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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.

Often geographical boundaries of the climatic zones identified differ from the administrative boundaries. Eventually planners and administrators are unable to use these classifications while formulating new developmental programmes. Though few studies attempted to bring the climatic classification to district level in the past, the climatic datasets used in such studies were found to be relatively old. Climate change literature pertaining to India showed evidence of rising mean temperatures during post-1970 period. The temperature rise affects potential evapotranspiration and consequently the aridity is expected to increase at least at macro level though there may be spatial variation at a smaller geographical scale. In the present study, an attempt has been made to assess the climate at district level using latest data and examine climatic shift occurred, if any, as compared to the climatic classification given by Krishnan in 1988. The study used 0.5° × 0.5° grid level rainfall data and average potential evapotranspiration for 144 stations located across India to compute moisture index needed for delineation of different climatic zones. Both datasets refer to the period 1971–2005. Significant reflections resulting from the study indicated a substantial increase of arid region in Gujarat and, a decrease of arid region in Haryana. Other notable observations included the increase in semi-arid region in Madhya Pradesh, Tamil Nadu and Uttar Pradesh due to shift of climate from dry sub-humid to semi-arid. Likewise, the moist sub-humid pockets in Chhattisgarh, Orissa, Jharkhand, Madhya Pradesh and Maharashtra states have turned dry sub-humid to a larger extent. Updated climatic classification of this sort at district level shall be useful to various stakeholders for agricultural planning, assessment of water demand by different sectors, drought preparedness, assessment of climate driven pests/diseases in humans, crops and livestock, etc.

This study attempts to quantitatively understand the impact of changes in meteorological drivers due to climate change on spring wheat in northern India using numerical experiments with the Simple and Universal CRop growth Simulator (SUCROS) model.The model was calibrated and evaluated for spring wheat cultivar HD2967 using observed crop and meteorological data from a field site at the Indian Agricultural Research Institute, New Delhi. Sensitivity studies were performed with the SUCROS model by incrementally changing the meteorological drivers to understand the underlying processes through which each meteorological driver affects spring wheat crop growth. The effect of climate change on spring wheat growth was estimated by conducting numerical experiments where the SUCROS model was driven with bias-corrected projections of future climate from six climate models for two scenarios for mid and end century. Results show that competitive/synergistic interactions between meteorological drivers lead to a slight increase in growth at the beginning of the growing season, and a strong decrease of about 50 per cent during the later stage. Apart from improving our understanding of crop growth processes, this study has also policy implications for agriculture and food security in the context of climate change.

Amount of available net energy and its partitioning into sensible, latent and soil heat fluxes over an agricultural landscape are critical to improve estimation of evapotranspiration and modelling parse (ecosystem modelling, hydrological and meteorological modelling). Scintillometry is a peculiar and robust methodology to provide structure parameter of refractive index and energy balance. Scintillometer has proven for assessment of sensible and latent heat flux, which is based on the principle of Monin–Obukhov similarity theory. Scintillometer has been installed in the agricultural experimental farm of ICAR-Indian Agricultural Research Institute, New Delhi, with a spatial covering path length of 990 m of irrigated and cultivable agricultural landscape. This paper discusses the patterns of energy flux as diurnal and seasonal basis at scintillometer path which was mainly covered by maize in Kharif and wheat in Rabi season during a crop growing seasons of 2014–2015. The biophysical parameters (leaf area, soil moisture, crop height) were recorded at a temporal resolution of fortnight basis along the path length at usual sampling distance. The Bowen ratio value for both Kharif and Rabi season was 0.76 and 0.88, respectively by scintillometer. Leaf area index had a significantly positive correlation with latent heat flux ( R 2 = 0.80 ) while a significantly negative correlation with sensible heat flux ( R 2 = - 0.79 ). Soil moisture had a significant negative correlation with sensible heat flux ( R 2 = - 0.68 ). The average evapotranspiration from crop land was 1.58 mm d - 1 and total evapotranspiration was 543 mm over the 12 months study period. This study defines that large aperture scintillometer is robust instrument which can evaluate energy flux over a large area with a long term series time domain. Moreover, further studied should be conducted to use in crop simulation modelling, developing of new model with calibration and validation of remote sensing energy balance algorithm, etc.

Agricultural field experiments are costly and time-consuming, and often struggling to capture spatial and temporal variability. Mechanistic crop growth models offer a solution to understand intricate crop-soil-weather system, aiding farm-level management decisions throughout the growing season. The objective of this study was to calibrate and the Crop Environment Resource Synthesis CERES-Maize (DSSAT v 4.8) model to simulate crop growth, yield, and nitrogen dynamics in a long-term conservation agriculture (CA) based maize system. The model was also used to investigate the relationship between, temperature, nitrate and ammoniacal concentration in soil, and nitrogen uptake by the crop. Additionally, the study explored the impact of contrasting tillage practices and fertilizer nitrogen management options on maize yields. Using field data from 2019 and 2020, the DSSAT-CERES-Maize model was calibrated for plant growth stages, leaf area index-LAI, biomass, and yield. Data from 2021 were used to evaluate the model's performance. The treatments consisted of four nitrogen management options, viz., N0 (without nitrogen), N150 (150 kg N/ha through urea), GS (Green seeker-based urea application) and USG (urea super granules @150kg N/ha) in two contrasting tillage systems, i.e., CA-based zero tillage-ZT and conventional tillage-CT. The model accurately simulated maize cultivar’s anthesis and physiological maturity, with observed value falling within 5% of the model’s predictions range. LAI predictions by the model aligned well with measured values (RMSE 0.57 and nRMSE 10.33%), with a 14.6% prediction error at 60 days. The simulated grain yields generally matched with measured values (with prediction error ranging from 0 to 3%), except for plots without nitrogen application, where the model overestimated yields by 9–16%. The study also demonstrated the model's ability to accurately capture soil nitrate–N levels (RMSE 12.63 kg/ha and nRMSE 12.84%). The study concludes that the DSSAT-CERES-Maize model accurately assessed the impacts of tillage and nitrogen management practices on maize crop’s growth, yield, and soil nitrogen dynamics. By providing reliable simulations during the growing season, this modelling approach can facilitate better planning and more efficient resource management. Future research should focus on expanding the model's capabilities and improving its predictions further.

Spring wheat is a major food crop that is a staple for a large number of people in India and the world. To address the issue of food security, it is essential to understand how the productivity of spring wheat varies with changes in environmental conditions and agricultural management practices. The goal of this study is to quantify the role of different environmental factors and management practices on wheat production in India in recent years (1980 to 2016). Elevated atmospheric CO2 concentration ([CO2]) and climate change are identified as two major factors that represent changes in the environment. The addition of nitrogen fertilizers and irrigation practices are the two land management factors considered in this study. To study the effects of these factors on wheat growth and production, we developed crop growth processes for spring wheat in India and implemented them in the Integrated Science Assessment Model (ISAM), a state-of-the-art land model. The model is able to simulate the observed leaf area index (LAI) at the site scale and observed production at the country scale. Numerical experiments are conducted with the model to quantify the effect of each factor on wheat production on a country scale for India. Our results show that elevated [CO2] levels, water availability through irrigation, and nitrogen fertilizers have led to an increase in annual wheat production at 0.67, 0.25, and 0.26 Mt yr−1, respectively, averaged over the time period 1980–2016. However, elevated temperatures have reduced the total wheat production at a rate of 0.39 Mt yr−1 during the study period. Overall, the [CO2], irrigation, fertilizers, and temperature forcings have led to 22 Mt (30 %), 8.47 Mt (12 %), 10.63 Mt (15 %), and −13 Mt (−18 %) changes in countrywide production, respectively. The magnitudes of these factors spatially vary across the country thereby affecting production at regional scales. Results show that favourable growing season temperatures, moderate to high fertilizer application, high availability of irrigation facilities, and moderate water demand make the Indo-Gangetic Plain the most productive region, while the arid north-western region is the least productive due to high temperatures and lack of irrigation facilities to meet the high water demand.

Drought is an important limiting factor for wheat production in most agricultural areas of the world. A study was conducted to analyze the effect of cytokinin [benzyl amino purine (BAP), 40 µM] on growth and yield vis-à-vis nitrogen metabolism in two contrasting wheat cultivars, viz., C-306 (drought tolerant) and PBW-343 (drought susceptible) under water deficit stress condition. Water deficit stress significantly decreased yield and total biomass, while cytokinin-treated wheat plants retained higher biomass and yield. Positive effect of cytokinin on yield and biomass was due to cytokinin induced N-metabolism under both water regimes. Water deficit stress decreases activity of two major enzymes of nitrogen assimilation pathway, viz, nitrate reductase (NR) and glutamine synthetase (GS) and increased total protease activity. Cytokinin enhanced the activity of NR and GS enzymes and reduced the protease activity in both the cultivars and water regimes, which also led to increase in level of total nitrogen and total protein content. Overall, cytokinin was able to delay senescence of leaves under water deficit stress conditions by enhancing N-metabolism in general and specifically at the reproductive stage, contributing to increase in grain yield of both the cultivars under both the water regimes.

To compare ventricular repolarization and heart rate variability in hypothyroid and healthy children and to assess the effects of levothyroxine therapy on cardiac electrophysiological and autonomic parameters. This study investigated ventricular repolarization parameters and heart rate variability (HRV) in hypothyroid children (5–12 years) compared with age-matched healthy controls and patients before and after thyroxine treatment. This study included 64 participants divided into hypothyroid and healthy groups (32 each). Parameters such as the Tpe interval, QT interval, and HRV indices were measured via standard electrocardiographic and HRV analysis techniques. Thyroid hormone levels were measured. Post treatment measurements were also performed on hypothyroid children following 3 months of levothyroxine therapy. Hypothyroid children presented significantly prolonged Tpe intervals (58.07 ± 9.21 ms vs. 53.80 ± 8.89 ms, p = 0.039), reflecting increased heterogeneity in ventricular repolarization. HRV analysis revealed decreased parasympathetic modulation (e.g., lower RMSSD and pNN50 values) in hypothyroid participants. Posttreatment improvements in HRV indices and thyroid hormone levels correlated with normalization of cardiac electrophysiological parameters. This study highlights that even mild thyroid dysfunction in children can subtly disrupt cardiac electrical stability and autonomic balance which may increase the risk of arrhythmia in this population. Timely thyroxine therapy not only restores thyroid levels but also powerfully rebalances the electrical and autonomic balance of the heart. These findings reaffirm the critical need for early detection and proactive treatment of pediatric hypothyroidism to safeguard lifelong cardiovascular health.

Understanding the physiological mechanism of tolerance under stress conditions is an imperative aspect of the crop improvement programme. The role of plant hormones is well-established in abiotic stress tolerance. However, the information on the role of gibberellic acid (GA) in abiotic stress tolerance in late sown wheat is still not thoroughly explored. Thus, we aimed to investigate the role of endogenous GA 3 level in stress tolerance in contrasting wheat cultivars, viz ., temperature-tolerant (HD 2643 and DBW 14) and susceptible (HD 2189 and HD 2833) cultivars under timely and late sown conditions. We created the variation in endogenous GA 3 level by exogenous spray of GA 3 and its biosynthesis inhibitor paclobutrazol (PBZ). Tolerant genotypes had higher antioxidant enzyme activity, membrane stability, and photosynthesis rate, lower lipid peroxidase activity, and better growth and yield traits under late sown conditions attributed to H 2 O 2 content. Application of PBZ escalated antioxidant enzymes activity and photosynthesis rate, and reduced the lipid peroxidation and ion leakage in stress, leading to improved thermotolerance. GA 3 had a non-significant effect on antioxidant enzyme activity, lipid peroxidation, and membrane stability. However, GA 3 application increased the test weight in HD 2643 and HD 2833 under timely and late sown conditions. GA 3 upregulated GA biosynthesis and degradation pathway genes, and PBZ downregulated kaurene oxidase and GA 2 ox gene expression. GA 3 also upregulated the expression of the cell expansins gene under both timely and late sown conditions. Exogenous GA 3 did not increase thermotolerance but positively affected test weight and cell expansins gene expression. No direct relationship existed between endogenous GA 3 content and stress tolerance traits, indicating that PBZ could have conferred thermotolerance through an alternative mechanism instead of inhibiting GA 3 biosynthesis.

An experiment was conducted in the Free Air Ozone and Carbon dioxide Enrichment (FAOCE) facility to study the impact of elevated O3, CO2 and their interaction on chickpea crop (cv. Pusa-5023) in terms of phenology, biophysical parameters, yield components, radiation interception and use efficiency. The crop was exposed to elevated O3 (EO:60ppb), CO2 (EC:550 ppm) and their combined interactive treatment (ECO: EC+EO) during the entire growing season. Results revealed that the crop’s total growth period was shortened by 10, 14 and 17 days under elevated CO2, elevated O3 and the combined treatment, respectively. Compared to ambient condition, the leaf area index (LAI) under elevated CO2 was higher by 4 to 28%, whilst it is reduced by 7.3 to 23.8% under elevated O3. The yield based radiation use efficiency (RUEy) was highest under elevated CO2 (0.48 g MJ−1), followed by combined (0.41 g MJ−1), ambient (0.38 g MJ−1) and elevated O3 (0.32 g MJ−1) treatments. Elevated O3 decreased RUEy by 15.78% over ambient, and the interaction results in a 7.8% higher RUEy. The yield was 31.7% more under elevated CO2 and 21.9% lower in elevated O3 treatment as compared to the ambient. The combined interactive treatment recorded a higher yield as compared to ambient by 9.7%. Harvest index (HI) was lowest under elevated O3 (36.10%), followed by ambient (39.18%), combined (40.81%), and highest was under elevated CO2 (44.18%). Chickpea showed a positive response to elevated CO2 resulting a 5% increase in HI as compared to ambient condition. Our findings quantified the positive and negative impacts of elevated O3, CO2 and their interaction on chickpea and revealed that the negative impacts of elevated O3 can be compensated by elevated CO2 in chickpea. This work promotes the understanding of crop behaviour under elevated O3, CO2 and their interaction, which can be used as valuable inputs for radiation-based crop simulation models to simulate climate change impact on chickpea crop.