• Energy Research

A study was conducted to examine the interrelationships among socioeconomic factors, household consumption patterns, calorie intake and greenhouse gas emissions factors in rural eastern India based on household survey data. Findings indicated that higher monthly per capita incomes (12.1–80.1$) were associated with greater average calorie intakes (2021–2525 kcal d−1). As estimated by the FEEDME model, in total 17.2% of the population was calorie malnourished with a regional disparity of 29.4–18.2% malnourishment. Greenhouse gas (GHG) emissions were calculated only on the basis of crop and livestock production and consumption. Rice accounted for the highest share of total GHG emissions, on average 82.6% on a production basis, which varied from 58.1% to 94.9% in regional basis. Rice contributed the greatest share (~ 65% and 66.2%) in terms of both calories and GHG emissions (CO2 eq y−1), respectively, on a consumption basis. We conclude that extensive rice farming and increasing animal product consumption are dominant factors in the higher carbon footprint in this region and are likely to further increase with increase in per capita income. This study provides useful information to help for better crop planning and for fine-tuning food access policy, to reduce carbon footprint and calorie malnutrition.

Abstract Biochar plays a pivotal role in carbon storage-fractionation-mineralization process in soil. However, uncertainty still remains about the influence of biochar on these inter-related processes that links to C cycling in soil. A three years field experiment was initiated in 2013 at ICAR-National Rice Research Institute, Cuttack, India, to study the deviation in C mineralization and C fractions caused by the application of six doses of rice husk derived biochar (RHB), ranging from 0.5 t ha−1 to 10.0 t ha−1. The results showed an increase in cumulative CO2-C emission with increasing RHB rates. However, the model-fitted mineralization rates (dC/dt) did not show significant difference between treated and control soils at the end of incubation period in a laboratory study. In addition, microbial quotient and % C from RHB utilized showed a decreasing trend with increasing rates of RHB application, establishing the carbon sequestration potential of RHB. The highest rate (10.0 t ha−1) of RHB application accumulated maximum total organic C (3.26%) and a larger share of non-labile C (63.8%) among the treatments. An increase in rice grain yield (1–24%, depending on rate of RHB application) was observed with increasing rates of RHB which further established that RHB application not only enhanced C storage but also enhanced the productivity of rice by enhancing the soil fertility.

Land use and land cover (LULC) change have considerable influence on ecosystem services. Assessing change in ecosystem services due to LULC change at different spatial and temporal scales will help to identify suitable management practices for sustaining ecosystem productivity and maintaining the ecological balance. The objective of this study was to investigate variations in ecosystem services in response to LULC change over 27 years in four agro-climatic zones (ACZ) of eastern India using satellite imagery for the year 1989, 1996, 2005, 2011 (Landsat TM) and 2016 (Landsat 8 OLI). The satellite images were classified into six LULC classes, agriculture land, forest, waterbody, wasteland, built-up, and mining area. During the study period (1989 to 2016), forest cover reduced by 5.2%, 13.7%, and 3.6% in Sambalpur, Keonjhar, and Kandhamal districts of Odisha, respectively. In Balasore, agricultural land reduced by 17.2% due to its conversion to built-up land. The value of ecosystem services per unit area followed the order of waterbodies > agricultural land > forests. A different set of indicators, e.g., by explicitly including diversity, could change the rank between these land uses, so the temporal trends within a land use are more important than the absolute values. Total ecosystem services increased by US$ 1296.4 × 105 (50.74%), US$ 1100.7 × 105 (98.52%), US$ 1867 × 105 (61.64%), and US$ 1242.6 × 105 (46.13%) for Sambalpur, Balasore, Kandhamal, and Keonjhar, respectively.

A pot experiment was carried out under controlled condition to investigate the accumulation, uptake and toxicity effects of fluoride (F) in onion (Allium cepa L.) grown on the soil contaminated by inorganic fluoride (NaF). Six different levels of soil contamination were used by adding 0, 100, 200, 400, 600 and 800 mg NaFkg(-1) to the soil. The F concentration in shoot, bulb and root varied between 16.3 and 109.1mg Fkg(-1), 15.8 and 54.3mg Fkg(-1) and 18.6 and 151.6 mg Fkg(-1), respectively. The visible symptoms of F toxicity in terms of tip burning and death of the plant was noticed in highly contaminated soils (>400mg NaFkg(-1) soil). The phyto-toxic threshold limit (LC(50)) in onion shoot was found to be 55 mg Fkg(-1), beyond which the biomass yield decreased by 50%. It was also inferred from the study that there is a partitioning of F in onion, with more accumulation in roots and shoots than in bulbs. The order of retention of fluoride in onion found to be roots>shoot>bulb.

In order to identify the viable option of tillage practices in rice-maize-cowpea cropping system that could cut down soil carbon dioxide (CO2) emission, sustain grain yield, and maintain better soil quality in tropical low land rice ecology soil respiration in terms of CO2 emission, labile carbon (C) pools, water-stable aggregate C fractions, and enzymatic activities were investigated in a sandy clay loam soil. Soil respiration is the major pathway of gaseous C efflux from terrestrial systems and acts as an important index of ecosystem functioning. The CO2-C emissions were quantified in between plants and rows throughout the year in rice-maize-cowpea cropping sequence both under conventional tillage (CT) and minimum tillage (MT) practices along with soil moisture and temperature. The CO2-C emissions, as a whole, were 24 % higher in between plants than in rows, and were in the range of 23.4-78.1, 37.1-128.1, and 28.6-101.2 mg m(-2) h(-1) under CT and 10.7-60.3, 17.3-99.1, and 17.2-79.1 mg m(-2) h(-1) under MT in rice, maize, and cowpea, respectively. The CO2-C emission was found highest under maize (44 %) followed by rice (33 %) and cowpea (23 %) irrespective of CT and MT practices. In CT system, the CO2-C emission increased significantly by 37.1 % with respect to MT on cumulative annual basis including fallow. The CO2-C emission per unit yield was at par in rice and cowpea signifying the beneficial effect of MT in maintaining soil quality and reduction of CO2 emission. The microbial biomass C (MBC), readily mineralizable C (RMC), water-soluble C (WSC), and permanganate-oxidizable C (PMOC) were 19.4, 20.4, 39.5, and 15.1 % higher under MT than CT. The C contents in soil aggregate fraction were significantly higher in MT than CT. Soil enzymatic activities like, dehydrogenase, fluorescein diacetate, and β-glucosidase were significantly higher by 13.8, 15.4, and 27.4 % under MT compared to CT. The soil labile C pools, enzymatic activities, and heterotrophic microbial populations were in the order of maize > cowpea > rice, irrespective of the tillage treatments. Environmental sustainability point of view, minimum tillage practices in rice-maize-cowpea cropping system in tropical low land soil could be adopted to minimize CO2-C emission, sustain yield, and maintain soil health.

Aunque el cultivo de arroz es una de las fuentes agrícolas más importantes de metano (CH4) y contribuye con ~8% del total de las emisiones antropogénicas globales, persisten grandes discrepancias entre las estimaciones de las emisiones globales de CH4 del cultivo de arroz (que van de 18 a 115 Tg CH4 año−1) debido a la falta de limitaciones observables. La distribución espacial de las emisiones de arrozales se ha evaluado a escalas regionales a globales mediante inventarios ascendentes y modelos de superficie terrestre sobre resolución espacial gruesa (por ejemplo, > 0,5°) o unidades espaciales (por ejemplo, zonas agroecológicas). Sin embargo, las estimaciones de flujo de CH4 de alta resolución capaces de capturar los efectos del clima local y las prácticas de gestión sobre las emisiones, así como la replicación de datos in situ, siguen siendo difíciles de producir debido a la escasez de mapas de arroz de alta resolución y a la insuficiente comprensión de los predictores de CH4. Aquí, combinamos datos de flujo de metano de arroz con arroz de 23 sitios de covarianza de remolinos globales y datos de teledetección MODIS con aprendizaje automático para 1) evaluar el rendimiento del modelo basado en datos y la importancia variable para predecir los flujos de CH4 de arroz; y 2) producir estimaciones cuadriculadas de aumento de escala de las emisiones de CH4 de arroz a una resolución de 5000 m en toda Asia monzónica, donde se cultiva ~87% del área mundial de arroz y se produce ~ 90% de la producción mundial de arroz. Nuestro modelo de bosque aleatorio logró valores de eficiencia de Nash-Sutcliffe de 0,59 y 0,69 para flujos de CH4 de 8 días y flujos de CH4 medios del sitio, respectivamente, con índices relacionados con la temperatura de la superficie terrestre, la biomasa y la disponibilidad de agua como los predictores más importantes. Estimamos que las emisiones anuales promedio de arroz con cáscara CH4 (excluida la temporada de barbecho invernal) en toda Asia monzónica son de 20.6 ± 1.1 Tg año−1 para 2001–2015, que se encuentra en el rango más bajo de las estimaciones anteriores basadas en el inventario (20–32 CH4 Tg año−1). Nuestras estimaciones también sugieren que las emisiones de CH4 del arroz con cáscara en esta región han estado disminuyendo desde 2007 hasta 2015 después de las disminuciones tanto en el área de cultivo de arroz con cáscara como en las tasas de emisión por unidad de área, lo que sugiere que las emisiones de CH4 del arroz con cáscara en el monzón de Asia probablemente no hayan contribuido al renovado crecimiento del CH4 atmosférico en los últimos años. Bien que la riziculture soit l'une des plus importantes sources agricoles de méthane (CH4) et contribue à environ8% des émissions anthropiques mondiales totales, de grands écarts subsistent entre les estimations des émissions mondiales de CH4 provenant de la riziculture (allant de 18 à 115 Tg de CH4 par an) en raison d'un manque de contraintes d'observation. La distribution spatiale des émissions de riz paddy a été évaluée à l'échelle régionale et mondiale par des inventaires ascendants et des modèles de surface terrestre sur une résolution spatiale grossière (par exemple, > 0,5°) ou des unités spatiales (par exemple, des zones agro-écologiques). Cependant, les estimations de flux de CH4 à haute résolution capables de capturer les effets du climat local et des pratiques de gestion sur les émissions, ainsi que de reproduire les données in situ, restent difficiles à produire en raison de la rareté des cartes à haute résolution du riz paddy et d'une compréhension insuffisante des prédicteurs de CH4. Ici, nous combinons les données de flux de méthane de riz paddy provenant de 23 sites mondiaux de covariance des tourbillons et les données de télédétection MODIS avec l'apprentissage automatique pour 1) évaluer les performances du modèle basé sur les données et l'importance variable pour prédire les flux de CH4 du riz ; et 2) produire des estimations maillées des émissions de CH4 du riz à une résolution de 5000 m dans toute l'Asie de la mousson, où ∼87 % de la superficie mondiale du riz est cultivée et ∼ 90 % de la production mondiale de riz se produit. Notre modèle de forêt aléatoire a atteint des valeurs d'efficacité de Nash-Sutcliffe de 0,59 et 0,69 pour les flux de CH4 sur 8 jours et les flux de CH4 moyens du site, respectivement, la température de surface du sol, la biomasse et les indices liés à la disponibilité de l'eau étant les prédicteurs les plus importants. Nous estimons que les émissions annuelles moyennes de CH4 de riz paddy (hors saison de jachère hivernale) dans toute l'Asie de la mousson sont de 20,6 ± 1,1 Tgan-1 pour 2001–2015, ce qui se situe dans la fourchette inférieure des estimations antérieures basées sur les inventaires (20–32 Tgan-1 de CH4). Nos estimations suggèrent également que les émissions de CH4 du riz paddy dans cette région ont diminué de 2007 à 2015 à la suite de baisses à la fois de la superficie cultivée en riz paddy et des taux d'émission par unité de surface, ce qui suggère que les émissions de CH4 du riz paddy dans Monsoon Asia n'ont probablement pas contribué à la croissance renouvelée du CH4 atmosphérique ces dernières années. Although rice cultivation is one of the most important agricultural sources of methane (CH4) and contributes ∼8% of total global anthropogenic emissions, large discrepancies remain among estimates of global CH4 emissions from rice cultivation (ranging from 18 to 115 Tg CH4 yr−1) due to a lack of observational constraints. The spatial distribution of paddy-rice emissions has been assessed at regional-to-global scales by bottom-up inventories and land surface models over coarse spatial resolution (e.g., > 0.5°) or spatial units (e.g., agro-ecological zones). However, high-resolution CH4 flux estimates capable of capturing the effects of local climate and management practices on emissions, as well as replicating in situ data, remain challenging to produce because of the scarcity of high-resolution maps of paddy-rice and insufficient understanding of CH4 predictors. Here, we combine paddy-rice methane-flux data from 23 global eddy covariance sites and MODIS remote sensing data with machine learning to 1) evaluate data-driven model performance and variable importance for predicting rice CH4 fluxes; and 2) produce gridded up-scaling estimates of rice CH4 emissions at 5000-m resolution across Monsoon Asia, where ∼87% of global rice area is cultivated and ∼ 90% of global rice production occurs. Our random-forest model achieved Nash-Sutcliffe Efficiency values of 0.59 and 0.69 for 8-day CH4 fluxes and site mean CH4 fluxes respectively, with land surface temperature, biomass and water-availability-related indices as the most important predictors. We estimate the average annual (winter fallow season excluded) paddy rice CH4 emissions throughout Monsoon Asia to be 20.6 ± 1.1 Tg yr−1 for 2001–2015, which is at the lower range of previous inventory-based estimates (20–32 CH4 Tg yr−1). Our estimates also suggest that CH4 emissions from paddy rice in this region have been declining from 2007 through 2015 following declines in both paddy-rice growing area and emission rates per unit area, suggesting that CH4 emissions from paddy rice in Monsoon Asia have likely not contributed to the renewed growth of atmospheric CH4 in recent years. على الرغم من أن زراعة الأرز هي واحدة من أهم المصادر الزراعية للميثان (CH4) وتساهم بنسبة 8 ٪ من إجمالي الانبعاثات العالمية البشرية المنشأ، إلا أنه لا تزال هناك اختلافات كبيرة بين تقديرات انبعاثات الميثان العالمية من زراعة الأرز (التي تتراوح من 18 إلى 115 تيراغرام من الميثان في السنة−1) بسبب نقص قيود المراقبة. تم تقييم التوزيع المكاني لانبعاثات الأرز والأرز على المستويات الإقليمية إلى العالمية من خلال قوائم الجرد التصاعدية ونماذج سطح الأرض على الدقة المكانية الخشنة (على سبيل المثال، > 0.5درجة) أو الوحدات المكانية (على سبيل المثال، المناطق الزراعية الإيكولوجية). ومع ذلك، لا تزال تقديرات تدفق الميثان عالية الدقة القادرة على التقاط آثار المناخ المحلي وممارسات الإدارة على الانبعاثات، وكذلك تكرار البيانات في الموقع، صعبة الإنتاج بسبب ندرة الخرائط عالية الدقة لأرز الأرز وعدم كفاية فهم تنبؤات الميثان. هنا، نجمع بين بيانات تدفق الميثان من الأرز والأرز من 23 موقعًا عالميًا للتباين الدوامي وبيانات الاستشعار عن بعد MODIS مع التعلم الآلي من أجل 1) تقييم أداء النموذج القائم على البيانات والأهمية المتغيرة للتنبؤ بتدفقات CH4 للأرز ؛ و 2) إنتاج تقديرات شبكية لانبعاثات CH4 للأرز بدقة 5000 متر في جميع أنحاء آسيا الموسمية، حيث تتم زراعة 87 ٪ من مساحة الأرز العالمية و 90 ٪ من إنتاج الأرز العالمي. حقق نموذجنا للغابات العشوائية قيم كفاءة ناش- سوتكليف البالغة 0.59 و 0.69 لتدفقات الميثان لمدة 8 أيام ومتوسط تدفقات الميثان في الموقع على التوالي، مع مؤشرات درجة حرارة سطح الأرض والكتلة الحيوية وتوافر المياه كأهم المؤشرات. نقدر المتوسط السنوي (باستثناء موسم الإراحة الشتوية) لانبعاثات الميثان من الأرز في جميع أنحاء آسيا الموسمية بـ 20.6 ± 1.1 تيراغرام في السنة-1 للفترة 2001–2015، وهو في النطاق الأدنى للتقديرات السابقة القائمة على المخزون (20–32 تيراغرام في السنة-1). تشير تقديراتنا أيضًا إلى أن انبعاثات الميثان من أرز الأرز في هذه المنطقة قد انخفضت من عام 2007 حتى عام 2015 بعد الانخفاضات في كل من مساحة زراعة أرز الأرز ومعدلات الانبعاثات لكل وحدة مساحة، مما يشير إلى أن انبعاثات الميثان من أرز الأرز في الرياح الموسمية في آسيا من المحتمل ألا تساهم في النمو المتجدد للميثان في الغلاف الجوي في السنوات الأخيرة.

The microbial biomass carbon (MBC) and carbon mineralization of fly ash (FA) amended soil at (0 %, 1.25 %, 2.5 %, 5 %, 10 % and 20 % FA; v/v) was investigated under laboratory conditions for 120 days at 60 % soil water-holding capacity and 25 ± 1°C temperature. The results demonstrated that soil respiration and microbial activities were not suppressed up to 2.5 % FA amendment and these activities decreased significantly at 10 % and 20 % FA treatment with respect to control. Application of 10 % and 20 % FA treated soils showed a decreasing trend of soil MBC with time; and the decrease was significant throughout the period of incubation. The study concluded that application of FA up to 2.5 % can thus be safely used without affecting the soil biological activity and thereby improve nutrient cycling in agricultural soils.

Rice-rice system and rice fallows are no longer productive in Southeast Asia. Crop and varietal diversification of the rice based cropping systems may improve the productivity and profitability of the systems. Diversification is also a viable option to mitigate the risk of climate change. In Eastern India, farmers cultivate rice during rainy season (June-September) and land leftovers fallow after rice harvest in the post-rainy season (November-May) due to lack of sufficient rainfall or irrigation amenities. However, in lowland areas, sufficient residual soil moistures are available in rice fallow in the post-rainy season (November-March), which can be utilized for raising second crops in the region. Implementation of suitable crop/varietal diversification is thus very much vital to achieve this objective. To assess the yield performance of rice varieties under timely and late sown conditions and to evaluate the performance of dry season crops following them, three different duration rice cultivars were transplanted in July and August. In dry season several non-rice crops were sown in rice fallow to constitute a cropping system. The results revealed that tiller occurrence, biomass accumulation, dry matter remobilization, crop growth rate, and ultimately yield were significantly decreased under late transplanting. On an average, around 30% yield reduction obtained under late sowing may be due to low temperature stress and high rainfall at reproductive stages of the crop. Dry season crops following short duration rice cultivars performed better in terms of grain yield. In the dry season, toria was profitable when sown earlier and if sowing was delayed greengram was suitable. Highest system productivity and profitability under timely sown rice may be due to higher dry matter remobilization from source to sink. A significant correlation was observed between biomass production and grain yield. We infer that late transplanting decrease the tiller occurrence and assimilate remobilization efficiency, which may be responsible for the reduced grain yield.

A laboratory study was conducted with four pesticides, viz. a fungicide (carbendazim), two insecticides (chlorpyrifos and cartap hydrochloride) and an herbicide (pretilachlor) applied to a sandy clay loam soil at a field rate to determine their effect on microbial biomass carbon (MBC) and carbon mineralization (C(min)). The MBC content of soil increased with time up to 30 days in cartap hydrochloride as well as chlorpyrifos treated soil. Thereafter, it decreased and reached close to the initial level by 90th day. However, in carbendazim treated soil, the MBC showed a decreasing trend up to 45 days and subsequently increased up to 90 days. In pretilachlor treated soil, MBC increased through the first 15 days, and thereafter decreased to the initial level. Application of carbendazim, chlorpyrifos and cartap hydrochloride decreased C(min) for the first 30 days and then increased afterwards, while pretilachlor treated soil showed an increasing trend.

Abstract The study investigates trend in extreme daily precipitation and temperature over coastal Odisha, India. 18 weather indices (8 related to temperature and 10 related to rainfall) were calculated using RClimDex software package for the period 1980–2010. Trend analysis was carried out using linear regression and non-parametric Mann-Kendall test to find out the statistical significance of various indices. Results indicated, a strong and significant trend in temperature indices while the weak and non-significant trend in precipitation indices. The positive trend in Tmax mean, Tmin mean, TN90p (warm nights), TX90p (warm days), diurnal temperature range (DTR), warm spell duration indicator (WSDI), consecutive dry days (CDD) indicates increasing the frequency of warming events in coastal Odisha. Similarly, positive trend in highest maximum 1-day precipitation (RX1), highest maximum 2 consecutive day precipitation (RX2), highest maximum 3 consecutive day precipitation (RX3), highest maximum 5 consecutive day precipitation (RX5), number of heavy precipitation days (≥ 64.5mm), number of very heavy precipitation days (≥ 124.5mm) and negative trend in the number of rainy days (R2.5mm), consecutive wet days (CWD) indicate changes toward the more intense and poor distribution of precipitation in coastal Odisha. The combined effect of precipitation and temperature extreme events showed negative effects on rice grain yield. With the increasing number of extreme events there was sharp decline in rice grain yield was observed in the same year in all the coastal districts. This study emphasizes the need for new technology/management practice to minimize the impacts of extreme weather events on rice yield.