Organic matter quality defined by 13C NMR spectroscopy explains nitrogen mineralization and soil aggregation better than C/N ratio

Soil organic matter (SOM) plays a key role in sustainable agricultural production by the improvement of physical, chemical and biological properties of soils. The decline in organic matter (OM) content of many soils is becoming a major process of soil infertility and degradation, particularly in European semi-arid Mediterranean regions. Organic amendments can increase SOM content, thus influence soil characteristics by the interdependent modification of biological, chemical and physical properties. Then, a better understanding of the impact of organic amendment on soil processes is required. The underlying hypothesis of this thesis is that the organic amendment can regulate soil processes which directly linked to its initial chemical characteristics. However, identifying and defining OM quality based on molecular composition is operationally difficult. In fact, OM contain multiple types of biomolecules with different aqueous solubility, and, hence, the different susceptibility to microbial decomposition (e.g. peptides, carbohydrates, lipids, lignin, organic acids, and polyphenols). Generally, lignin/N and C/N ratios are extensively used as descriptors of OM quality, but those simple indicators are not always give reliable information about their potential of effects on soil functions. In this context, several chemical throughput methods, such as pyrolysis-gas chromatography/mass spectrometry, near infrared reflectance spectroscopy and nuclear magnetic resonance (NMR) spectroscopy have been utilized to characterize OM at the molecular level. In particular, solid-state13C-CPMAS NMR spectra were found useful to provide an overview of the total organic chemical composition of complex matrices of SOM. This thesis showed that the chemical quality of OM, defined by solid-state 13C-CPMAS NMR spectra, can be an important indicator of soil functions, which explain nitrogen mineralization and soil aggregation process better than classical C/N and lignin/N ratio indices. Finally, modeling approach based on novel implementation of OM quality by 13C-CPMAS NMR, to purposely overcome the limitations of C/N as a single OM quality indicator and to explore the relationship between OM quality and soil structural stability. This thesis provides evidence for the importance of OM, and in particular its chemical quality, which influences soil processes by inter-depended modification of soil physical, chemical and biological parameters

Linking organic matter chemistry with soil aggregate stability: Insight from 13C NMR spectroscopy

Soil aggregation is considered as a crucial process in agro-system sustainability due to the role in soil physical, chemical and biological dynamics. Here we tested the hypothesis that the initial chemical traits of organic matter (OM) may help to explain the variability of soil aggregation dynamics after organic amendment. We characterized ten OM types (alfalfa litter, biochar, cellulose, glucose, green compost, maize litter, manure compost, meat powder, sawdust, and solid digestate) by 13C-CPMAS NMR and elemental chemical features to investigate the effects of amendment quality on soil aggregation. In a manipulative factorial experiment, dry samples (200 g) of three soil types (S1, S2 and S3) with different texture, high pH (7\u20139), and similar OM content, were incorporated with 4 g (2% w/w) of dry, 2 mm-grounded OM, incubated in mesocosms for 300 days under controlled temperature (18 \ub1 2 \ub0C night and 24 \ub1 2 \ub0C day), and sampled at 4 dates for measuring aggregation index (AI), based on water stability of soil aggregates (WSA). We found that meat powder and alfalfa litter induced a rapid initial increase of AI, exceeding that of the controls by one to two orders of magnitude, likely acting as a C source for microbes. Biochar incorporation in soil barely affected AI, with intermediate effects with other OM types. Considering C bond types corresponding to OM 13C-CPMAS NMR spectral regions, carbonyl C was only correlated to early AI, possibly due to overlapping signals of amide structures; O-alkyl C and di-O-alkyl C (carbohydrate fraction) were positively associated to AI, indicating a promoting effect on soil structure, while aromatic C fractions showed an opposite pattern, possibly related to aggregate protection by coatings associated to water repellency, or to direct aggregate internal binding. This study demonstrates that OM chemical quality plays an important role in soil aggregation process, with the molecular composition defined by 13C-CPMAS NMR spectroscopy being more predictive of aggregation dynamics compared to classical elemental features. As such, this study provides a significant novel contribution to clarify the relationships between OM chemistry and soil aggregation

Linking organic matter chemistry with soil aggregate stability: Insight from 13C NMR spectroscopy

Soil aggregation is considered as a crucial process in agro-system sustainability due to the role in soil physical, chemical and biological dynamics. Here we tested the hypothesis that the initial chemical traits of organic matter (OM) may help to explain the variability of soil aggregation dynamics after organic amendment. We characterized ten OM types (alfalfa litter, biochar, cellulose, glucose, green compost, maize litter, manure compost, meat powder, sawdust, and solid digestate) by 13C-CPMAS NMR and elemental chemical features to investigate the effects of amendment quality on soil aggregation. In a manipulative factorial experiment, dry samples (200 g) of three soil types (S1, S2 and S3) with different texture, high pH (7\u20139), and similar OM content, were incorporated with 4 g (2% w/w) of dry, 2 mm-grounded OM, incubated in mesocosms for 300 days under controlled temperature (18 \ub1 2 \ub0C night and 24 \ub1 2 \ub0C day), and sampled at 4 dates for measuring aggregation index (AI), based on water stability of soil aggregates (WSA). We found that meat powder and alfalfa litter induced a rapid initial increase of AI, exceeding that of the controls by one to two orders of magnitude, likely acting as a C source for microbes. Biochar incorporation in soil barely affected AI, with intermediate effects with other OM types. Considering C bond types corresponding to OM 13C-CPMAS NMR spectral regions, carbonyl C was only correlated to early AI, possibly due to overlapping signals of amide structures; O-alkyl C and di-O-alkyl C (carbohydrate fraction) were positively associated to AI, indicating a promoting effect on soil structure, while aromatic C fractions showed an opposite pattern, possibly related to aggregate protection by coatings associated to water repellency, or to direct aggregate internal binding. This study demonstrates that OM chemical quality plays an important role in soil aggregation process, with the molecular composition defined by 13C-CPMAS NMR spectroscopy being more predictive of aggregation dynamics compared to classical elemental features. As such, this study provides a significant novel contribution to clarify the relationships between OM chemistry and soil aggregation

Environmental Accounting Disclosure Practices in Bangladesh and Its Impact on Investor Decisions

The focus of this study is to identify the environmental disclosures made by Bangladeshi companies and analyze the overall disclosure practice of the countries’ industries. And also collect the investor’s feedback on whether or not environmental disclosure information is making a difference in their decision making process and their opinion about the company. For conducting the research, the study has used 5 sectors- Engineering, Pharmaceuticals, Food, Textile and Fuel and Power along with 10 companies with each stratum. This study has used the standard environmental disclosure index developed by prior researchers to show the volume of the selected companies’ environmental disclosures in the annual reports. To show the impact of the environmental disclosures on the investors’ decision, the study has conducted a survey among the investors. The study shows evidence that reinforces the fact that Bangladeshi companies are disclosing less environmental information than an ideal company should. Also there are lack of regulation and interest in disclosing proper information. Although by conducting a survey it was seen that majority of investors and probable investors are interested in these information and are supportive of eco-friendly companies

Different pathways but same result? Comparing chemistry and biological effects of burned and decomposed litter

Litter burning and biological decomposition are oxidative processes co-occurring in many terrestrial ecosystems, producing organic matter with different chemical properties and differently affecting plant growth and soil microbial activity. Here, we tested the chemical convergence hypothesis (i.e. materials with different initial chemistry tend to converge towards a common profile, with similar biological effects, as the oxidative process advances) for burning and decomposition. We compared the molecular composition of 63 organic materials - 7 litter types either fresh, decomposed for 30, 90, 180 days, or heated at 100, 200, 300, 400, 500 \ub0C - as assessed by 13C NMR. We used litter water extracts (5% dw) as treatments in bioassays on plant (Lepidium sativum) and fungal (Aspergillus niger) growth, and a washed quartz sand amended with litter materials (0.5 % dw) to assess heterotrophic respiration by CO2 flux chamber. We observed different molecular variations for materials either burning (i.e. a sharp increase of aromatic C and a decrease of most other fractions above 200 \ub0C) or decomposing (i.e. early increase of alkyl, methoxyl and N-alkyl C and decrease of O-alkyl and di-O-alkyl C fractions). Soil respiration and fungal growth progressively decreased with litter age and temperature. Plant growth underwent an inhibitory effect by untreated litter, more and less rapidly released over decomposing and burning materials, respectively. Correlation analysis between NMR and bioassay data showed that opposite responses for soil respiration and fungi, compared to plants, are related to essentially the same C molecular types. Our findings suggest a functional convergence of decomposed and burnt organic substrates, emerging from the balance between the bioavailability of labile C sources and the presence of recalcitrant and pyrogenic compounds, oppositely affecting different trophic levels

Faster N release, but not C loss, from leaf litter of invasives compared to native species in mediterranean ecosystems

Plant invasions can have relevant impacts on biogeochemical cycles, whose extent, in Mediterranean ecosystems, have not yet been systematically assessed comparing litter carbon (C) and nitrogen (N) dynamics between invasive plants and native communities. We carried out a 1-year litterbag experiment in 4 different plant communities (grassland, sand dune, riparian and mixed forests) on 8 invasives and 24 autochthonous plant species, used as control. Plant litter was characterized for mass loss, N release, proximate lignin and litter chemistry by 13C CPMAS NMR. Native and invasive species showed significant differences in litter chemical traits, with invaders generally showing higher N concentration and lower lignin/N ratio. Mass loss data revealed no consistent differences between native and invasive species, although some woody and vine invaders showed exceptionally high decomposition rate. In contrast, N release rate from litter was faster for invasive plants compared to native species. N concentration, lignin content and relative abundance of methoxyl and N-alkyl C region from 13C CPMAS NMR spectra were the parameters that better explained mass loss and N mineralization rates. Our findings demonstrate that during litter decomposition invasive species litter has no different decomposition rates but greater N release rate compared to natives. Accordingly, invasives are expected to affect N cycle in Mediterranean plant communities, possibly promoting a shift of plant assemblages

Windstorm disturbance triggers multiple species invasion in an urban Mediterranean forest

Plant invasion in forest ecosystems is a serious ecological and economic issue, deserving attention by researchers, managers and policy-makers worldwide. Many invasive plants have been reported as early successional species able to colonize disturbed areas following abrupt changes in microhabitat and resource availability. We investigated disturbance effects of a severe windstorm generated by a wet microburst (hail and rain at 160 mm h-1) remarkably affecting the canopy cover of an old-growth Quercus ilex urban forest in Southern Italy. This stand-replacing disturbance produced a mosaic of 103 gaps, 5.6 to 1632 m2 in size, over an area of 1.53 ha, uprooting 76% of the trees and decreasing thereby 85% of the standing above-ground dry biomass into the gaps. By intensive monitoring we compared above- and below-ground microclimate, soil moisture and mineral N availability in paired disturbed and control areas of the study forest. Within newly formed gaps we observed a seasonally consistent 70% higher content of nitrate nitrogen, 29% and 47% decreases of ammonia nitrogen in summer and autumn, respectively, and a higher moisture in topsoil, in addition to different above- and below-ground microclimatic conditions, with canopy cover mitigating extreme temperatures. One year after the windstorm, the microhabitat shift promoted the establishment in gaps of 15 native and 10 alien taxa previously absent in both disturbed and control plots. In such conditions, the rarefaction of the dominant Q. ilex canopy cover and the occurrence of empty niches prone to invasion could dramatically affect the local community structure and diversity. Our data indicate that stand-replacing windstorm can transiently transform the studied urban evergreen forest to an early allogenic successional community dominated, in the medium and large gaps, by annual and perennial non-native species. This is particularly relevant under a perspective of possible increasing frequency of windstorm events in the Mediterranean region in the near future

Quality of Life in Geriatric Population in a Community Development Block of Kishanganj, Bihar, India

Background: Ageing universally affects individual, family, community and society with reduction in quality of life on chronologic, biological, social, and psychological dimensions. Aim and Objectives: The study was done to assess quality of life in physical, psychological, social and environmental domains among elderly population in relation to sociodemographic character. Material and Methods: A cross-sectional study was conducted among census population of 63 elderly individuals in Chanamana village, a community development block of Potia, Kishanganj, Bihar from 1st June –31st July 2014. By interview technique the quality of life was assessed using World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire. Mean score was computed and compared by Z -test and one-way ANOVA using SPSS software, version 19.0. Results: Among the study participants with alike gender distribution, majority (68.25% were in age group of 60-69 years, general caste (69.85%), joint family (84.12%) and residing with their children (82.54%). Of them 47.62 percent were illiterates and 42.86 percent were still earning. The mean score in the distinct four domains had no significant difference in genders and age groups. Yet, residing with children and belonging to joint family were noted to be significantly improving the scores in all the four domains. Mean scores were also significantly superior in physical, psychological and environmental domains among persons who were married and had their own income. Conclusion: The study showed the quality of life within diverse domains among elderly population need to be addressed with certain socio-demographic factors (joint family, marital status, own earning and children accompanying the geriatric population)

Electricity Generating Using Gravitational Water Vortex Power Plant

In this modern age, everyone depends on electricity. So, the global energy demand is increasing rapidly. For covering this huge demand, the amount of power plants like gas, nuclear, steam, coal, diesel is increasing. This kind of power plant emits greenhouse gas and other materials, which is harmful to the environment. Moreover, the storage of coal, fuel, and methane gas is decreasing day by day. This kind of resource will end soon. The Gravitational Water Vortex Power Plant (GWVPP) offers a variant energy source that can resolve the energy demand. Low head hydropower has been one of the main focuses in recent years. GWVPP is already remarkable for low head, is environmentally friendly, and cost-efficient. So, for developing countries, it is very suitable. In the GWVPP, water enters a basin with the help of an inlet. For the shape of the basin and gravitational force, it creates a water vortex. The energy is generated from the water vortex by the rotation of the turbine. This project is an attempt to underline a theoretical and experimental understanding of GWVPP. The governing equation is the Navier-Stokes equation. The project includes the design of two different basins of different shapes, the capacity performance characteristics of the basins have been compared to understand the strength of water vortex, understanding flow rates and their effect on the strength of the vortex to generate more power, the size of the outlet diameter, and its effect on the vortex. Comparative analysis has been done to find the most optimized design

Biochar and Compost Application either Alone or in Combination Affects Vegetable Yield in a Volcanic Mediterranean Soil

The aim of this work was to compare the application of biochar, compost, and their mixtures on soil fertility and crop yields using a volcanic Mediterranean soil. For this reason, three types of organic amendments (OAs) were selected: compost1, made from olive mill waste and orchard pruning residues; compost2, made from olive mill waste, animal manure and wool residues; and biochar made from beech wood pyrolyzed at 550 °C. When selected, the OAs were characterized chemically for organic carbon (OC), total N, pH, electric conductivity (EC) and the bulk fraction of organic matter using 13C CPMAS NMR spectroscopy. In addition, soil chemistry was analysed at the end of each year for the following parameters: pH, OC, total N, CaCO3, P2O5, NH4, FDA and EC. Results showed that biochar had the highest OC and the lowest N and EC compared to both composts. Moreover, 13C CPMAS NMR showed that biochar had the lowest content of O-alkyl, methoxyl- and alkyl-C and the highest content of aromatic-C. On the other hand, compost2 and compost2+biochar mixture reduced Aubergine yield by −60% and −40%, respectively, and tomato yield by −50% and −100%, respectively. Nevertheless, a significant increase in onion and rape yields were observed when compost1, compost1+biochar and compost2 were applied, while biochar and compost2+biochar significantly decreased the yield of these crops. Overall, our results highlight that the effect of OAs on crops yield is largely variable and influenced by the interaction with soil chemistry