• Authors:
    • Egbemba, B.
    • Ezeaku, P.
  • Source: African Journal of Biotechnology
  • Volume: 13
  • Issue: 11
  • Year: 2014
  • Summary: The study is aimed at evaluating the effects of compost manure on the remediation of automobile oil waste polluted soils, and on the yield parameters (plant height, leave surface and dry matter weight) of maize ( Manoma spp.). Analyses of soil samples of contaminated and uncontaminated sites collected with core samplers at 10 cm depth and auger samplers at two depths (surface, 0-20 cm; subsurface, 20-40 cm) were examined for chemical and physical properties, including poly aromatic hydrocarbons. Polluted soils were biotreated for testing maize in a greenhouse. Soil physical and chemical properties decreased with depth and were significantly (P1) of heavy metals (for example; Zn, Cu, Mn) was high for maize cultivation. Paradigm approach emphasizing sustainable biological soil systems management is desired. Particularly, bioremediation of oil polluted soils using organic materials, and siting of mechanic villages several kilometers away from major land uses (residential houses, farm lands, and usable water bodies) are important for protecting the soil resources for agricultural purposes, and to ensuring environmental sanity and sustainability.
  • Authors:
    • Villalobos, P.
    • Gabriela Almeida, M.
    • Iriarte, A.
  • Source: Science of the Total Environment
  • Volume: 472
  • Year: 2014
  • Summary: Nowadays, the new international market demands challenge the food producing countries to include the measurement of the environmental impact generated along the production process for their products. In order to comply with the environmentally responsible market requests the measurement of the greenhouse gas emissions of Ecuadorian agricultural goods has been promoted employing the carbon footprint concept Ecuador is the largest exporter of bananas in the world. Within this context, this study is a first assessment of the carbon footprint of the Ecuadorian premium export banana (Musa AAA) using a considerable amount of field data. The system boundaries considered from agricultural production to delivery in a European destination port The data collected over three years permitted identifying the hot spot stages. For the calculation, the CCaLC V3.0 software developed by the University of Manchester is used. The carbon footprint of the Ecuadorian export banana ranged from 0.45 to 1.04 kg CO2-equivalent/kg banana depending on the international overseas transport employed. The principal contributors to the carbon footprint are the on farm production and overseas transport stages. Mitigation and reduction strategies were suggested for the main emission sources in order to achieve sustainable banana production. (C) 2013 Elsevier B.V. All rights reserved.
  • Authors:
    • Polprasert, C.
    • Tangtham, N.
    • Chidthaisong, A.
    • Jaiarree, S.
    • Sarobol, E.
    • Tyler, S.
  • Source: Land Degradation and Development
  • Volume: 25
  • Issue: 2
  • Year: 2014
  • Summary: The effects of compost application on soil carbon sequestration potential and carbon budget of a tropical sandy soil was studied. Greenhouse gas emissions from soil surface and agricultural inputs (fertiliser and fossil fuel uses) were evaluated. The origin of soil organic carbon was identified by using stable carbon isotope. The CO2, CH4 and N2O emissions from soil were estimated in hill evergreen forest (NF) plot as reference, and in the corn cultivation plots with compost application rate at 30 Mg ha(-1) y(-1) (LC), and at 50 Mg ha(-1) y(-1) (HC). The total C emissions from soil surface were 8 center dot 54, 10 center dot 14 and 9 center dot 86 Mg C ha(-1) y(-1) for NF, HC and LC soils, respectively. Total N2O emissions from HC and LC plots (2 center dot 56 and 3 center dot 47 kg N2O ha(-1) y(-1)) were significantly higher than from the NF plot (1 center dot 47 kg N2O ha(-1) y(-1)). Total CO2 emissions from fuel uses of fertiliser, irrigation and machinery were about 10 per cent of total CO2 emissions. For soil carbon storage, since 1983, it has been increased significantly (12 Mg ha(-1)) under the application of 50 Mg ha(-1) y(-1) of compost but not with 30 Mg ha(-1) y(-1). The net C budget when balancing out carbon inputs and outputs from soil for NF, HC and LC soils were +3 center dot 24, -2 center dot 50 and +2 center dot 07 Mg C ha(-1) y(-1), respectively. Stable isotope of carbon (delta C-13 value) indicates that most of the increased soil carbon is derived from the compost inputs and/or corn biomass. Copyright (c) 2011 John Wiley & Sons, Ltd.
  • Authors:
    • Noor, N.
    • Chowhdhury, M. S.
    • Mahmud, K.
    • Huq, S. M. I.
  • Source: Canadian Journal of Pure and Applied Sciences
  • Volume: 8
  • Issue: 2
  • Year: 2014
  • Summary: Addition of biochar to soils has the potentials to reduce the emission of greenhouse gases from soil. The primary objectives of this study were to see the impacts of biochar and the corresponding biomass application on the emission of carbon dioxide (CO 2), carbon monoxide (CO), phosphine (PH 3) and volatile organic compounds (VOCs) from soil investigated in a closed container experiment. Three replications of seven different treatments were applied: (i) soil only (control), soil incorporated with - (ii) rice husk, (iii) biochar produced from rice husk, (iv) straw, (v) biochar from straw, (vi) saw dust and (vii) biochar produced from saw dust. The study reveals that addition of biochar had significant effects (P<0.05) on reducing CO 2 and PH 3 emission while no statistically significant effects on VOCs emanation was evident. Application of biochar could not suppress the CO emissions. Our study indicates that, different types of biochars have different effects on the emission of different gases.
  • Authors:
    • Sanabria, C.
    • Rodriguez, E.
    • Xiomara Pullido, S.
    • Loaiza, S.
    • del Pilar Hurtado, M.
    • Gutierrez, A.
    • Gomez, Y.
    • Chaparro, P.
    • Botero, C.
    • Bernal, J.
    • Arguello, O.
    • Rodriguez, N.
    • Lavelle, P.
    • Velasquez, E.
    • Fonte, S.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 185
  • Year: 2014
  • Summary: In the Orinoco River Basin of eastern Colombia large scale and rapid conversion of natural savannas into commercial agriculture exists as a critical threat for the ecological integrity of this fragile region. The highly acidic and compacted soils inherent to this region require thorough physical and chemical conditioning in order for intensive cropping systems to be established. Assessing the impact of this dramatic soil perturbation on biodiversity, ecosystem services and other elements of the natural capital is an urgent task for designing sustainable management options in the region. To address this need, we evaluated soil macro invertebrate communities and soil-based ecosystem services (climate regulation, hydrologic functions, soil stability provided by macro aggregation and nutrient provision potential) in four major production systems: improved pastures, annual crops (rice, corn and soy bean), oil palm and rubber plantations, and compared them to the original savanna. Fifteen plots of each system were sampled along a 200 km natural gradient of soil and climatic conditions. In each plot, we assessed climate regulation by measuring green house gas emissions (N2O, CH4 and CO2) and C storage in aboveground plant biomass and soil (0-20 cm). Soil biodiversity (macro invertebrate communities) and three other soil-based ecosystem services, were assessed using sets of 12-20 relevant variables associated with each service and synthesized via multivariate analyses into a single indicator for each ecosystem function, adjusted in a range of 0.1-1.0. Savannas yielded intermediate values for most indicators, while each production system appeared to improve at least one ecosystem service. For example, nutrient provision (chemical fertility) was highest in annual cropping systems (0.78 +/- 0.03) due to relatively high concentrations of Ca, Mg, N, K, and available P and low Al saturation. Hydrological functions and climate regulation (C storage and GHG emissions) were generally improved by perennial crops (oil palm and rubber), while indicators for macro invertebrate biodiversity and activity (0.73 +/- 0.05) and soil macro aggregation (0.76 +/- 0.02) were highest within improved pastures. High variability within each system indicates the potential to make improvements in fields with lowest indicator values, while differences among systems suggest the potential to mitigate negative impacts by combining plots with contrasted functions in a strategically designed landscape mosaic. (C) 2014 Elsevier B.V. All rights reserved.
  • Authors:
    • Mendoza, T.
  • Source: International Journal of Agricultural Technology
  • Volume: 10
  • Issue: 1
  • Year: 2014
  • Summary: This study involved estimating the carbon foot print (CF) of sugar production in Eastern Batangas, Philippines whose aims were to identify the "hot spots" of sugar production, to suggest practical options to "cool" these identified hot spots, and to recommend policy options to address the social cost of carbon (SCC). The sources of CF included the detailed operations involved in sugarcane production (plant cane and ratoon) up to milling to produce raw sugar, and the associated CF in cane burning (expressed in CO 2 equivalence). The carbon foot print (CF) of sugarcane production (farm level) was estimated at 5.56 CO 2 t/ha, 16% of total (or 0.067 tCO 2/ton cane) while processing the canes in the mill contributed 47% (16.5 tCO 2), (200 tCO 2/ton cane, 1.98 kg CO 2/kg sugar). The conventional practice of burning canes contributed 37% greenhouse gases at 12.9 tCO 2/ha which led to a considerable increase in CF from 22.03 tCO 2/ha to 34.9 tCO 2/ha or 2.64 to 4.2 kg CO 2/kg sugar. Deducting the equivalent CO 2 sequestered in the soil due to the unburned trash, roots, and stumps retained in the soil as humus - C (at 2.06 t CO 2/ha) decreased the carbon foot print of sugar slightly from 4.2 to 3.98 kg CO 2 per kg sugar. At P13.51/tCO 2, the estimated social cost of carbon (SCC) as year 2011 was PhP 2.34/kg. The SSC of sugar is instructive to (1) the environmental cost of sugar and (2) the needed adjustments in production practices to reduce the sugar carbon foot print in order to ecologically sustain sugarcane production. There is a need to increase the soil organic matter to improve fertilizer use efficiency, soil water-holding capacity, and ultimately increase the energy efficiency of sugar production. N-fertilizer input and cane burning were the two identified major sources of GHG emission. Shifting the conventional production systems to an alternative cane production system where there would be no cane burning and only 50% N-fertilizer would be applied would lead to 40% reduction in CF, from 3.98 to 2.32 kg CO 2 per kg sugar. Accordingly, SCC would decrease from PhP 2.34 to PhP 1.38 per kg sugar. Issuance of a sugar order is necessary to provide the legal basis of charging SCC to the industry key players to fund the programmatic shift of the conventional sugarcane production to an alternative systems to reduce the CF of sugar and to improve the economic viability and the long term sustainability of sugarcane production.
  • Authors:
    • Cerri, C. C.
    • Bernoux, M.
    • Cerri, C. E. P.
    • Frazao, L. A.
    • Raucci, G. S.
    • Nunes Carvalho, J. L.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 183
  • Issue: January
  • Year: 2014
  • Summary: The objective of this study was to quantify the soil greenhouse gas (GHG) balance after the conversion of native vegetation (NV) to pasture and agricultural land and the conversion of agriculture to crop-pasture rotation (CPR) by evaluating changes in C stocks and N2O and CH4 fluxes. Soil sampling was carried out in March 2007 and April 2009 and GHG fluxes were sampled nine times between April 2007 and March 2009. The conversion of NV to pasture and agriculture decreased soil C stocks, with loss rates ranging from 0.25 to 0.64 Mg C ha(-1) yr(-1), respectively. The implementation of CPR in,agriculture areas increased soil C stocks by 0.60 Mg ha(-1) yr(-1). N2O emissions were higher in CPR and lower in NV. Emission of 1.03 kg CH4-C ha(-1) yr(-1) was observed in pasture, while in other areas consumption of CH4 was observed. The net GHG emission from the soil, including all GHG expressed in C-equivalent, indicated that the conversion of NV to pasture and agricultural land results in emissions of 0.54 and 0.72 Mg C ha(-1) yr(-1), respectively. In contrast, the adoption of CPR in areas under crop succession was a sink of 0.36 Mg ha(-1) yr(-1). Among the evaluated land use changes, only the implementation of CPR proved to be a good strategy to mitigate soil GHG emissions in Brazilian Cerrado. (C) 2013 Elsevier B.V. All rights reserved.
  • Authors:
    • Gatere, L.
    • DeClerck, F.
    • Blanco-Canqui, H.
    • Palm, C.
    • Grace, P.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 187
  • Issue: April
  • Year: 2014
  • Summary: Conservation agriculture (CA) changes soil properties and processes compared to conventional agriculture. These changes can, in turn, affect the delivery of ecosystem services, including climate regulation through carbon sequestration and greenhouse gas emissions, and regulation and provision of water through soil physical, chemical and biological properties. Conservation agriculture can also affect the underlying biodiversity that supports many ecosystem services. In this overview, we summarize the current status of the science, the gaps in understanding, and highlight some research priorities for ecosystem services in conservational agriculture. The review is based on global literature but also addresses the potential and limitations of conservation agriculture for low productivity, smallholder farming systems, particularly in Sub Saharan Africa and South Asia. There is clear evidence that topsoil organic matter increases with conservation agriculture and with it other soil properties and processes that reduce erosion and runoff and increase water quality. The impacts on other ecosystem services are less clear. Only about half the 100+ studies comparing soil carbon sequestration with no-till and conventional tillage indicated increased sequestration with no till; this is despite continued claims that conservation agriculture sequesters soil carbon. The same can be said for other ecosystem services. Some studies report higher greenhouse gas emissions (nitrous oxide and methane) with conservation agriculture compared to conventional, while others find lower emissions. Soil moisture retention can be higher with conservation agriculture, resulting in higher and more stable yields during dry seasons but the amounts of residues and soil organic matter levels required to attain higher soil moisture content is not known. Biodiversity is higher in CA compared to conventional practices. In general, this higher diversity can be related to increased ecosystem services such as pest control or pollination but strong evidence of cause and effect or good estimates of magnitude of impact are few and these effects are not consistent. The delivery of ecosystem services with conservation agriculture will vary with the climate, soils and crop rotations but there is insufficient information to support a predictive understanding of where conservation agriculture results in better delivery of ecosystem services compared to conventional practices. Establishing a set of strategically located experimental sites that compare CA with conventional agriculture on a range of soil-climate types would facilitate establishing a predictive understanding of the relative controls of different factors (soil, climate, and management) on ES outcomes, and ultimately in assessing the feasibility of CA or CA practices in different sites and socioeconomic situations. The feasibility of conservation agriculture for recuperating degraded soils and increasing crop yields on low productivity, smallholder farming systems in the tropics and subtropics is discussed. It is clear that the biggest obstacle to improving soils and other ES through conservation agriculture in these situations is the lack of residues produced and the competition for alternate, higher value use of residues. This limitation, as well as others, point to a phased approach to promoting conservation agriculture in these regions and careful consideration of the feasibility of conservation agriculture based on evidence in different agroecological and socioeconomic conditions.
  • Authors:
    • Huang, Y.
    • Sun, W.
    • Li, T.
    • Yu, Y.
    • Zhang, W.
  • Source: Environmental Science & Technology
  • Volume: 48
  • Issue: 5
  • Year: 2014
  • Summary: Cropland soils have been shown to emit nitrous oxide (N2O) and methane (CH4) into the atmosphere and to sequester carbon when field management is improved, yet the spatiotemporal changes in the N2O and CH4 emissions and the soil organic carbon (SOC) in China's croplands are unclear with regard to an integrated global warming potential (GWP). This limits our overall evaluation of anthropogenic greenhouse gas (GHG) emissions and impairs effective decision making. On the basis of model simulations primarily from 1980 to 2009, we estimated a 69% increase in the gross GWP of CH4 and N2O emissions, from 244 Tg CO2-equiv yr(-1) in the early 1980s to 413 Tg CO2-equiv yr(-1) in the late 2000s. The SOC was estimated to have increased from 54 Tg CO2-equiv yr(-1) to 117 Tg CO2-equiv yr(-1) during the same period. A reduction in the carbon input during the rice season, along with an improvement of synthetic nitrogen use efficiency in crops to 40%, would mitigate GHG emissions by 111 Tg CO2-equiv yr(-1) and keep SOC sequestration at 82 Tg CO2 yr(-1). Together, this would amount to a reduction of 193 Tg CO2-equiv yr(-1), representing similar to 47% of the gross GWP in the late 2000s. The mitigation of GHG emissions in Henan, Shandong, Hunan, Jiangsu, Hubei, Sichuan, Anhui, Jiangxi, Guangdong and Hebei Provinces could lead to a similar to 66% national improvement and should be given priority.
  • Authors:
    • El-Sharkawy, M.
  • Source: Photosynthetica
  • Volume: 52
  • Issue: 2
  • Year: 2014
  • Summary: Earth's climate has experienced notable changes during the past 50-70 years when global surface temperature has risen by 0.8°C during the 20th century. This was a consequence of the rise in the concentration of biogenic gases (carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and ozone) in the atmosphere that contribute, along with water vapor, to the so-called 'greenhouse effect'. Most of the emissions of greenhouse gases have been, and still are, the product of human activities, namely, the excessive use of fossil energy, deforestations in the humid tropics with associated poor land use-management, and wide-scale degradation of soils under crop cultivation and animal/pasture ecosystems. General Circulation Models predict that atmospheric CO 2 concentration will probably reach 700 mol(CO 2) mol -1. This can result in rise of Earth's temperature from 1.5 to over 5°C by the end of this century. This may instigate 0.60-1.0 m rise in sea level, with impacts on coastal lowlands across continents. Crop modeling predicts significant changes in agricultural ecosystems. The mid- and high-latitude regions might reap the benefits of warming and CO 2 fertilization effects via increasing total production and yield of C 3 plants coupled with greater water-use efficiencies. The tropical/subtropical regions will probably suffer the worst impacts of global climate changes. These impacts include wide-scale socioeconomic changes, such as degradation and losses of natural resources, low agricultural production, and lower crop yields, increased risks of hunger, and above all waves of human migration and dislocation. Due to inherent cassava tolerance to heat, water stress, and poor soils, this crop is highly adaptable to warming climate. Such a trait should enhance its role in food security in the tropics and subtropics.