• Authors:
    • Rati Mukteshawar
    • Shehrawat,P. S.
  • Source: Annals of Biology
  • Volume: 31
  • Issue: 1
  • Year: 2015
  • Summary: As we know, that agriculture has been an important profession for Indian as well as for the people of the world. The world's population is growing at an alarming rate with corresponding increase in demand for food goods and natural resources, so it directly burdens the agriculture to meet the consumption needs, farmers really more depend upon inorganic farm inputs. As a consequence of increase in inorganic farm inputs consumption, vast quantities of gases and effluents are discharged that may change the climate composition of the atmosphere and its capacity to regulate its temperature that's why world agriculture is facing numerous newly emerged challenges, the most prominent challenges are such as climate change and effect of greenhouse gases on agricultural practice. Mostly scientists now agree that rising atmospheric concentrations of GHG threaten to have severe impacts on food production, natural ecosystems and human health. Now-a-days, the agricultural scientists and extension clienteles have preference for demand driven and participatory approaches. The need to provide up-to-date information by the extension workers regarding to causes of GHG emissions and how it affects the agricultural production. Due and focuses efforts have to be made regarding the transfer of new agricultural technologies efficiently and effectively. A total number of eight villages were selected randomly. From each village, 15 farmers were selected randomly. Hence, a total number of 120 farmers were interviewed. The study revealed that farmers had awareness about GHG (65.00%), followed by knowledge about GHG (39.16%), major source of GHG emissions (73.33%), livestock also emit GHG (35.83%) and losses due to GHG in agriculture (68.33%). Whereas farmers were not aware regarding attending any meeting/workshop/training regarding sequestration of GHG (67.50%), farmers changed their cropping patterns (50.00%) and observation regarding deterioration in quality of crop produce (42.50%). The study further revealed that farmers were found agreed about change in current farm management practices (85.00%), change in season length (89.16%), altering the farming practices of field operations (97.50%), change in seasonal temperature (91.66%), changes in time of precipitation (82.00%), increase in flood and drought (72.50%) and 'fluctuation in ground water table' (88.33%). Whereas farmers were found undecided about emission of GHG which is not a problem for agricultural practices (82.50%), no effect of GHG emission on crop production (64.16%) and no effect of GHG emission on livestock production (70.00%). Farmers' were found disagreed regarding no effect of GHG emission on bio-diversity (33.33%), change in timing of precipitation (17.50%) and increase the incidence of falling hail (14.16%).
  • Authors:
    • Smith,E. G.
    • Janzen,H. H.
    • Larney,F. J.
  • Source: Canadian Journal of Soil Science
  • Volume: 95
  • Issue: 2
  • Year: 2015
  • Summary: Long-term cropping system studies offer insights into soil management effects on agricultural sustainability. In 1995, a 6-yr bioassay study was superimposed on a long-term crop rotation study established in 1951 at Lethbridge, Alberta, to determine the impact of past cropping systems on soil quality, crop productivity, grain quality, and the relationship of yield productivity to soil quality. All plots from 13 long-term crop rotations were seeded to wheat ( Triticum aestivum L.) in a strip plot design [control, nitrogen (N) fertilizer]. Prior to seeding, soils were sampled to determine soil chemical properties. Total wheat production for the last 4 yr of the study was used as the measure of productivity. The 1995 soil analysis indicated crop rotations with less frequent fallow and with N input had higher soil quality, as indicated by soil organic carbon (SOC) and light fraction carbon (LF-C) and N (LF-N). SOC had a positive relationship to total wheat yield, but was largely masked by the application of N in this bioassay study. Frequent fallow in the previous crop rotation lowered productivity. The concentration of LF-C had a negative relationship, whereas LF-N had a positive relationship to total wheat yield, with and without N fertilization in this bioassay study. Grain N concentration was higher with applied N and when the long-term rotation included the addition of N by fertilizer, livestock manure, annual legume green manure or legume hay. This study determined that long-term imposition of management practices have lasting effects on soil quality and crop productivity.
  • Authors:
    • Yoshida,H.
    • Nielsen,M. P.
    • Scheutz,C.
    • Jensen,L. S.
    • Christensen,T. H.
    • Nielsen,S.
    • Bruun,S.
  • Source: Acta Agriculturae Scandinavica, Section B — Soil & Plant Science
  • Volume: 65
  • Issue: 6
  • Year: 2015
  • Summary: Application of sewage sludge on agricultural land becomes more and more common in many parts of the world in order to recycle the nutrients from the sludge. A range of sewage sludge stabilization techniques are available to make the sludge more stable prior to storage, transportation, and application. These stabilization techniques include dewatering, drying, anaerobic digestion, composting, and reed bed sludge treatment. However, very few studies have investigated the effect of these techniques after the sludge has been applied to agricultural land. The objective of the current study was therefore to investigate the effect of sewage sludge stabilization techniques on the C and N mineralization and gaseous emissions from soil. A soil incubation was conducted to determine the rate of C and N mineralization and N 2O and CH 4 emissions of sewage sludge stabilized using different techniques. Unstabilized sludge released up to 90% of their C content as CO 2, part of which could be caused by release of CO 2 from carbonates. Compared with this, sludge stabilization including anaerobic digestion and drying resulted in a reduction of the C mineralization rate of about 40%. Liming reduced C mineralization with around 29%, while treatment in a reed bed system reduced it by 74%. The current study thus clearly demonstrated that stabilization techniques resulted in sludge that was more stable once they were applied to agricultural land. Stabilization also reduced the N immobilization phase, potentially improving the value of the sludge as a fertilizer. Emissions of CH 4 were also reduced through sludge stabilization and mainly occurred after application of easily degradable sludge types, which is likely to have enhanced the creation of anaerobic microsites. The stabilization processes also decreased emissions of N 2O. The results for both CH 4 and N 2O indicate that the stabilization tends to reduce the chance of developing conditions where these gases could be produced.
  • Authors:
    • Buentgen,Ulf
    • Tegel,Willy
    • Carrer,Marco
    • Krusic,Paul J.
    • Hayes,Michael
    • Esper,Jan
  • Source: Climatic Change
  • Volume: 131
  • Issue: 2
  • Year: 2015
  • Summary: Wetter et al. (2014; hereinafter W14) conclude that western Europe experienced significantly higher temperatures in AD 1540 compared to all other years in the instrumental record, including the summer heat waves of 2003 and 2010 (Schar et al. 2004; Barriopedro et al. 2011). Based on 300+ first-hand documentary weather reports, the authors argue that large parts of Europe were hit by an unprecedented, 11-month-long, 'Megadrought' in 1540 exceeding all recorded and reconstructed levels, and falling outside the probability range of state-of-the-art palaeoclimate model simulations. Despite compiling, transforming and interpreting an exceptional pool of documentary evidence, W14 neglected to systematically analyse the existing collection of European tree ring-based climate reconstructions. An independent comparison of their findings from societal entries against natural proxy archives, however, would have been beneficial. For example, Pauling et al. (2006), already identified low precipitation amounts in 1540 derived mainly from tree-ring analyses, a study not cited in W14. In this reply we look into some of the tree-ring data available back to 1540 and before, and demonstrate that W14's conclusion regarding the inability of natural proxy archives to record climate extremes is not defensible.
  • Authors:
    • Fernandez-Llamazares,Alvaro
    • Elena Mendez-Lopez,Maria
    • Diaz-Reviriego,Isabel
    • McBride,Marissa F.
    • Pyhala,Aili
    • Rosell-Mele,Antoni
    • Reyes-Garcia,Victoria
  • Source: Climatic Change
  • Volume: 131
  • Issue: 2
  • Year: 2015
  • Summary: Indigenous societies hold a great deal of ethnoclimatological knowledge that could potentially be of key importance for both climate change science and local adaptation; yet, we lack studies examining how such knowledge might be shaped by media communication. This study systematically investigates the interplay between local observations of climate change and the reception of media information amongst the Tsimane', an indigenous society of Bolivian Amazonia where the scientific discourse of anthropogenic climate change has barely reached. Specifically, we conducted a Randomized Evaluation with a sample of 424 household heads in 12 villages to test to what degree local accounts of climate change are influenced by externally influenced awareness. We randomly assigned villages to a treatment and control group, conducted workshops on climate change with villages in the treatment group, and evaluated the effects of information dissemination on individual climate change perceptions. Results of this work suggest that providing climate change information through participatory workshops does not noticeably influence individual perceptions of climate change. Such findings stress the challenges involved in translating between local and scientific framings of climate change, and gives cause for concern about how to integrate indigenous peoples and local knowledge with global climate change policy debates.
  • Authors:
    • Ingrao,Carlo
    • Rana,Roberto
    • Tricase,Caterina
    • Lombardi,Mariarosaria
  • Source: Applied Energy
  • Volume: 149
  • Year: 2015
  • Summary: Over the last few years, agro-biogas has been receiving great attention since it enables replacement of natural gas, thereby representing a tool which reduces greenhouse gas emissions and other environmental impacts. In this context, this paper is aimed at the application of the Carbon Footprint (CF) to an agro-biogas supply chain (SC) in Southern Italy, according to ISO/TS 14067:2013, so as to calculate the related 100-year Global Warming Potential (GWP(100)). The topic was addressed because agro-biogas SCs, though being acknowledged worldwide as sustainable ways to produce both electricity and heat, can be source of GHG emissions and therefore environmental assessments and improvements are needed. Additionally, the performed literature review highlighted deficiencies in PCF assessments, so this study could contribute to enriching the international knowledge on the environmental burdens associated with agro-biogas SCs. The analysis was conducted using a life-cycle approach, thus including in the assessment: functional unit choice, system border definition and inventory analysis development. The primary data needed was provided by a farm located in the province of Foggia (Apulia region in Southern Italy), already equipped with anaerobic digestion and cogeneration plant for biogas production and utilisation. Results from this study are in agreement with those found by some of the most relevant studies in the sector. Indeed, it was possible to observe that GWP100 was almost entirely due to cropland farming and, in particular, to the production of ammonium nitrate in the amount required for fertilisation. Furthermore, environmental credits were observed thanks to: carbon sequestration enabled by no-tillage practice; and avoided production of chemical fertiliser thanks to 50% organic farming. Based upon the results obtained, a sensitivity analysis was carried out, thus highlighting reduced environmental impacts if ammonium nitrate was replaced with urea. Finally, thanks to this study, all the target stakeholders will learn more about the input/output flows involved in the system analysed, the related environmental impacts and the improvements needed to reduce them. In this way, it could be possible to compare the analysed agro-biogas SC with others of equal functionality, and so to enable considerations to be made on the resulting similarities and differences in terms of methodological approach, inventory flows and environmental impact. (C) 2015 Elsevier Ltd. All rights
  • Authors:
    • Miao ShuJie
    • Qiao YunFa
    • Zhang FuTao
  • Source: Polish Journal of Environmental Studies
  • Volume: 24
  • Issue: 3
  • Year: 2015
  • Summary: In converting cropland to grassland and forest, more carbon is sequestered in grassland soil and forest biomass, but the mitigation of global warming potential (GWP) is not clear. In this study, we use the longterm conversion from cropland to grassland (28 y) and forest (14 y) to comprehensively assess the impact on GWP of soil carbon (C), nitrogen (N), CO 2, and N 2O emissions. The results showed that compared to the original cropland, conversion to grassland increased soil C content by 51.1%, soil N content by 28.4%, soil C stock (SCS) by four times, CO 2 emission by 17%, and N 2O emission by 40%; soil N stock (SNS) decreased by half. The corresponding values after afforestation were 7.2%, 5.2%, three times, 3%, -80%, and half, respectively. Overall GWP in the cropland system was calculated using the fuel used for farming production, the change in soil C, and N 2O emissions. Due to large C sequestration, the GWP of conversion to grassland (-1667 kg CO 2-C equivalent ha -1.y -1) and forest (-324 kg CO 2-C equivalent ha -1.y -1) were significantly lower than the cropland system (755 kg CO 2-C equivalent ha -1.y -1). The relationship between GWP and greenhouse gas, between GWP and the change of total C and N, suggest that in rain-fed agricultural systems in northeast China, the conversion from cropland to grassland and forest can mitigate GWP through changing CO 2 and N 2O emissions.
  • Authors:
    • Möller,K.
  • Source: Agronomy for Sustainable Development
  • Volume: 35
  • Issue: 3
  • Year: 2015
  • Summary: Sustainability in agriculture means the inclusion of several aspects, as sustainable agriculture systems must not compromise not only their ability to satisfy future needs by undermining soil fertility and the natural resource base but also sustainable agriculture has had to address a range of other issues including energy use, efficient use, and recycling of nutrients, the effects on adjacent ecosystems including the effects on water bodies and climate change. Organic manures are an important factor to keep the soil fertility level of soils. However, their management is often related to large emissions. In this context, anaerobic digestion is—similarly to composting—a treatment option for stabilization of biogenic wastes leading to a residual product called digestates, enabling the sanitation and the recycling and use as fertilizer. It is also a means to obtain energy from wastes as well as from dedicated energy crops. Therefore, anaerobic digestion potentially addresses several aspects of agricultural sustainability. This review discusses the current state of knowledge on the effects of anaerobic digestion on organic compounds in digestates and the most important processes influencing N emissions in the field, as well as the possible long-term effects on soil microbial biomass and soil fertility. The main findings are that (1) the direct effects of anaerobic digestion on long-term sustainability in terms of soil fertility and environmental impact at the field level are of minor relevance. (2) The most relevant effects of anaerobic digestion on soil fertility as well as on N emissions will be expected from indirect effects related to cropping system changes such as changes in crop rotation, crop acreage, cover cropping, and total amounts of organic manures including digestates. Furthermore, (3) the remaining organic fraction after anaerobic digestion is much more recalcitrant than the input feedstocks leading to a stabilization of the organic matter and a lower organic matter degradation rate after field application, enabling a similar reproduction of the soil organic matter as obtained by direct application of the feedstock or by composting of the feedstock. (4) Regarding emissions, the main direct effect of anaerobic digestion on a farm level is the influence on gaseous emissions during manure or digestate treatment and handling, whereas the direct effects of anaerobic digestion on a field level on emissions (NH3− and N2O− emissions, NO3- leaching) are negligible or at least ambiguous. (5) The main direct effects of anaerobic digestion on the field level are short-term effects on soil microbial activity and changes in the soil microbial community. Therefore, in terms of the effects on agricultural sustainability, potential cropping system-based changes induced by introduction of biogas plants are probably much more relevant for the overall performance and sustainability of the cropping system than the direct effects triggered by application of digestates in comparison to the undigested feedstocks. Furthermore, to get the full potential advances from implementation of biogas plants in terms of improvement of the nutrient use efficiency and reduction of greenhouse gas emissions, there is the need to introduce more sophisticated techniques to avoid counteracting effects by pollution swapping, e.g., by gas-tight closure of the digestate stores and direct soil incorporation of the field-applied digestates. © 2015, INRA and Springer-Verlag France.
  • Authors:
    • Monier,Erwan
    • Gao,Xiang
  • Source: Climatic Change
  • Volume: 131
  • Issue: 1
  • Year: 2015
  • Summary: In this study, we analyze changes in extreme temperature and precipitation over the US in a 60-member ensemble simulation of the 21st century with the Massachusetts Institute of Technology (MIT) Integrated Global System Model-Community Atmosphere Model (IGSM-CAM). Four values of climate sensitivity, three emissions scenarios and five initial conditions are considered. The results show a general intensification and an increase in the frequency of extreme hot temperatures and extreme precipitation events over most of the US. Extreme cold temperatures are projected to decrease in intensity and frequency, especially over the northern parts of the US. This study displays a wide range of future changes in extreme events in the US, even simulated by a single climate model. Results clearly show that the choice of policy is the largest source of uncertainty in the magnitude of the changes. The impact of the climate sensitivity is largest for the unconstrained emissions scenario and the implementation of a stabilization scenario drastically reduces the changes in extremes, even for the highest climate sensitivity considered. Finally, simulations with different initial conditions show conspicuously different patterns and magnitudes of changes in extreme events, underlining the role of natural variability in projections of changes in extreme events.
  • Authors:
    • Monteleone,M.
    • Garofalo,P.
    • Cammerino,A. R. B.
    • Libutti,A.
  • Source: Italian Journal of Agronomy
  • Volume: 10
  • Issue: 2
  • Year: 2015
  • Summary: Climate change mitigation is the most important driving force for bioenergy development. Consequently, the environmental design of bioenergy value chains should address the actual savings of both primary energy demand and greenhouse gases (GHG) emissions. According to the EU Renewable Energy Directive (2009/28/EC), no direct impacts and no GHG emissions should be attributed to crop residues (like cereal straws) when they are removed from agricultural land for the purpose of bioenergy utilisation. The carbon neutral assumption applied to crop residues is, however, a rough simplification. Crop residues, indeed, should not be viewed simply as a waste to be disposed, because they play a critical role in sustaining soil organic matter and therefore have an inherent C-capturing value. Moreover, considering straws as an energy feedstock, its status of co-product is clearly recognised and its availability could be obtained according to different cropping systems, corresponding to different primary energy costs and GHG emissions. This paper highlights some hidden features in the assessment of agricultural energy and carbon balance, still very difficult to be detected and accounted for. Although they are frequently disregarded, these features (such as long term dynamic trend of soil organic carbon and annual nitrous oxide emissions from the soil) should be carefully considered in assembling the energy and emission balance. By using a crop simulation model, the long-term soil organic matter and annual N2O soil emissions were estimated. Consequently, a comprehensive energy and GHG balance was determined in accordance with the life cycle assessment methodology. Contrasting methods of straw management and wheat cultivation were compared: straw retention vs removal from the soil; conventional vs conservation tillage; wheat cropping system as a single-crop or in rotation. The resulting carbon footprint of straws has different magnitudes with respect to the several experimental conditions. By selecting the best agricultural practices, energy from straw can be optimally coupled with grain productions, without detrimental effects on soil fertility. An improved and specifically tailored cropping system is designed to obtain an optimal trade-off. © M. Monteleone et al., 2015.