Organic Sources Research Articles

Co-composting: A Comprehensive Review of Its Potential in Transforming Coir Pith Waste into Nutrient-rich Manure

Coir industries in India generates around 7.5Mt of coir waste yearly, which is unsuitable for agricultural use due to its high C:N ratio, lignin, phenol, cellulose and tannin content. The accumulation of coir pith leads to adverse environmental problems due to the release of phenolic compounds, lignin, tannins etc. Biodegradation or composting is the best way to manage coir waste and thereby the environmental pollution can be avoided. Co-composting is a method of decomposing multiple organic materials, which aims to create stable humus, and overcome the limitations of composting with a single organic source. Co-composting of coir pith reduces the C:N ratio, lignin content, cellulose content and increases the nutrient contents. In co-composting technology more than one feed stock are used for composting. It can be done by treating the coir pith with organic source of nutrients viz., farm yard manure or poultry manure or agro-industrial wastes or green manure crops or leguminous weeds or treating the coir pith with organic wastes and earthworms, or treating the coir pith lignin degrading micro-organisms and or supplementing the coir pith with lime, rock phosphate etc. along with the organic sources of nutrients mentioned above to speed up the composting process. Co-composting of coir pith resulted in the production of nutrient rich organic manure within a short period of time. Application of coir pith compost had significant effect on the growth and yield attributes of crops. Harnessing the potential of coir pith can lead us towards a more sustainable and greener future.

Enhancement of removing OH bonds from low-temperature deposited silicon oxide films by adding water vapor into NH3 gas annealing at 130 oC

Abstract It was found that annealing with water-vapor-added NH3 gas (water-added NH3) is more effective than with dry NH3 at removing residual OH bonds in silicon oxide (SiOx) films deposited by atmospheric chemical vapor deposition with an organic silicon source. Fourier transform infrared spectra showed that reduction amount of OH bonds using the water-added NH3 was ~4 or ~1.3 times larger than using the conventional dry N2 or dry NH3 mixed with N2 gas without water, respectively. This result is something strange because water can be a potential candidate of OH sources. The effect of water vapor on OH-bond removal can be explained by considering following three factors. One is that low-temperature SiOx films are constrained somewhat, the second is that strained Si-O-Si bonds are in higher or more unstable energy state than strain-free ones, and the third is that highly strained bonds are easily hydroxylated to form Si-OH bonds.

Thiourea-Driven Mild Synthesis of Photochromic Zeolite without H2 for Transient Information Storage.

The synthesis of hackmanite has been a topic of research for nearly 100 years, but up to now, the reported synthesis methods inevitably use reducing H2 to introduce the F-center through high-temperature calcination to make it change color, which extremely hinders its energy efficient large-scale synthesis before commercial applications. Herein, we present a facile route to synthesize hackmanite by using organic sulfur source thiourea as a precursor in a mild and hydrogen-free process. The synthesized hackmanite exhibits UVC-specific response, fast response, high contrast coloring, and fast fading at room temperature. In view of its photochromic features, a proof-of-concept is presented for transient information storage and burning-after-reading protection; the written information can be automatically erased within 8 min at room temperature.

Different elemental stoichiometries of Fe‐limited Trichodesmium when grown under inorganic and organic phosphorus sources

AbstractTrichodesmium spp. is a colonial diazotrophic cyanobacterium found in the oligotrophic (sub)tropical oceans, where its distribution is strongly regulated by the availability of phosphorus and iron. The bulk carbon : nitrogen : phosphorus elemental composition of phytoplankton has previously been shown to depart from classical “Redfield” values under nutrient‐limitation conditions. We hypothesized that the abundance of intracellular metabolites and the extended Redfield ratios of Trichodesmium, including a range of trace elements, are variable in response to conditions of phosphorus and iron limitation that are found in the ocean. To test this, we grew Trichodesmium under trace metal–controlled conditions, where phosphorus was supplied as either dissolved inorganic phosphorus (DIP) or dissolved organic phosphorus (DOP) from iron depleted to elevated levels. We found that the steady‐state extended Redfield ratios of Trichodesmium under the iron‐depleted condition was (C106N15.82P0.62)1000Fe2.26Zn2.37Mn1.68Cu0.68Ni0.31Mo0.42Co0.03 for the DIP treatment where Trichodesmium was under iron limitation, and (C106N13.89P0.49)1000Fe3.38Zn2.51Mn0.97Cu0.52Ni0.42Mo0.33Co0.03 for the DOP treatment where Trichodesmium was under iron–phosphorus co‐limitation. Mean steady‐state cellular iron : carbon in the DIP treatment (iron limited) was only 50% of that in the control treatment, while zinc : carbon was elevated twofold. The average extended Redfield ratios following recovery from iron limitation was (C106N16.8P0.7)1000Fe4.41Zn1.44Mn1Cu0.52Ni0.19Mo0.3Co0.03 for the DIP and (C106N15.9P0.73)1000Fe7.36Zn2.24Mn1.08Cu0.71Ni0.63Mo0.38Co0.02 for the DOP treatment. No significant changes were observed in the carbon‐normalized abundance of targeted metabolites produced by Trichodesmium, under the different treatments. These results suggest Trichodesmium employs different strategies to cope with iron/phosphorus limitation, which is reflected in its extended Redfield ratios.

Unlocking the potential of hydrogen isotopes (δ2H) in tracing riverine particulate organic matter sources and dynamics

Unlocking the potential of hydrogen isotopes (δ2H) in tracing riverine particulate organic matter sources and dynamics

Utilizing fluorescence indicators to apportion organic sources in estuarine/coastal sediments: A comparison with a stable isotopic model

Coastal sediments accumulate organic matter (OM) from diverse sources, including local anthropogenic pollution. Effective source tracking of sediment OM is crucial for pollution source management. This study compares fluorescence proxies and stable isotopic ratios as tracers for sediment OM in Gangu Port, Korea. An optimized extraction method using distilled water for 0.5 h yielded distinct fluorescence signatures. The humification index (HIX) and protein-like component (C3%) showed ideal mixing behavior with two end-members (fishery market sediment and algae). A Bayesian end-member mixing analysis model revealed that agricultural soil is the prevalent contributor to sediments, aligning with land use patterns. The fluorescence-based model showed higher sensitivity to anthropogenic influences compared to traditional stable isotope ratios. The results strongly agreed with isotope ratio-based predictions, exhibiting a positive correlation (p < 0.05) at 8 out of 14 sites. This study highlights the potential of fluorescence-based tracking to complement or replace conventional stable isotope methods.

Selenomethionine alleviates kidney necroptosis and inflammation by restoring lipopolysaccharide-mediated mitochondrial dynamics imbalance via the TLR4/RIPK3/DRP1 signaling pathway in laying hens

Selenomethionine (SeMet) is a beneficial organic source of selenium that is extensively used as a food additive owing to its antioxidant and anti-inflammatory properties. Due to the sensitivity of the kidneys to noxious stimuli, they are more susceptible to various injuries. To investigate the protective mechanisms of SeMet supplementation against kidney injury, we established an in vivo experimental model using laying hens treated with SeMet (0.5 mg/kg diet) and/or lipopolysaccharide (LPS) (0.2 mg/kg. BW) and an in vitro model of chicken embryo primary kidney (CEK) cells treated with SeMet (0.075 mM) and with/ without LPS (60 μg/mL). SeMet treatment alleviated the LPS-induced kidney insufficiency and mitochondrial damage. Furthermore, it reduced the expression of TLR4, RIPK3, MLKL, DRP1, NLRP3, and IL-1β in the kidneys of laying hens. RIPK3 is known to induced necroptosis and inflammation by activating of the downstream factors DRP1 and MLKL. To investigate the mechanism whereby SeMet alleviates LPS-induced necroptosis in the kidney, we pretreated CEK cells with TLR4, RIPK3, and DRP1 inhibitors. The results demonstrated that RIPK3 inhibition resulted in a significantly increased in the mitochondrial membrane potential and downregulation of DRP1. Upon the inhibition of DRP1 expression, MLKL, NLRP3, and IL-1β expression also decreased. In summary, SeMet regulates the TLR4/RIPK3/DRP1 signaling pathway to restore the LPS-induced imbalances in mitochondrial dynamics, thereby alleviating necroptosis and inflammation in the kidneys of laying hen. Selenium also increases the expression of selenoproteins. This study provides valuable information for the development of new therapeutic strategies using SeMet to alleviate kidney injury.

An Assessment of Water Quality and Pollution Sources in a Source Region of Northwest China

China prioritizes ensuring drinking water safety, particularly in the water-scarce northwest region. This study, utilizing water quality data from 52 village and town water sources since August 2022, assesses water quality, with a specific focus on key indicators related to organic pollution sources. This study provides a scientific foundation for enhancing water quality in these sources. Employing category factor analysis for classification and grading, principal component analysis for qualitative analysis of key evaluation indicators, and the absolute principal component linear regression equation for quantitative calculation of pollution sources, this study reveals that all 52 water sources meet quality standards. Principal component analysis categorizes pollution sources as diverse types of organic compounds in surface water. Source analysis calculations highlight decay-type organic substances as major contributors to increased water color and permanganate index, with pollution contribution rates of 54.78% and 31.31%, respectively. Fecal-type organic substances dominate the increase in dissolved total solids and total coliforms, with pollution contribution rates of 56.65% and 40.16%, respectively. Additionally, high-molecular-weight organic substances exhibit lower concentrations in the water. This article presents a systematic water quality assessment methodology, which is used for the first time to qualitatively assess the types of water sources and to quantitatively trace specific sources of organic pollution in source water in northwest China. This systematic study’s results, involving initial assessment followed by traceability, recommend the adoption of a simple contact filtration and disinfection process to enhance water quality in the region.

Effects of Organic Manures and Foliar Sprays on Growth and Yield of Finger Millet

Experiments were conducted at the Centre of Excellence in Millets, Athiyandal, Thiruvannamalai, India to evaluate various organic nutrient sources with foliar application over three seasons from kharif 2015 to 2017 in Split Plot Design (SPD). Applying farmyard manure (FYM) @ 12.5 t ha-1 along with in-situ incorporation of sunhemp green manuring SGM @ 6.50 t ha-1 at 45 days after planting (DAP) resulted in higher grain and straw yields of 2,420 kg ha-1 and 3,549 kg ha-1, respectively. A foliar spray of Panchakavya at a 3% concentration increased grain and straw yields to 2,423 kg ha-1 and 3,338 kg ha-1. The B4 treatment yielded the highest gross income (₹84,724 ha-1), net income (₹55,372 ha-1), and benefit-cost ratio (2.84). Vermicompost application at 5 t ha-1 led to lower gross income. Among the foliar sprays, Panchakavya at 3% produced the highest gross income (₹84,478 ha-1), net income (₹43,534 ha-1), and benefit-cost ratio (2.36), followed by vermiwash at 3%.

A global assessment of mangrove soil organic carbon sources and implications for blue carbon credit.

Mangroves can retain both autochthonous and allochthonous marine and/or terrestrial organic carbon (OC) in sediments. Accurate quantification of these OC sources is essential for the proper allocation of blue C credits. Here, we conduct a global-scale analysis of sediments autochthonous and allochthonous OC contributions in estuarine and marine mangroves using stable isotopes. Globally, mangrove-derived autochthonous OC was the main contributor to estuarine and marine mangrove top-meter soil organic carbon (SOC) (49% and 62%, respectively). Less marine allochthonous OC (21%) was deposited than terrestrial allochthonous OC (30%) in estuarine mangrove sediments. Estuarine mangroves accumulated more SOC in sediments than marine mangroves (282 ± 8.1 Mg C ha-1 and 250 ± 5.0 Mg C ha-1, respectively), primarily due to the additional terrestrial OC inputs. Globally, marine mangroves held 67% of the total mangrove SOC, reaching 3025 ± 345 Tg C, while 1502 ± 154 Tg C was stored in estuarine mangrove sediments. The findings emphasize the substantial influence of coastal environmental settings on OC contributions, underlining the necessity of accurate OC source quantification for the effective allocation of blue carbon credits.

The super-intensive culture of Penaeus vannamei in low salinity water: A comparative study among recirculating aquaculture system, biofloc, and synbiotic systems

The culture of Penaeus vannamei in inland regions using low salinity water is a reality in several regions of the world. The dissemination of culture techniques that allow high stocking density and reduced water use can be used to optimize the production process, but they require comparative studies to better understand the functioning of these systems in those salinity conditions. Therefore, this study aimed to analyze the effects of different culture systems, which were recirculating aquaculture system (RAS), biofloc technology (BFT), and synbiotic system (Synbiotic) on the water quality, plankton composition, and growth of P. vannamei in low salinity (2 g L−1) and high stocking density (500 shrimp m−3) for 30 days. The shrimp were stocked at a mean weight of 1.27 ± 0.06 g. In the BFT, dextrose was used as the organic carbon source and administered at a carbon: nitrogen ratio of 15:1. In the Synbiotic, rice bran processed by probiotic microorganisms was used as an organic fertilization strategy. In the RAS treatment, all nitrogen species remained stable throughout the trial, without spikes, and with ammonia and nitrate concentrations lower than in BFT and Synbiotic. The BFT treatment had more events when total ammonia nitrogen exceeded 1 mg L−1, requiring water changes. The Synbiotic treatment had better control of nitrogenous compounds, and a more accentuated accumulation of nitrate compared to BFT, suggesting more effective nitrification. The BFT treatment had more microalgae than Synbiotic and RAS. However, the abundance of zooplankton was higher than that of phytoplankton in BFT and Synbiotic, indicating a dominance by heterotrophic organisms. The Synbiotic treatment had a higher abundance of ciliates and amoeba than the other treatments. Furthermore, the Synbiotic treatment provided higher survival, yield, and lower FCR than BFT and RAS. Our findings indicate that the Synbiotic system can be considered as an alternative for the P. vannamei super-intensive culture in low salinity water, as it presented better control of nitrogenous compounds compared to BFT, higher abundance of ciliates and amoeba, and provided better production rates to the culture.

Effects of maize residue and biochar applications on soil δ13C and organic carbon sources in a subtropical paddy rice ecosystem

AbstractThis study investigates the utility of plant δ¹3C natural labeling in predicting the impacts of environmental shifts on carbon cycling within ecosystems, particularly focusing on paddy fields treated with maize (Zea mays L.) residues and biochar. Specifically, it examines how soil δ¹3C and the sources of soil organic carbon (SOC), respond in paddy fields (which cultivate C3 plants like rice) when amended with maize residues, maize biochar, and silica‐enriched biochar (derived from C4 plants). Conducted in the Fuzhou paddy fields, the experiment included control groups and treatment groups with maize residue (4 t ha⁻¹), maize biochar (4 t ha⁻¹), and silicon‐modified maize biochar (4 t ha⁻¹) during both the early and late rice growth periods. The results indicate that all soil treatments increased soil δ¹3C. The application of maize residues notably affected the δ¹3C of the upper soil profile (0–15 cm) differently from the deeper layers (15–30 cm), and it increased soil organic C more than biochar or silicon‐modified maize biochar. Soil available P (AP) and pH emerged as significant factors linking δ¹3C, influencing rice yield through changes in soil physicochemical properties. Unlike maize residues, which reduced rice yields, applications of biochar and silicon‐modified maize biochar increased rice yields. The latter, which was particularly effective in lowering SOC decomposition rates and addressing rice's silica needs, emerged as the preferred option. The study highlights maize biochar and silicon‐modified maize biochar as sustainable alternatives to maize residues for rice cultivation, enhancing soil fertility, carbon pool stability, and yields.

Clavulanic Acid Overproduction: A Review of Environmental Conditions, Metabolic Fluxes, and Strain Engineering in Streptomyces clavuligerus

Clavulanic acid is a potent β-lactamase inhibitor produced by Streptomyces clavuligerus, widely used in combination with β-lactam antibiotics to combat antimicrobial resistance. This systematic review analyzes the most successful methodologies for clavulanic acid overproduction, focusing on the highest yields reported in bench-scale and bioreactor-scale fermentations. Studies have demonstrated that glycerol is the preferred carbon source for clavulanic acid production over other sources like starch and dextrins. The optimization of feeding strategies, especially in fed-batch operations, has improved glycerol utilization and extended the clavulanic acid production phase. Organic nitrogen sources, particularly soybean protein isolates and amino acid supplements such as L-arginine, L-threonine, and L-glutamate, have been proven effective at increasing CA yields both in batch and fed-batch cultures, especially when balanced with appropriate carbon sources. Strain engineering approaches, including mutagenesis and targeted genetic modifications, have allowed for the obtainment of overproducer S. clavuligerus strains. Specifically, engineering efforts that overexpress key regulatory genes such as ccaR and claR, or that disrupt competing pathways, redirect the metabolic flux towards CA biosynthesis, leading to high clavulanic acid titers. The fed-batch operation at the bioreactor scale emerges as the most feasible alternative for prolonged clavulanic acid production with both wild-type and mutant strains, allowing for the attainment of high titers during cultivations.

Efficiency of Penicillium sp. and Aspergillus sp. for bioleaching lithium cobalt oxide from battery wastes in potato dextrose broth and sucrose medium

Lithium-ion batteries, a primary power source, generate electronic hazardous waste at the end of their lifespan, which is a richer source of highly concentrated metals such as cobalt and lithium than those in natural resources. The waste is a potential renewable resource for the extraction of metals. Bioleaching, a process utilizing microbial activity, was used in this study to investigate the cobalt and lithium leaching efficiency from battery wastes. Two fungal strains, Aspergillus sp. strain JMET 15 and Penicillium sp. strain JMET 24 were used with different organic carbon sources (sucrose medium and potato dextrose broth) at 1 % pulp density. The sucrose medium derived a higher acid quantity and leached higher concentration of cobalt and lithium than in potato dextrose broth. Leaching efficiency by JMET 24 was higher than JMET 15. Cobalt (32.57 % and 27.19 %) and lithium (65.07 % and 40.58 %) were bioleached by JMET 24 and JMET 15, respectively, after 30 d cultivation in the sucrose medium. Lower pulp density was conducted to achieved higher leaching efficiency by JMET24, cobalt (77.87 % and 74.5 %) and lithium (99.88 % and 78.4 %) were bioleached at 0.1 % and 0.5 % pulp density, respectively. Cobalt oxide (Co3O4) was the product of the one-step recovery (leaching and precipitation) process. Cobalt was transformed from lithium cobalt oxide to cobalt phosphate-oxalate by JMET 24 in the sucrose medium. Thus, the potential of bioleaching as an effective method for recovering valuable metals from lithium-ion battery waste is demonstrated, presenting a promising approach for both waste management and resource recovery.

Effect of Organic and Inorganic Sources of Nitrogen on Growth, Yield, Quality and Soil Properties of Wheat (Triticum aestivum L.)

Background: The concept of combined use of both organic and inorganic fertilizer should be followed to prevent severe health hazards and to protect the environment. The combined use of organic and inorganic fertilizers is an effective way to maintain nutrient supply, gives organic carbon to soil microbes and mobilizes soil-bound nutrients on decomposition through the release of organic acid. Combined use refers to combining all available nutrient sources, such as organic and inorganic sources with components in a prudent manner to create an environment that is both environmentally sound and economically ideal for farming. Methods: The experiment was conducted at the research farm of the School of Agriculture, Department of Agronomy, Lovely Professional University, Phagwara (Punjab) during rabi season in the year 2021-2022. The objective of the study was to evaluate the "Effect of organic and inorganic source of nitrogen on growth and yield of wheat (Triticum aestivum L.)". Data recorded on different aspects of crop, viz., growth, yield attributes, yield, quality as well as soil chemical properties were recorded and subjected to statistical analysis. Result: Among various treatments 25% RDN with vermicompost + 75% RDN from inorganic fertilizers showed a significant impact on the growth and yield parameters of wheat crop. Significantly higher growth parameters viz., plant height, number of tillers m-2, dry matter and relative growth rate were observed in T12 (25% RDN with vermicompost + 75% RDN from inorganic fertilizers) of crop. It was also showed higher significant impact on yield attributes i.e., number of effective tillers-2, grain yield, straw yield, harvest index, quality parameters as well as soil parameter like available nitrogen, phosphorus and potassium in T12 (25% RDN with vermicompost + 75% RDN from inorganic fertilizers).

Comparison of Waste Reduction and NPK value between Black Soldier Fly and vermi

Vermicomposting and the employment of black soldier fly larvae (BSFL) for waste management can be compared to learn more about two different but related methods for recycling organic waste. Both approaches are green and support long-term waste management, but they differ in their features and intended uses. Here is a summary of the comparison between using black soldier flies can take longer to break down some materials, they can process organic matter more quickly, the potential of black soldier fly larvae (BSFL) and vermicomposting as organic fertilizer sources for agricultural and horticultural applications can be better understood by comparing nutritional composition of the two. Analyzing the availability, balance, and use of the vital plant nutrients nitrogen (N), phosphorus (P), and potassium (K) in each of these organic products is necessary to comprehend the extent of this comparison Key Words: black soldier fly larvae, vermicomposting, nitrogen (N), phosphorus (P), and potassium (K)

Source of Ore-Forming Fluids and Ore Genesis of the Batailing Au Deposit, Central Jilin Province, Northeast China: Constraints from Fluid Inclusions and H-O-C-S-Pb Isotopes

The Batailing Au deposit is a vein-type deposit in central Jilin Province, situated in the southern sector of the Lesser Xing’an–Zhangguangcai Range within the eastern Central Asian Orogenic Belt. NE-trending fault-controlled orebodies occur in the Upper Permian Yangjiagou Formation and quartz diorite–porphyrite. The mineralisation process was delineated into three stages: (I) quartz–arsenopyrite–pyrite, (II) quartz–polymetallic sulphides (main Au mineralisation stage), and (III) quartz–pyrite–carbonate. Fluid inclusions (FIs) in quartz were identified as four types: PC-type (pure CO2), C1-type (CO2-bearing), C2-type (CO2-rich), and W-type (aqueous two-phase). Raman spectroscopy analysis revealed that the vapor components of the FIs predominantly comprised CO2 with minor quantities of CH4 in stages I–II. Stages I and II encompassed four types of FIs with homogenisation temperature ranging from 264 to 332 °C and 213 to 292 °C and salinity spanning from 4.7 to 11.2 wt% and 1.8 to 11.6 wt%, respectively. Stage III exclusively contained W-type FIs with homogenisation temperature ranging from 152 to 215 °C and salinity spanning from 1.4 to 6.4 wt%. H-O isotopic values (δD = −84 to −79.6‰, δ18OH2O = 6.2 to 6.4‰ in stage I and δD = −96.4 to −90.4‰, δ18OH2O = 2.8 to 4.4‰ in stage II) and microthermometric data indicated that the ore-forming fluids are initially from a magmatic source, with later meteoric water input. Low C isotopic data from CO2 in FIs in quartz (−24.4 to −24.3‰ in stage I and −23.7 to −22.6‰ in stage II) indicated an organic carbon source. Ore precipitation is mainly attributable to fluid immiscibility. S-Pb isotopic data (δ34S = −3.5 to −1.6‰; 206Pb/204Pb = 18.325–18.362, 207Pb/204Pb = 15.523–5.562, 208Pb/204Pb = 38.064–38.221) revealed that ore metals primarily originated from magma. Based on this research, the origin of the Batailing Au deposit is of the mesothermal magmatic–hydrothermal lode type.

Prospect for Fine and Coarse Coal Waste Deployment for a Constructed Technosol and Eragrostis Tef Growth

The aim of this study was to evaluate soil properties and Eragrostis tef (teff) growth on Technosols produced from coarse and fine coal wastes from Moatize Mine, Mozambique. The experiment was performed in triplicate in 30 L containers filled with different substrate conditions, composed of fine coal waste, coarse coal waste, agricultural soil, and sewage sludge as an organic matter source. The soil analyses included bulk density, available water capacity, permeability, and fertility. Plant growth was monitored for biomass production and plant tissue composition. All the substrates presented a good available water capacity and a proper drainage condition. Regarding soil fertility, there were shortages of potassium and boron in the substrates composed exclusively of coal wastes, which was reflected in the composition of the plant tissue. Even so, plant growth was statistically equivalent to the control in all conditions, except for the substrate produced exclusively with fine coal waste and sewage sludge, which presented a better performance. Technosols are an alternative for reducing the final mine waste volume, and Eragrostis tef is used as a means for land use after the mining process, with social gains, and as a tool in an ecological process for restoring coal mining sites.

Impact of freeze-thaw cycles and influent C/N ratios on N2O emissions in subsurface wastewater infiltration systems

Subsurface wastewater infiltration system (SWIS) is important source of N2O emission, biological denitrification process relies on organic carbon source as electron donor, enabling denitrifying reductase (NAR, NIR, NOR, and N2OR) to reduce nitrate nitrogen to N2. However, freeze-thaw cycles cause changes in soil structure through physical and biological processes that increase organic matter availability and microbial activity, thereby accelerating upper (aerobic) organic matter degradation. This leads to carbon deficiency in the lower (anaerobic) layer, which reduces denitrification efficiency increasing N2O production and emissions. This study investigated effects of influent C/N ratios on N2O emissions from SWIS under freeze-thaw stress, and changes in denitrifying reductase and microbial communities. Results showed that as influent C/N ratio increased from 6:1–10:1, average TN removal of SWIS decreased from 89.59 % to 84.95 %, while N2O emission rate decreased from 0.106 mg·m−2·h−1 to 0.0333 mg·m−2·h−1, a reduction of 68.61 %. Meanwhile, N2OR activity increased by 29.95 % with C/N ratio increasing from 6 to 10, showing a significant reduction of N2O. High-throughput sequencing results revealed that Proteobacteria and Firmicutes showed a linear relationship with influent C/N. As C/N increased from 6 to 8 and 10, Proteobacteria relative abundance increased from 22.24 % ± 1.79–32.51 % ± 2.51 % and 39.59 % ± 3.45 %, while Firmicutes relative abundance decreased from 31.73 % ± 7.87–3.34 % ± 0.27 % and 2.19 % ± 0.07 %. These results indicated that sufficient supply of organic carbon provided abundant electron donors for denitrifying reductases in freeze-thaw-affected SWIS, promoting influent NO3--N reduction and decreasing N2O release rates. Conversely, under low C/N ratio conditions, electron acceptance capacity of N2OR was limited and N2OR activity was inhibited, resulting in N2O accumulation and emission. SynopsisThis paper shows how increasing the organic carbon supply in SWIS can reduce N2O emissions and improve nitrogen removal under freeze-thaw stress.

Integrated Nutrient Management for Growth, Yield and Economic Assessment in Black Gram in Dehradun Valley

The field experiment was carried out at a designated location on the Agricultural Research Farm of Graphic Era Hill University in Dehradun during the kharif season of 2023 to study the influence of integrating organic and inorganic sources of nutrients on growth and productivity of black gram (Vigna mungo). The experiment was laid out in Randomized Complete Block Design (RCBD) consisting of nine treatments viz Control (T1), 100% RDF (20:40:20 Kg/ha NPK)(T2), Vermicompost @ 5 t ha-1 (T3) Bio nitrogen @ 20gm kg-1 seed (T4), 100% RDF+ Vermicompost @ 5 t ha-1 (T5), 100% RDF + Bio nitrogen @ 20gm kg-1 seed (T6), Vermicompost @ 5 t ha-1 + Bio nitrogen @ 20gm kg-1 seed (T7), 70% RDF + Vermicompost @ 5 t ha-1 + Bio nitrogen @ 20gm kg-1 seed (T8), 100% RDF+ Vermicompost @ 5 ha-1+ Bio-Nitrogen (T9) each replicated thrice. Integrated Nutrient Management had significantly affected growth, yield and economics of black gram. Maximum emergence count (13.3 m2) was recorded with 70% RDF + Vermicompost @ 5 t ha-1 + Bio nitrogen @ 20gm kg-1 seed which at par with 100% RDF + Bio nitrogen@ 20gm kg-1 seed (T6) and 100% RDF+ Vermicompost @ 5 ha-1+ Bio-Nitrogen (T9). Growth parameter viz. plant height, number of nodules/plant, dry matter accumulation/m2, branches/plant were reported to be significantly influenced by INM with 70% RDF + Vermicompost @ 5 t ha-1 + Bio nitrogen @ 20gm kg-1 seed. Similarly, maximum seed yield (36.33 q ha-1) was obtained under 70% RDF + Vermicompost @ 5 t ha-1 + Bio nitrogen @ 20gm kg-1 seed. Increase in seed yield with the application of by 358.1% and 233.3% was obtained over control (T1) and 100% RDF (T2). The study highlights that combining organic and inorganic sources of nutrients is a simple and effective strategy to improve initial plant stand of black gram crop, ultimately contributing to increased crop growth, yield and better economic returns.