Sustainable Production Technologies Research Articles

Intracellular spectral recompositioning of light enhances algal photosynthetic efficiency.

Diatoms, considered as one of the most diverse and largest groups of algae, can provide the means to reach a sustainable production of petrochemical substitutes and bioactive compounds. However, a prerequisite to achieving this goal is to increase the solar-to-biomass conversion efficiency of photosynthesis, which generally remains less than 5% for most photosynthetic organisms. We have developed and implemented a rapid and effective approach, herein referred to as intracellular spectral recompositioning (ISR) of light, which, through absorption of excess blue light and its intracellular emission in the green spectral band, can improve light utilization. We demonstrate that ISR can be used chemogenically, by using lipophilic fluorophores, or biogenically, through the expression of an enhanced green fluorescent protein (eGFP) in the model diatom Phaeodactylum tricornutum. Engineered P. tricornutum cells expressing eGFP achieved 28% higher efficiency in photosynthesis than the parental strain, along with an increased effective quantum yield and reduced nonphotochemical quenching (NPQ) induction levels under high-light conditions. Further, pond simulator experiments demonstrated that eGFP transformants could outperform their wild-type parental strain by 50% in biomass production rate under simulated outdoor sunlight conditions. Transcriptome analysis identified up-regulation of major photosynthesis genes in the engineered strain in comparison with the wild type, along with down-regulation of NPQ genes involved in light stress response. Our findings provide a proof of concept for a strategy of developing more efficient photosynthetic cell factories to produce algae-based biofuels and bioactive products.

GA-based robust LQR controller for interleaved boost DC–DC converter improving fuel cell voltage regulation

Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising technologies for sustainable energy production due to the high power density, low operative temperature and more convenient use for several applications. Nevertheless, the high generated current that characterizes PEMFC requires a specific power conditioning. In addition, specific controller must be designed to fit with system operative points changing associated with the variation of this high current. To deal with this challenge, in this paper, an electrochemical system composed of a Proton Exchange Membrane Fuel Cell (PEMFC) feeding via two phases IBC has been proposed and investigated. For robustness, the used IBC for fuel cell voltage regulation is controlled by linear quadratic regulator (LQR). Then, genetic algorithms technique is applied to optimize the LQR controller parameters giving optimal control coefficients and can if necessary be adjusted according to each working situation change. The model of the entire system is studied using Matlab/Simulink environment. The simulation’s comparative standard and robustness results both demonstrate that the proposed GA-based LQR controller outperforms the conventional PI in terms of performance metrics (overshoot reduction: between 58.93% and 97.09%; response time reduction: between 56.40% and 77.00% and ripple reduction: between 84.00% and 94.86%).

Review of sustainable solar hydrogen production using photon fuel on artificial leaf

Energy conversion from the renewable energy sources with suitable energy storage plays a vital role in the sustainable development. Sustainable hydrogen production from the solar energy is well suited for energy storage applications because of inherent high mass energy density of hydrogen. This manuscript reviewing the techniques required for the sustainable solar hydrogen production using photon fuel on artificial leaf, i.e. solar cell. The designing and assembling of artificial solar leaf, which is the replica of natural leaf and capable of harnessing full solar spectrum, are deliberated. This technology for sustainable solar hydrogen production will overlay a viable way for more real-world applications of traditional as well new generation solar cells, e.g. multi-junction solar cells coated with variable band gap of quantum materials, in the future. This, also, results in the successive control on carbon emission by converting abundantly present CO2/CO into meaningful future industrial fuel, therefore, generating hydrogen, known as photon fuel, via successfully harnessing the wide spectrum of the solar radiation.

Development of natural cellulase inhibitor mediated intensified biological pretreatment technology using Pleurotus florida for maximum recovery of cellulose from paddy straw under solid state condition

Inhibitor mediated intensified bio-pretreatment (IMBP) technology using natural cellulase inhibitor (NCI) for maximum cellulose recovery from paddy straw was studied. Pretreatment was carried out under solid state condition. Supplementation of 8% NCI in pretreatment medium improves cellulose recovery and delignification by 1.2 and 1.5-fold respectively, compared to conventional bio-pretreatment due to inhibition of 61% of cellulase activity in IMBP. Further increase in NCI concentration showed negative effect on Pleurotus florida growth and suppress the laccase productivity by 1.1-fold. Laccase activity in IMBP was found to be 2.0U/mL on 19thday, which is higher than (1.5U/mL) conventional bio-pretreatment. Physico-chemical modifications in paddy straw before and after pretreatment were analysed by SEM, ATR-FTIR, XRD and TGA. According to these findings, the IMBP technology can be a viable eco-friendly technology for sustainable production of bioethanol with maximum cellulose recovery.

Effective bio-pretreatment of sawdust waste with a novel microbial consortium for enhanced biomethanation

Anaerobic digestion (AD) is considered an efficient cost-effective technology for sustainable biogas production from lignocellulosic wastes. A novel lignocellulosic degradation microbial consortium (LCDC) was isolated from rotten sawdust, and further used for sawdust pretreatment prior to AD. Results showed that pretreatment of sawdust for 10days led to significant reduction in cellulose, hemicelluloses, and lignin contents by 37.5%, 39.6%, and 56.7%, respectively, with respect to the control. In addition, the pretreatment enhanced cumulative biogas yield, which reached its maximum value of 312.0Lkg−1VS after 28days of AD (25.6% higher than the corresponding control). Moreover, the maximum significant cumulative methane yield was recorded after 28days of AD of the pretreated sawdust (155.2Lkg−1VS), which represented 72.6% higher than the corresponding control. Significantly higher biomethane yield from sawdust pretreated with LCDC confirms that this process is more economical than the previous reports.

A comprehensive overview on electro-active biofilms, role of exo-electrogens and their microbial niches in microbial fuel cells (MFCs)

Microbial fuel cells (MFCs) are biocatalyzed systems which can drive electrical energy by directly converting chemical energy using microbial biocatalyst and are considered as one of the important propitious technologies for sustainable energy production. Much research on MFCs experiments is under way with great potential to become an alternative to produce clean energy from renewable waste. MFCs have been one of the most promising technologies for generating clean energy industry in the future. This article summarizes the important findings in electro-active biofilm formation and the role of exo-electrogens in electron transfer in MFCs. This study provides and brings special attention on the effects of various operating and biological parameters on the biofilm formation in MFCs. In addition, it also highlights the significance of different molecular techniques used in the microbial community analysis of electro-active biofilm. It reviews the challenges as well as the emerging opportunities required to develop MFCs at commercial level, electro-active biofilms and to understand potential application of microbiological niches are also depicted. Thus, this review is believed to widen the efforts towards the development of electro-active biofilm and will provide the research directions to overcome energy and environmental challenges.

Alkali pretreatment at ambient temperature: A promising method to enhance biomethanation of rice straw

Anaerobic digestion is the most cost effective technology for sustainable biogas production from rice straw. Rice straw was subjected to ambient pretreatment with alkali and subsequently digested anaerobically. A dimensional equation was developed to predict the efficacy of alkali treatment in terms of soluble COD. Biomethanation process parameters like temperature, initial pH, particle size, substrate/inoculum ratio, trace element supplementation, C/N ratio and hydraulic retention time were optimized. The highest biogas production under optimized conditions was 514L/kg VS/day (∼59% CH4) from milled rice straw (1mm) pretreated with sodium hydroxide (1% w/v) at ambient temperature for 180min. The digester was operated at 15days HRT at 37°C and neutral pH. C/N ratio was optimized at 25 using urea. Higher biogas yield from rice straw treated with lower concentration of NaOH at ambient temperature may make this process more economical than the previous reports.

Characterization of [FeFe] Hydrogenase O2 Sensitivity Using a New, Physiological Approach

[FeFe] hydrogenases catalyze rapid H2 production but are highly O2-sensitive. Developing O2-tolerant enzymes is needed for sustainable H2 production technologies, but the lack of a quantitative and predictive assay for O2 tolerance has impeded progress. We describe a new approach to provide quantitative assessment of O2 sensitivity by using an assay employing ferredoxin NADP+ reductase (FNR) to transfer electrons from NADPH to hydrogenase via ferredoxins (Fd). Hydrogenase inactivation is measured during H2 production in an O2-containing environment. An alternative assay uses dithionite (DTH) to provide reduced Fd. This second assay measures the remaining hydrogenase activity in periodic samples taken from the NADPH-driven reaction solutions. The second assay validates the more convenient NADPH-driven assay, which better mimics physiological conditions. During development of the NADPH-driven assay and while characterizing the Clostridium pasteurianum (Cp) [FeFe] hydrogenase, CpI, we detected significant rates of direct electron loss from reduced Fd to O2 However, this loss does not interfere with measurement of first order hydrogenase inactivation, providing rate constants insensitive to initial hydrogenase concentration. We show increased activity and O2 tolerance for a protein fusion between Cp ferredoxin (CpFd) and CpI mediated by a 15-amino acid linker but not for a longer linker. We suggest that this precise, solution phase assay for [FeFe] hydrogenase O2 sensitivity and the insights we provide constitute an important advance toward the discovery of the O2-tolerant [FeFe] hydrogenases required for photosynthetic, biological H2 production.

How to Efficiently Shake Viscous Culture Broths

Genetic Engineering & Biotechnology NewsVol. 36, No. 15 Bioprocessing TutorialHow to Efficiently Shake Viscous Culture BrothsCulture Broth Viscosity Evaluated in Shake Flasks StudiesJolanda Meister, Rüdiger W. Maschke, Sören Werner, Gernot T. John, and Dieter EiblJolanda MeisterJolanda Meister, Rüdiger W. Maschke, Sören Werner, and Prof. Dieter Eibl are with the Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Institute of Chemistry and Biotechnology, and Dr. Gernot T. John (E-mail Address: g.john@presens.de) is with PreSens Precision Sensing. Website: www.presens.de.Search for more papers by this author, Rüdiger W. MaschkeJolanda Meister, Rüdiger W. Maschke, Sören Werner, and Prof. Dieter Eibl are with the Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Institute of Chemistry and Biotechnology, and Dr. Gernot T. John (E-mail Address: g.john@presens.de) is with PreSens Precision Sensing. Website: www.presens.de.Search for more papers by this author, Sören WernerJolanda Meister, Rüdiger W. Maschke, Sören Werner, and Prof. Dieter Eibl are with the Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Institute of Chemistry and Biotechnology, and Dr. Gernot T. John (E-mail Address: g.john@presens.de) is with PreSens Precision Sensing. Website: www.presens.de.Search for more papers by this author, Gernot T. JohnJolanda Meister, Rüdiger W. Maschke, Sören Werner, and Prof. Dieter Eibl are with the Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Institute of Chemistry and Biotechnology, and Dr. Gernot T. John (E-mail Address: g.john@presens.de) is with PreSens Precision Sensing. Website: www.presens.de.Search for more papers by this author, and Dieter EiblJolanda Meister, Rüdiger W. Maschke, Sören Werner, and Prof. Dieter Eibl are with the Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Institute of Chemistry and Biotechnology, and Dr. Gernot T. John (E-mail Address: g.john@presens.de) is with PreSens Precision Sensing. Website: www.presens.de.Search for more papers by this authorPublished Online:25 Aug 2016https://doi.org/10.1089/gen.36.15.14AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetailsCited byDetermination of culture design spaces in shaken disposable cultivation systems for CHO suspension cell culturesBiochemical Engineering Journal, Vol. 6Bioreactor Technology for Sustainable Production of Plant Cell-Derived Products21 April 2018Bioreactor Technology for Sustainable Production of Plant Cell-Derived Products28 April 2017 Volume 36Issue 15Sep 2016 InformationCopyright © by GEN PublishingTo cite this article:Jolanda Meister, Rüdiger W. Maschke, Sören Werner, Gernot T. John, and Dieter Eibl.How to Efficiently Shake Viscous Culture Broths.Genetic Engineering & Biotechnology News.Sep 2016.28-29.http://doi.org/10.1089/gen.36.15.14Published in Volume: 36 Issue 15: August 25, 2016PDF download

Response of Land Configuration and Mulches on Maize–Frenchbean–Toria Cropping System

Alteration in soil‐topography and placement of mulches could play an important role in in situ conservation of resources. The objective of this study was to assess the productivity, water use, and weed smothering in the rainfed maize (Zea mays L.)–frenchbean (Phaseolus vulgaris L.)–toria (Brassica campestris L.) cropping system. Results revealed that the yield improvement under broad bed and furrow (BBF) was noticed up to 33.7% in maize grain, 35.3% in frenchbean green pod, and 28.2% in toria seeds followed by ridges and furrow (R&F) over flat bed (FB). Placement of mulch improved the crop yield by 14.2, 14.4 and 12.4%, respectively than without mulch plots. The FB plots recorded with profuse growth of weeds and obtained highest weed dry biomass. Weed smothering efficiency (WSE) improved by 43.6 to 65.1% in BBF and 54.4 to 72.8% with mulch over FB and without mulch, respectively. Maize and frenchbean under FB plots utilized 43.1 and 14.2% more rain water than the R&F, whereas, R&F plots in toria utilized 12% more than FB plots. The BBF improved the water‐use efficiency (WUE) by 77.9, 40.6, and 37.2% respectively in maize, frenchbean, and toria over FB plots. Placement of mulch utilized the rain water to the tune of 10.4 to 36.1% higher, but WUE was considerably improved by 7.8 and 21.2%, respectively with frenchbean and toria under without mulch plots. Permanent beds along with crop residues as mulch can be utilized as promising resource conserving sustainable production technology in Southeast Asia.Core Ideas Land configuration and mulches improved the crop productivity. Highest weed smothering obtained under broad bed and furrow with mulch. Water‐use efficiency improved under broad bed and furrow along with mulch.

Physiochemical Properties of Soil in Selected Sites of the Lake Chilwa Basin after 5 years of Conservation Agriculture Practice

Conservation Agriculture (CA) has been implemented in the Lake Chilwa basin for over 5 years in response to the rising interest in exploring the potential of CA as one of the sustainable agricultural production technologies in Malawi. Soil physiochemical characterization was carried out in some selected Extension Planning Areas (EPAs) before CA implementation. The aim was to lay basis for future monitoring of the physiochemical soil changes that the CA intervention might bring. Collected soil samples were analyzed in a laboratory using standard analysis procedures. Soils were found to be generally nitrogen deficient during baseline study. The results were attributed to unsustainable land use practices that required interventions such as CA practice. The physiochemical status of the soil was once again reviewed after 5years of CA practice and current results show some improvements in some soil properties and a decline in others. Recorded changes continue to show significant differences (P≤0.05) across the EPAs under study but no significant variation (P≥0.05) along the soil depth (0 – 30cm). The negative decline in soil status is attributed to nutrient loss through heavy leaching under waterlogged conditions experienced in the basin prior to the second soil review.

Assessment of Nutrient Management Technologies for Broccoli to Improve Productivity and Quality and Soil Resources in the Subtropics

ABSTRACTAssessment of nutrient management (NM) technologies for sustainable crop production requires a detailed understanding of the entire production system and how it affects quantity and quality of the yield, economic profitability, energy balance, environmental health, and soil quality. The influence of NM technologies on broccoli (Brassica oleracea L. var. italica Plenk) productivity and quality and effects on soil were determined. Fifteen NM technologies including a control (farmer’s production practice with 80N–15P kg·ha−1 of fertilizer); organics (vermicompost, cow manure, and mustard oil cake); inorganic fertilizer (recommended N–P–K at the rate of 150–33–63 kg ha−1 and 125% of recommended N–P–K [N–P–K^]); and their selected combinations were tested. Cow manure at 6.25 Mg·ha−1 + 125% of recommended N–P–K outperformed others with higher curd yield (11.4 Mg·ha−1), greater energy efficiency (net energy 39 GJ·ha−1; output–input energy ratio 2.77), higher economic return (benefit–cost ratio 8.7; marginal rate of return 25.3), and greater soil (2.65) and crop quality index (9.80). Organics used alone or in combinations were less productive, energetically less efficient, and less profitable compared to inorganic or integrated NM practices for growing broccoli under hot, humid, subtropical conditions.

Approaches to definition of complex influence of major components of agriculture on productivity agrophytocenoses and soil fertility

The purpose - to determine the most productive crop rotation with a corresponding set, ratio and placement of field crops for different ways of basic soil tillage, fertilizer levels and weather conditions. Identify the main parts of the interplay of farming on soil fertility, productive and sustainable land use. Methods. Field, laboratory, comparative and analytical. Conclusions. U article summarizes experimentally developed and theoretically grounded and economically approved agri-environmental and biological basis of efficiency scientifically based crop rotation of different rotation group left bank steppe of Ukraine with optimal saturation ratio and placement agrophytocenoses depending on fertilization, tillage methods that enhances fertility and stabilization soil, increase quality agricultural products obtained by reducing the cost of its production.
 Objective scientific information that could serve as a basis for the development of modern agriculture can only be obtained by an integrated approach to the formulation of research in the field of long multifactor stationary experiment, conducted in the NSC "Institute of Agriculture NAAS." Establishing quantitative patterns of action the main factors in its comprehensive and manifestation of the separation opens up opportunities to create sustainable crop production technologies and development of soil fertility management. Besides great theoretical interest, they immediately practical.
 Long-term studies (1975-2015 gg.) Typical black soil unstable wetting left-bank forest-steppe Drabiv Experimental Station (now the experimental field) Cherkassy DSHDS NSC "Institute of Agriculture NAAS" set action and mutual influence of crop rotation, fertilizers, basic soil, weather agrophytocenoses on productivity and soil fertility. In view of climate change and market relations, ecological factor rotation is stabilizing soil-plant system for current and future agriculture. It selectively acts on mutual share of productivity crops grown on various soil cultivation technologies, reveals the features of formation of indicators of soil fertility, especially the humus balance and quality.
 The leading factor in the performance of field crop rotation is: after placing the best predecessors in the application of optimal doses of fertilizers and differentiated cultivation provides a stable grain yield at 5.5-6.5 t / ha. Collecting fodder units 1 hectare of crop rotation area was 10.8 and digestible protein 0,68-0,70 t / ha. Preference is for crop rotation with cereals 80%: 20% peas, 20 - winter wheat, 40% corn.
 In terms Panfyly research station on the same soil in average for 2004-2013 years. Short rotation driving and the effects of crop rotation and use of fertilizers on the characteristics of water and nutritious regime of soil, humus balance and nutrients, microbial activity processes, weed-infested state of agricultural crops. The meaning of income and quality of plant residues. The dependence of productivity, economic and energy efficiency different rotation types of field rotation.
 The technique for conducting reconstruction programs researching and the portion of the main factors of interference farming system and weather conditions on land use management.

Anaerobic digestion of food waste to methane at various organic loading rates (OLRs) and hydraulic retention times (HRTs): Thermophilic vs. mesophilic regimes

Generation of food waste is a serious issue that needs to be addressed worldwide. Developing suitable treatment methods while generating energy (methane) is a common practice for sustainable treatment of waste. In this study, methane generation by food waste was investigated in mesophilic and thermophilic regimes at various hydraulic retention times (HRTs) and organic loading rates (OLR). In temperature regimes, influent concentrations and HRTs ranged from 30 to 110 g COD/L and 18 to 30 days, respectively, which corresponding to an OLR of 1.0 to 6.1 kg COD/㎥-d. Better methane production and organic removal was observed under thermophilic conditions because of the enhanced hydrolysis of complex polymers and microbial activity at higher temperature. The peak methane productivities attained in thermophilic and mesophilic regimes were 1.30 and 0.99 ㎥/㎥-d, respectively. The maximum methane yields were achieved at 50 g COD/L and HRT of 24 d in both cases, and the values were 264 and 221 ㎥/ton COD, respectively. The results of this study will facilitate the development of sustainable methane production technologies using food waste as a feedstock.

Indium Oxide as a Superior Catalyst for Methanol Synthesis by CO2 Hydrogenation

AbstractMethanol synthesis by CO2 hydrogenation is attractive in view of avoiding the environmental implications associated with the production of the traditional syngas feedstock and mitigating global warming. However, there still is a lack of efficient catalysts for such alternative processes. Herein, we unveil the high activity, 100 % selectivity, and remarkable stability for 1000 h on stream of In2O3 supported on ZrO2 under industrially relevant conditions. This strongly contrasts to the benchmark Cu‐ZnO‐Al2O3 catalyst, which is unselective and experiences rapid deactivation. In‐depth characterization of the In2O3‐based materials points towards a mechanism rooted in the creation and annihilation of oxygen vacancies as active sites, whose amount can be modulated in situ by co‐feeding CO and boosted through electronic interactions with the zirconia carrier. These results constitute a promising basis for the design of a prospective technology for sustainable methanol production.

Indium Oxide as a Superior Catalyst for Methanol Synthesis by CO2 Hydrogenation

Methanol synthesis by CO2 hydrogenation is attractive in view of avoiding the environmental implications associated with the production of the traditional syngas feedstock and mitigating global warming. However, there still is a lack of efficient catalysts for such alternative processes. Herein, we unveil the high activity, 100 % selectivity, and remarkable stability for 1000 h on stream of In2 O3 supported on ZrO2 under industrially relevant conditions. This strongly contrasts to the benchmark Cu-ZnO-Al2 O3 catalyst, which is unselective and experiences rapid deactivation. In-depth characterization of the In2 O3 -based materials points towards a mechanism rooted in the creation and annihilation of oxygen vacancies as active sites, whose amount can be modulated in situ by co-feeding CO and boosted through electronic interactions with the zirconia carrier. These results constitute a promising basis for the design of a prospective technology for sustainable methanol production.

Applications of Microbial Fuel Cell on Sewage Treatment by Using Electrogens

Renewable and clean forms of energy are one of the major needs at present. Microbial Fuel Cells (MFC’s) offers unambiguous advantages over other renewable energy conversion methods. Production of energy resources while minimizing waste is one of the best ways for sustainable energy resource management practices. The application of Microbial Fuel Cells (MFCs) may represent a completely new approach to wastewater treatment with the production of sustainable clean energy. The increase in energy demand can be fulfilled by Microbial Fuel Cell (MFC) in the future. In recent years, researchers have shown that MFCs can be used to produce electricity from water containing glucose, acetate, or lactate. Studies on electricity generation using organic matter from wastewater as substrate are in progress. Waste biomass is a cheap and relatively abundant source of electrons for microbes capable of producing electrical current outside the cell. Rapidly developing microbial electrochemical technologies, such as microbial fuel cells, are part of a diverse platform of future sustainable energy and chemical production technologies. In the present investigation to study the two wastewater samples, municipal wastewater from nearby areas of Guntur (A.P.) and Dairy waste from Guntur (A.P.) were used as substrates in Microbial Fuel Cells (MFCs) to generate electricity. Along with electricity generation, the MFCs can successfully help in treating the same sewage samples. The parameters like pH, TS, TSS, TDS, BOD, and COD were analyzed for all two samples. The COD removal efficiency of the MFCs was analyzed using the standard reflux method. All the MFCs were efficient in COD removal. 50%, 75%, and 85% COD removal was observed after 10, 15, and 30 days respectively of operation of MFCs with municipal waste as substrate.

A sustainable rice production technology: problems and prospects

The study has focused on problems and prospects perceived by farmers’ for growing rice in direct seeded cultivation mode i.e. Direct Seeded Rice (DSR) in Haryana (India). Overall adoption of DSR technology was low to moderate since 70 per cent respondents belonged to these categories. The method of sowing (weighted mean score 3.0), depth of sowing (2.93) and seed treatment (2.93) were highly adopted agronomic practices, whereas least adopted practices were like recommended seed rate (1.94), timely application of fertilizers (1.87) and their recommended doses (1.73), and ferrous sulphate use only at deficiency syndrome (1.19) not as per recommended schedule. Among constraints non-availability of quality seeds, fertilizers, weedicides and pesticides in required quantity and at proper time (1.64), high weed infestation in DSR in comparison to transplanting (2.88), wide fluctuation in prices (2.83) of basmati paddy due to lack of MSP, lack of storage facilities in villages (2.78), lack of proper knowledge of irrigation schedule (1.73), non-availability of extension personnel (1.64), lack of low credit facility (1.62), non-availability of agricultural magazines and literature in time in villages (2.78), lack of stable procurement policy for basmati rice (2.78) and lack of trained field staff to provide technical guidance during cultivation (2.02) process were serious constraints faced by farmers in adoption of DSR technology in Haryana. Since majority of respondent farmers agreed that DSR technology give better net returns in comparison to transplanting (2.95), less labour requirement (2.92) and best suited to climate change risks (2.66).

Effect of herbicides on weed management in dry-seeded rice sown under different tillage systems

In India, dry-seeded rice (DSR) production systems are rapidly replacing conventional rice production systems due to various advantages. DSR systems can be managed under zero-till (ZT) conditions or after a preparatory tillage, often referred to as conventional tillage systems (CONT). Although previous reports indicate the contribution of tillage to weed suppression, the effect of one-time preparatory tillage in a DSR system could vary depending on the dominant weeds in the system, vertical seed distribution and the weed seed dynamics. A study was conducted to test the efficacy of ZT and CONT and their interaction with herbicide treatments on the weed population dynamics and rice grain yield in 2010 and 2011. Tillage systems did not affect weed emergence, weed biomass, tiller production and crop yield. However, herbicide treatments varied in their efficacy on individual weeds. Hand-weeding treatments and pendimethalin combined with hand weeding did not effectively control Cyperus rotundus L. and Panicum maximum Jacq. (a perennial grass weed with underground parts). The herbicide combination of metsulfuron and chlorimuron was effective in controlling C. rotundus but not grass weeds. This indicates the need for sequential applications of herbicides for grass weed control or integration of hand weeding to achieve broad-spectrum weed control. Apart from hand weeding (three times), treatment with penoxsulam–cyhalofop and pendimethalin followed by (fb) hand weeding resulted in low weed density, high tiller production and grain yield. The study clearly indicates that tillage does not always lead to weed suppression compared with ZT, and herbicides must be chosen based on the dominant weeds in a system. The results of this study are pertinent as herbicide-resistant weeds are rapidly evolving under continuous herbicide selection pressure, which warrants studies on enhancing productivity through low-input, environmentally friendly and sustainable production technology.

Hydrogen production in single chamber microbial electrolysis cells with stainless steel fiber felt cathodes

Microbial electrolysis cell (MEC) is a promising technology for sustainable production of hydrogen from biodegradable carbon sources. Employing a low-cost and high efficient cathode to replace platinum catalyzed cathode (Pt/C) for hydrogen generation is a challenge for commercialization of MEC. Here we show that a 3D macroporous stainless steel fiber felt (SSFF) with high electrochemical active surface area has an excellent catalytic activity for hydrogen generation, which is comparable to Pt/C cathode and superior to stainless steel mesh (SSM) cathode in the single-chamber MEC. The SSFF cathode (mean filter rating 100 μm) produces hydrogen at a rate of 3.66 ± 0.43 m3 H2 m−3d−1 (current density of 17.29 ± 1.68 A m−2), with a hydrogen recovery of 76.37 ± 15.04% and overall energy efficiency of 79.61 ± 13.07% at an applied voltage of 0.9 V. The performance of SSFF cathode improves over time due to a decrease in overpotential which caused by corrosion. These results demonstrate that SSFF can be a promising alternative for Pt catalytic cathode in MEC for hydrogen production.