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In India, stubble burning is frequently practiced in the dominant rice-growing states of the Indo-Gangetic Plains, primarily in Punjab, Haryana and Uttar Pradesh. We attempted monitoring and mapping of the active fire events in real time for all the 3 states by acquiring thermal datasets from 3 different sensors i.e. Visible Infrared Imaging Radiometer Suite (VIIRS) at 375 m aboard Sumo-NPP, Moderate-Resolution Imaging Spectro-Radiometer (MODIS) at 1000 m aboard Terra & Aqua, and Advanced Very High Resolution Radiometer (AVHRR) at 1,100 m aboard NOAA 18/19 & MetOp 1/2, made available by IARI Satellite Ground Station during Kharif crop harvest season (October–November) 2018. The standard algorithm of detection of the temperature of a pixel at (4.0 µm and/or 10 to 12 µm) and its difference from the temperature of surrounding pixels was employed for day and night passes. Analysis of active fire locations detected from VIIRS, MODIS and AVHRR between 01st October and 30th November 2018 suggests continuing practice of stubble burning with a total of 75563 burning events distributed as 59695, 9232 and 6636 in Punjab, Haryana and Uttar Pradesh, respectively. District-wise monitoring showed a significant upsurge of fire events during the study period in the south-western and eastern districts of Punjab. Intense fire was witnessed in northern districts of Haryana and western districts of Uttar Pradesh. Comparative analysis shows that the burning events in the current year up till 30th November 2018 are 85% of the events detected in 2017 and about 59.10% of the events detected in 2016. It implies that the burning of rice stubble in the current year has reduced significantly over the past years due to various scheme implemented by the State and Central government.

Irrigated transplanted flooded rice is a major source of methane (CH4) emission. We carried out experiments for 2 years in irrigated flooded rice to study if interventions like methane-utilizing bacteria, Blue-green algae (BGA), and Azolla could mitigate the emission of CH4 and nitrous oxide (N2O) and lower the yield-scaled global warming potential (GWP). The experiment included nine treatments: T1 (120 kg N ha−1 urea), T2 (90 kg N ha−1 urea + 30 kg N ha−1 fresh Azolla), T3 (90 kg N ha−1 urea + 30 kg N ha−1 Blue-green algae (BGA), T4 (60 kg N ha−1 urea + 30 kg N ha−1 BGA + 30 kg N ha−1 Azolla, T5 (120 kg N ha−1 urea + Hyphomicrobium facile MaAL69), T6 (120 kg N ha−1 by urea + Burkholderia vietnamiensis AAAr40), T7 (120 kg N ha−1 by urea + Methylobacteruim oryzae MNL7), T8 (120 kg N ha−1 urea + combination of Burkholderia AAAr40, Hyphomicrobium facile MaAL69, Methylobacteruim oryzae MNL7), and T9 (no N fertilizer). Maximum decrease in cumulative CH4 emission was observed with the application of Methylobacteruim oryzae MNL7 in T7 (19.9%), followed by Azolla + BGA in T4 (13.2%) as compared to T1 control. N2O emissions were not significantly affected by the application of CH4-oxidizing bacteria. However, significantly lower (P

Intermittent flooding (IF) of rice has been encouraged as an approach to reduce water use and methane emissions compared with continuous flooding (CF), but may involve trade-offs. This study compared the contrasting effect of IF and CF flooding regimes on emissions of methane (CH4), nitrous oxide (N2O) and ammonia (NH3), nitrogen use efficiency (NUE) and yield. A split plot design was used which assessed the effects of four different fertiliser types. The results suggest that converting from CF to IF irrigation does lower CH4 emissions (by approximately 18%); however, this comes at a cost. IF irrigation resulted in a significant decrease in grain yield, regardless of fertiliser type (6.1% in this study) and also a significant decrease in NUE (a drop of 22.5% when compared to CF). IF irrigation also resulted in a small, but statistically significant (t-test p < 0.01) increase in N2O emissions. Difference in NH3 emission between the flooding regimes was not statistically significant. Our study concludes that conversion from CF to IF irrigation methods may well reduce overall global warming potential of greenhouse gas emissions from rice production; however, yield penalties and nitrogen pollution are likely to increase as a result. Leaf colour chart based application of Neem coated urea may lower the yield scaled GHG emissions under CF irrigation and NH3 loss in IF irrigation.

Methane (CH4) emissions are responsible for the higher global warming potential of rice cultivation. There are scattered reports on the use of chemical interventions for reducing CH4 emissions from rice. A laboratory study was carried out to estimate the CH4 mitigation potential of oxygen releasing chemicals such as magnesium peroxide (MgO2) and calcium peroxide (CaCO2), chelating agent ethylene diamine tetra acetic acid (EDTA), nitrification inhibitors thiourea and neem oil, limus (urease inhibitors), phosphogypsum (PG) a byproduct of phosphate fertilizer industry and ammonium sulfate (AS). The cumulative CH4 emission from soil reduced by 2.0–32.3% under the different treatments during the 45 days’ incubation study. Subsequently, four chemicals having the highest CH4 reduction potential i.e. PG, EDTA, AS, and MgO2 were further evaluated for the mitigation of CH4 and their concurrent impact on nitrous oxide (N2O) emission in a two-year experiment growing rice. PG, EDTA, AS, and MgO2 significantly (p = 0.0025) decreased CH4 emissions by 9.3−27.5% as compared to the control. The cumulative N2O emission were significantly lower by 13.9% under PG as compared to control. The global warming potential decreased by 6.8% with MgO2 to 23.6% with PG. The grain yield increased by 3.1–11.2% under the different treatments. The greenhouse gas intensity (GHGI) was the highest in control (0.309 kg CO2 eq. kg-1 grain yield) and lowest in PG (0.212 kg CO2 eq. kg-1 grain yield). The findings suggest that PG, EDTA, AS, and MgO2 can be used to plummet the global warming potential of irrigated rice soils without any yield penalty. More research is required to be undertaken to evaluate the impact of these chemicals from the perspective of food security in the farmers’ fields.

Methane is one of the critical greenhouse gases, which absorb long wavelength radiation, affects the chemistry of atmosphere and contributes to global climate change. Rice ecosystem is one of the major anthropogenic sources of methane. The anaerobic waterlogged soil in rice field provides an ideal environment to methanogens for methanogenesis. However, the rate of methanogenesis differs according to rice cultivation regions due to a number of biological, environmental and physical factors like carbon sources, pH, Eh, temperature etc. The interplay between the different conditions and factors may also convert the rice fields into sink from source temporarily. Mechanistic understanding and comprehensive evaluation of these variations and responsible factors are urgently required for designing new mitigation options and evaluation of reported option in different climatic conditions. The objective of this review paper is to develop conclusive understanding on the methane production, oxidation, and emission and methane measurement techniques from rice field along with its mitigation/abatement mechanism to explore the possible reduction techniques from rice ecosystem.

Rice–wheat cropping systems (RWCS) of the Indo-Gangetic plains (IGP) of India are tillage, water and energy intensive and an important source of greenhouse gas (GHG) emission. Developing agronomic management in RWCS that lead to minimum adverse impact on soil, enhances water use efficiency, reduces GHG emission and are climate resilient is required. The aim of this study was to evaluate different combinations of GHG mitigation technologies for rice and wheat and to find suitable low carbon options for RWCS in the IGP. Seven management systems i.e. conventionally tilled wheat (CTW); zero tilled wheat (ZTW); transplanted puddled rice (TPR); dry direct seeded rice (DSR); intermittent wetting and drying (IWD); application of neem oil coated urea (NOCU); and surface application of rice residue (RR) were experimented in six combination of rotations [CTW-TPR, ZTW-TPR, ZTW-IWD, ZTW-DSR, ZTW + RR-DSR and (ZTW-TPR) + NOCU] for two consecutive years. Among these rotations, ZTW-DSR and ZTW + RR-DSR showed the lowest global warming potential (GWP) and GHG intensity in both the years. Adoption of these systems in the Indian-IGP can reduce GWP of the conventional RWCS (CTW-TPR) by 44–47% without any significant loss in the system yield. This was mainly due to significantly low CH4 emission (82.3–87.2%) in DSR as compared to TPR due to prolonged aerobic condition under DSR. However, frequent wetting and drying in DSR led to higher denitrification emissions of N2O (60–70%). Significantly higher emissions of N2O were observed in ZTW treatments (8–11%). NOCU was found effective in reducing N2O emission from ZTW (17.8–20.5%) leading to lower GWP as compared to CTW. Application of rice residue in ZTW treatment also reduced N2O emission (11–12.8%). There was no significant effect of different treatments in rice on GHG emission from the succeeding wheat crop; however, ZTW and ZTW + RR were found to enhance CH4 emission from the succeeding rice treatments.

Water, carbon (C) and nitrogen (N) are important natural resources required for crop production. Footprints of these three natural resources are useful indicators of consumption and pollution. The present project is aimed to determine the water, carbon and nitrogen footprints of major crops of the Indo-Gangetic Plains (IGPs). Field experiments were conducted, and modelling tools were used to quantify water, C and N footprints of rice and wheat crops in IGP. Four locations (Karnal, Delhi, Varanasi and Kalyani) were selected for the study representing different transects of IGP. Carbon footprint (CFP) of rice crop in Karnal and Delhi was found to be higher than Varanasi and Kalyani due to application of more amounts of agri-inputs and more use of farm machineries leading to higher GHG emission. Although GHG emission in wheat is also more in Karnal, higher yield of wheat crop led to lower CFP than Varanasi. Water footprint (WFP) of rice production was higher in Karnal, Delhi and Varanasi than Kalyani region mainly due to higher evapotranspiration. QGIS software was used to prepare geospatial maps of carbon and water footprint for IGP. The study will help in identifying regions and crops having higher footprints and also select alternative management practices which will help in lowering water, C and N footprints of agricultural production.

Summary Background Multidrug-resistant Candida auris infection has been reported from five continents in recent years. The prevalence of C. auris invasive infection has been estimated at 5.3% for intensive-care-acquired candidaemia in India. The transmission of the organism between the patients and from environment to patients is rapid. Aim To understand the intra-hospital dynamics of C. auris transmission and to determine the possible interventions to prevent its spread. Methods Surveillance of intensive care units was carried out to assess patient colonization, environmental contamination and hand carriage of the yeast among healthcare workers. Interventions including chlorhexidine washing of patients and decontamination of environmental surfaces with stabilized hydrogen peroxide disinfectant (Ecoshield) were undertaken. We further evaluated the effectiveness of frequently used disinfectants in the hospital against C. auris on various inanimate surfaces, and its persistence on hospital fabrics. Findings Three cases of C. auris bloodstream infection were detected over a period of three months. Many patients admitted at the same time, in the same area, were colonized by C. auris . Surveillance detected C. auris contamination of environmental surfaces and hands of healthcare workers. Interventions such as chlorhexidine washing and appropriate use of disinfectants could eradicate C. auris from patients and hospital environment. Conclusion The frequently used disinfectants in our hospital and current hand hygiene practices were efficient against C. auris if proper contact time and procedures were followed. Evaluation of possible persistence of C. auris on dry fabrics showed that they can persist for up to seven days.

Nitrogen (N) use in agriculture substantially alters global N cycle with the short- and long-term effects on global warming and climate change. It increases emission of nitrous oxide, which contributes 6.2%, while carbon dioxide and methane contribute 76% and 16%, respectively of the global warming. However, N causes cooling due to emission of NOx, which alters concentrations of tropospheric ozone and methane. NOx and NH3 also form aerosols with considerable cooling effects. We studied global temperature change potential (GTP) of N use in agriculture. The GTP due to N2O was 396.67 and 1168.32 Tg CO2e on a 20-year (GTP20) and 439.94 and 1295.78 Tg CO2e on 100-year scale (GTP100) during years 1961 and 2010, respectively. Cooling effects due to N use were 92.14 and 271.39 Tg CO2e (GTP20) and 15.21 and 44.80 Tg CO2e (GTP100) during 1961 and 2010, respectively. Net GTP20 was 369.44 and 1088.15 Tg CO2e and net GTP100 was 429.17 and 1264.06 Tg CO2e during 1961 and 2010, respectively. Thus net GTP20 is lower by 6.9% and GTP100 by 2.4% compared to the GTP considering N2O emission alone. The study shows that both warming and cooling effects should be considered to estimate the GTP of N use.

Agricultural crop residue burning contribute towards the emission of greenhouse gases (CO2, N2O, CH4), air pollutants (CO, NH3, NOx, SO2, NMHC, volatile organic compounds), particulates matter and smoke thereby posing threat to human health. In the present study a state-wise inventory of crop residue burnt in India and the air pollutants emitted was prepared using the Inter-Governmental Panel on Climate Change (IPCC) national inventory preparation guidelines for the year 2008–09. Total amount of residue generated in 2008–09 was 620 Mt out of which ~15.9% residue was burnt on farm. Rice straw contributed 40% of the total residue burnt followed by wheat straw (22%) and sugarcane trash (20%). Burning of crop residues emitted 8.57 Mt of CO, 141.15 Mt of CO2, 0.037 Mt of SOx, 0.23 Mt of NOx, 0.12 Mt of NH3 and 1.46 Mt NMVOC, 0.65 Mt of NMHC, 1.21 Mt of particulate matter for the year 2008–09. The variability of 21.46% in annual emission of air pollutants was observed from 1995 to 2009.

System of rice intensification (SRI) is an alternate method of conventional puddled, transplanted, and continuously flooded rice cultivation for higher yield, water saving, and increased farmer’s income. The SRI may also have considerable impact on greenhouse gas emission because of difference in planting, water and nutrient management practices. A field experiment was conducted with three planting methods: conventional puddled transplanted rice (TPR), conventional SRI with 12-days-old seedling (SRI) and modified SRI with 18-days-old seedling (MSRI) to study their effect on methane and nitrous oxide emission. Seasonal integrated flux (SIF) for methane was highest in the conventional method (22.59 kg ha−1) and lowest in MSRI (8.16 kg ha−1). Methane emissions with SRI and MSRI decreased by 61.1 and 64 %, respectively, compared to the TPR method. Cumulative N2O–N emission was 0.69, 0.90, and 0.89 kg ha−1 from the TPR, SRI, and MSRI planting methods, respectively. An average of 22.5 % increase in N2O–N emission over the TPR method was observed in the SRI and MSRI methods. The global warming potential (GWP), however, reduced by 28 % in SRI and 30 % in MSRI over the TPR method. A 36 % of water saving was observed with both SRI and MSRI methods. Grain yield in the SRI and MSRI methods decreased by 4.42 and 2.2 %, respectively, compared to the TPR method. Carbon efficiency ratio was highest in the MSRI and lowest in the TPR method. This study revealed that the SRI and MSRI methods were effective in reducing GWP and saving water without yield penalty in rice.

Agricultural soils contribute toward the emission of methane (CH4) and nitrous oxide (N2O), the two important greenhouse gases (GHGs) causing global warming. A state-wise inventory of CH4 and N2O emissions from agricultural soils of India was prepared for the base year 2007 using the Intergovernmental Panel on Climate Change (IPCC) national inventory preparation guidelines. For CH4 inventory, state-specifi c emission coeffi cients were used for rice grown under upland, rain-fed, irri- gated, and deepwater, the four major rice ecosystems of the country. In case of N2O, both direct and indirect emissions from agricultural soils in different states were calculated using indigenous country specifi c emission factors. The change in annual emission of CH4 and N2O during the period 1980 to 2007 was estimated using the same emission coeffi cients. Indian rice fi elds covering an area of 43.86 million ha under the different rice ecosystems emitted 3.37 million tons of CH4 (84.25 Tg CO2 equivalents) in 2007. The annual direct and indirect N2O-N emissions from Indian agricultural soils was estimated to be 118.67 Gg (55.5 Tg CO2 equivalent) and 19.48 Gg (9.1 Tg CO2 equivalent), respec- tively. The global warming potential of the agricultural soils was estimated to be 148 Tg for the year 2007. Emissions from fi eld burning of agricultural residues resulted in an annual emission of 250 Gg of CH4 (6.2 Tg CO2 equivalent) and 6.5 Gg of N2O (1.9 Tg CO2 equivalent). Emission of CH4 from Indian rice fi elds has remained almost constant during this period whereas there has been an increase of 176% in N2O emissions from agricultural soils due to increased inorganic fertilizer application, however the greenhouse gas emission intensity has declined over the years due to increase in food production. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd

Human activities have massively altered the global nitrogen (N) cycle, doubling annual production of reactive N (Nr) compounds from atmospheric dinitrogen (N2). The use of 120 Mt year−1 fertilizer N, with a global terrestrial/atmospheric N fixation of 285 Mt year−1, has provided huge benefits for global food production. However, nitrogen use efficiency (NUE) of the world food system is only ∼15%. The lost Nr creates a cascade of air and water pollution and greenhouse gas emissions, until it is eventually denitrified back to N2. India clearly illustrates a dual N challenge for food and environment, consuming 17 Mt of N fertilizer annually (14% of the global total), which has increased since 1970 at 6% year−1 approximately. Emissions of nitrogen oxides (NOx) from combustion sources are also increasing rapidly at 6.5% year−1 currently. By comparison, population growth rate is lower (2% year−1), while ammonia (NH3) emission increase is even less (1%), pertaining to smaller changes in livestock numbers. At current rate, Indian NOx emissions will exceed NH3 emissions by 2055. India currently loses Nr worth US$10 billion year−1 as fertilizer value, while costs of Nr to health, ecosystems, and climate are estimated at US$75 (38–151) billion year−1. Only a small fraction of the Indian population consumes animal products, hence per capita Nr use and pollution is much less than in many developed countries. However, rates of meat consumption are increasing. While published projections from the UN Food and Agriculture Organization anticipate a doubling of South Asian fertilizer consumption from 2006 to 2050 (equivalent to 1.9% year−1 increase), these projections lack transparency and require reevaluation. In practice, the future nitrogen cycle for India will depend on scientific advances in agronomy, genetics and environment, and the extent to which government and society grasp the emerging opportunities for optimizing N management.

Conventional puddled transplanted rice (TPR) is a major source of greenhouse gas (GHG), particularly methane, causing global warming. Direct-seeded rice (DSR) is a feasible alternative to mitigate methane emission, besides saving water and labor. A 2-year field experiment was carried out to quantify GHG mitigation and water- and labor-saving potentials of the DSR crop compared to TPR in three villages in Jalandhar district of Punjab, India. The InfoRCT simulation model was used to calculate the emission of CO2 besides CH4 and N2O in different districts of Punjab, India. Total global warming potential (GWP) in transplanted rice in various districts of Punjab ranged from 2.0 to 4.6 t CO2 eq. ha−1 and in the DSR it ranged from 1.3 to 2.9 t CO2 eq. ha−1. Extrapolation analysis showed that if the entire area under TPR in the state is converted to DSR, the GWP will be reduced by 33 %, and if 50 % area is converted to DSR the GWP will be reduced by 16.6 % of the current emission. The DSR crop saved 3–4 irrigations compared to the transplanted rice without any yield penalty. Human labor use also reduced to 45 % and tractor use to 58 % in the DSR compared to TPR.

The intensifi ed rice and wheat cropping systems consume most of the fertilizer and irrigation water in India and are major sources of greenhouse gas (GHG) emissions. The InfoCrop simulation model was evaluated to calculate methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emis- sions from soils under rice and wheat. Indian rice fi elds covering 42.21 million ha (Mha) emitted 2.07, 0.02, and 72.9 Tg of CH4-C, N2O-N and CO2-C, respectively, with a global warming potential (GWP) of 88.5 Tg CO2-C eq. Annual GHG emission from 28.08 Mha of wheat-growing areas was 0.017 and 43.2 Tg of N2O-N and CO2-C, respectively, with a GWP of 44.6 Tg CO2-C eq. Intermittent irrigation in rice reduced methane emissions by 40%. However, application of farmyard manure in rice increased the GWP by 41%. This study suggests that the InfoCrop model could be applied for simulating the impacts of crop management and soil and climatic parameters on GHG emission from agricultural areas. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd

Conventional blanket application of nitrogen (N) fertilizer results in more loss of N from soil system and emission of nitrous oxide, a greenhouse gas (GHG). The leaf color chart (LCC) can be used for real-time N management and synchronizing N application with crop demand to reduce GHG emission. A 1-year study was carried out to evaluate the impact of conventional and LCC-based urea application on emission of nitrous oxide, methane, and carbon dioxide in a rice-wheat system of the Indo-Gangetic Plains of India. Treatments consisted of LCC scores of ≤4 and 5 for rice and wheat and were compared with conventional fixed-time N splitting schedule. The LCC-based urea application reduced nitrous oxide emission in rice and wheat. Application of 120 kg N per hectare at LCC ≤ 4 decreased nitrous oxide emission by 16% and methane by 11% over the conventional split application of urea in rice. However, application of N at LCC ≤ 5 increased nitrous oxide emission by 11% over the LCC ≤ 4 treatment in rice. Wheat reduction of nitrous oxide at LCC ≤ 4 was 18% as compared to the conventional method. Application of LCC-based N did not affect carbon dioxide emission from soil in rice and wheat. The global warming potential (GWP) were 12,395 and 13,692 kg CO(2) ha(-1) in LCC ≤ 4 and conventional urea application, respectively. Total carbon fixed in conventional urea application in rice-wheat system was 4.89 Mg C ha(-1) and it increased to 5.54 Mg C ha(-1) in LCC-based urea application (LCC ≤ 4). The study showed that LCC-based urea application can reduce GWP of a rice-wheat system by 10.5%.

Carbon emission occurs during various stages of life cycle of food products. Greenhouse gases (GHG) emission from 24 Indian food items showed that animal food products (meat and milk) and rice cultivation mostly contributed to methane (CH4) emission, while food products from crops contributed to emission of nitrous oxide (N2O). Emission of CO2 occurred during farm operations, production of farm inputs, transport, processing and preparation of food. The GHG emission during the life cycle of cooked rice was 2.8 times the GHG emission during the life cycle of chapatti, a product of wheat flour. Mutton emitted 11.9 times as much GHG as milk, 12.1 times fish, 12.9 times rice and 36.5 times chapatti. As Indians mostly consume fresh foods produced locally, 87% emission came from food production followed by preparation (10%), processing (2%) and transportation (1%). For a balanced diet (vegetarian) an adult Indian man consumed 1165 g food and emitted 723.7 g CO2 eq. GHG d−1. A non-vegetarian meal with mutton emitted GHG 1.8 times of a vegetarian meal, 1.5 times of a non-vegetarian meal with chicken and an ovo-vegetarian meal and 1.4 times a lacto-vegetarian meal. Change in food habit thus could offer a possibility for GHG mitigation.

Increased use of irrigation and nitrogen (N) in rice and wheat would increase productivity. It would also enhance the emission of greenhouse gases from soil causing global warming and climate change. This study quantified the trade-offs between increased production with N fertilizer and irrigation application and the global warming potential (GWP) in the major rice and wheat growing regions of India. The InfoCrop model was used to simulate yield and GWP of rice and wheat for five regions in the country for two climatic scenarios i.e., current (1990–1999) and future (2050), two irrigation practices i.e., supply-driven irrigation (SDI) and demand-driven irrigation (DDI), and 10 levels of N and organic manure. Rice and wheat productivity of India can be increased from their current productivity of 3.26 and 2.73 Mg ha−1 to 5.66 and 6.15 Mg ha−1, respectively with increased irrigation and N use. But this would increase the GWP by 27 and 40%, respectively. In spite of the increased GWP the carbon efficiency ratio (CER) would increase from the current values of 0.67 and 0.85 to 1.06 and 1.75 in rice and wheat, respectively. Thus there is a ‘win-win’ situation in terms of increased CER for increasing productivity. These situations need to be identified to harness the benefit with more rational management practices including efficient use of irrigation and N, the major drivers for yield and GWP.

Nutrient budgeting is a useful tool in determining present and future productivity of agricultural land as well as undesirable effects of nutrient mining and environmental pollution. Budgets of N, P, and K were calculated for India for 2000–2001 taking into consideration the inputs through inorganic fertilizer, animal manure, compost, green manure, leguminous fixation, non-leguminous fixation, crop residues, rain and irrigation water and outputs through crop uptake and losses through leaching, volatilization and denitrification. Inorganic fertilizer was the dominant source contributing 64% of N and 78% of P inputs in Indian agriculture, whereas K input through inorganic fertilizer was 26%. Removals of N, P, and K by major agricultural crops in the country were 7.7, 1.3 and 7.5 Mt, respectively. There were positive balances of N (1.4 Mt) and P (1.0 Mt) and a negative balance of K (3.3 Mt). It was projected that N, P, and K requirement by Indian agriculture would be 9.78, 1.57 and 9.52 Mt, respectively, to meet the food demand of 1.3 billion people by 2020. The study identified the ‘hotspots’ of excess nutrient loads as well as of nutrient mining regions in India to improve our ability to predict environmental degradation due to imbalanced fertilizer use. However, there are some uncertainties in India’s nutrient budget and more research is required to reduce these uncertainties.

Burning of rice straw is a common practice in northwest India, where rice–wheat cropping system is extensively followed. The practice results in loss of nutrients, atmospheric pollution and emission of greenhouse gases. A field experiment was conducted at Indian Agricultural Research Institute, New Delhi, India during the rabi season (November to April) of 2002–2003 to evaluate the efficacy of the various modes of rice straw recycling in soil in improving yield and soil fertility and reducing not only carbon dioxide emission but also nitrous oxide (N2O) emission. The treatment with no rice straw incorporation and application of recommended doses of fertilizer (120, 26 and 50 kg N, P and K ha−1, respectively), gave the highest yield of wheat. Treatments with the incorporation of rice straw at 5 Mg ha−1 with additional amount of inorganic N (60 kg N ha−1) or inoculation of microbial culture had similar grain yields to that of the treatment with no straw incorporation. The lowest yield was recorded in the plots where rice straw was incorporated in soil without additional inorganic N and with manure application. All the treatments with rice straw incorporation had larger soil organic C despite the effect on the mineralisation of soil organic matter. Emission of N2O was more when additional N was added with rice straw and secondary when straw was added to the soil because of higher microbial activity. The study showed that burning of rice straw could be avoided without affecting yield of wheat crop by incorporating rice straw in soil with an additional dose of inorganic N or microbial inoculation. However, the reduction of N2O emission due to avoiding burning is in part counterbalanced by an increase in emission during the subsequent wheat cultivation.

Use of organic amendments such as farmyard manure (FYM), green manure (GM) and crop residues is important to improve soil health and reduce the dependence on synthetic chemical fertilizer. However, these organic amendments also effect the emissions of greenhouse gas (GHG) from soil. Influence of different organic amendments on emissions of GHG from soil and their global warming potential (GWP) was studied in a field experiment in rice–wheat cropping system of Indo-Gangetic plains (IGP). There was 28% increase in CH4 emissions on addition of 25% N through Sesbania GM along with urea compared to urea alone. Substitution of 100% inorganic N by organic sources lead to a 60% increase in CH4 emissions. The carbon equivalent emission from rice–wheat systems varied between 3816 and 4886 kg C equivalent ha−1 depending upon fertilizer and organic amendment. GWP of rice–wheat system increased by 28% on full substitution of organic N by chemical N. However, the C efficiency ratios of the GM and crop residue treatments were at par with the recommended inorganic fertilizer treatment. Thus use of organic amendments along with inorganic fertilizer increases the GWP of the rice–wheat system but may improve the soil fertility status without adversely affecting the C efficiency ratio. However, the trade-off between improved yield and soil health versus GHG emissions should be taken into account while promoting the practice of farming with organic residues substitution for mineral fertilizer.

Molasses-based distilleries generate large quantities of effluent, which is used for irrigation in many countries including India. The effluent is rich in organic and inorganic ions, which may leach down and pollute the groundwater. An on-farm experiment was conducted to assess the impact of long-term irrigation with post-methanation distillery effluent (PMDE) on nitrate, sulphate, chloride, sodium, potassium, and magnesium contents in the groundwater of two sites in northwest India. Electrical conductivity (EC), pH, total dissolved solids (TDS), sodium adsorption ratio (SAR) and colour were also determined to assess the chemical load in the groundwater. Nitrate content in the groundwater samples ranged from 16.95 mg L(-1) in the unamended fields to 59.81 mg L(-1) in the PMDE-amended fields during the 2-year study (2001-2002). Concentrations of TDS in water samples from tubewell of the amended field was higher by 40.4% over the tubewell water of the unamended field. Colour of the water samples of the amended fields was also darker than that of the unamended fields. The study indicated that the organic and inorganic ions added through the effluent could pose a serious threat to the groundwater quality if applied without proper monitoring.

Mitigation of methane (CH4) and nitrous oxide (N2O) emissions from soil is important to reduce the global warming. Efficacy of five nitrification inhibitors, i.e. neem (Azadirachta melia) cake, thiosulphate, coated calcium carbide, neem oil coated urea and dicyandiamide (DCD) and one urease inhibitor, hydroquinone, in mitigating N2O and CH4 emissions from fertilized soil was tested in rice-wheat system in the Indo-Gangetic plains. The closed chamber technique was used for the collection of gas samples, which were analyzed using gas chromatography. Reduction in N2O emission on the application of nitrification/urease inhibitors along with urea ranged from 5% with hydroquinone to 31% with thiosulphate in rice and 7% with hydroquinone to 29% with DCD in wheat crop. The inhibitors also influenced the emission of CH4. While application of neem coated urea, coated calcium carbide, neem oil and DCD reduced the emission of CH4; hydroquinone and thiosulphate increased the emission when compared to urea alone. However, the global warming potential was lower with the inhibitors (except hydroquinone) as compared to urea alone, suggesting that these substances could be used for mitigating greenhouse gas emission from the rice-wheat systems.

This paper presents a zero-voltage-transition (ZVT) boost converter using a soft switching auxiliary circuit for power factor correction (PFC) applications. The improvement over existing topologies lies in the positioning of the auxiliary circuit capacitors and the subsequent reduction in the resonant current and therefore the conduction losses as compared to other similar topologies. The proposed converter operates in two modes - Mode 1 and Mode 2. It is shown in the paper that the converter should be designed using the constraints obtained in Mode 1 to achieve low-loss switching. The converter is analyzed and characteristic curves presented which are then used in a detailed design example. Experimental results from a 250 W, 127 V input laboratory prototype switching at 100 kHz verify the design process and highlight the advantages of the proposed topology. The proposed converter is suitable for single-phase, two stage power factor correction circuits with universal input voltage range and power levels up to 3 kW.

An outbreak of watery diarrhoea accompanied by low-grade fever and weight loss in 16 preterm neonates (age range 2-20 days) admitted to a neonatal intensive care unit (NICU) over four days in August 2000 is reported. Escherichia coli having similar antibiograms were identified on routine bacterial stool cultures in 14 (87.5%) neonates and none of the other known enteropathogens were detected. An investigation was undertaken to trace the source of infection. Surveillance cultures of swabs from the utensils used to prepare milk feed, culture of the formula feed and all items handled by one particular cook yielded growth of E. coli as did culture of his hand swabs and faecal sample. The causative agent was identified as enterotoxigenic E. coli (ETEC) as toxin production could be demonstrated by reverse passive latex agglutination in all the strains of E. coli isolated both from the infected neonates and the source of infection. The outbreak was effectively controlled by appropriate therapy and institution of proper measures of hygiene after identification of the source of infection.

Quantification of greenhouse gases (GHGs) emissions from agriculture is necessary to prepare the national inventories and to develop the mitigation strategies. Field experiments were conducted during 2008-2010 at the experimental farm of the Indian Agricultural Research Institute, New Delhi, India to quantify nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions from soils under cereals, pulses, millets, and oilseed crops. Total cumulative N2O emissions were significantly different (P>0.05) among the crop types. Emission of N2O as percentage of applied N was the highest in pulses (0.67%) followed by oilseeds (0.55%), millets (0.43%) and cereals (0.40%). The emission increased with increasing rate of N application (r(2)=0.74, P

Jatropha (Jatropha curcas L.) seed coat (JSC) and fruit coat (JFC) were investigated for adsorption of Cd(II) from aqueous solutions. JFC and JSC fine powders were characterized using FTIR and SEM which indicated that both the adsorbents have high surface area, pore space on their surface, and anionic sites for metal ion binding. Batch adsorption study was conducted to study the effect of adsorption time, agitation speed, and initial concentration of Cd(II) ion, pH, and temperature on the adsorption of Cd(II) by adsorbents. The equilibrium isotherm, kinetics, and thermodynamics of the adsorption process were studied. Adsorption equilibrium followed both Langmuir and Freundlich isotherm. The adsorption capacity (Q m ) of Cd(II) on JSC and JFC were 22.83 and 21.97 mg g−1, respectively. The adsorption of Cd(II) on JSC and JFC is endothermic in nature. The change of free energy (∆G) of the biosorption of Cd(II) on JSC ranged from −37.05 to −40.54 kJ mol−1 and for JFC −34.50 to −37.35 kJ mol−1. The enthalpy change (∆H) and entropy change (∆S) was 15.84 kJ mol−1 and −0.17 kJ mol−1 K−1 for JSC and 8.77 kJ mol−1 and −0.14 kJ mol−1 K−1 for JFC. Elovich model provided a better correlation of the experimental data in comparison with pseudo-first-order and pseudo-second-order kinetic models. The study indicated that JFC and JSC have good adsorption capacity for Cd(II).

Phytochemical investigation of the heartwood of Myristica malabarica has led to the isolation of the new 7,4′-dimethoxy-5-hydroxyisoflavone together with two other isoflavones, biochanin A and prunetin, and a 1,3-diarylpropanol and a rare α-hydroxydihydrochalcone.

A total of 384 sheep serum samples collected from two organised sheep farms was tested by dot immunobinding assay (DIA) and indirect enzyme-linked immunosorbent assay (I-ELISA) for the presence of bluetongue virus (BTV) antibodies. The results of both these assays were compared to find a sensitive, specific, rapid, easily performed and economical test for the diagnosis of bluetongue disease. DIA detected BTV antibodies in 210 samples (54.94%) and I-ELISA detected 157 positive samples (40.88%). Competitive ELISA (C-ELISA) was performed to check the discrepancies in I-ELISA and DIA. On the basis of these tests the overall agreement, relative specificity and sensitivity between ELISA and DIA were 75%, 87.6% and 100%, respectively. DIA was found to be a rapid, sensitive, easily performed and economical test as compared to ELISA.

Nitrogen is the most widely used fertilizer nutrient, and it is a universally deficient nutrient too, which often severely restricts the growth and yield of crops. To improve N fertilizer management, soil–plant system models can be applied to simulate adequate N supply for both, optimal crop growth and minimal N losses. The likely impact of climate change on the cereal production is of paramount importance in the planning strategies to meet the future growing needs on sustainable grounds. In this scenario models are the effective tools to foresee the probable impacts and for choosing appropriate land use options. The study reported in this thesis, employs field experiments and use of simulation tools to understand the dynamics of soil N balance and relate growth and yield of rice under varying nitrogen inputs. The InfoCrop model was used in this study, which was calibrated with the historic data sets, and subsequently validated with the field experiment conducted at IARI Farm, New Delhi. Simulated results matched well with the observed values in terms of growth and yield of rice and seasonal nitrogen uptake. The components of soil nitrogen balance differed among varying nitrogen level treatments, which was also captured by use of InfoCrop. The model was then taken to climate change impact analysis. The results clearly revealed that when temperature increased, the soil N losses, like denitrification, volatilization, N2O emission increased, whereas grain and biomass yields decreased. The further scope of the study is to validate the study in contrasting agroenvironments.

This paper presents a Zero-Voltage-Transition (ZVT) boost converter using a soft switching auxiliary circuit. This converter has the following features: (1) soft switching of the main switch and boost diode under all operating conditions; (2) reduced auxiliary circuit losses due to soft switching of the auxiliary switch; (3) feed-forward of a part of the auxiliary circuit energy to the output thereby reducing the conduction losses of the main and auxiliary switches. The principle of operation and design of the proposed converter is given in the paper. Experimental results, from a 250 W, 127 Volt input laboratory prototype switching at 100 kHz, are given to verify 'proof-of-concept' of the proposed topology.