levels were much higher, while the Ntot deficiency was a crisis. Due to the presence of tall trees and the recovery process, the growth of nitrogen fixation mediated by attached microalgae on the surface sediments and the microbes living in the rhizosphere. Follow-up assessments and field experiments are needed to understand the sediment characteristics vary during the self-recovery of the ecosystem.

Agroeconomic Value of Some Lathyrus and Vicia Species in the Republic of Moldova

The efficient use of the biological potential of the leguminous plants that are adapted to the local climatic conditions becomes more and more relevant. The local ecotype of the species Lathyrus sativus, Lathyrus sylvestris, Lathyrus tuberosus, Vicia hirsuta, Vicia sativa, Vicia tenuifolia maintained in monoculture on experimental land in the NBGI Chişinău, served as objects of study. We found that the dry matter of the studied whole plants contained 169-257 g/kg CP, 96-125 g/kg ash, 219-346 g/kg CF, 244-371 g/kg ADF, 427-576 g/kg NDF, 34-58 g/kg ADL, 210-313 g/kg Cel, 183-205 g/kg HC, 64-150 g/kg TSS, with 59.3-69.4% DMD, RFV = 93-151, 11.87-13.55 MJ/kg DE, 9.75-11.13 MJ/kg ME, 5.77-7.22 MJ/kg NEl. The prepared hay contained 153-264 g/kg CP, 91-135 g/kg ash, 244-356 g/kg CF, 294-393 g/kg ADF, 475-606 g/kg NDF, 36-65 g/kg ADL, 258-329 g/kg Cel, 191-214 g/kg HC, 6-99 g/kg TSS, with 59.2-66.0% DMD, RFV = 90-129, 11.57-12.95 MJ/kg DE, 9.50-11.09 MJ/kg ME, 5.51-7.10 MJ/kg NEl. The haylage is characterized by pleasant smell and color, pH = 4.40-4.95, 4.7-6.1 g/kg acetic acid, 27.9-38.0 g/kg lactic acid, butyric acid was not detected, 159-180 g/kg CP, 105-125 g/kg ash, 296-343 g/kg CF, 316-360 g/kg ADF, 460-579 g/kg NDF, 51-55 g/kg ADL, 263-309 g/kg Cel, 142-219 g/kg HC, 43-106 g/kg TSS, 60.9-64.1% DMD, RFV = 98-129, 12.03-12.61 MJ/kg DE, 9.88-10.35 MJ/kg ME, 5.89-6.37 MJ/kg NEl. The harvested fresh mass and the haylage prepared from the studied species can be used as substrates in biogas production via anaerobic digestion for renewable energy production, with carbon nitrogen (C/N) ratios 12-20. The biochemical methane potential reached 320-378 litre/kg organic matter. The investigated leguminous species are an important forage source for livestock, many birds, bees and entomophagous insects, and they are excellent plants for erosion control and for reseeding and increasing the economic value of permanent and temporary grasslands. The harvested biomass can be used as alternative fodder for farm animals or as substrates in biogas generators for the production of renewable energy.

Study on the Application of Bio-flocs Technology in Tail Water Treatment

In aquaculture, the deposition of biological manure and residual bait in water can cause water pollution. If the discharged aquaculture tail water is not treated in time, the surrounding water environment will be affected and the quality of aquaculture organisms will be reduced. Controlling inorganic nitrogen by controlling the carbon-nitrogen ratio is a potential aquaculture system control method. This method can effectively reduce the accumulation of inorganic nitrogen in ponds, convert ammonia and nitrite nitrogen in water into proteins for culture organisms, and inhibit the growth of harmful microorganisms. This paper discusses the research development of bio-flocs technolgy at home and abroad, how to treat tail water with maximum efficiency in order to solve the problems of debris and feed retention in aquaculture water and realize the reuse of bait, and purifying water quality.

Changes in cropland soil carbon through improved management practices in China: A meta-analysis

Recommended management practices (RMPs, e.g., manuring, no-tillage, crop residue return) can increase soil organic carbon (SOC), reduce greenhouse gas emissions, and maintain soil health in croplands. However, there is no consensus on how RMPs affect the SOC storage potential of cropland soils for climate change mitigation. Here, based on 2301 comparisons from 158 peer-reviewed papers, a meta-analysis was conducted to explore management-induced SOC stock changes and their variations under different conditions. The results show that SOC stocks in the 0–20 cm layer were increased by 31.8% when chemical fertilization combined with manure application was compared with no fertilizer; 9.98% when no-tillage was compared with plow tillage; and 10.84% when straw return was compared with removal. The RMPs favorably increased SOC stock in arid areas, and in alkaline and fine-textured soils. Initial SOC, carbon-nitrogen ratio, and experimental duration could also affect SOC storage. Compared with the initial SOC stock, RMPs increased the SOC sequestration potential by 2.6–4.5% in the 0–20 cm soil depth, indicating that these practices can help China achieve targets to increase SOC by 4.0‰. Hence, it is essential to implement RMPs for climate change mitigation and soil fertility improvement.

Evaluation of Pollution Level, Spatial Distribution, and Ecological Effects of Antimony in Soils of Mining Areas: A Review.

The first global-scale assessment of Sb contamination in soil that was related to mining/smelting activities was conducted based on 91 articles that were published between 1989 and 2021. The geographical variation, the pollution level, the speciation, the influencing factors, and the environmental effects of Sb that were associated with mining/smelting-affected soils were analyzed. The high Sb values mainly occurred in developed (Poland, Italy, Spain, Portugal, New Zealand, Australia) and developing (China, Algeria, Slovakia) countries. Sb concentrations of polluted soil from mining areas that were reported in most countries significantly exceeded the maximum permissible limit that is recommended by WHO, except in Turkey and Macedonia. The soil Sb concentrations decreased in the order of Oceania (29,151 mg/kg) > North Africa (13,022 mg/kg) > Asia (1527 mg/kg) > Europe (858 mg/kg) > South America (37.4 mg/kg). The existing extraction methods for Sb speciation have been classified according to the extractant, however, further research is needed in the standardization of these extraction methods. Modern analytical and characterization technologies, e.g., X-ray absorption spectroscopy, are effective at characterizing chemical speciation. Conditional inference tree (CIT) analysis has shown that the clay content was the major factor that influenced the soil Sb concentration. Non-carcinogenic risks to the public from soil Sb pollution were within the acceptable levels in most regions. An Sb smelter site at the Endeavour Inlet in New Zealand, an abandoned open-pit Sb mine in Djebel Hamimat, Algeria, an old Sb-mining area in Tuscany, Italy, and Hillgrove mine in Australia were selected as the priority control areas. Cynodon dactylon, Boehmeria, Pteris vittata, and Amaranthus paniculatus were found to be potential Sb accumulators. All of the values of bioaccumulation factors for the crops were less than one. However, ingestion of Sb through crop consumption posed potential non-carcinogenic health risks, which should not be neglected. The soil variables (pH, Eh, total sulfur, carbon nitrogen ratio, total organic carbon, and sulfate), the total Sb and the bioavailable Sb, and heavy metal(loid)s (As, Pb, and Fe) were the major parameters affecting the microbial community compositions.

Physico-Chemical Properties of Wetland Soils Affected by Crude Oil Spillage in Niger Delta Area, Nigeria

Loss of soil fertility through loss of soil organic matter, leaching of nutrients, loss of the nutrient-laden topsoil, changes in soil-pH, reduction in cation exchange capacity, salinization, water logging and other forms of soil degradation are major problems associated with agricultural productivity in the oil producing areas of Nigeria. This analysis investigated some selected physico-chemical properties of wetland soils affected by crude oil spillage in Bodo city in the Niger Delta region of Nigeria. Field reconnaissance survey using a handheld Geographic Positioning system (GPS) and survey technique involving random sampling, was used in siting soil profile pits. The unpolluted samples were collected 50 meters away from the polluted site but in the same geographic region and was used as control site. Soil samples were collected based on degree of horizon differentiation and analyzed using routine and special analytical techniques. Soil data were subjected to analysis of variance using Genstat program. Result shows that soil physical properties of the polluted site: moisture content, soil bulk density, and soil texture were highly significant (p=0.01 and 0.05) when compared to the unpolluted site while some chemical soil properties analysed especially soil pH, organic matter, carbon-nitrogen ratio, available phosphorus were affected by crude oil spillage. Results from this study affirm that crude oil can have detrimental effect on soil physico-chemical properties, which implies low soil fertility and thereby affect crop production and increase food insecurity within the study site. Further studies involving more edaphic properties, biotoxic metals and their bioaccessibility in crops growing on waterside affected by crude oil spill will surely enhance knowledge and management of the these highly industrially influenced soils. Also, international and national oil and gas companies should carry out their activities with international best practice.

PENGARUH RASIO KARBON-NITROGEN DALAM ENSILAGE CAMPURAN MUKUNA LOKAL (MUCUNA SP) DAN RUMPUT KUME (SORGHUM PLUMOSUM VAR. TIMORENSE) SEGAR TERHADAP KANDUNGAN NUTRISI PRODUK (The effects of carbon-nitrogen ratio in ensilage of local mucuna (mucuna sp.) And...

The main problem in preservation of protein source forages in silage making is spoilage due to high buffering characteristic of protein. This might relates to low carbon-nitrogen (C-N) ratio in these plants. This study aimed at determining the best level of C-N ratio in ensilage process of a grass-legume mixture. A 3x4 completely randomized design (CRD) was deployed to test three C-N ratio levels as treatments. The treatments were CN20 (Mucuna sp + kume grass + rice bran to reach C-N ratio of 20, or 30 (CN30) or 40 (CN40). Variables measured were dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), and crude fiber (CF) content of the silage. Data were analyzed using General Linear Model for CRD with an alfa value of 0.05. Treatment differences were determined using Duncan test. The results showed that C-N ratio had high significant effects on DM content (ranged from 22.5 to 32.0%), and CP content (ranged from 7.5 to 9.6%). Significant treatment effects were detected in OM content (ranged from 90.5 to 91.8%), and EE content (ranged from 2.82 to 3.66%). Meanwhile, CF was not effected by C-N ratio (ranged from 39.0 to 3.0%. 44.2%). It could be concluded that C-N the ratio of 30 is the best treatment in silage making using mixture of lelehanak-kume grass as it shows the highest OM content and had no significant difference with CN20 in CP content.

The Effects of Suillus luteus Inoculation on the Diversity of Fungal Communities and Their Structures in the Soil under Pinus massoniana Located in a Mining Area

As important decomposers and plant symbionts, soil fungal communities play a major role in remediating heavy-metal-polluted soils. However, the diversity and structures of fungal communities generally remain unclear in mining areas. This study aimed to assess the rhizospheric fungal-community composition of Masson pine (Pinus massoniana) in the lead-zinc mining area of Suxian District, Hunan Province, China. This experiment undertook the following three treatments: Masson pine inoculated with or not inoculated with Suillus luteus, and bulk soil without plants as a control. The results thereof showed that inoculation of ectomycorrhizal fungi could enlarge plants’ capability to absorb heavy metals and secrete soil enzymes. The richness and diversity of fungi in the rhizospheric soil were significantly higher than of those in the bulk soil (p &lt; 0.05), but no significant difference was noted between the rhizospheric soils inoculated with and not inoculated with ectomycorrhizal (ECM) fungi as the community structure changed. The rhizospheric fungi belonged to 6 phyla, 25 classes, 65 orders, 115 families, and 150 genera, and the dominant phyla were Chytridiomycota (50.49%), Ascomycota (38.54%), and Basidiomycota (9.02%). Through use of LEfSe and heatmapping, the relative abundances of Suillus, Paraglomus, Agaricus, and Tulasnella were found to be the highest in the soil with ECM fungus inoculation. RDA showed that the community structure nearly changed with ECM-fungus inoculation; this was significantly related to soil water content, the carbon–nitrogen ratio, bulk density, available potassium, and soil enzymes. Altogether, inoculation with ECM fungi may change the habitation environments of microorganisms and dominant fungi in soil, providing keystone screenings in heavy-metal-contaminated mining areas.

Discrepant Effects of Flooding on Assembly Processes of Abundant and Rare Communities in Riparian Soils.

Numerous rare species coexist with a few abundant species in microbial communities and together play an essential role in riparian ecosystems. Relatively little is understood, however, about the nature of assembly processes of these communities and how they respond to a fluctuating environment. In this study, drivers controlling the assembly of abundant and rare subcommunities for bacteria and archaea in a riparian zone were determined, and their resulting patterns on these processes were analyzed. Abundant and rare bacteria and archaea showed a consistent variation in the community structure along the riparian elevation gradient, which was closely associated with flooding frequency. The community assembly of abundant bacteria was not affected by any measured environmental variables, while soil moisture and ratio of submerged time to exposed time were the two most decisive factors determining rare bacterial community. Assembly of abundant archaeal community was also determined by these two factors, whereas rare archaea was significantly associated with soil carbon-nitrogen ratio and total carbon content. The assembly process of abundant and rare bacterial subcommunities was driven respectively by dispersal limitation and variable selection. Undominated processes and dispersal limitation dominated the assembly of abundant archaea, whereas homogeneous selection primarily driven rare archaea. Flooding may therefore play a crucial role in determining the community assembly processes by imposing disturbances and shaping soil niches. Overall, this study reveals the assembly patterns of abundant and rare communities in the riparian zone and provides further insight into the importance of their respective roles in maintaining a stable ecosystem during times of environmental perturbations.

Effect of pretreatment on Typha biomass for biogas production

Plant biomass as an alternative energy source serves as a viable option for improving sustainable development and reducing greenhouse gas emissions. However, the tight bonding within its constituents may hinder anaerobic digestion, thus, requires pretreatment to break down the complex polysaccharide structure into simpler disaccharide and monosaccharide sugars to facilitate digestion and enhance the production of biogas. The research determined the effect physical and chemical pre-treatment methods of Typha biomass for biogas production. Characteristics determined include; carbonnitrogen (C-N) ratio for Typha biomass, temperature, pH, total solids (TS) and volatile solids (VS) of slurry formed by mixing the biomass with cow-dung in ratio 1:1. The volume of biogas produced was determined by water displacement method using an anaerobic digester while the mass balance approach was used to estimate the biogas yield from the TS/VS lost. Results indicated 31.6 C-N ratio; pH of 6.7; Temperature of 32.4OC and TS of 11.3%, which falls within suitable ranges reported for biogas production. The volume of biogas produced was 180 cm3, 235cm3 and 118cm3 for control, physical and chemical pre-treated samples respectively. Similarly, the biogas yield was 21mg/l, 15mg/l and 48mg/l for control, physical and chemical pre-treatment respectively. Hence the findings revealed physical pre-treatment as the best pretreatment method for biogas generation from Typha biomass in relation to chemical pretreatment and untreated Typha biomass.

Differences in the composition, source, and stability of suspended particulate matter and sediment organic matter in Hulun Lake, China.

The occurrence, migration, transformation, and stability of sediment (SOM) and suspended particulate (SPOM) organic matters have important effects on the environmental behaviors of carbon, nitrogen, phosphorus, and other pollutants in a water environment. The content, composition, fluorescence characteristics, source, and stability of SOM and SPOM in Hulun Lake, a typical lake in cold and arid region of China, were compared by sequential extraction, three-dimensional fluorescence spectroscopy, parallel factor technique, carbon-nitrogen ratio, and stable carbon isotope. Contents of SOM and SPOM in north and west were higher than those in east and south. The average content of SPOM (24.70 ± 4.63g/kg) was slightly higher than that of SOM (23.04 ± 10.27g/kg), but the difference was not significant. Humin was the dominant component in SOM and SPOM, accounting for 73.7% and 61.2%, respectively. Humus was the main fluorescence component of water-extractable organic matter in SOM and SPOM, accounting for 79.9% and 70.4%, respectively, of the total fluorescence intensity. SOM and SPOM were derived from terrestrial sources with a relative contribution rate of about 70%. SPOM was more influenced by autochthonous sources and had a significantly lower humification degree and stability than SOM. Effects of climate changes on migration, transformation, stability, and bioavailability of organic matters and endogenous pollutants closely related to organic matters in lakes of cold and arid regions should be paid attention in the future.