Estimation of Methane Emission Potentials in Landmark University Open Dump Site, Omu-Aran, Kwara State Nigeria

Most of the increasing quantity of wastes in institutions of higher learning, are disposed of through open dumping. The decomposition of these wastes has been identified to be a source of methane emissions. This study estimated methane emissions from the open dumpsite in Landmark University. An exploratory study design was adopted. The study involved physical characterization of solid wastes at the Landmark University for a period of three months and the estimation of methane emission potentials of the dumpsite for the years 2011 to 2031 using IPCC Default Method (DM) and the Landfill Gas Emission (LandGEM) Model Version 3.02.The study revealed the percentage composition of waste to be 48, 16, 12, 10, 5 and 3% for plastics, garden trimmings, paper, metal, food waste and textile respectively. The maximum methane emission is 11.65 and 2.48 Mg/year for DM and LandGEM respectively in the year 2021 while the methane emissions will decline to 7.06 and 1.50 Mg/year for DM and LandGEM respectively in the year 2031. The contribution of methane emissions in the University is still little as reflected in the values of 11.65 and 2.48 Mg/year although there is a tendency to increase as population increases. Further studies should be carried out to provide methane specific properties of the solid waste generated in Omu-Aran in order to build an inventory of methane emission parameters.

Nitrous oxide and methane emissions from cattle manure heaps in Kenya

<p>Agricultural greenhouse gas (GHG) emissions in Africa contribute 15 % to the global total agricultural emissions, which is in the same range as agricultural emissions from Europe. The majority of these agricultural GHG emissions is attributed to livestock farming (up to 80 % at national scale), of which 10-25 % originate from livestock manure. At the same time, livestock production is essential for the livelihoods of millions of people in Sub-Saharan Africa (SSA), where 45-80 % of livestock production occurs in smallholder systems. With the growing population in SSA, the demand for livestock products is expected to increase, and – without low-emission manure management – a rise in manure-borne GHG emissions will occur. However, reliable <em>in situ</em> measurements from SSA are scarce, leading to substantial uncertainties in agricultural GHG budgets and making assessments of potential mitigation options difficult.</p><p>Here we present results from two cattle manure incubation experiments in Kenya, using manure from Boran (<em>Bos indicus</em>) cattle, a breed common in East Africa that were fed with typical feeds used in SSA smallholder farms. Manure was collected and piled in heaps (solid storage), the most common form of manure storage in Kenyan smallholder systems, and CH<sub>4</sub> and N<sub>2</sub>O emissions were measured over 140 days. In the first trial, cattle were fed a diet that either met their maintenance-energy requirements (i.e. animals received enough food to support their metabolism), or a diet at sub-maintenance energy levels to simulate common conditions in smallholder farming systems, particularly during the dry seasons. Cumulative manure N<sub>2</sub>O emissions from the sub-maintenance diet (i.e. the “hungry” cows) were lower than from cattle fed at maintenance energy levels. These lower N<sub>2</sub>O emission likely resulted from lower N concentration and a wider C:N ratio in the manure than in the “better fed” animals. Furthermore, the urine-N:faecal-N ratio in the “hungry” cows decreased, indicating a shift from urine-N (mostly inorganic N) to faecal-N (mostly organic N), which further backs the lower observed N<sub>2</sub>O emissions. Both N<sub>2</sub>O as well as CH<sub>4</sub> emissions from manure were lower than the IPCC default emission factors for solid storage in tropical regions across all diets tested.</p><p>In the second trial, Boran cattle were fed with three different tropical forage grasses common in Kenya: Napier (<em>Pennisetum purpureum</em>), Rhodes (<em>Gloris gayana</em>), and Brachiaria (<em>Brachiaria brizantha</em>). Manure from the Rhodes grass diet had the lowest N concentration and also the lowest cumulative CH<sub>4</sub> emissions, while N<sub>2</sub>O emissions did not differ between diets. Similar to the sub-maintenance feeding trial, total CH<sub>4</sub> and N<sub>2</sub>O emissions were lower than the IPCC default factors. Taken together, these results are an important step towards reducing the uncertainties in GHG emissions from agriculture in SSA. Furthermore, if African nations use IPCC default values for their national GHG reporting on livestock, emissions are likely to be overestimated, highlighting the importance and benefits of localized data from Africa.</p>

Assessing nitrous oxide emissions from European peatlands at variable degradation status and land use to improve national GHG inventories

<p>Nitrous oxide (N<sub>2</sub>O) is 300 times more potent than carbon dioxide in atmospheric warming and it is the main driver of stratospheric ozone depletion. The N<sub>2</sub>O emissions from peatlands are often estimated by applying published IPCC default emission factors, neglecting the stages of peat degradation. Here, we introduce soil bulk density (BD) as a proxy for peat degradation to estimate N<sub>2</sub>O emissions. A synthesis of soil physical and geochemical data from global boreal and temperate peatlands revealed a strong relationship between BD and annual N<sub>2</sub>O emissions (R2=0.56, p<0.001), and the BD was superior to other parameters (C/N, pH) in estimating annual N<sub>2</sub>O emissions. The results indicate that the more a peat soil is degraded, and the larger the values for BD are the larger the risk of N<sub>2</sub>O emission in peaty landscapes. Even after rewetting, highly degraded soils may exhibit large N<sub>2</sub>O release rates. A BD distribution map of European peatlands was generated and the estimated annual N<sub>2</sub>O-N emissions from European peatlands sum up to approximately 46.9 Gg. In conclusion, this research shows that explicitly accounting for the stage of peat degradation as expressed in measured BD values gives reliable N<sub>2</sub>O emission estimates from peatlands on a national scale.</p>

Methane Flux Estimation in MSW Open Dump Site by In-Situ Measurement and IPCC (DM and FOD) Model

This paper deals with the use of different methods to predict methane generation on an open dump site. Methane recovery data obtained on site as part of a research program being carried out at the Devguradia dumpsite, Indore, is analyzed and used to obtain field methane emission in three seasons. Field data from Municipal solid waste (MSW) dump site are presented and discussed measured in-situ technique i.e. using close chamber methods. The Intergovernmental Panel on Climate Change (IPCC) Default Method (DM) and First order Decay (FOD) method is used to estimate methane generation. It is found that despite the assumptions and the simplicity of the adopted procedures, the values methane obtained are slightly varying to those measured in the field. The values obtained were 4.5, 2.9 and 0.35 Gg/y respectively.

Quantifying N2O emissions from intensive grassland production: the role of synthetic fertilizer type, application rate, timing and nitrification inhibitors

SUMMARYIncreasing recognition of the extent to which nitrous oxide (N2O) contributes to climate change has resulted in greater demand to improve quantification of N2O emissions, identify emission sources and suggest mitigation options. Agriculture is by far the largest source and grasslands, occupying c. 0·22 of European agricultural land, are a major land-use within this sector. The application of mineral fertilizers to optimize pasture yields is a major source of N2O and with increasing pressure to increase agricultural productivity, options to quantify and reduce emissions whilst maintaining sufficient grassland for a given intensity of production are required. Identification of the source and extent of emissions will help to improve reporting in national inventories, with the most common approach using the IPCC emission factor (EF) default, where 0·01 of added nitrogen fertilizer is assumed to be emitted directly as N2O. The current experiment aimed to establish the suitability of applying this EF to fertilized Scottish grasslands and to identify variation in the EF depending on the application rate of ammonium nitrate (AN). Mitigation options to reduce N2O emissions were also investigated, including the use of urea fertilizer in place of AN, addition of a nitrification inhibitor dicyandiamide (DCD) and application of AN in smaller, more frequent doses. Nitrous oxide emissions were measured from a cut grassland in south-west Scotland from March 2011 to March 2012. Grass yield was also measured to establish the impact of mitigation options on grass production, along with soil and environmental variables to improve understanding of the controls on N2O emissions. A monotonic increase in annual cumulative N2O emissions was observed with increasing AN application rate. Emission factors ranging from 1·06–1·34% were measured for AN application rates between 80 and 320 kg N/ha, with a mean of 1·19%. A lack of any significant difference between these EFs indicates that use of a uniform EF is suitable over these application rates. The mean EF of 1·19% exceeds the IPCC default 1%, suggesting that use of the default value may underestimate emissions of AN-fertilizer-induced N2O loss from Scottish grasslands. The increase in emissions beyond an application rate of 320 kg N/ha produced an EF of 1·74%, significantly different to that from lower application rates and much greater than the 1% default. An EF of 0·89% for urea fertilizer and 0·59% for urea with DCD suggests that N2O quantification using the IPCC default EF will overestimate emissions for grasslands where these fertilizers are applied. Large rainfall shortly after fertilizer application appears to be the main trigger for N2O emissions, thus applicability of the 1% EF could vary and depend on the weather conditions at the time of fertilizer application.

FATOR DE EXPANSÃO DE BIOMASSA E RAZÃO DE RAÍZES -PARTE AÉREA PARA Pinus spp. PLANTADAS NO SUL DO BRASIL

ResumoO fator de expansão da biomassa (FEB) e a razão de raízes (R) são usados na quantificação de carbono em florestas. Geralmente essas grandezas são consideradas constantes. 70 árvores foram usadas para demonstrar a correlação entre FEB e R e as variáveis dendrométricas e a idade. Doze modelos foram testados para FEB e R, e DAP, altura (H) e idade. Foram estimados biomassa seca total, carbono e equivalente em CO2, com FEB e R default, valores médios e valores via equações. Obtiveram-se valores de FEB = 1,47 e de R = 0,17, o que significa que 47% da biomassa aérea correspondem à copa e 17% da biomassa total são raízes. A correlação entre FEB e R com as variáveis DAP, H e idade apresentaram-se significativos. As equações geradas foram eleitas como de melhor desempenho, tanto para FEB como para R. A comparação mostrou que o uso de valores fixos de FEB e R, seja o default do IPCC ou valores médios calculados com dados de campo, pode conduzir a erros. Concluiu-se que devem ser considerados FEB e R em função de variáveis dendrométricas DAP e H e idade, para se ter estimativas mais fidedignas da biomassa, do carbono fixado e do carbono equivalente em CO2.AbstractBiomass expansion factor and root-to-shoot ratio for Pinus spp. in southern Brazil. Biomass expansion factor (BEF) and root-to-shoot ratio (R) are variables for quantification of carbon in forests. These are considered as constant values in most studies. 70 sample trees were used to BEF and R, and DBH, tree height and age. Dry total biomass, carbon and CO2 equivalent were simulated by using the IPCC default values of FEB and R, corresponding average calculated from data using in this study and as well as the values estimated by regression equations. The values of FEB=1.47 and R=0.17 in this study means that 47% of total biomass corresponds to tree crown and 17% of it comprises tree roots or below-ground biomass. The correlation BEF and R with tree DAP, H and age were significant. Some equations to FEB and R as functions of the tree variables revealed better performance than others, as they fitted better. The simulations indicated that use of fixed values of BEF and R, either IPCC default or average actual data may lead to unreliable of carbon and CDM projects. As result, FEB and R use in regression equations relating them to DBH, tree height and age are fundamental to get reliable estimates of tree biomass, carbon sink and CO2 equivalent.Keywords: Allometry; carbon; regression; CDM; modeling.