Average Production Research Articles

The role of superior varieties in increasing rice productivity on tidal lands in South Sumatra

The development of tidal land as agricultural land is one opportunity to meet food needs. The study aimed to determine the contribution of superior varieties in increasing tidal rice productivity in South Sumatra. The research was conducted in Banyuasin Regency in 2021 using survey and interview methods. The number of sub-districts where sampling was taken was 9 sub-districts which are representative of low tide land. The data collected in this research were the results of harvested dry grain (tiles), the varieties used, the type and dose of fertilizer used, planting methods and cropping index. Apart from primary, secondary data was also collected as supporting data in the form of land area for each region and climatic conditions. The data taken was tabulated and analyzed descriptively. The research results show that the productivity level of superior rice varieties is higher than the district average productivity. Increasing productivity by applying superior varieties reaches 1.5 t/ha.

Construction of Bi5O7I/Bi3O4Br heterojunction with abundant oxygen vacancies to enhance photocatalytic performance

The low separation efficiency of photogenerated charge carriers is the main impediment to the practical application of photocatalysis. Herein, Bi5O7I nanoparticles with abundant oxygen vacancies (DBOI) were deposited on Bi3O4Br nanosheets (BOBr) to create a novel 0D/2D DBOI/BOBr heterojunction (DBOI-Br) using a facile solution method. The structure of surface oxygen vacancies (SOVs) was demonstrated using HRTEM, low-temperature EPR, and XPS. The effective interface contact between DBOI and BOBr resulted in the establishment of an internal electric field (IEF) and band bending. The photogenerated charge transfer mechanism was validated through in situ irradiated XPS, work function calculation, and ERS measurement. The synergistic effect of IEF, band bending, and SOVs efficiently suppressed the recombination of photogenerated charge carriers, enhancing the photocatalytic activity. Almost 100% of tetracycline, oxytetracycline, levofloxacin, ciprofloxacin, methylene blue, and rhodamine B, as well as 92.3% of phenol, could be decomposed using DBOI-Br under visible light irradiation. The average production rates of H2, O2, and H2O2 were 805, 3800, and 562 μmol h-1 g-1 over 4h, corresponding to quantum efficiencies of 3.67%, 10.4%, and 5.26% at 420nm, respectively. This study introduces a new promising DBOI-Br heterojunction photocatalyst with rich SOVs to enhance the charge separation efficiency for various photocatalytic applications.

Research and Application of Smart Temporary Plugging Gel for Small Casing Cementing in Changqing Oilfield

Abstract In response to the serious leakage and low productivity recovery rate after cement plugging during the secondary cementing process of repairing small casing in the old wells of Changqing Oilfield, this study draws on the theory of shielding and temporary plugging in the drilling process to propose an adaptive smart temporary plugging gel technology. This technology has developed a weak gel suspension base liquid and synthesized a polymer material with good viscosity, high deformability, high sealing strength, and the ability to automatically hydrate and degrade at a certain temperature. It synergistically cooperates with other auxiliary temporary plugging materials to form an adaptive and self-degrading temporary plugging gel system, which can quickly form a sealing barrier at severely leaking areas such as corroded perforations, effectively preventing cement slurry leakage during subsequent cementing processes, shortening the operation cycle, and protecting the reservoir. Experimental evaluations indicate that the gel system can withstand pressure up to 15MPa, degrades in 7-10 days, and achieves a reservoir recovery rate of over 90%, effectively achieving the goals of plugging, releasing, and minimizing reservoir pollution. It has been applied in 30 wells in the Changqing Oilfield, with a success rate of over 96% in the first plugging operation, and an average production recovery rate of over 95%, significantly protecting the oil reservoir.

Production Performance and Cost Analysis of 60 Kwp Grid-Connected Photovoltaic System in Ayaş

The Ankara University Ayaş Horticulture Research and Application Station was chosen as the study area for this investigation. It is situated in the Uğurçayırı neighborhood of Ayaş district, in the center of the districts of Ayaş, Güdül, Beypazarı, and Polatlı. Saplings, vegetables, fruits, clover, medicinal, and spice plants are all produced on the 406 decares land. The analysis employed a variety of solar energy potential sources, including Ayaş, GEPA, MGM HELİOSAT, PVGIS, IRENA, Solar Med Atlas, NASA SSE, SOLARGIS, Global Solar Atlas, and NREL data. In addition, the design cost of a 60 kW photovoltaic system connected to the grid in Ayaş and the daily average/annual total production values according to months were calculated, taking into account the installed solar energy capacity and production values of the Ministry of Energy in the area. The annual solar radiation for Ayaş is 1628 kWh/m2. The average daily electricity production is 252 kWh, and the total annual production is 91,980 kWh. The installation cost of a 60 kW PV system is 50,150 USD. The repayment period of the system is six years. Furthermore, the PV system will mitigate 59.7 kilograms of CO2 emissions annually.

IMPLEMENTATION OF AN ENTREPRENEURSHIP LEARNING MODEL IN THE CREATIVE PRODUCT AND ENTREPRENEURSHIP COURSE FOR VOCATIONAL HIGH SCHOOLS

The learning model is one of the main factors that need to be considered in the learning process. This study aims to reveal the effect of applying the “EkRenFaTiHa” entrepreneurship learning model in vocational high schools. The research design is quasi-experimental. Determination of the sample using the purposive sampling technique. Data collection techniques using observation, documentation, and tests the prerequisite tests carried out are validity tests, reliability tests, normality tests, and hypothesis tests. The research location was in class XI at one of the state vocational schools in the Province of DIY. It was agreed with the school that it was not permissible to mention the name of the school, so the research location was named X’s vocational high schools. The results of the hypothesis testing showed that the cognitive value in the experimental class was significant, which was 0.001, where the value was < 0.05. This means that the “EkRenFaTiHa” entrepreneurship learning model can have a significant influence on student learning outcomes in the subject of creative products and entrepreneurship. While the value of product results in the experimental class is still higher than in the control class. The experimental class got an average product value of 75.455, while the control class average product value was 74.773.

Correlation between Farmers' Activeness in Farmer Groups with Productivity and Income of Cocoa Farming in Trenggalek Regency

The cocoa plantation in Suruh Village, Trenggalek Regency is the main supplier of cocoa beans to UPH Rumah Coklat owned by the Department of Agriculture and Food of Trenggalek Regency. For example, in cocoa farmers' participation in the "Tunggal Jaya" Farmers Group, farmers are taught to make rorak and worm palaces to deal with climate change which helps maintain soil moisture and increase fertility. The objectives of this study are to determine 1) the level of farmer activeness, 2) the level of productivity, 3) the level of income, and 4) the correlation between farmer activeness in farmer groups with productivity and income of cocoa farming in Suruh Village, Trenggalek Regency. The number of samples used was 111 respondents. Data analysis used the Likert scale, productivity analysis, income analysis, and Pearson correlation. The results of the study showed: 1) cocoa farmer activeness in farmer groups in Suruh Village, Trenggalek Regency is in the active category with an overall average score of 3.56; 2) the average productivity of cocoa farming is in the medium category at 0.54 tons/ha/year; 3) the average income of cocoa farming is Rp6,016,562/year; 4) the correlation between farmer activeness with productivity is 0.865, farmer activeness with income is 0.760, and productivity with income is 0.868. The direction of the three correlations is positive and significant.

Performance analysis of a pilot gasification system of biomass with stepwise intake of air-steam considering waste heat utilization

Although the fixed-bed gasifier is widely used because of their simple structure, easy operation, and strong adaptability to biomass type, its economy is weakened by their low bioenergy conversion ability and heat utilization efficiency. Therefore, a novel biomass gasifier with stepwise intake of air–steam is proposed, which also innovatively integrates the concept of multi-stage utilization of waste heat generated during the gasification process into its design. And a pilot system comprising the novel biomass gasifier with a biomass consumption of 30 kg/h has been built. A series of continuous air-steam gasification experiments on pine wood particles shown that, the high-temperature steam in the reduction zone enhanced the ring opening of aromatic hydrocarbons, decarboxylation, dehydroxylation, and the conversion of long-chain to short-chain hydrocarbons, thus increasing the yield of small-molecule gases. The steam reforming reaction played an active role in increasing the hydrogen content, the gasification gas's production and low calorific value. And the relationship among the reaction rates on the surface of char should be VC + H2O＞VC+2H2O＞VC + CO2＞VC+2H2. The minimum input temperature of steam was 350 °C, otherwise more char would be consumed in the oxidation zone to provide heat. The proposed steam-air gasification system achieved optimal performance with an air-to-steam mass ratio (A/S) of approximately 8, a steam temperature of 400 °C, and an air-to-biomass mass ratio (A/B) of 1.2. The average gas production could reach 2.67 m3/kg, with the average low calorific value of 5.1 MJ/m3. The average hydrogen content could reach 20 %, with the average H2/CO ratio of 2. The average effective gasification efficiency could reach 69.72 %. Compared with air gasification, the proposed air-steam gasification was equivalent to the use of 1 kWh of electricity to produce 2.4 kWh of electricity. Combining market research, the price of steam produced by the proposed system was approximately 70 CNY/t less than when using natural gas. This study aims to provide a technical reference for improving the performance of biomass gasification in practical applications.

Assessment of occupational dose during abdominal fluoroscopic-guided procedures in Thailand using nanoDot OSL dosimeters

Interventional radiology is one of the most widely used treatment options for abdominal abnormality. Due to new dose limitations, radiation is a hazard that needs to be considered when choosing the international treatment technique. The aim of this study was to measure the effective/equivalent doses and to investigate the associated factors correlating with the doses during Transarterial Chemoembolization (TACE) and Percutaneous Transhepatic Biliary Drainage (PTBD) for radiologists, technologists and nurses involved with the treatment. This prospective study reports occupational dose per procedure of 57 cases (TACE = 42, PTBD = 15) in a Thailand hospital spanning one year. All staff included in this study wore 30 nanoDot Optically Stimulated Luminescence Dosimeter for measuring doses at 7 bodily locations. The average dose area product and cumulative doses was 151.3 Gy·cm2, 1,185.1 mGy during TACE and 21.3 Gy·cm2, 212.2 mGy during PTBD. The radiation exposure of the radiologists was significantly higher than technologists and nurses (p-value < 0.05). The lead protection equipment was a dose-reducing factor which decreased the dose up to 93%. The present study also contributes to the establishment of an individual dose location report and identifies significant correlations between associated factors and dose values. The left hand (1.2 mSv) and the left eye (1.1 mSv) showed maximum doses during the PTBD procedure. The exceeded dose over the limitation was observed in the left eye. We concluded that the dose feedback was able to increase awareness of the occupation staff. So, dose monitoring, updating education and regular training could be applied simply and effectively to improve skills, while reducing the occupational dose.

Phytoplankton as CO2 Sinks: Redirecting the Carbon Cycle

Since the Industrial Revolution, nearly 700 Gt of carbon (GtC) have been emitted into the atmosphere as CO2 derived from human activities, of which 292 GtC remain uncontrolled. By the end of this century, the atmospheric CO2 concentration is predicted to surpass 700 ppm. The effects of this sudden carbon release on the worldwide biogeochemical cycles and balances are not yet fully understood, but global warming and climate change are undeniable, with this gas playing a starring role. Governmental policies and international agreements on emission reduction are not producing results quickly enough, and the deadline to act is running out. Biological CO2 capture is a fast-acting carbon cycle component capable of sequestering over 115 GtC annually through photosynthesis. This study analyses a hypothetical scenario in which this biological CO2 capture is artificially enhanced through the large-scale cultivation of phytoplankton in partially natural photobioreactors (PBRs). To develop this approach, the current figures of the carbon cycle have been updated, and the key aspects of phytoplankton cultivation technology have been analysed. Our results show that a global increase of 6.5% in biological capture, along with the subsequent stabilization of the produced biomass, could counteract the current CO2 emission rate and maintain atmospheric levels of this gas at their current levels. Based on a review of the available literature, an average production rate of 17 g/m2·day has been proposed for phytoplankton cultivation in horizontal PBRs. Using this value as a key reference, it is estimated that implementing a large-scale production system would require approximately 2.1 × 106 km2 of the Earth’s surface. From this, a production system model is proposed, and the key technological and political challenges associated with establishing these extensive cultivation areas are discussed.

Effect of water occurrence in coal reservoirs on the production capacity of coalbed methane by using NMR simulation technology and production capacity simulation

The occurrence of gas and water is a critical factor affecting the production capacity of coalbed methane. Therefore, occurrence and dynamic interaction between gas and water in coal reservoirs need to be studied. T2 spectrum of all the samples were studied by NMR technique at 0, 5, 9, and 28 h of natural evaporation. Then, multifractal model was used to characterize water distribution heterogeneity, and a novel evaluation coefficient was proposed to characterize distribution heterogeneity of water content, the correlation among evaluation coefficient, water distribution heterogeneity and pore structure parameters was analyzed. The results are as follows. In the saturated state, the moisture distribution of three types is heterogeneous. Type A of adsorption pore-developed exhibits strong moisture variation heterogeneity of small pores, in contrast to the uniform moisture variation in large pores. Type B of fracture-developed has the highest coefficient of variation in moisture distribution. The coefficient of variation A1 for moisture content can determine the speed of moisture transport and evaporation in the pore structure. A lower A1 indicates a greater moisture transport volume and faster moisture transport rate over the same time. The coefficient of variation A2 for moisture distribution represents the heterogeneity of moisture content variation in the pore structure. That is, a smaller A2 indicates better heterogeneity in the distribution of moisture content in the pore structure. Numerical simulation indicates the average gas production and the peak gas production time increase and decrease with the initial moisture content (Sgrw) increases, respectively. These findings provide practical guidance for coalbed methane development, especially in optimizing coalbed methane production capacity prediction and improving recovery efficiency.

Characterization of &amp;lt;i&amp;gt;Adansonia Digitata&amp;lt;/i&amp;gt; Seed Cake with a View to Identifying an Energy Recovery Strategy

Agri-food processing emits huge quantities of waste and is considered one of today&amp;apos;s major environmental problems. There are many different options (anaerobic digestion, thermochemistry and feed production) that can be applied to the management and evaluation of waste treatment. The aim of the present study was to explore the appropriate recovery option for Adansonia digitata seed cake through its characterization. The physicochemical characteristics of &amp;lt;i&amp;gt;Adansonia digitata&amp;lt;/i&amp;gt; seed cakes were determined in accordance with international standards. Anaerobic digestion was tested under thermophilic conditions in batch mode over 75 days. Results showed that dry matter content averaged 87.35 ± 0.03%, organic matter content averaged 95.03 ± 0.41%, carbon to nitrogen ratio averaged 19.75. Digestion of &amp;lt;i&amp;gt;Adansonia digitata&amp;lt;/i&amp;gt; seed cakes proved highly productive, with a maximum percentage of 68.5% CH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt; for 185.57 liters of biogas, i.e. an average production of 2.47 liters per day for 1720 g DM. The methanogenic potential (BMP) of &amp;lt;i&amp;gt;Adansonia digitata&amp;lt;/i&amp;gt; seed cake was 331.21 ml/g of organic matter introduced. &amp;lt;i&amp;gt;Adansonia digitata&amp;lt;/i&amp;gt; oilcake had an average gross calorific value of 18.54MJ/Kg. These results are encouraging and mark the start of any study on the energy recovery of &amp;lt;i&amp;gt;Adansonia digitata&amp;lt;/i&amp;gt; seed cake in biogas.

The Gas Production Characteristics of No. 3 Coal Seam Coalbed Methane Well in the Zhengbei Block and the Optimization of Favorable Development Areas

The characteristics and influencing factors of gas production in CBM wells are analyzed based on the field geological data and the productivity data of coalbed methane (CBM) wells in the Zhengbei block, and then the favorable areas are divided. The results show that the average gas production of No. 3 coal seam CBM wells in the study area is in the range of 0~1793 m3/d, with an average of 250.97 m3/d; 80% of the wells are less than 500 m3/d, and there are fewer wells above 1000 m3/d. The average gas production is positively correlated with gas content, critical desorption pressure, permeability, Young’s modulus, and Schlumberger ratio, and negatively correlated with fracture index, fault fractal dimension, Poisson’s ratio, and horizontal stress difference coefficient. The relationship between coal seam thickness and the minimum horizontal principal stress is not strong. The low-yield wells have the characteristics of multiple pump-stopping disturbances, unstable casing pressure control, overly rapid pressure reduction in the single-phase flow stage, sand and pulverized coal production, and high-yield water in the later stage during the drainage process. It may be caused by the small difference in compressive strength between the roof and floor and the coal seam, and the small difference in the Young’s modulus of the floor. The difference between the two high-yield wells is large, and the fracturing cracks are easily controlled in the coal seam and extend along the level. The production control factors from strong to weak are as follows: critical desorption pressure, permeability, Schlumberger ratio, fault fractal dimension, Young’s modulus, horizontal stress difference coefficient, minimum horizontal principal stress, gas content, Poisson’s ratio, fracture index, coal seam thickness. The type I development unit (development of favorable areas) of the Zhengbei block is interspersed with the north and south of the block on the plane, and the III development unit is mainly located in the east of the block and near the Z-56 well. The comprehensive index has a significant positive correlation with the gas production, and the prediction results are accurate.

Agronomic features of introduced Argan tree in eastern of Morocco and optimization of their propagation

Argania spinosa or argan is an endemic plant of Morocco that belongs to sapotaceae family. This species has significant ecological and socioeconomical impact in Morocco and is mainly recognized by argan oil that is very known for its nutritional quality and health benefits. Our study aims to elaborate an agronomical and pomological characterization of introduced argan trees in Oujda, Morocco (about 200 trees, 10 years old) , select high-performance clone heads based on their productivity and stability criteria, by measuring various productivity parameters over a tree years study period (fresh fruit production, almonds production and oil production), and successfully propagate them asexually using apical grafting technique in controlled condition ( phytotron ) with the aim of stabilizing the high-performance clone. The obtained results indicated the existence of high diversity in terms of the various pomological parameters assessed. Parallelly, productivity and profitability parameters, the average production of fresh fruits, almonds and oil per tree and per year was 8.62 kg, 0.253 kg and 0.133 L, respectively. While, the maximal production was 34.4 kg/year for fresh fruits production, 1.07 kg/year/tree for almonds, and 0.575 liter/year/tree oil produced. Regarding the propagation of these clones, the results showed that the grafting success rate depended on the mother stock and the season, with 100% success rate. The results obtained show that the argan tree is an adaptive species, and the most suitable grafting method for the argan tree is apical split grafting during the autumn season.

Does perceptual high variability phonetic training improve L2 speech production? A meta-analysis of perception-production connection

Abstract This meta-analysis of 31 studies aimed to determine the effectiveness of perception-based high variability phonetic training (HVPT) for second language (L2) production learning and to identify learner-related and methodological variables that influence production gains. Based on independent effect sizes for 43 within-participant and 17 between-participant designs, small-to-medium effects of post-training improvement were found. The average production gains for trained items and untrained items were 10.50% and 4.50%, respectively. Neither strong support for long-term retention of production learning nor generalization to untrained stimuli was observed, however. Moderator analyses showed that post-training production gains were influenced by a number of factors related to learner profiles (age and learning context), training features (provision of phonetic information, training duration, and training time per session), and features of production tests (elicitation tasks, prompt modality, and outcome measures). The relationship between perception and production gains was negligible at the participant level, but was significant and moderate at the level of individual studies for post-training and retention data. These findings provide partial support for a perception-production link. This study makes several recommendations for future studies investigating the effects of HVPT on L2 speech production learning.

Exploring sustainable agricultural production models to coordinate system productivity, soil biological health and eco-efficiency in the semi-arid region

Designing sustainable agricultural models is imperative to enhance farm productivity, and soil health with minimum ecological footprints. Therefore, three cropping systems viz., maize-mustard (M-Mus), maize + cowpea-mustard (M + C-Mus), pigeon pea-wheat (PP-W) were tested under four production scenarios viz., integrated organic management (IOM), integrated crop management (ICM), conventional system (CS), and conservation agriculture (CA) for three consecutive years (2018–2021) to find out the productive, soil supportive, and eco-efficient production model. The ICM recorded significantly higher system productivity i.e. 12107, 12889, and 12866 kg ha−1 during 2018–19, 2019–20, and 20–21 over other production system, respectively. Among the cropping systems, the PP-W system registered the maximum system productivity of 12007.0 kg ha−1 during 2018–19, 11899 kg ha−1 in 2019–20, and 12247 kg ha−1 during 20–21. This led to ∼15% higher average system productivity over the maize-mustard system. Nutrient (N, P, and K) acquisition was the highest by the M + C-Mus system followed by the PP-W system. All soil biological indicators considerably improved under IOM followed by ICM across the soil profile after three years. Cultivation of the PP-W system under IOM registered the highest energy use efficiency (73.24). Concerning the eco-efficiency index (EEI), cultivation of PP-W under the IOM production scenario registered ∼ 2.85 times higher EEI (0.20 US$ MJ−1) over the M-Mus cropping under CS. Thus, findings inferred that legume-embedded systems under either IOM or ICM production scenarios are sustainable production models for fetching higher profitability with minimum environmental impact under semi-arid regions.

Carbon monoxide conversion by anaerobic microbiome in a thermophilic trickle bed reactor

Biomethanation offers a promising route for the valorization of synthesis gas, yet significant challenges arise from the limited conversion of carbon monoxide (CO). This study investigated the adaptation of an anaerobic microbiome in a continuous trickle bed reactor (TBR) with CO as the sole carbon and energy source. We evaluated reactor performance and microbial community changes under different CO loading rates and gas retention times (GRT). Optimal performance was achieved at a CO loading rate of 5.16 Nm³ m⁻³ d⁻¹ and a GRT of 60.6 min, resulting in average production rates of 0.99 Nm³ m⁻³ d⁻¹ for CH₄ and 2.55 Nm⁻³ m⁻³ d⁻¹ for CO₂, with an 88 % CO conversion rate. Microbial analysis indicated that the community was dominated by the genus Methanothermobacter, known for its ability to utilize CO as a sole substrate, followed by a co-dominance of syntrophic acetate-oxidizing bacteria Syntrophaceticus. This syntrophic relationship between Methanothermobacter and Syntrophaceticus is expected to be crucial for the efficient CO conversion process. Additionally, the study proposes a two-reactor system for converting synthesis gas to grid-quality methane.

PSVIII-6 Effect of adding plant extracted saponin (PES) on accumulative gas production kinetics and methane emission of the prairie blend pelleted feed products in ruminant system

Abstract The objectives of this study were to study the effect of adding plant extracted saponin (PES) as phytochemical feed additive on in vitro accumulative gas production kinetics and methane (CH4) emission of blend pelleted feed products in ruminant system. Four levels of PES (0, 1, 2, 3%) were added to canola meal and pea mixtures with two different ratios (CMP1: 50:50; CMP2: 70:30) which were used to make Prairie blend pellet feed products. The accumulative gas production kinetics and CH4 were determined using in vitro systems. Ruminal fluid for in vitro studies was obtained from rumen fistulated lactation dairy cows. The experimental design was a randomized complete block design with the PES level as a fixed effect and in vitro run with fistulated animals as a random effect. The data were analyzed using Mixed Model Procedure of SAS. Polynomial contract was used to determine linear and quadratic relationship. The results showed that adding PES did not significantly affect the asymptotic production (a) with an average of 104.06 ± 12.38 (SD) mL/g DM, the gas production fractional rate (c) with an average of 1.00 ± 0.90 %/h, the average production at one-half of asymptotic production (AP) with an average 11.26 ± 0.87 mL and lag time with an average of 2.08 ± 0.81 h. As to CH4 emission at different incubation times, the result showed that at short incubation times (2 h, 4 h, 12 h), adding PES showed numerically reduced CH4 from 277 to 1.08 mL/g (at 2 h) and 4.39 to 1.59 mL/g (at 4 h). With increasing PES level, CH4 was significantly linearly reduced (P = 0.019) from 8.31 to 6.30 mL/g at 12h incubation time. At long incubation (24 h), adding PES did not have significant impact on CH4. In conclusion, adding PES at the studied levels to Prairie blend pellet feed products did not significantly affect accumulative gas production kinetics but it had a high potential to decrease CH4 emission at short incubation times.

Unveiling primary production dynamics in the southern Bay of Bengal: Comparative analysis of in-situ measured data with multiple primary production models

In this study, marine water samples were collected at 18 sampling stations. The collected marine water samples were analysed using a well-calibrated UV spectrophotometer for chlorophyll-a estimation, and using a hyperspectral underwater radiometer, both buoy mode and profile mode in-situ data were collected. The study evaluated four different primary production models to study the dynamics of the southern Bay of Bengal. The simple Eppley model used in the study resulted in huge variations in the nearshore and frontal regions; the dark and light bottle methods showed enormous variations along all 18 sampling stations and underestimated the productivity of the southern Bay of Bengal. However, the VGPM model and its variants showed similar trends in near shore, frontal, and off-shore waters for all three transects, and the Kameda model closely matched the available literature for the primary production estimates of the southern Bay of Bengal. From the detailed analysis of the Kameda model, it is found that the average primary production for the Southern Bay of Bengal for the post monsoon season (February 2023) is estimated as 339.08 mgC/m2/d.

499 Effect of adding plant extracted hydrolysable tanning and saponin combination to prairie blend pelleted feed products on accumulative gas production kinetics and methane emission in ruminant systems

Abstract The objectives of this study were to study the effect of adding plant extracted hydrolysable tanning (HT) and saponin (S) combination as a combined phytochemical feed additive (HTS) on in vitro accumulative gas production kinetics and methane (CH4) emission of blend pelleted feed products in ruminant systems. Four combination levels [0 (control), 1.5 (1% HT + 0.5% S), 3 (2% HT + 1%S), 4.5 (3% HT + 1.5% S)] were added to canola meal and pea mixtures with two different ratios (CMP1: 50:50; CMP2: 70:30) which were used to make Prairie blend pellet feed products. The accumulative gas production kinetics and CH4 were determined using in vitro systems. The ruminal fluid was obtained from rumen fistulated lactation dairy cows. The experimental design was a randomized complete block design with the HTS level as a fixed effect and in vitro run with fistulated animals as a random effect. The data were analyzed using SAS Mixed Procedure. Polynomial contract was used to determine linear and quadratic relationship. The results showed that adding HTS level linearly reduced asymptotic production a) from 110.5 to 82.7 mL/g DM (P = 0.043) and average production at one-half of asymptotic production (AP) from 11.9 to 9.5 mL (P = 0.069) without significantly affecting gas production fractional rate (c, %/h) with an average of 0.58 ± 0.49 %/h and lag time with an average of 1.95 ± 0.50 h. As to CH4 emission at different incubation times, the result showed that at short incubation times (2 h, 4 h, 12 h), adding HTS had numerically reduced methane emission (CH4) from 2.77 to 0.98 mL/g (at 2 h) and 4.39 to 1.38 mL/g (at 4 h). with increasing HTS level, CH4 was significantly quadratically reduced (P = 0.028) at 12 h incubation time from 8.31 to 5.76 mL/g. After long incubation (24 h), adding HTS did not have significant impact on CH4. In conclusion, adding HTS to prairie blend pellet feed products significantly affected gas production kinetics (the asymptotic production and average production at one-half of asymptotic production). Adding HTS had an increased potential to decrease CH4 emission at short incubation times.

453 Fluxes of greenhouse gases from pastures and methane emissions from beef cattle in Australia

Abstract The carbon footprint of beef cattle production may need to consider both the fluxes of greenhouse gases (GHG) of pasture ecosystems and cattle enteric emissions because these are the largest contributors to the carbon balance. The objective of the present study was to measure the fluxes of greenhouse gases from pastures and enteric methane (CH4) emissions from cattle throughout long periods of time under commercial conditions. The fluxes of CH4, carbon dioxide (CO2), and nitrous oxide (N2O) were measured throughout a period of 3 yr in multiple pasture types ranging from native to sown, and from temperate to summer pastures in New South Wales, Australia. A set of 8 dynamic chambers that automatically close for 10 min every 1.5 h were used for this purpose. The chambers measured the change in the concentration of GHG to allow for the estimation of emissions (positive flux) or sinks (negative flux). All data was then summarized to estimate daily fluxes and the global warming potential (CO2e) was calculated multiplying CH4 by 28 and N2O by 265. The final dataset contained 2,709 d of measurements across the 8 chambers. The GreenFeed system was used to measure CH4 production from cattle under varying conditions fed various diets throughout the same period. Cattle categories included weaners, heifers and steers, bulls and cows under both grazing or pen conditions. Cattle were fed a variety of diets ranging from low quality forages to high quality forages, grain supplementation, and grain-based diets. Data were averaged across many days for each animal and the final dataset contained 1,014 measurements. The CO2 flux from pastures ranged from -855 (uptake) to +339 kg CO2ּ ha-1ּ d-1 with a mean of -10.4 ± 2.19 kg CO2ּ ha-1ּ d-1. The minimum, mean and maximum CH4 fluxes were -192 (uptake), 0.015 ± 0.488, 434 g CH4 ּha-1ּ d-1, respectively, whereas NO2 values -146 (uptake), 17.1 ± 1.23, 1,293 g N2O ּ ha-1ּ d-1, respectively. These fluxes resulted in a GWP ranging from -855 (uptake), -5.83 ± 2.222, 445 kg CO2e ּha-1ּ d-1suggesting that pastures were on average a net sink of GHG throughout the present study. The CH4 production from cattle ranged from 43.6 to 404.6, with an average CH4 production of 192 ± 90.3 g CH4ּ animal-1ּ d-1, which is equivalent to 5.37 kg CO2eqּ animal-1ּ d-1. These results suggest that a hectare of livestock pastures offsets more than the CH4 produced by the average beef cattle in the present study. The fluxes of GHG from vegetation may need to be considered when estimating the contribution of livestock production to global warming.