• Energy Research

Field study was conducted during winter seasons (November–March) of 2015–2016 and 2016–2017 at the Research Farm of Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India, with an aim to investigate the crop productivity, energy and C budget, carbon footprint and economic sustainability of peanut cultivation fertilized with varied levels of nitrogen under polythene mulching. The experiment laid out in split-plot design comprised of two mulching practices as the main-plot treatments and seven doses of N with or without supplementation of Rhizobium bio-fertilizer as the sub-plot treatments. Fertilization with 100% recommended dose of nitrogen (RDN) + Rhizobium under polythene mulching brought about significant enhancement in pod yield over other nutrient management practices. The effects on yield attributing characters were similar to that of pod yield. Energy indices namely net energy gain, energy productivity, energy intensiveness and energy profitability were the highest with 100% RDN + Rhizobium, irrespective of mulching situations. However, the maximum values of specific energy and nutrient energy ratio were recorded when the crop received 50% RDN with and without Rhizobium, respectively, under mulching and non-mulching situations. Human energy profitability was always greater under mulching situations over non-mulching. Total estimated carbon footprints improved with increase in N level from 0 to 100% RDN with Rhizobium under polythene mulching over non-mulching situations. Highest value of C sustainability index was also observed with polythene covering particularly with the application of 100% RDN + Rhizobium. This treatment combination also proved its superiority with respect to economic benefits in peanut cultivation.

Understanding the interactions between shallow saline groundwater and surface water is crucial for managing water logging in deltaic islands. Water logging conditions result in the accumulation of salt in the root zone of crops and detrimentally affect agriculture in the economically and socially backward deltaic region of West Bengal and Bangladesh. In this paper, we undertook a modeling study of surface water–groundwater interactions in the Gosaba Island of Sundarbans region of the Ganges delta using MODFLOW followed by comprehensive parameter sensitivity analysis. Further, scenario analyses (i.e., no-drain, single drain, three drains) were undertaken to evaluate the effectiveness of drainage infrastructure to reduce saline water logging conditions. The evaluation indicated that installation of three drains can remove water at a rate of up to −123.3 m3day−1 and lower the water table up to 0.4 m. The single drain management scenario could divert water at the rate of −77.9 m3day−1 during post monsoon season, lowering the shallow saline groundwater table up to 0.1 m. This preliminary modeling study shows encouraging results to consider drainage management as to solve the increasing challenge of water logging and salinity management in the deltaic region. The insights will be useful for farmers and policymakers in the region for planning various sustainable saline groundwater management. Building drainage infrastructure could potentially be part of initiatives like the national employment guarantee scheme in India. In the future, this model can be coupled with solute transport models for understanding the current status and future expansion of salinity in the study area. Further modeling and optimization analysis can help identify the optimal depth and spacing of drains.

Declining rate of productivity and environmental sustainability is forcing growers to use organic manures as a source of nutrient supplement in maize farming. However, weed is a major constraint to maize production. A field study was carried out over two seasons to evaluate various integrated nutrient and weed management practices in hybrid maize. The treatment combinations comprised of supplementation of inorganic fertilizer (25% nitrogen) through bulky (Farmyard manure and vermicompost) and concentrated (Brassicaceous seed meal (BSM) and neem cake (NC)) organic manures and different mode of weed management practices like chemical (atrazine 1000 g ha−1) and integrated approach (atrazine 1000 g ha−1 followed by mechanical weeding). Repeated supplementation of nitrogen through concentrated organic manures reduced the density and biomass accumulation of most dominant weed species, Anagalis arvensis by releasing allelochemicals into the soil. But organic manures had no significant impact on restricting the growth of bold seeded weeds like Vicia hirsuta and weed propagated through tubers i.e., Cyperus rotundus in maize. By restricting the weed growth and nutrient removal by most dominating weeds, application of BSM enhanced the growth and yield of maize crop. Repeated addition of organic manures (BSM) enhanced the maize grain yield by 19% over sole chemical fertilizer in the second year of study. Application of atrazine as pre-emergence (PRE) herbicide significantly reduced the density of A. arvensis, whereas integration of mechanical weeding following herbicide controlled those weeds which were not usually controlled with the application of atrazine. As a result, atrazine at PRE followed by mechanical weeding produced the highest maize grain yield 6.81 and 7.10 t/ha in the first year and second year of study, respectively.

The multifarious relationships between nitrogen application, energy consumption and GHG emissions are still not well understood in irrigated potato production system. There is a need to ensure that N and energy use are closely considered to provide useful options for adaptation and to build resilience at the farm level. A field experiment was conducted during the winter (November–March) of 2012–2013 and 2013–2014 at the District Seed Farm, Adisaptagram, Hooghly, West Bengal, India (23°26′N latitude and 88°22′E longitude with an altitude of 12 m above mean sea level), under sub-humid subtropical climatic condition of West Bengal, India. The objective of the study was to assess environmental and economic sustainability in potato cultivation as influenced by nitrogen fertilization. This paper examines nitrogen application and energy consumption relationships for irrigated potato production system in eastern India. Results showed that net energy gain was the highest with the supply of 225 kg N/ha for both Kufri Himalini and Kufri Jyoti and 150 kg N/ha for Kufri Shailja. However, maximum values of energy ratio, specific energy and energy intensiveness were recorded with 300 kg N/ha for all three tested cultivars. Total estimated GHG emission per ha increased with the increase in N level from 0 to 300 kg N/ha, regardless of cultivars. Net benefit of potato cultivation was observed to increase with increasing levels of N application up to 300 kg N/ha (for K. Himalini) and up to 225 kg N/ha (for K. Shailja and K. Jyoti). The highest GRF for K. Himalini was observed at 300 kg N/ha, while for K. Shailja and K. Jyoti the maximum GRF was associated with 150 and 250 kg N application per hectare, respectively.

In the coastal zone of the Ganges Delta, water shortages due to soil salinity limit the yield of dry season crops. To alleviate water shortage as a consequence of salinity stress in the coastal saline ecosystem, the effect of different water-saving (WS) and water-conserving options was assessed on growth, yield and water use of tomato; two field experiments were carried out at Gosaba, West Bengal, India in consecutive seasons during the winter of 2016–17 and 2017–18. The experiment was laid out in a randomized block design with five treatments viz., surface irrigation, surface irrigation + straw mulching, drip irrigation at 100% reference evapotranspiration (ET0), drip irrigation at 80% ET0, drip irrigation at 80% ET0 + straw mulching. Application of drip irrigation at 80% ET0 + straw mulching brought about significantly the highest fruit as well as the marketable yield of tomato (Solanum lycopersicum L.). The soil reaction (pH), post-harvest organic carbon, nitrogen, phosphorus and potassium (N, P and K) status and soil microbial population along with the biochemical quality parameters of tomato (juice pH, ascorbic acid, total soluble solids and sugar content of fruits) were significantly influenced by combined application of drip irrigation and straw mulching. Surface irrigation significantly increased the salinity level in surface and sub-surface soil layers while the least salinity development was observed in surface mulched plots receiving irrigation water through drip irrigation. The highest water productivity was also improved from drip irrigation at 80% ET0 + straw mulched plots irrespective of the year of experimentation. Such intervention also helped in reducing salinity stress for the tomato crop. Thus, straw mulching along with drip irrigation at 80% ET0 can be recommended as the most suitable irrigation option for tomato crop in the study area as well as coastal saline regions of South Asia. Finally, it can be concluded that the judicious application of irrigation water not only increased growth, yield and quality tomatoes but also minimized the negative impact of soil salinity on tomatoes grown in the coastal saline ecosystem of Ganges Delta.

Identifying productive, profitable, and less risky cropping systems is pivotal for ensuring sustainable farm–based livelihoods in the context of climatic uncertainties and market volatility, particularly in many developing nations. Conventional field crop research often identifies the best or optimal solutions based on treatment replicates at a specific point in time without considering the influence of market volatility and climatic uncertainties. To address this gap, we conducted an assessment of productivity profitability and climate– and market–uncertainty-driven risk for eleven different rice-based cropping systems (eight existing and three potential systems) in the coastal region of Gosaba Block, West Bengal, India. Farmers’ observations of the best, typical, and worst seasonal yields and price data for the selected cropping systems over the last five to seven years were collected from fifty farm households. Irrespective of the scenarios, the rice–lathyrus systems, followed by rice–onion and rice–lentil systems, recorded the lowest rice equivalent yields and system yields. However, the highest rice equivalent yields and system yields were recorded for rice–chilli systems, followed by rice–tomato and rice–potato–green-gram systems. Per hectare, total paid–out cost (TPC) of rice–tomato systems was higher, followed by rice–chilli, rice–potato–green–gram, and rice–potato systems. However, irrespective of seasonal conditions (best, normal, and worst), rice–chilli systems gave a higher net return followed by rice–tomato and rice–potato–green–gram systems. The rice–fallow system recorded the lowest value for both parameters. Under the worst seasonal conditions, the rice–onion system gave a negative net return. Under all the scenarios, the rice–chilli system gave the highest benefit over cost, followed by the rice–tomato, rice–potato–green-gram, and rice–potato systems. The cumulative probability distribution (CDF) of per ha net income of the rice–tomato system showed first–degree stochastic dominance over other systems, implying that the system is economically the most profitable and less risky. Additionally, the CDF of net income per ha of the rice–chilli system showed second–degree stochastic dominance over the rest of the systems, indicating that the system is economically more profitable and less risky than other rice/non–rice cropping systems except for the rice–tomato system. Furthermore, the risk analysis results suggest that the likelihood of obtaining negative net income was nil for the selected cropping systems, except the rice–onion system had a slight chance (<1%) of providing a negative net return. Considering the productivity and economic viability (e.g., profitability and risk) of different rice–based systems, it is recommended to promote the adoption of the rice–vegetable systems, especially rice–tomato and rice–chilli from among the existing systems and rice–potato–green-gram systems from among the potential systems, for achieving sustainable intensification in these coastal saline tracts of the region.

Facing cold stress is amajor constraint in seedling production during the winter season as, most particularly in recent times due to uncertain climatic conditions, no sustainable technology has been reported that could be easily adopted by farmers withlimited resources. Therefore, field experiments were carried out during winter 2017–2018 and 2018–2019 at the Central Research Farm of Bidhan Chandra KrishiViswavidyalaya, West Bengal, India to study the growth, survival potential, yield and nutritional and biochemical properties of boro rice seedlings as influenced by two seedbed management practices viz. conventional seedbed (farmers’ practice) and improved seedbed (polythene protected with micronutrient supplementation). The major objective was to lower the nurserybed duration without compromising seedlings’ health and to studythe economic viability during the winter season. The experiment was laid out in ten experimental units and deployed anindependent-sample t-test to compare the performance of the seedlings. The microclimatic changes were also itemized from both seedbeds. The seeds sownunder improved nursery conditions resulted in better seedling emergence (~90%) and survival percentage (~85%) as compared to the conventional seedbed (~70% and 65%). Growth attributes in terms of plant height, biomass accumulation, root characteristics, tiller count, and growth rate were observed to be better from the polythene-protected nursery bed. Theimproved nursery bed accounted for 20% higher seedling count at the time of transplantation over the conventional bed. The microclimatic situation under a polythene covering was also favorable for germination and seedling growth. Maximum nutrient (N, P, and K) concentrations, as well as chlorophyll content, wererecorded from improved seedlings. Results suggested that the improved seedbed management was apotential alternative toearly embolden seedling production during the winter to avoid climatic abnormalities. Most importantly, improved seedbeds ensured a comprehensive route from germination to healthy seedling production without any failure in thesmalltime window, which involvedless input as well as cost involvement. This technique could diffusethe problem oflate sowing conditions in the rice–rice cropping system.

Synthetic fertilizer and herbicides encompass the largest share in nutrient and weed management on food grain crops that create serious environmental issues. Integrated nutrient and non-chemical weed management approaches may help to reduce the chemical load in the environment, maintaining higher weed control efficiency and yield. A field experiment was conducted for two consecutive monsoon seasons during 2015 and 2016 in farm fields to develop a profitable and sustainable rice production system through integrated nutrient and weed management practices. A varied combination of nutrients either alone or integrated with chemical and non-chemical weed management were tested on transplanted rice in a factorial randomized block design with three replications. The results showed that the integration of concentrated organic manures with chemical fertilizer effectively inhibited weed growth and nutrient removal. Integration of nutrient and weed management practices significantly enhanced 9% biomass growth, 10% yield of the rice crop along with 3–7% higher nutrient uptake. Brassicaceous seed meal (BSM) and neem cake also had some influence on weed suppression and economic return. Thus, the integrated nutrient and weed management practices in rice cultivation might be an effective way to achieve economic sustainability and efficient rice cultivation in eastern India. Shortages of farmyard manure and vermicompost could be supplemented by BSM and neem cake in the integrated module.