Lower Brahmaputra Research Articles

Seasonal and diurnal changes of pCO2 in the lower Brahmaputra River, Bangladesh

Monthly 24-h real-time high-resolution monitoring was conducted for 1 year to investigate the carbon dioxide (CO2) dynamics in the lower Brahmaputra River. The partial pressure of CO2 (pCO2) was observed between 136 and 1213 µatm. The pCO2 was almost 1.5 times higher during the wet season (May–October) than during the dry season (November–April). Diurnal variation in pCO2 was pronounced during the dry season. In contrast, no clear diurnal pattern was observed during the wet season. The combined measurements of O2–CO2 in river water provide insights into net chemical and microbial activity. In January and March, there was a bidirectional exchange of CO2, occurring from air to water (sink) and from water to air (source). However, in April, the CO2 exchange was unidirectional, taking place solely from air to water, whereas in all other months, it occurred from water to air. The carbon dioxide flux (FCO2) in the river ranged from − 31.12 to 137.74 mmol m−2 day−1, with an average of 25.26 mmol m−2 day−1 during the dry season and 78.56 mmol m−2 day−1 in the wet season. This flux significantly contributes to the regional net carbon budget of the world's largest delta.

Settling-on-the-Move: Birsing Char-scapes in the Brahmaputra Valley

Chars are shifting riverine islands. This article focuses on Birsing Char, part of Birsing Jarua Village Panchayat, in the Brahmaputra River near the Indo-Bangladesh border. Generations of families have migrated across this porous border, settling in the Lower Brahmaputra Valley. This migration has intensified the sociocultural othering of Bengali Muslims amid Assam’s identity politics and India’s rising authoritarianism. Through fieldwork and interpretative mapping, the article uncovers forms of alternative knowledge, including local spatial practices and intangible heritage like songs and poetry, threatened by infrastructural development, policies of the Indian government and climate change. It explores how such knowledge can be harnessed and inspire alternative development policy and design in the context of global warming in the Brahmaputra Valley and in Assam’s sociopolitical climate. The case underscores the urgency of recognizing marginalized chars as vital to the region’s water legacy, as they contribute both to local livelihoods and broader ecological systems.

Application of GRACE-based satellite estimates in the assessment of flood potential: A case study of Gangetic-Brahmaputra basin, India.

The high frequency of flood occurrences and the uneven distribution of hydrological stations make it difficult to monitor large-scale floods. Emergence of the Gravity Recovery and Climate Experiment (GRACE) satellite system sets up a new era of large-scale flood monitoring without much reliance on in situ hydrological observations. The GRACE-derived flood potential index (FPI) exhibits its ability to monitor major events of 2003, 2004, 2007, and 2008 over the Indo-Gangetic-Brahmaputra Basin (IGBB). Precipitation and soil moisture are the major influencing factors of flood. However, the response of potential flooding to such parameters is little known. Pearson's lag correlation analysis is used to examine the response of the GRACE-based FPI to precipitation and soil moisture over the study region comparing seasonal time series of the variables. Results exhibited a 2-month lagged response of FPI to precipitation in the Upper Gangetic Yamuna Chambal Basin (UGYCB) and the Lower Gangetic Basin (LGB) and 1-month lagged response in the Lower Brahmaputra Basin (LBB). With context to soil moisture, a 1-month lag is observed in the Gangetic basins, and no lag is observed in the LBB. Event wise analysis of the lags portrays slightly varying lags for different events; however, it provides a picture on the interaction between these variables. This study also assesses the agreement between FPI and satellite-based river discharge, i.e. Dartmouth Flood Observatory (DFO) discharge. A good correlation (> 0.60) between the two is observed. Threshold values of FPI are determined for the LBB due to its annual flood frequency. The nearly similar accuracy of threshold FPI, determined using DFO discharge, in monitoring floods and the predictive skill measure of FPI for LBB to the previous studies demonstrates the utility of satellite-based discharge in the quantification of threshold FPI values for different percentile floods.

Livelihood strategies of farm households of lower Brahmaputra valley zone of Assam: An empirical study

Livelihood strategies of farm households of lower Brahmaputra valley zone of Assam: An empirical study

A novel approach to flood risk assessment: Synergizing with geospatial based MCDM-AHP model, multicollinearity, and sensitivity analysis in the Lower Brahmaputra Floodplain, Assam

Floods persist as a recurring and daunting peril in the Brahmaputra plain of Assam. Notwithstanding advancement, Bongaigaon is a highly flood-afflicted district in the lower part of this region, inflicting significant damage to both lives and property almost every consecutive year. Hence, the delineation of precise and reliable flood risk susceptibility zones within the district constitutes the foremost concern of the study. The present work considered a total of sixteen multi-collinearity free parameters integrating with the GIS- based Multi-Criteria Decision Making-Analytical Hierarchy Process (MCDM-AHP) model for identifying potential flood hazard zones (FHZ), flood vulnerability zones (FVZ), and flood risk zones (FRZ) for the region. The result revealed that over 28% of the district's total area falls under the high to very high flood risk zone. Srijangram circle covers the highest flood risk zone with 343.19 sq. km. The FHZ map of the district demonstrated reliability exceeding 90% in ROC-AUC and below 40% in MSE and RMSE. Additionally, sensitivity analyses depict the role indicators in the predictive model, placed as a virgin gap for study in the region. Moreover, a multivariate correlation statistic is used to examine the potential risk zones and temporal flood effects on different Revenue Circles (RC), showing R2 over 0.6 in each category. The robustness of this model manifests sensible findings, aiding in fortifying sustainable flood management strategies to mitigate risks at different levels. Strategies adopted here contain greater potential for current as well as future trends in similar domains of research. This study may provide invaluable insights for decision-makers, thinkers, administrators, and developers working in this region.

Assessment of flood disaster and management strategies in the lower Brahmaputra valley of Assam

Floods are common in every rainy season in the Brahmaputra valley. Several districts in Assam experience flooding every year. One of the flood-prone districts in Assam is Bongaigaon, which is situated in the lower reach of Brahmaputra River. The present work aims to examine the threats associated with floods and the role of government in management strategies. For the study, primary and secondary data have been gathered from different sources, including the District DC office (DDMA branch), Assam Secretariat office (ASDMA Branch), Sentinel 1, ICIMOD and field surveys and have been analyzed with the help of different tools. In this study, 2015, 2017, 2019, 2021 and 2022 flood hazard scenarios of the district have been considered for the case evaluation. The result shows that flooding in this area has a wide range of negative impacts. Furthermore, different efforts have notably been made by the district and state administration to reduce the impact and promote sustainable management.

Wetland Changes and Ecosystem Services Valuation of Kapla Beel in Assam

Background: Wetlands are productive ecosystem with immense potentiality of providing various goods and services. But they are fast depleting due to various natural and anthropogenic causes. Kapla beel is a freshwater wetland located in Barpeta district in the lower Brahmaputra valley of Assam. Area of the Kapla beel has been decreasing over the years. This study shall make an attempt to analyse the causes of land use and land cover changes of Kapla beel of Assam and assess its ecosystem services value changes during the period 1990 to 2022. Methods: To assess the changes, two Landsat images for the year 1990 and 2022 of Kapla beel were taken from the United State Geological Survey (USGS) Earth Explorer. Land-use change analysis was assessed by comparing the areas occupied by each land use in each period using the ArcGIS software. The dynamicity index is used to calculate the rate of change in land cover. In order to assess the changes in the wetland ecosystem service value due to wetland changes, Benefit Transfer Method is used which involves transferring monetary values of ecosystem services from previous studies. Result: The valuation of ecosystem services underlines the fact that wetlands are highly productive and economically viable ecosystems. Accounting of ecosystem services provides information about the need for optimal decision -making towards judicious use of wetland resources for their sustenance.

Critical Analysis of Group Dynamics Effectiveness of Farmer Producer Organisations (FPOs) Members in Assam, India

Farmer Producer Organisation (FPO) is a legal entity formed by farmers with a major role in integrating both forward and backward linkages in the agricultural sector for enhancing farmers' income and their livelihoods through reduced cultivation and transaction costs. The present study to analyse the effectiveness of group dynamics of FPOs members was conducted in Lower Brahmaputra Valley Zone (LBVZ) of Assam. In doing so, it utilized the descriptive research design following an ex-post-facto approach to fulfil the objectives of the study and to collect the cross-sectional data from 120 FPO member respondents through personal interview method during 2022. The study reveals that majority of the FPO members had a medium level of group dynamics effectiveness in all selected 12 indicators. The study also shows that among the identified 12 indicators to measure group dynamic effectiveness (GDE) of FPOs, group atmosphere was found with the highest mean value closely followed by teamwork, participation and group cohesiveness. The other indicators in order of importance based on their corresponding mean values were achievement of FPOs, confirmation to group norms, task function, decision making procedure, interpersonal trust, empathy and group communication. As many as 70 per cent members of FPOs in study areas had reported medium level of achievement of FPO, still there is huge scope for their further improvement and achievement in agriculture and allied activities and thereby enhance their income on sustainable basis. The study further reveals that Manikpur Joha Rice Producer Company Ltd. of Chirang district had the highest total GDEI score of 91.027. While Aya Baikho FPO Co-operative Society Ltd. of Goalpara district had the lowest GDEI score of 60.441.

Demographic Characteristics of Members of Farmer Producer Organisations (FPOs) in Effectiveness of Group Dynamics and their Perceived Constraints in Lower Brahmaputra Valley Zone of Assam, India

The present study to investigate demographic profile of FPOs members in the effectiveness of group dynamics and their perceived constraints was conducted in Lower Brahmaputra Valley Zone (LBVZ) of Assam comprising six districts viz., Kamrup, Bongaigaon, Nalbari, Chirang, Barpeta and Goalpara. In doing so, it utilized the descriptive research design following an ex-post-facto approach to fulfil the objectives of the study. A total of eight FPOs promoted by Assam Agricultural University through CBBO-AAU and World Bank supported APART project were selected purposively. From each FPO, 15 active members were approached for data collection through personal interview method during 2022, which made 120 as final size of sample. The analysis of profile characteristics of the respondents revealed that majority of the respondents (FPOs members) in study areas were middle aged (66.67%) between 29 to 50 years with education level from high school to graduate/ above (80.83%), 64.17 percent were from small family size upto 4 members, 90.83 percent of the respondents had medium level of annual income (i.e. Rs 33190-379866.6), 46.67 percent had medium level of socio- political participation and 38.33 percent low and 35.83 percent high levels of material possession. The study also found that lack of co-ordination for different group activities, ineffective linkage and ineffective monitoring, lack of professional management, non-availability of timely credit and inadequate access to credit, weak financial position, absence of adequate market linkage, lack of storage facilities, distance from existing markets, lack of market information, lack of marketing knowledge and skills and difficulty in getting skilled labour were the perceived problems faced by FPO members in effective functioning of FPOs.

Brahmaputra River Bank Erosion as a Major Geo-Environmental Problem in Lower Assam, India

Abstract The concepts as well as the methodological approaches for investigating geo-environmental pattern, process and problems in a region have been continuously getting their holds since few decades past to make them firm-footed in the contemporary trend of geo-environmental studies. The lower Brahmaputra River valley of Assam, like other parts of northeast India, stands amidst complex geotectonic and physiographic set-up because, of its hills, foothills and river plain topography. The state of Assam as a whole, eventually have been experiencing natural hazards like floods including flash floods, river bank erosion, landslide, etc. Out of which bank erosion heavily affects on the life and land properties of the peoples in affected area by completely damaging it. The river Brahmaputra has a tendency to shifting southward due to various geo-tectonic and seismic instabilities of the region. It is found that during the last 50 years nearly 100 sq km of the study area is eroded in the southern part of the district of Goalpara only. The intensity of shifting is very high mostly in the lower Brahmaputra valley including western margin of the districts of Goalpara, South Salmara Mankachar and Dhubri. The data derived from 14 cross sections along the selected points of lower Brahmaputra reveals that the average annual southward shifting of the river due to bank erosion is 109.14 m/year. Hence, bank erosion has been a serious problem, which is caused mainly by the seismic instability, stream bed rise-up, continuous sedimentation; Intense rainfall, etc. And eventually the phenomenon results into the loss of large tracts of fertile agricultural lands on both the banks of the river Brahmaputra in the study area. The present paper is an attempt to analyze the cause and consequences of Brahmaputra River Bank Erosion as a major geo-environmental problem with special reference to the bank line at Goalpara district of lower Assam in India.

Exploring Climate Change Adaptation Practices and Agricultural Livelihoods among Rice Farmers of the Brahmaputra Valley in Northeast India.

Global climate change has seriously threatened agriculture and connected sectors, especially in developing countries like India. The Brahmaputra Valley in Assam, Northeast India, is vulnerable to climate change due to its agrarian economy, fragile geo-ecological setting, recurrent floods and droughts, and poor socioeconomic conditions of the farmers. The climate-induced hindrances faced by the rice farming community of this region and the local adaptation practices they employ have not been adequately studied. Therefore, we carried out a survey among 635 rice farmers across four agro-climatic zones of Assam, namely the Upper Brahmaputra Valley Zone, North Bank Plain Zone, Central Brahmaputra Valley Zone, and Lower Brahmaputra Valley Zone, to understand how they perceive and respond to climatic changes. The survey revealed that all the respondents have perceived an increase in ambient temperature, and 65% of the respondents have perceived a slight change in rainfall characteristics over the years. Most farmers reported adjusting the existing farming practices and livelihood choices to adapt to the changing climate. Farming adjustments were made mainly in terms of field preparation and management of water, rice variety, nutrients, and pests. Environmental variables like rainfall, flood, drought, and pest level, and socioeconomic variables like family size, education, farming experience, training, digital media exposure, and land area were found to influence farmers' adaptation choices. The findings imply that policies to strengthen flood, drought, pest management, education, land-use planning, agricultural training, and digital media applications in agriculture are needed for effective climate change adaptation in this region.

A cost-benefit analysis of flood early warning system: Evidence from lower Brahmaputra River Basin, Bangladesh

Bangladesh is a severely flood-affected country that ranks fifth globally. Although it is well established that regional and community-based flood early warning systems (FEWS) may minimize the effects of floods, cost-benefit analyses of FEWS are still limited in Bangladesh. This is the first study to assess the cost-benefit of the FEWS in lower Brahmaputra River basin in Bangladesh which included 1000 household surveys, 32 focus group discussion, and key informant interviews. The findings indicated that during the floods, families considered the FEWS to be useful and trustworthy, enabling them to preserve household assets, agricultural, and livestock expenditures worth of BDT 267713 (USD 2525.59) per household. Based on the different scenarios, the benefit-cost ratio (BCR) ranged from 79.87 to 213. About 92% of the respondents expressed willingness to pay an annual charge of BDT 100.63 (USD 0.94) for five years if the community disaster committees were to handle the current FEWS. This might generate BDT 100637 (USD 949.40) annually, to pay for the system's maintenance and operations. As communities' advance confidence in the FEWS system and lead times are enhanced, FEWS increasingly changes their behaviors over time, leading to enhanced social capital and a broader range of early interventions that lessen preventable loss and damage. By extending the forecast lead time by two days, the present savings could increase by 21.7 times. To increase funding, government and non-government organizations may make decisions based on the findings of the cost-benefit analysis. This study also proposed a FEWS applicable in the local level.

Flood risk assessment for Indian sub-continental river basins

Abstract. Floods are among India's most frequently occurring natural disasters, which disrupt all aspects of socio-economic well-being. A large population is affected by floods, which leave their footprints through human mortality, migration, and damage to agriculture and infrastructure, during almost every summer monsoon season in India. Despite the massive imprints of floods, sub-basin level flood risk assessment is still in its infancy and requires advancements. Using hydrological and hydrodynamic models, we reconstructed sub-basin level observed floods for the 1901–2020 period. Our modeling framework includes the influence of 51 major reservoirs that affect flow variability and flood inundation. Sub-basins in the Ganga and Brahmaputra river basins witnessed substantial flood inundation extent during the worst flood in the observational record. Major floods in the sub-basins of the Ganga and Brahmaputra occur during the late summer monsoon season (August–September). While the Beas, Brahmani, upper Satluj, upper Godavari, middle and lower Krishna, and Vashishti are among the sub-basins influenced by the presence of dams on downstream flood dynamics, the Beas, Brahmani, Ravi, and lower Satluj sub-basins are the most impacted by floods and the presence of dams. Bhagirathi, Gandak, Kosi, lower Brahmaputra, and Ghaghara are India's sub-basins with the highest flood risk. Our findings have implications for flood risk assessment and mitigation in India.

Evaluation of Promising Lines of Vegetable Amaranth (Amaranthus viridis L.) Suitable for Cultivation in North Eastern India

Sixteen accessions of vegetable amaranth (Amaranthus viridis L.) were collected from different locations of the state of Assam and North East. The accessions were tested for leaf and plant yield and component characters under different breeding trials. They were evaluated consecutively for three years in the Deptt. of Horticulture, AAU, Jorhat in station trials. The accessions viz., Am-1, Am-2, Am-3, Am-4, Am-5, Am-6, Am-7, Am-8, Am-9, Am-10, Am-11, Am-12, Am-13 (Boga Morisa), Am-14 (Ranga Morisa), Am-15 and Am-16 were tested in zonal trials covering UBVZ (Upper Brahmaputra valley zone), NBPZ (North Bank Plains zone) and LBVZ(Lower Brahmaputra valley zone) also. In these trials, among all genotypes JorAm-1(Shyamali) and JorAm-2 (Rodali) were found to be the best for leaf and plant yield and other component characters.The AICRP(VC) trials conducted throughout the country exhibited average plant yield of 137q/ha inJorAm-1 and 133.18 q/ha in JorAm-2 with 25 – 30% yield increase over the best check variety. Shyamaliwas a green leaf variety whereas Rodali was a purplish variety. The edible leaves were getting ready for plucking at 30 – 35 days after sowing. Both of them were found to be tolerant with 5% infection to leaf spot and aphids. They have been recommended in the Zonal Research Committee Meeting (ZREAC)andAnnual Technical Committee Meeting (ATCM) held at Assam Agricultural University (AAU), Jorhatfor release in the state of Assam. In view of the consumer preference and taste, the varieties are spreading very fast and getting popularity throughout entire NE states.Considering yield performance and other desirable characteristics, extensive cultivation of these varieties may be done in better performing states also.

The Himalayan uplift and evolution of aquatic biodiversity across Asia: Snowtrout (Cyprininae: Schizothorax) as a test case.

Global biodiversity hotspots are often remote, tectonically active areas undergoing climatic fluctuations, such as the Himalaya Mountains and neighboring Qinghai-Tibetan Plateau (QTP). They provide biogeographic templates upon which endemic biodiversity can be mapped to infer diversification scenarios. Yet, this process can be somewhat opaque for the Himalaya, given substantial data gaps separating eastern and western regions. To help clarify, we evaluated phylogeographic and phylogenetic hypotheses for a widespread fish (Snowtrout: Cyprininae; Schizothorax) by sequencing 1,140 base pair of mtDNA cytochrome-b (cytb) from Central Himalaya samples (Nepal: N = 53; Bhutan: N = 19), augmented with 68 GenBank sequences (N = 60 Schizothorax/N = 8 outgroups). Genealogical relationships (N = 132) were analyzed via maximum likelihood (ML), Bayesian (BA), and haplotype network clustering, with clade divergence estimated via TimeTree. Snowtrout seemingly originated in Central Asia, dispersed across the QTP, then into Bhutan via southward-flowing tributaries of the east-flowing Yarlung-Tsangpo River (YLTR). Headwaters of five large Asian rivers provided dispersal corridors from Central into eastern/southeastern Asia. South of the Himalaya, the YLTR transitions into the Brahmaputra River, facilitating successive westward colonization of Himalayan drainages first in Bhutan, then Nepal, followed by far-western drainages subsequently captured by the (now) westward-flowing Indus River. Two distinct Bhutanese phylogenetic groups were recovered: Bhutan-1 (with three subclades) seemingly represents southward dispersal from the QTP; Bhutan-2 apparently illustrates northward colonization from the Lower Brahmaputra. The close phylogenetic/phylogeographic relationships between the Indus River (Pakistan) and western tributaries of the Upper Ganges (India/Nepal) potentially implicate an historic, now disjunct connection. Greater species-divergences occurred across rather than within-basins, suggesting vicariance as a driver. The Himalaya is a component of the Earth's largest glacial reservoir (i.e., the "third-pole") separate from the Arctic/Antarctic. Its unique aquatic biodiversity must be defined and conserved through broad, trans-national collaborations. Our study provides an initial baseline for this process.

Nitrogen, Rhizobium and molybdenum for higher soil bacterial population, N uptake and productivity of lentil (Lens culinaris) grown under rice (Oryza sativa)-fallow conditions

A field experiment was conducted during the winter (rabi) seasons of 2014–15, 2015–16 and 2016–17 in loamy soils of the Regional Agricultural Research Station, Assam Agricultural University, Shillongani, Assam, to study the effect of varying doses of nitrogen, Rhizobium and molybdenum on bacterial population in soil, N uptake, yield attributes, grain yield and economics of lentil (Lens culinaris Medikus spp. culinaris) grown after the harvesting of winter rice (Oryza sativa L.) variety ‘Gitesh’. Soil bacterial population increased with the increase in nitrogen doses. The crop grown using seeds inoculated with Rhizobium @ 50 g/kg seed and sodium molybdate @ 1 g/kg seed along with 100% of recommended dose (RD) of N (15 kg/ha) accrued in the highest bacterial population in the soil at harvesting. Seed inoculation with Rhizobium and sodium molybdate led to considerably higher bacterial population build up in soil than seed inoculation with Rhizobium and sodium molybdate separately. Nitrogen uptake by lentil got reduced with decreasing N doses, being 28.54 kg/ha under RD of N and 28.03 kg/ha under 75% of recommended N. The treatment combinations involving RD and 75% of RD of N (11.25 kg/ha) and seed inoculation with Rhizobium and sodium molybdate recorded 35.16 kg/ha and 34.97 kg/ha N uptake respectively. These 2 treatment combinations ultimately accrued in higher values for plant height, pods/plant, seeds/pod and 100-seed weight and significantly higher grain yield (928.90 and 868.89 kg/ha respectively) as compared to all other treatment combinations. Benefit: cost ratios under these 2 treatment combinations were 2.18 and 2.09 respectively. The treatment combinations were tested for maximizing lentil production utilizing rice-fallows and farmers’ acceptability in farmers’ fields during rabi 2017–18 through 3 Krishi Vigyan Kendras (KVK) in Upper Brahmaputra Valley (UBV) in Jorhat district, Central Brahmaputra Valley (CBV) in Nagaon district and Lower Brahmaputra Valley (LBV) in Nalbari district of the state. The RD of N + seed inoculation with Rhizobium and sodium molybdate yielded the highest (5.8–8.2 q/ha) at all the locations closely followed by 75% RD of N + Rhizobium + sodium molybdate (5.93–7.25 q/ha).

Reckoning flood frequency and susceptibility area in the lower Brahmaputra floodplain using geospatial and hydrological approach

AbstractClimate change has remarkably intensified the occurrence of floods around the globe. Flooding causes loss of life and property. Flood frequency analysis (FFA) is an important investigation and plays a key role in flood‐related studies. Geographically, the study area is confined in the lower Brahmaputra floodplains, flat slope, and rivers are braided in nature. Because of Heavy rainfall, major rivers in the area carry huge influxes of surged water during the summer period. Hence, disastrous flooding can be seen every year in the study region. The present study aims to model flood frequency using the hydrological data to understand the effects within the area. FFA approaches like Gumbel, Log Pearson type 3 (LP‐3), and Log‐Normal (LN) were used, and comparative analyses were done using water level data for the Manas, Aie, and Brahmaputra Rivers. Moreover, remote sensing and the geographic information system (GIS) environment were used to generate FFA‐based flood predictive inundation map at 5, 10, 50, 100, and 200 years of return periods. Here, Gumbel's distribution has found the best fit for all the rivers among the three. The distribution reveals that at a 200‐year return period, the highest water level would be increased by 1.45, 2.41, and 4 m for the Manas, Aie, and Brahmaputra Rivers, respectively. The study shows that almost 493.54 and 673.72 km2 of areas are expected to be submerged at 5 and 200‐year return periods according to Gumbel's distribution; LP‐3 distribution predicted 493.01 and 555.66 km2, and the log‐normal distribution method predicted 432.51 and 555.74 km2 of flood‐sensitive areas at 5 and 200‐year return periods, respectively. The FFA highlighted spatio‐temporal effects on the expansion of submerged areas. We hope that the findings of the present study will aid in the different flood hazard management strategies for future endeavors.

Regional Rainfall Frequency Analysis in the Lower Brahmaputra Basin

Regional Rainfall Frequency Analysis in the Lower Brahmaputra Basin

Analysis of Food Security Status and Coping Strategies of Rural Households in Assam, India

The study was attempts to estimate the food security status and access the coping strategies utilized during food shortages among the rural households of Assam. Data were collected in the year of 2016-17 from 120 farmers, who were selected using a stratified random sampling method and were classified according to their possession of land. Data were analyzed using descriptive statistics, food security index and tabular and percentage analysis. The study revealed that in Lower Brahmaputra Valley Zone, 30 % of sample households were food secure while 70 % households were food insecure. Moreover, 76.92 % of medium farmers were food secure and 77.78 % of marginal farmers were food insecure which indicates that the farm size could be a significant factor to the food security status of farming households. Average daily calorie intake of food secure households was 2318.10, 2443.58, 2355.37 and 2600.37 kcal which was higher than the national average calorie intake and for food insecure households was 1754.94, 1856.43, 1862.46 and 1845.11 kcal which was much lower than the national average calorie 2,200 kcal intake by the marginal, small, semi medium and medium households respectively. It indicates that size of household is dependent to average daily calorie intake by the households in the both district. The study also revealed that the most important way of obtaining food when stocks run out was to purchase food on credit from the market followed by selling productive assets like land or livestock during the food shortages. Other options like reduce quantity, consume seed stock held for next season, take money from money lenders etc. were also adopted by rural households during shortage period. Therefore, there is need to increase the volume of food production as well as improvement on income generating activities on sustainable basis.

Characterization of Rice Growing Soils of Lower Brahmaputra Valley Zone (LBVZ) of Assam, India

An experiment was conducted to characterize and classify the physico-chemical properties of different rice growing soils namely Ahu, Sali and Boro rice of Boko block of Assam. A total of sixty (60) geo-referenced and representative (0-15 cm) samples of soil were collected from the three different rice growing soils (20 each) viz., Ahu, Sali and Boro. The soils were then tested for their different physico-chemical properties. Soil textural classes varied from sandy loam to clay loam for Ahu and Sali rice while clay loam in Boro rice with strongly acidic to moderately acidic in their reactions (pH 4.52 to 5.85). Soil organic carbon was found to be medium to high in Ahu and Sali rice but high in Boro rice growing soils. The clay content was found to be significantly more in Boro rice growing soils as a contrary to Ahu and Sali rice growing soils. The EC values represented the non-saline nature of the soils and the CEC of all the rice growing soils of Boko block was invariably low with the mean values of 8.66 cmol (p+) kg-1 for Ahu rice growing soils, 8.80 cmol (p+) kg -1 for Sali rice growing soils and for Boro rice growing soils it was 8.90 cmol (p+) kg-1. All the available primary nutrients were medium in their status except available phosphorus which was low to medium. Exchangeable Ca2+ was the dominant basic cation followed by Mg2+.