[Show abstract][Hide abstract] ABSTRACT: Climate is a very decisive factor in water resource availability of a region. Warming of the climate system in
recent decades is evident from increase in global average air and ocean temperatures, widespread melting of snow and ice, and rising global sea level. The hydrological cycle is intimately linked with changes in atmospheric temperature and radiation balance. A warmer climate may lead to intensification of the hydrological cycle, resulting in higher rates of evaporation and increase of liquid precipitation. These processes, in association with a shifting pattern of precipitation, may affect the spatial and temporal distribution of runoff, soil moisture, groundwater reserves etc. and may increase the frequency of droughts and floods. Agricultural demand, particularly for irrigation water is considered more sensitive to climate change. A change in field-level climate may alter the need and timing of irrigation. Increased dryness may lead to increased demand, but demand may be reduced if soil moisture content rises at critical times of the year. It is projected that most irrigated areas in India would require more water around 2025 and global net irrigation requirements would increase relative to the situation without climate change by 3.5–5% by 2025, and 6–8% by 2075. The effect of climate change on water resources may be mitigated through better water harvesting through the creation of micro-storage facilities in watersheds. These would not only provide supplemental irrigation but also recharge the groundwater aquifers.
Indian Journal of Agricultural Sciences 06/2014; 84(6):671-679. · 0.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mixing ratio of ambient ammonia (NH3) was measured at various locations of the National Capital Region (NCR) of Delhi, India using a NH3-analyzer during January 2010 to June 2012 in campaign mode. The present study has been carried out on campaign based measurement of mixing ratios of NH3 and NO x for short period of time over the NCR of Delhi represent the indicative values over the region. The average mixing ratio of ambient NH3 was 20.9 ± 1.6 ppb during the period. The maximum average mixing ratio of ambient NH3 (28.8 ± 3.0 ppb) was recorded in an industrial area surrounded by intensive vehicular traffic followed by an agricultural farm (27.5 ± 2.1 ppb), whereas the minimum (6.4 ± 1.2 ppb) was recorded in the semi-urban area. The diurnal trend of NH3 depended on the ambient temperature at most of the sites and was affected by wind direction. Ambient NH3 was correlated with the NO x mixing ratio suggesting that the vehicular emission may be one of the sources of ambient NH3 in the NCR of Delhi. However, long-term measurements of ambient NH3 and their precursors will lead to seasonal variation of source apportionment over the NCR, Delhi, India.
MAPAN-Journal of Metrology Society of India 02/2014; · 0.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Direct dry-seeding of rice could be a potential option for reducing methane emission. Methane and nitrous oxide emissions were estimated from conventionally transplanted puddled rice (TPR) and direct seeded rice (DSR) using close chamber technique. DSR reduced methane emission drastically as compared to TPR, whereas the emissions of nitrous oxide were marginally higher under DSR. Brown manuring with daincha increased the nitrous oxide emissions from DSR marginally but no significant impact was seen on emissions of methane. The cumulative methane emissions were 1.49 kg ha -1 in DSR and 30.72 kg ha -1 in TPR whereas the nitrous oxide emissions varied from 670 g N 2 O ha -1 in TPR to 1008 g N 2 O ha -1 in DSR. DSR and DSR with brown manuring reduced the global warming potential (GWP) of soil in rice by 70% and 43% respectively over TPR and increased the carbon efficiency ratio.
International journal of agricultural and statistical sciences. 01/2014; 9(2):729-736.
[Show abstract][Hide abstract] ABSTRACT: Cotton–wheat cropping system is the second most important wheat based system in the South Asia (4.5 M ha) and India (2.6 M ha) and contributes significantly to the food security in the region. However, with the conventional method of crop establishment and crop management, the productivity and profitability of the cotton–wheat system is low. Hence, despite non-suitability of growing situations, farmers are inclined towards cultivating the conventionally tilled rice–wheat rotation which has got severe consequences on the natural resources as well as the future food security. Therefore, an attempt was made to develop and evaluate the performances (in terms of system productivity, water productivity and profitability) of conservation agricultural technologies (like permanent narrow and broad-bed planting and residue management under zero tillage) under an irrigated cotton–wheat system in the region. Treatments included farmers’ practice (conventional tillage and flat-bed sowing without residue recycling; CT), and four combinations of raised-bed planting and residue management under zero tillage (viz., narrow-bed and broad-bed sowing with and without crop residue retention) in the first year. During the second year onwards two additional treatments were included: flat-bed sowing under zero tillage with and without residue retention. Results indicate that mean (of last two years) seed cotton yield in the plots under zero tilled permanent broad-bed sowing with residue retention (PBB + R) was about 24 and 51% higher compared with zero tilled narrow-bed sowing without residue retention (PNB; 2.91 Mg ha−1) and CT plots (2.59 Mg ha−1), respectively. Similarly, plots under PBB + R had significantly higher mean (of last two years) wheat grain yield than flat-bed zero tilled (ZT) and CT plots. Unlike seed cotton yield, wheat grain yield was not affected by the treatments in the first year. In the second year, plots under PBB + R had about 9 and 11% higher wheat grain yield than PNB (4.37 Mg ha−1) and CT (4.29 Mg ha−1) plots, respectively. Although the system productivity in terms of wheat equivalent yield (WEY) was similar in the plots under PBB + R and zero tilled-broad permanent bed sowing without residue retention (PBB) and zero tilled narrow-bed sowing with residue retention (PNB + R) in the first year, plots under PBB + R had about 15 and 13% higher WEY than PBB and PNB + R plots. Similarly, mean (of the last two years) water productivity of the system in the PBB + R treated plots (12.58 kg wheat grain ha−1 mm−1) was 48, 22, 12, 15, 13, 24% higher compared with CT, PNB, PNB + R, PBB, ZT + R and ZT plots, respectively. The above-said PBB + R plots also had the highest net returns (based on mean values of last two years) that was 36 and 13% higher compared with CT and PNB plots, but was similar to other treatments. Therefore, growing cotton–wheat system under permanent beds with residue retention is recommended under irrigated conditions in this region due to its potential of increased productivity, profitability and resource conservation.
Field Crops Research 01/2014; 158:24–33. · 2.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ammonia (NH3) emission from rice (July–October) and wheat (November–April) cropping system was
measured using the chemiluminescence method at the subtropical agricultural land of Delhi, India during 2009–2010 and 2010–2011. The measurement was carried out from the canopy height (1.2–1.3 m) during the different growth stages of rice and wheat crops to quantify NH3 emission and assess the variations in emission during the crop growth stages. The background atmospheric concentration of NH3 was measured at 5 m height at the study site and subtracted from the NH3 concentration at crop canopy height to quantify the emission of NH3 from crops. The NH3 emission in wheat crops were 35.9 ± 6.3, 24.5 ± 5.5, 15.8 ± 4.5, 18.6 ± 3.9, and 20.8 ± 3.8 lg m-2 d-1 during sowing, crown root initiation, panicle initiation, grain filling, and maturity stages, respectively. In rice crops, the emissions during transplanting, tillering, panicle
initiation, grain filling, and maturity stages were 29.7 ± 7.4, 16.2 ± 3.7, 19.0 ± 3.7, and 18.4 ± 3.9 lg m-2 d-1,
respectively. The emission was higher during sowing/transplanting compared to other stages in both the crops. About 9 % of applied fertilizer N was emitted as NH3 from the rice–wheat cropping system in the subtropical soils of India.
[Show abstract][Hide abstract] ABSTRACT: The Indian agriculture, despite making significant progress, is facing the challenges of stagnating net sown area, reducing per capita land availability, deteriorating soil health and diminishing natural resources. Additionally, climate variability and changes are the emerging challenges being faced by this sector for ensuring national food security in both short and long terms and making agriculture sustainable and climate-resilient, appropriate adaptation and mitigation strategies have to be developed. Assessing vulnerability of agriculture to climate change is the pre-requisite for developing and disseminating climate-smart technologies. Decision-makers and planners need this information to prepare strategy for addressing the adverse impacts of climate change and prioritize vulnerable regions for resource allocations. Under this background the present study has been undertaken to demonstrate a methodology to assess and map the composite vulnerability of agriculture to climate variability and changes in the Indo-Gangetic Plains (IGP), which is one of the most populous and productive agricultural ecosystems in the world.
The vulnerability of Indian agriculture has been determined at the district level in the IGP using three core components: (i) exposure to hazards, (ii) sensitivity to climate change, i.e. the amount of damage expected to be caused by a particular event, and (iii) adaptive capacity to recover from stress. A novelty of this study is that it has considered climatic, physical and socio-economic factors together to arrive at vulnerability rating. A total of 8 indicators have been computed using gridded meteorological data for the period 1951-2009 for exposure. Sensitivity has been computed from 6 indicators based on crop and soil characteristics. Computation of adaptive capacity has been based on socio-economic indicators of agricultural technology, infrastructure and human development. These spatial datasets of the key indicators contributing to agricultural vulnerability have been generated for 164 districts in the IGP. These indicators were ranked; weight of each factor was estimated using multi-criteria decision-making techniques such as analytic hierarchal process and finally, the vulnerability maps of agriculture to climate change in the IGP districts were developed. These districts have been tabulated as per the vulnerability rank based on which highly vulnerable, medium vulnerable and less vulnerable districts have been identified. It has been found that the districts located in the eastern and southern parts of Uttar Pradesh and Bihar are most vulnerable, whereas the districts in Punjab and Haryana are of low vulnerability due to their higher adaptive capacity to recover from the climatic stresses.
The study has provided a methodology to identify the vulnerability of any district/region to climate change and has demonstarted its utility in the identification of vulnerability status of the districts in the Indo-Gangetic Plains. The study has provided vulnerability rank of each district in the following modes: (i) vulnerability rank-wise, (ii) state-wise and (iii) district-wise (in alphabetic order) to make the findings user-friendly. The districts which are most vulnerable to climate change, need support on a higher priority. The findings of the study will be useful for targeting financial resources and better management of resources towards adaptive capacity. In the regions, which have been found to be highly vulnerable, policy makers should enact measures to support effective management of environmental resources (e.g., soil, vegetation and water resources); promote increased market participation, especially within the large subsistence farming sector; stimulate both agricultural intensification and diversification of livelihoods away from risky agriculture; and enact programs and extention services on health, education and social welfare, which can help in maintain and augment both physical and intangible human capital.
First 06/2013; Indian Agricultural Research Institute, New Delhi., ISBN: 978-81-88708-97-0
[Show abstract][Hide abstract] ABSTRACT: 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.
[Show abstract][Hide abstract] ABSTRACT: Abiotic stress causes abrupt increase in the expression of stress-associated proteins, which provide tolerance by modulating the defense mechanism of plants. Small heat shock proteins (sHSPs) and anti-oxidant enzymes are important for environmental stress tolerance of the plants. In this study, two full-length cDNAs encoding small heat shock protein (sHSP) and superoxide dismutase (SOD), designated as TasHSP and SODI were identified and characterized from C-306 (thermotolerant) and PBW343 (thermosusceptible) cultivars of wheat (Triticum aestivum L.). An alpha crystalline domain was observed in TasHSP and manganese/iron binding domain in case of SODI. Quantitative real-time PCR showed very high transcript level of TasHSP and SOD in C-306 compared to PBW343 at different stages of growth and against differential heat stress (HS). Under differential HS at milky-dough stage, the fold change in transcript of both TasHSP and SOD was observed maximum in C-306, compared to PBW343. Protein profiling and isoenzymes analysis showed the expression of several heat-stable proteins and prominent isoenzymes of SOD in C-306, compared to PBW343. Scanning electron microscopy (SEM) of starch granules showed globular, well-shaped and more numbers of endospermic cells in C-306, compared to defragmented, irregular shaped and shrunken granules in case of PBW343 under HS treatment (42 degrees C for 2 h). Diurnal change in soluble starch synthase (SSS) activity showed an increase in the activity during afternoon (35 degrees C), compared to morning (29 degrees C) and evening (32 degrees C) in both the cultivars. Under heat stress (42 degrees C for 2 h), a drastic decrease in the SSS activity was observed, due to the thermal denaturation of the enzyme. Thermotolerance capacity analyzed using cell membrane stability (CMS) showed significantly higher CMS in case of C-306, compared to PBW343 at different stages of growth. Findings suggest that abundance of TasHSP and SODI during milky-dough stage plays a very important role in starch granule biosynthesis. The mechanism may be further exploited to develop tolerant wheat cultivar with high quality seeds.
Indian journal of biochemistry & biophysics 04/2013; 50(2):126-38. · 1.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Sequestration of C in arable soils has been considered as a potential mechanism to mitigate the elevated levels of atmospheric greenhouse gases. We evaluated impacts of conservation agriculture on change in total soil organic C (SOC) and relationship between C addition and storage in a sandy loam soil of the Indo-Gangetic Plains. Cotton (Gossypium hirsutum L.) and wheat (Triticum aestivum L.) crops were grown during the first three years (2008–2011) and in the last year, maize (Zea mays L.), wheat and green gram (Vigna radiate L.) were cultivated. Results indicate the plots under zero tillage with bed planting (ZT-B) and zero tillage with flat planting (ZT-F) had nearly 28 and 26% higher total SOC stock compared with conventional tillage and bed planting (CT-B) (∼5.5 Mg ha−1) in the 0–5 cm soil layer. Plots under ZT-B and ZT-F contained higher total SOC stocks in the 0–5 and 5–15 cm soil layers than CT-B plots. Although there were significant variations in total SOC stocks in the surface layers, SOC stocks were similar under all treatments in the 0–30 cm soil layer. Residue management had no impact on SOC stocks in all layers, despite plots under cotton/maize + wheat residue (C/M+ W RES) contained ∼13% higher total SOC concentration than no residue treated plots (N RES; ∼7.6 g kg−1) in the 0–5 cm layer. Hence, tillage and residue management interaction effects were not significant. Although CT-B and ZT-F had similar maize aboveground biomass yields, CT-F treated plots yielded 16% less maize biomass than CT-B plots. However, both wheat and green gram (2012) yields were not affected by tillage. Plots under C/M + W RES had ∼17, 13, 13 and 32% higher mean cotton, maize, wheat and green gram aboveground biomass yields than N RES plots, yielding ∼16% higher estimated root (and rhizodeposition) C input in the 0–30 cm soil layer than N RES plots. About 9.3% of the gross C input contributed towards the increase in SOC content under the residue treated plots. However, ∼7.6 and 10.2% of the gross C input contributed towards the increase in SOC content under CT and ZT, respectively. Thus, both ZT and partial or full residue retention is recommended for higher soil C retention and sustained crop productivity.
European Journal of Agronomy 01/2013; 51:34–42. · 2.80 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Heat stress causes an array of physiological, biochemical and morphological changes in plants, affecting growth and yield. Here, we report cloning of HSP90 gene of 2,323 bp from C-306 cultivar of wheat having ORF from 62 to 2,164 bp encoded for 700 amino acids. Quantitative real time expression analysis of HSP90 gene in C-306 showed 1.5, 1.2, 2.5 fold (in root), 4.5, 4.3 and 6.5 fold increase (in flag leaf) in the transcript level at pollination, milky dough and seed hardening stages. HSP90 transcript level was observed low in root as well as shoot of susceptible cultivar (PBW343) at different stages of growth. A significant difference in the fold expression of HSP90 was observed in C-306 and PBW343 against differential heat shock. An altered expression of H2O2 and decline in proline accumulation was observed in C-306 at different stages of growth. Western blot analysis revealed the presence of 5, 6 and 5 multiprotein chaperone complexes of HSP90 in the range of 95 Da to 70 KDa at pollination, milky dough and seed hardening stages. An expression of few novel isoenzymes of superoxide dismutase and catalase was observed against differential heat shock. A decrease in cell membrane stability was observed at different stages of growth in C-306 cultivar of wheat. In conclusion, we suggest that a high HSP90 transcript level along with high activities of antioxidant isoenzymes and low proline accumulation is a promising target for developing wheat genotypes with tolerance to heat stress.
Journal of Plant Biochemistry and Biotechnology 01/2013; 22(1). · 0.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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 (CH 4), nitrous oxide (N 2 O), and carbon dioxide (CO 2) 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 CH 4 -C, N 2 O-N and CO 2 -C, respectively, with a global warming potential (GWP) of 88.5 Tg CO 2 -C eq. Annual GHG emission from 28.08 Mha of wheat-growing areas was 0.017 and 43.2 Tg of N 2 O-N and CO 2 -C, respectively, with a GWP of 44.6 Tg CO 2 -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.
[Show abstract][Hide abstract] ABSTRACT: A low-cost free-air carbon dioxide enrichment (FACE) system has been developed at the Indian Agri-cultural Research Institute, for assessing the climate change impacts on crops. In the FACE system, the supply and monitoring of CO 2 is regulated by the computer-based SCADA system. Carbon dioxide con-centration recorded at 5 min intervals varied from 507 to 559 ppm in an hourly period. Monthly mean values of CO 2 concentration inside the ring ranged from 525 to 553 ppm from July to April. Crops grown inside the FACE ring showed increased yield over ambient CO 2 condition. The operating cost of the system is US$ 100 m –2 yr –1 , which is much less compared to similar set-ups in other countries. Keywords: Carbon dioxide, climate change, crop pro-ductivity, free air carbon dioxide enrichment. IN the 20th century anthropogenic activities have caused excessive emission of greenhouse gases (GHG) such as carbon dioxide (CO 2), methane (CH 4) and nitrous oxide (N 2 O) into the atmosphere, contributing to global warm-ing and climate change. The global atmospheric concen-tration of CO 2 increased from a pre-industrial value of about 280–389 ppm in 2010. Annual CO 2 concentration growth rate was larger during the last 10 years (1995– 2005 average: 1.9 ppm/yr) than it has been since the be-ginning of continuous direct atmospheric measurements (1960–2005 average: 1.4 ppm/yr) 1 . Over the last 100 years global temperature has increased by 0.74°C. The recent report of IPCC 1 has reconfirmed the increasingly strong evidence of global climate change and projected that the globally averaged temperature of the air would rise by 1.8–6.4°C by the end of the century, depending upon the developmental pathways of the countries. Pri-mary effects of increased CO 2 on crops include higher photosynthetic rate, increased light-use efficiency, reduc-tion in transpiration and stomatal conductance and improved water-use efficiency 2 . On the other hand, bio-mass and yield tend to decline with increasing tempera-ture due to shortening of crop duration and lesser period of radiation interception 3 . However, it is a major chal-lenge to evaluate the impact of rising CO 2 and tempera-ture on crop productivity in the ambient condition. Since future environment needs to be simulated, most of the studies on impact of elevated CO 2 on crops are based on controlled environment or enclosures like green-houses, controlled chambers and open-top chambers 4,5 . The results of these experiments have been reviewed by several workers 5–7 . The environment inside these small chambers, however, varies from the open, natural field conditions and has serious limitations in terms of their small size, reduced radiation, restricted air flow, change in humidity and microclimatic conditions affecting plant growth and physiological processes. Chamber-effects have been very large in some cases 8 and there have been concerns that the results obtained from such enclosure-based CO 2 enrichment systems might not be representa-tive of open-field conditions. Free-air carbon dioxide enrichment (FACE) experi-ments allow studying the effects of elevated atmospheric CO 2 on plants grown under natural conditions 9 . In this system CO 2 -enriched air is released into the ambient environment without causing appreciable changes in other environmental variables. Early types of FACE systems were built in The Netherlands 10 and UK 11,12 for exposing short-stature vegetation to elevated concentrations of atmospheric trace gases like ozone (O 3) and sulphur dioxide (SO 2). In India, impact of elevated CO 2 on rice crop grown inside the FACE ring was studied 13 . The most sophisticated FACE system was designed by Brookhaven National Laboratory's FACE Group, which employs computer regulation of CO 2 concentration in the FACE rings 14 . But the systems had serious constraint in terms of the high installation and operational cost involved in set-ting up these facilities in agricultural fields. Such high cost of FACE technology restricted its large-scale use, particularly in the developing countries with limited funds for research. Although annual operating cost of the FACE systems is about three times the cost of field chambers, FACE plots are relatively large leading to an economy of scale 15 . However, there is an urgent need to develop a automated, low-cost FACE system for assess-ing climate-change impacts on crops for wide and large-scale use. The objectives of the present study were to: (1) develop low-cost FACE system with high precision and accuracy and (2) assess performance of these low-cost systems in maintaining desired CO 2 concentration in am-bient condition during two major cropping seasons (July– October and November–April) of India. FACE ring: A typical FACE is a circular array of verti-cal or horizontal pipes that release CO 2 or air enriched with CO 2 to the crop canopy (Figure 1). The system we developed consists of a ring (plenum) made up of eight horizontal polyvinyl chloride (PVC) pipes each with a length of 2 m and diameter of 20 cm (arm). The diameter of the ring is 8 m. These pipes arranged in octagonal shape, were placed on a height-adjustable stand at 40 cm
Current science 01/2012; 102(7):1035-1040. · 0.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Rice-wheat (RW) cropping system is one of the major agricultural production systems in four Indo-Gangetic Plains (IGP) countries: India, Pakistan, Bangladesh and Nepal of South Asia covering about 32% of the total rice area and 42% of the total wheat area. The excessive utilization of natural resource bases and changing climate are leading to the negative yield trend and plateauing of Rice-wheat (RW) system productivity. The conservation agriculture based efficient and environmental friendly alternative tillage and crop establishment practices have been adopted by the farmers on large scale. A few tools have been evolved to simulate the different tillage and crop establishment. In the present study, InfoRCT (Information on Use of Resource Conserving Technologies), a excel based model integrating biophysical, agronomic, and socioeconomic data to establish input-output relationships related to water, fertilizer, labor, and biocide uses; greenhouse gas (GHG) emissions; biocide residue in soil; and Nitrogen (N) fluxes in the rice-wheat system has been validated for farmer participatory practices. The assessment showed that double no-till system increased the farmer’s income, whereas raised-bed systems decreased it compared with the conventional system. The InfoRCT simulated the yield, water-use, net income and biocide residue fairly well. The model has potential to provide assessments of various cultural practices under different scenarios of soil, climate, and crop management on a regional scale.
Journal of Soi Science and Environmental Management. 01/2012; 3(1):9-22.
[Show abstract][Hide abstract] ABSTRACT: â–º AquaCrop was simulated for kharif Maize cultivar BIO9681 in semi arid environment of India. â–º Experiment on different irrigation and N fertilizer regimes were used in AquaCrop. â–º AquaCrop was calibrated and validated using the experimental data of two years 2009 and 2010. â–º Water driven AquaCrop model performance results were in line with experimental data. â–º AquaCrop performed best for full irrigation and 25% deficit irrigation with normal N fertilizer.
[Show abstract][Hide abstract] ABSTRACT: 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%.
Environmental Monitoring and Assessment 06/2011; 184(5):3095-107. · 1.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Carbon sequestration in tropical soils has potential for mitigating global warming and increasing agricultural productivity. We analyzed 26 long-term experiments (LTEs) in different agro-climatic zones (ACZs) of India to assess the potential and cost of C sequestration. Data on initial and final soil organic C (SOC) concentration in the recommended N, P and K (NPK); recommended N, P and K plus farmyard manure (NPK + FYM) and unfertilized (control) treatments were used to calculate carbon sequestration potential (CSP) i.e., capacity to sequester atmospheric carbon dioxide (CO2) by increasing SOC stock, under different nutrient management scenarios. In most of the LTEs wheat equivalent yields were higher in the NPK + FYM treatment than the NPK treatment. However, partial factor productivity (PFP) was more with the NPK treatment. Average SOC concentration of the control treatment was 0.54%, which increased to 0.65% in the NPK treatment and 0.82% in the NPK + FYM treatment. Compared to the control treatment the NPK + FYM treatment sequestered 0.33 Mg C ha−1 yr−1 whereas the NPK treatment sequestered 0.16 Mg C ha−1 yr−1. The CSP in different nutrient management scenarios ranged from 2.1 to 4.8 Mg C ha−1 during the study period (average 16.9 yr) of the LTEs. In 17 out of 26 LTEs, the NPK + FYM treatment had higher SOC and also higher net return than that of the NPK treatment. In the remaining 9 LTEs SOC sequestration in the NPK + FYM treatment was accomplished with decreased net return suggesting that these are economically not attractive and farmers have to incur into additional cost to achieve C sequestration. The feasibility of SOC sequestration in terms of availability of FYM and other organic sources has been discussed in the paper.
[Show abstract][Hide abstract] ABSTRACT: The rice-wheat system is the main source of food and income for millions of people in South
Asia. However, because of increasing pressure of biotic and abiotic stresses in response to soil degradation
and changing climate, crop productivity and farmers’ profi ts are on a downward trend. Recent
efforts have attempted to develop and deliver resource-conserving technologies (RCTs) with effi cient
and environmentally friendly tillage/crop establishment and water use compared with the conventional
practices of farmers. No tool, however, is available to evaluate the RCTs quantitatively, particularly in
terms of greenhouse gas (GHG) emissions and other environmental impacts. A simulation model,
named InfoRCT (Information on Use of Resource-Conserving Technologies), has been developed
integrating biophysical, agronomic, and socio-economic data to establish input-output relationships
related to water, fertilizer, labor, and biocide uses; GHG emissions; biocide residue in soil; and N fl uxes
in the rice-wheat system. The model provided a comparative assessment of RCTs in yield, income,
global warming potential (GWP), biocide residue index, and N loss. The assessment showed that
mid-season drying and no-till systems increased income, and also reduced the GWP. The model could
be used for assessing impact of crop management practices on productivity and GHG emissions in
Greenhouse Gas Science Technology. 01/2011; 1:1-17.