Eastern Indo-Gangetic Plains Research Articles

Evaluation of Red Skinned Advance Potato (Solanum tuberosum L.) Clones for Tuber Yield and Yield Parameters in Eastern Indo-gangetic Plains of India

Potato is a very important tuber crop used as staple vegetable in almost every household. India ranks second in potato production after China. The production of potato increased significantly during last six decades. There is remarkable increase in potato yield and production during last decade 1.10 and 5.98% per annum respectively at national level (Rani & Prasoon, 2013). The important yield and yield attributing traits are plant emergence (%), number of tubers/plots, tuber yield/plot and tuber dry matter (%). The present experiment was conducted at experimental field of ICAR- Central Potato Research Institute Regional Station Patna, Bihar. In this experiment data were recorded for plant emergence (%), seed wt (t/ha), foliage senescence (%), total and marketable tuber yield (t/ha), dry matter content in percentage (tuber), late blight (%), leaf spot disease (%) during 75- and 90-days crop. The trial was conducted in randomized block design with three replications to evaluate nine advance clones namely MS/11-664, MS/13-527, MS/14-1381, MSP/16-307, MSP/16-375, PS/11-47, PS/13-45, CP-4409 and Memphis along with seven potato varieties Kufri Khyati, Kufri Lalima, Kufri Lalit, Kufri Manik, Kufri Mohan, Kufri Pukhraj and K Neelkanth as controls during 2020-21 & 2021-22. The advance clones PS/13-45 (36.97t/ha), PS/11-47 (35.87t/ha), MS/11-664 (35.39t/ha) were good candidates for future new potato varieties in Eastern Indo Gangetic plains of India.

Effect of conservation agriculture on soil fungal diversity in rice-wheat-greengram cropping system in eastern Indo-Gangetic plains of South Asia.

Conservation agriculture (CA) is emerging as an eco-friendly and sustainable approach to food production in South Asia. CA, characterized by reduced tillage, soil surface cover through retaining crop residue or raising cover crops, and crop diversification, enhances crop production and soil fertility. Fungal communities in the soil play a crucial role in nutrient recycling, crop growth, and agro-ecosystem stability, particularly in agricultural crop fields. This study investigates the impact of seven combinations of tillage and crop residue management practices of agricultural production systems, including various tillage and crop residue management practices, on soil fungal diversity. Using the Illumina MiSeq platform, fungal diversity associated with soil was analysed. The results show that the partial CA-based (pCA) production systems had the highest number of unique operational taxonomic units (OTUs) (948 OTUs) while the conventional production system had the lowest number (665 OTUs). The major fungal phyla identified in the topsoil (0-15 cm) were Ascomycota, Basidiomycota, and Mortierellomycota, with their abundance varying across different tillage-cum-crop establishment (TCE) methods. Phylum Ascomycota was dominant in CA-based management treatments (94.9±0.62), followed by the partial CA (pCA)-based treatments (91.0 ± 0.37). Therefore, CA-based production systems play a crucial role in shaping soil fungal diversity, highlighting their significance for sustainable agricultural production.

Decade-long effects of integrated farming systems on soil aggregation and carbon dynamics in sub-tropical Eastern Indo-Gangetic plains

Integrated farming system (IFS) aims to diversify the agricultural landscapes by incorporating different components to meet the multifarious needs of the burgeoning population. The present study was undertaken to understand the impact of different cropping systems on soil organic carbon (SOC) stock, aggregate distribution, and aggregate associated organic carbon (AAOC) in 2-IFS models of varying sizes (0.4 and 0.8 ha) established during 2008–2009. After 10 years of the study, the fodder system registered the greatest TOC and carbon stocks across IFS models, with surface soil (0–15 cm) accumulating 17 and 13% higher TOC and C stock, respectively, in 0.4 and 0.8 ha models. In 0–15 cm, macroaggregates (Ma) represented the highest proportion (75–76%) in both models. Among cropping systems, the fodder system recorded the highest large macroaggregates in both IFS models. Within 0–30 cm depth, small macroaggregates are mostly found in the perennial system (fodder, guava+turmeric, and lemon intercropping system), indicating the potential to improve the aggregate stability over the seasonal (shorter duration) system. In general, micro aggregate (Mi) fraction was pre-dominant in sub-surface soil (17.35%). The maximum AAOC was found in Ma compared to Mi fractions, with approximately 67 and 63% of total carbon associated with Ma in 0.4 and 0.8 ha IFS models, respectively. Interestingly, the 0.8 ha IFS model had higher TOC (~11%) and carbon stock (~12%) than the 0.4 ha model, but AAOC did not show a similar result, indicating the influence of cropping systems on AAOC. The study indicated that the fodder-based production system had better performance in terms of soil physical health and increased aggregate stability and content of soil carbon. This is indicative of the advantages of perennial-based systems over seasonal- or annual-based cropping systems for soil sustainability in Eastern Indo-Gangetic Plains.

Prediction of spatial heterogeneity in nutrient-limited sub-tropical maize yield: Implications for precision management in the eastern Indo-Gangetic Plains

Knowledge of the factors influencing nutrient-limited subtropical maize yield and subsequent prediction is crucial for effective nutrient management, maximizing profitability, ensuring food security, and promoting environmental sustainability. We analyzed data from nutrient omission plot trials (NOPTs) conducted in 324 farmers' fields across ten agroecological zones (AEZs) in the Eastern Indo-Gangetic Plains (EIGP) of Bangladesh to explain maize yield variability and identify variables controlling nutrient-limited yields. An additive main effect and multiplicative interaction (AMMI) model was used to explain maize yield variability with nutrient addition. Interpretable machine learning (ML) algorithms in automatic machine learning (AutoML) frameworks were subsequently used to predict attainable yield relative nutrient-limited yield (RY) and to rank variables that control RY. The stack-ensemble model was identified as the best-performing model for predicting RYs of N, P, and Zn. In contrast, deep learning outperformed all base learners for predicting RYK. The best model's square errors (RMSEs) were 0.122, 0.105, 0.123, and 0.104 for RYN, RYP, RYK, and RYZn, respectively. The permutation-based feature importance technique identified soil pH as the most critical variable controlling RYN and RYP. The RYK showed lower in the eastern longitudinal direction. Soil N and Zn were associated with RYZn. The predicted median RY of N, P, K, and Zn, representing average soil fertility, was 0.51, 0.84, 0.87, and 0.97, accounting for 44, 54, 54, and 48% upland dry season crop area of Bangladesh, respectively. Efforts are needed to update databases cataloging variability in land type inundation classes, soil characteristics, and INS and combine them with farmers' crop management information to develop more precise nutrient guidelines for maize in the EIGP.

Groundwater irrigation is critical for adapting wheat systems to warming temperatures in the Eastern Indo-Gangetic Plains in India

Warming temperatures are reducing wheat yields in India, and one way to reduce negative impacts is to sow wheat earlier. Yet farmers in Northeast India commonly sow wheat past the optimum time window. Previous studies have suggested this delay is driven by delays in the preceding rice growing season, which have cascading impacts on wheat sow date. It, however, remains unclear which specific rice management decisions are the most consequential for wheat sow date and what potential strategies may help advance the overall crop calendar. We used household survey data from 356 farmers in Bihar, India and structural equation modeling to identify the specific time points in the rice growing season that most impact wheat sow date. Our results suggest that late rice nursery establishment and rice harvest were associated with subsequent delays in the crop calendar. We also found that increasing groundwater irrigation access prior to the start of monsoon rains may be the most effective way to advance rice and wheat sowing. Our results provide insights into the specific time points in the crop calendar when interventions may be the most consequential, which is critical for developing interventions to help farmers adapt wheat systems to warming temperatures.

Effect of Zero Tillage and Different Weed Management Practices in Direct Seeded Rice (Oryza sativa L.) in Indo Gangetic Plains: A Review

Millions of rural and urban residents depend on the rice-wheat cropping system of the Indo-Gangetic plains (IGP) for their food security and means of subsistence. About 18 million hectares (m ha) of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) are rotated across Asia, of which 13.5 m ha are in the Indo-Gangetic Plains (IGP) of India. This agricultural system’s viability is currently in jeopardy due to static yields of both wheat and rice and a decline in total factor productivity. The North West IGP's high input crop culture has allowed weeds to dominate the weed flora, including P. minor in wheat and Echinochloa crus-galli L. in rice. Farmers in North West India have largely used zero tillage for growing wheat, and recently, farmers in the eastern IGP have done the same. Perennial weeds in the Eastern Indo-Gangetic Plain, such Cynodon dactylon L. and Cyperus rotundus L. can occasionally be a nuisance under zero tillage. As an alternative to puddled transplanted rice, the focus is currently on dry direct-seeded rice and machine transplanting of non-puddled rice. As a result of changes in tillage, crop establishment techniques, water use, and weed control brought on by the switch from transplanted rice to direct seeded rice, weed composition and diversity frequently vary. In nations where DSR is frequently used, weedy rice has become a significant concern. Using the Zero Tillage DSR system, certified seed, cultivars that are weed-competitive, stale seedbed procedures, living mulches, and chemical and biological weed control might change weed-crop competition in the crop's favour. However, more research on emergence characteristics and mulching effects of different crop residues on key weeds under zero tillage, cover cropping, and breeding crops for weed suppression will strengthen nonchemical weed management programs. In this review, we examine the extent of weed infestation, weed flora shift and the non-chemical alternative weed management in DSR.

Hydrological impacts of altered monsoon rain spells in the Indian Ganga basin: a century-long perspective

The Indian Ganga basin (IGB) is one of the most valuable socioeconomic regions in the Indian subcontinent. The IGB supports more than half a billion people due to an abundant supply of freshwater for agro-industrial purposes, primarily through Indian Summer Monsoon (ISM) rainfall contributions (∼85%). Any alterations in ISM characteristics would significantly affect freshwater availability, and as a result, socioeconomic activities would be affected. Therefore, in this study, we have attempted to assess how the monsoon rain spell characteristics, i.e. peak, volume, and duration, altered historically between 1901 to 2019. We further analyzed the specific IGB regions where monsoon rain spell changes are more prominent and their hydrological implications. Our estimates reveal that short-duration high-magnitude rain spells have significantly increased across the major regions of the IGB after 1960, which implies the increased probabilities of flash flood hazards. At the same time, the rain spell volumes have been depleted across the IGB after 1960, especially in the eastern Indo-Gangetic plains and southern IGB regions, indicating increased drought frequencies. Further, Himalayan regions, i.e. upper Ganga, upper Yamuna, and upper Ghaghra, have demonstrated increasing magnitudes of rain spell peaks, volume, and duration post-1960. In addition, the continuous warming and anthropogenic alterations might further exaggerate the current situation. Thus, these inferences are helpful for river basin management strategies to deal with the extreme hydrological disasters in the IGB.

Exploring rhizobacteria of wild sugarcane (Saccharum spontaneum L.) and their plant growth promoting potential

In this study, the rhizospheric soil of wild sugarcane from three different salt-affected soils of the eastern Indo-Gangetic Plains was sampled. Rhizospheric bacteria from S. spontaneum were isolated and they were characterized for growth-promoting traits with molecular identification. A total of 49 isolates were isolated from three S. spontaneum rhizosphere soils from different places. These isolates were shown to have differential tolerance to NaCl concentrations up to 2000 mM. Owing to their host habitat and poor nutrient availability, these bacteria were found to have excellent tolerance to high NaCl concentrations along with having multiple plant growth traits. Apart from salt tolerance, these isolates were screened for EPS production, phosphate solubilization, zinc solubilization, siderophore production and ammonia production and based on multiple plant growth-promoting traits, twenty isolates were taken for molecular identification and further in vivo screening. These twenty S. spontaneum rhizospheric microbes belonged to the classes Gammaproteobacteria, Firmicutes (Bacilli) and Actinomycetia, representing six genera and 15 species. In vivo growth promotion studies indicated that some of these isolates could improve germination and growth in rice seedlings. The results of this study signify the possibility of utilizing wild crop microbiomes to nurture cultivated crops under adverse growing conditions.

Crop establishment and nutrient management for production sustainability in rice (Oryza sativa)-wheat (Triticum aestivum) system in eastern India

In eastern Indo-Gangetic Plains (EIGP), conventional rice (Oryza sativa L.)-wheat (Triticum aestivum L.) system has led to a decline in total factor productivity, input-use efficiency, and profitability. A three-year (2020–2022) field experiment was conducted at the farmers’ fields in Merha village of Katoriya, Banka, Bihar on a sandy clay loam soil to evaluate the impact of crop establishment and nutrient management on production sustainability in rice-wheat cropping system. Experiments were conducted in a split-plot design and replicated thrice. The main-plot treatment had crop establishment methods, viz. (i) Broadcasting: paddy seed broadcasted manually; (ii) Dry seeding: seed drilled on moist soil; (iii) Drum-seeding: dry-seed planted using drum seeder on moist soil and; (iv) Wet-seeding: sprouted seeds broadcasted on puddle soil with variety Sabour Ardhjal in rainy (kharif) season and 4-wheat crop establishment method, viz. (i) Broadcasting in CT; (ii) Furrow irrigated raised-bed method; (iii) ZT-drill and; (iv) Seed-cum-ferti-drill machine for wheat variety HD 2967 in winter (rabi) season. The sub-plots were allotted four nutrient management treatments, viz. (i) Farmers’ practice (130:40:10 kg NPK/ha); (ii) 100% RDF (120: 60:40 kg NPK/ha); (iii) Soil- test-based nutrient management (100% chemical fertilizer-125:75:40 kg NPK/ha) and; (iv) Soil-test based nutrient management (75% chemical fertilizer-94:56:30 kg NPK/ha+25% FYM-6.2 t/ha) in wheat, and (i) Farmers practice (140:30:10 kg NPK/ha); (ii) 100% RDF (120:60:40 kg NPK/ha); (iii) Soil-test based nutrient management (100% chemical fertilizer-150:75:40 kg NPK/ha); (iv) Soil-test based nutrient management (75% chemical fertilizer-115:56:30 kg NPK/ha+25% FYM-7 t/ha) in wheat. Our results revealed that overall system productivity and profitability were higher by 44 and 155.5% in wet seeding paddy-ZT drill wheat system in comparison to broadcasting methods of rice and wheat. System productivity was significantly higher by 28.8% in soil-test based nutrient management production system as compared to the farmers' practices. Thus, to achieve better system productivity and profitability, crops may be grown with wet seeding paddy-ZT drill wheat with soil-test based nutrient management practices under eastern Indo-Gangetic Plains of eastern India.

Influence of tillage and nutrient management strategies on rice (Oryza sativa L.) productivity, nutrient uptake and soil properties

A field experiment was conducted during 2019 to study the effect of tillage and nutrient management strategies on rice productivity, nutrient uptake and soil properties in Eastern Indo Gangetic Plains (EIGP) of India. The experiment was laid out in split-plot design with three replications. Nine treatment combinations comprising of three tillage methods in the main plots viz., Conventional tillage, Zero tillage and Zero tillage + Residue management and three nutrient management practices viz., recommended dose of fertilizer (RDF), SSNM based on Nutrient expert and 60 % RDN + green seeker guided N application (GSGN) + 100% RDP + 100% RDK in the subplot. The results of the study revealed that residue management with zero tillage practice resulted in 14.03 % and 9.27 % higher grain and straw yield than conventional tillage respectively. Zero tillage with residue management increased nutrient uptake to the maximum of 86.71 kg N, 24.62 kg P and 99.99 kg K/ha as compared to conventional tillage. Among nutrient management, SSNM based on Nutrient expert exhibited the highest grain (4.5 t/ha ) and straw yields (6.4 t/ha ), while 60 % RDN+ GSGN + 100% RDP + 100% RDK showed at par of these values. Adoption of SSNM based on Nutrient expert resulted in maximum N, P and K uptake. Different tillage and nutrient management regimes did not affect the soil properties significantly. Thus, zero tillage and residue management with SSNM based on Nutrient expert is a viable management practice for improving productivity under DSR in EIGP of India.

Influence of 36 years of integrated nutrient management on soil carbon sequestration, environmental footprint and agronomic productivity of wheat under rice-wheat cropping system

A long-term field experiment was conducted to study the effects of different combinations of integrated nutrient management (INM) on carbon sequestration and wheat yield in a rice-wheat cropping system. The experiment consisted of 11 treatments that were replicated three times. The organic manures used in the study included farmyard manure (FYM), wheat straw (WS), and green manure (GM) with Sesbania aculeata. The results of the experiment revealed that the application of 50% of the recommended dose of fertilizers (RDF) along with 50% nitrogen (N) through FYM during rice cultivation, and RDF during wheat cultivation, led to a significant increase in soil organic carbon (SOC). Specifically, the SOC content was enhanced by 46.4% (18.29 Mg ha-1) compared to RDF in rice and wheat, resulting in a C sequestration rate of 0.22 Mg ha-1 year-1. These increases were higher in treatments that combined organic and inorganic inputs. Additionally, the application of 50% RDF and substituting 50% of the nitrogen with FYM during wheat cultivation resulted in a 24.7% increase in grain yield compared to RDF in rice and wheat. The INM treatments, showed significantly (p ≤ 0.05) higher agronomic efficiency (AE) of nitrogen (N), phosphorus (P) and potassium (K), partial factor productivity (PFP) of N, P and K, and carbon pool index (CPI) compared to the application of inorganic fertilizers at the recommended dose. Moreover, the INM treatments also exhibited lower greenhouse gas (GHG) emission intensity. Application of neither chemical fertilizers nor organic manure (T1) resulted in maximum GHG emission intensity (328.1 kg CO2 eq Mg−1 yield). Based on these findings, it can be concluded that the combined use of inorganic fertilizers and organic manures significantly increased crop yield and soil organic carbon sequestration while reducing GHG emissions in a rice-wheat cropping system in the eastern Indo-Gangetic Plains (EIGP) of India.

Functional groups and mineralization kinetics of soil organic matter under contrasting hydro‐thermal regimes under conservation agriculture‐based rice–wheat system in eastern Indo‐Gangetic Plains

AbstractSoil organic carbon (SOC) sequestration is important to counteract anthropogenic climate change at the global level. Studying the effect of conservation agriculture (CA) on SOC dynamics in the presence of two distinctively different hydro‐thermal regimes across the year in rice–wheat (RW) systems in eastern Indo‐Gangetic Plains (E‐IGP) is of topical interest. The stabilization mechanism of soil organic matter (SOM), and its effect on C mineralization kinetics in these conditions is not well understood. We collected soil samples from six combinations of CA and conventional farming in an ongoing experiment at CIMMYT‐Borlaug Institute for South Asia, Bihar, India. CA enhanced SOC, specifically labile C, while decreasing mineral N, as a result of encapsulation/assimilation in aggregates/microbial biomass. Humic acids registered characteristic Fourier transform infrared (FTIR) peaks at 3200–3600 cm−1, 2920–2930 cm−1, 1645–1655 cm−1 and 1220–1240 cm−1, and displayed lesser degree of humification, aromaticity and redox status under CA. SOC and N mineralization were studied in two different hydro‐thermal regimes pertaining to rice (submergence, 35°C; SM35) and wheat (field capacity, 25°C; FC25) growing periods of E‐IGP. SM35 displayed temperature‐mediated higher decay of SOC. Decay constants of C mineralization were lesser under CA compared with CT. CA promoted higher SOM stability, evidenced by lower decay rates of SOC and N, attributed to (1) better protection of SOM in well‐aggregated soil structure and (2) an excess supply of fresh crop residues ensuring higher rate of SOM formation than its decay. Practising CA in E‐IGP is imperative towards C‐neutral agriculture, especially in the impending global warming scenario.

PM2.5 pollution exceeding Indian standard over a semi-urban region at eastern IGP: Chemistry, meteorological impact, and long-range transport

A year-long study (January–December 2019) on the chemical characterization and meteorological impact on PM2.5 was conducted over a semi-urban station, Shyamnagar, in the easternmost part of the Indo-Gangetic Plains (IGP). PM2.5 concentrations (Mean = 81.69 ± 66.27 μgm−3; 7.10–272.74 μgm−3), the total carbonaceous aerosols (TCA) (Mean = 22.85 ± 24.95 μgm−3; 0.77–102.97 μgm−3) along with differential carbonaceous components like organic carbon (OC) (Mean = 11.28 ± 12.48 μgm−3; 0.48–53.01 μgm−3) and elemental carbon (EC) (Mean = 4.83 ± 5.28 μgm−3; 0.1–22.13 μgm−3) exhibited prominent seasonal variability with the highest concentrations during winter, followed by post-monsoon, pre-monsoon and lowest during monsoon. A similar seasonal variation was observed for the total water-soluble ionic species (Mean = 31.91 ± 20.12 μgm−3; 0.1–126.73 μgm−3). We observed that under the least favorable conditions (low ventilation coefficient), high PM2.5 pollution (exceeding Indian standard) was associated with a high increase in secondary components of PM2.5. Eastern, central and western parts of IGP, as well as Nepal, were the major long-distant source regions whereas the northern part of West Bengal and parts of Bangladesh were the major regional source region for high PM2.5 pollution over Shyamnagar. The ratios like char-EC/soot-EC, non-sea-K+/EC and non-sea-SO42−/EC strongly indicated the dominance of fossil fuel burning over biomass burning. Compared with other studies, we observed that the PM2.5 pollution over this semi-urban region was comparable (and even higher in some cases) with other parts of IGP. The high exceedance of PM2.5 over the Indian standard in Shyamnagar strongly demands an immediate initiation of systematic and regular based air pollution monitoring over semi-urban/non-urban regions in India, especially IGP, in addition to the polluted cities.

Influence of conservation agriculture-based production systems on bacterial diversity and soil quality in rice-wheat-greengram cropping system in eastern Indo-Gangetic Plains of India.

Conservation agriculture (CA) is gaining attention in the South Asia as an environmentally benign and sustainable food production system. The knowledge of the soil bacterial community composition along with other soil properties is essential for evaluating the CA-based management practices for achieving the soil environment sustainability and climate resilience in the rice-wheat-greengram system. The long-term effects of CA-based tillage-cum-crop establishment (TCE) methods on earthworm population, soil parameters as well as microbial diversity have not been well studied. Seven treatments (or scenarios) were laid down with the various tillage (wet, dry, or zero-tillage), establishment method (direct-or drill-seeding or transplantation) and residue management practices (mixed with the soil or kept on the soil surface). The soil samples were collected after 7 years of experimentation and analyzed for the soil quality and bacterial diversity to examine the effect of tillage-cum-crop establishment methods. Earthworm population (3.6 times), soil organic carbon (11.94%), macro (NPK) (14.50-23.57%) and micronutrients (Mn, and Cu) (13.25 and 29.57%) contents were appreciably higher under CA-based TCE methods than tillage-intensive farming practices. Significantly higher number of OTUs (1,192 ± 50) and Chao1 (1415.65 ± 14.34) values were observed in partial CA-based production system (p ≤ 0.05). Forty-two (42) bacterial phyla were identified across the scenarios, and Proteobacteria, Actinobacteria, and Firmicutes were the most dominant in all the scenarios. The CA-based scenarios harbor a high abundance of Proteobacteria (2-13%), whereas the conventional tillage-based scenarios were dominated by the bacterial phyla Acidobacteria and Chloroflexi and found statistically differed among the scenarios (p ≤ 0.05). Composition of the major phyla, i.e., Proteobacteria, Actinobacteria, and Firmicutes were associated differently with either CA or farmers-based tillage management practices. Overall, the present study indicates the importance of CA-based tillage-cum-crop establishment methods in shaping the bacterial diversity, earthworms population, soil organic carbon, and plant nutrient availability, which are crucial for sustainable agricultural production and resilience in agro-ecosystem.

Sources, transport pathways and radiative effects of BC aerosol during 2018–2020 at a receptor site in the eastern Indo-Gangetic Plain

This study reports black carbon (BC) characteristics and climate effects for a 22-month period during 2018–2020 at a receptor location in the eastern Indo-Gangetic Plains (IGP). The overall averaged BC mass concentration was 7.8 ± 4.7 μg m−3, and the nighttime average (9.1 ± 6.1 μg m−3) was nearly double that of the daytime (5.8 ± 3.5 μg m−3). BC was most enhanced during winter, with mean concentration (14.3 ± 3.8 μg m−3) higher by 4 times as compared to summer. A two-component mixing model, frequency distribution of the Angstrom exponent, and a simultaneous increase in brown carbon (BrC) absorption coefficient suggested that this enhancement was mostly due to the biomass burning (BB) fraction of BC. CALIPSO-derived products showed that the extinction coefficient was highest at 0.62 ± 0.31 km−1 in winter and lowest at 0.12 ± 0.05 km−1 in summer. Backscatter plots and particle depolarization ratios indicated presence of spherical dust particles during summer and smoke plumes during post-monsoon and winter. Concentration-weighted trajectories (CWTs) helped in quantifying significant contributions of the IGP outflow to BC, BC-BB and BrC absorption. Finally, a large direct radiative forcing of the atmosphere by BC (37 ± 22 W m−2) was estimated via the radiative transfer model SBDART, with an associated atmospheric heating rate of 1.02 K d−1.

Investigation of sources and atmospheric transformation of carbonaceous aerosols from Shyamnagar, eastern Indo-Gangetic Plains: Insights from δ13C and carbon fractions

This study reports the chemical characterization of the carbonaceous component of PM2.5 (particulate matter with aerodynamic diameter ≤2.5 μm) collected over a year-long campaign from a regional site in Shyamnagar, West Bengal, in the Indo-Gangetic Plains (IGP), India. The carbonaceous fractions (elemental and organic carbon), mass concentrations, and stable carbon isotopic composition (δ13C value) of aerosols were measured and utilized to characterize the sources and understand the atmospheric processing of aerosols. Cluster analysis, Potential Source Contribution Function (PSCF) modeling, and fire count data were analyzed to decipher the pattern of air masses, source contributions, and extent of burning activities. The PM2.5 mass concentrations were significantly higher during winter (168.3 ± 56.3 μg m−3) and post-monsoon (109.8 ± 59.1 μg m−3) compared to the monsoon (29.8 ± 10.7 μg m−3) and pre-monsoon (55.1 ± 23.0 μg m−3). Organic carbon (OC), elemental carbon (EC), and total carbon (TC) concentrations were also several factors higher during winter and post-monsoon compared to monsoon and pre-monsoon. The winter and post-monsoon experienced the impact of air masses from upwind IGP. On the other hand, long-range transported air masses from the South-West direction dominated during monsoon and pre-monsoon, which are also relatively cleaner periods. The average δ13C during post-monsoon and winter was ∼1‰ higher compared to monsoon and pre-monsoon. The vehicular exhaust and biomass/biofuel burning contributed dominantly in winter and post-monsoon. In comparison, lower δ13C in pre-monsoon and monsoon might be attributed to the dominance of biomass/biofuel combustion. Photochemical-induced aging of the anthropogenic aerosols resulted in a higher δ13C of TC in winter and post-monsoon, whereas the mixing of different local sources in pre-monsoon and monsoon resulted in lower δ13C values. These findings benefit policymakers in strategizing proper and effective management of biomass/biofuel burning in the IGP to minimize air pollution.

Weed dynamics, productivity and profitability of wheat as influenced by tillage and weed management practices in Eastern Indo-Gangetic Plains

Weed dynamics, productivity and profitability of wheat as influenced by tillage and weed management practices in Eastern Indo-Gangetic Plains

Assessment of spot blotch disease and terminal heat stress on the performance of spring wheat genotypes in eastern Indo-Gangetic plains of India

Assessment of spot blotch disease and terminal heat stress on the performance of spring wheat genotypes in eastern Indo-Gangetic plains of India

Effective antioxidant defense prevents nitro-oxidative stress under arsenic toxicity: A study in rice genotypes of eastern Indo-Gangetic plains

Arsenic (As) toxicity in humans and animals has become a major concern in the last few decades. Rice growing on As-contaminated soil is the principal dietary source of As that poses a significant health hazards to rice patrons, making it a global issue of concern to take necessary steps to counteract the problem. Eastern Indo-Gangetic plains (EIGP) is one of the world’s hotspot for As pollution. Arsenic contaminated irrigation is the principal reason for elevated As levels in the agricultural fields of EIGP, which affects rice productivity. The present study intended to explore the influences of As toxicity (arsenite and arsenate) on the morpho-physiology, ionomics, and biochemical performances of 18 rice genotypes of EIGP at the seedling stage. Arsenic exposure negatively affected plant height, root length, and biomass in rice. It also induced membrane degradation thereby, decreasing total chlorophyll content. It also impaired the nutrient uptake and root-to-shoot translocation abilities of plants. Arsenic toxicity led to the accumulation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) consequently, inducing nitro-oxidative stress in rice. Arsenic tolerance in rice was related to the antioxidant defense system that decreased the malondialdehyde (MDA) content and improved the membrane stability thereby, sustaining plant growth. Additionally, proline facilitated ROS eradication conferring protection against the As-induced nitro-oxidative stress. In this study genotypic variation was obvious in all traits associated with As toxicity. Among the rice genotypes studied, Sahbhagi Dhan and Sabour Ardhjal displayed considerably higher As tolerance with sustainable plant growth, membrane stability, nutrient homeostasis, enhanced antioxidant enzyme activities, lower ROS/RNS and MDA accumulations under different As treatments. Overall, the study revealed the association between proteomic and ionomic profiles in rice to understand the potential adaptive mechanisms in plants under As toxicity.

Climate adaptive rice planting strategies diverge across environmental gradients in the Indo-Gangetic Plains

Abstract The timing of rice planting has a profound influence on the productivity of the rice-wheat cropping pattern in the Indo-Gangetic Plains (IGP), a system that provides the foundation for food security in South Asia. Nevertheless, strategies for adaptive rice planting in a rapidly changing climate are not well established. In this ex-ante analysis, regional gridded crop model simulations are deployed to investigate the impact of different rice planting strategies on system level productivity, resilience, and environmental benefits. Our results suggest that synchronizing rice planting dates with the monsoon onset substantially outperforms farmer practice (+41%) and static state recommendations in the Eastern IGP. However, planting long-duration rice with the monsoon onset is ineffective in the Northwestern IGP since the later arrival of the monsoon increases the probability of cold damage to rice and terminal heat stress in wheat. Here, fixed planting dates (+12.5%) or planting medium duration varieties at monsoon onset (+18%) performed best. We conclude that resilient and productive rice planting strategies must account for interannual weather variability and divergent climate conditions across sub-regions in the IGP.