• Authors:
    • De Nocker, L.
    • Aertsens, J.
    • Gobin, A.
  • Source: Land Use Policy
  • Volume: 31
  • Year: 2013
  • Summary: Purpose: This paper aims at indicating the potential of agricultural measures in sequestering carbon as an option for climate change mitigation. The related value for society is estimated. Principle results: Agricultural practices like agroforestry, introducing hedges, low and no tillage and cover crops have an important potential to increase carbon sequestration. The total technical potential in the EU-27 is estimated to be 1566 million tonnes CO2-equivalent per year. This corresponds to 37% of all CO2-equivalent emissions in the EU in 2007. The introduction of agroforestry is the measure with the highest potential, i.e. 90% of the total potential of the measures studied. Taking account only of the value for climate change mitigation, the introduction of agroforestry is estimated to have a value of 282 euro/ha in 2012 that will gradually increase to 1007 euro/ha in 2030. Major conclusions: This implies that there is a huge potential which represents an important value for society in general and for the agricultural sector in specific. At the European level, only in the last few years policy makers have recognized the important benefits of agroforestry. In their rural development programmes some European countries now support farmers to introduce agroforestry. But still the current level of support is only a small fraction of the societal value of agroforestry. If this value would be fully recognized by internalizing the positive externality, we expect that agroforestry will be introduced to a very large extent in the next decades, in Europe and the rest of the world, and this will importantly change the rural landscapes. (C) 2012 Elsevier Ltd. All rights reserved.
  • Authors:
    • Jair Andrade, H.
    • Alvarado, J.
    • Segura, M.
  • Source: Revista Colombia Forestal
  • Volume: 16
  • Issue: 1
  • Year: 2013
  • Summary: The increase in greenhouse gas emissions from anthropogenic sources has resulted in climate change, which affects all living beings. Coffee (Coffea arabica L.) plantations, in monoculture or together with timber species such as salmwood (Cordia alliodora), mitigate climate change due to fixation of atmospheric CO 2 that is deposited in biomass and soils. This study was carried out in the municipality of Libano, Tolima, Colombia with the objective of defining which of the following coffee production systems store more soil organic carbon (SOC): (1) monoculture, (2) agroforestry systems (AFS) with salmwood, and (3) AFS with plantain. Farms with those systems that are the most dominant in the study zone were selected. From each system, five repetitions were identified to be analyzed with a completely randomized design. In each plot or repetition, five samples for bulk density (BD) using the cylinder method and a composite sample for concentration of SOC were taken and analyzed using the Walkley and Black approach. The systems of production did not significantly (p >0.05) affect either the BD or the concentration of SOC. However, AFS with plantain tended to have less BD than monoculture and AFS with salmwood (0.830.03 vs 0.880.03 vs 0.920.04 g.cm -3, respectively). These systems of production stored between 50 and 54 t.ha -1 of SOC in the top 30 cm, which indicates their capacity for climate change mitigation.
  • Authors:
    • Priesack, E.
    • Palosuo, T.
    • Osborne, T. M.
    • Olesen, J. E.
    • O'Leary, G.
    • Nendel, C.
    • Kumar, S. Naresh
    • Mueller, C.
    • Kersebaum, K. C.
    • Izaurralde, R. C.
    • Ingwersen, J.
    • Hunt, L. A.
    • Hooker, J.
    • Heng, L.
    • Grant, R.
    • Goldberg, R.
    • Gayler, S.
    • Doltra, J.
    • Challinor, A. J.
    • Biernath, C.
    • Bertuzzi, P.
    • Angulo, C.
    • Aggarwal, P. K.
    • Martre, P.
    • Basso, B.
    • Brisson, N.
    • Cammarano, D.
    • Rotter, R. P.
    • Thorburn, P. J.
    • Boote, K. J.
    • Ruane, A. C.
    • Hatfield, J. L.
    • Jones, J. W.
    • Rosenzweig, C.
    • Ewert, F.
    • Asseng, S.
    • Ripoche, D.
    • Semenov, M. A.
    • Shcherbak, I.
    • Steduto, P.
    • Stoeckle, C.
    • Stratonovitch, P.
    • Streck, T.
    • Supit, I.
    • Tao, F.
    • Travasso, M.
    • Waha, K.
    • Wallach, D.
    • White, J. W.
    • Williams, J. R.
    • Wolf, J.
  • Source: Nature Climate Change
  • Volume: 3
  • Issue: 9
  • Year: 2013
  • Summary: Projections of climate change impacts on crop yields are inherently uncertain(1). Uncertainty is often quantified when projecting future greenhouse gas emissions and their influence on climate(2). However, multi-model uncertainty analysis of crop responses to climate change is rare because systematic and objective comparisons among process-based crop simulation models(1,3) are difficult(4). Here we present the largest standardized model intercomparison for climate change impacts so far. We found that individual crop models are able to simulate measured wheat grain yields accurately under a range of environments, particularly if the input information is sufficient. However, simulated climate change impacts vary across models owing to differences in model structures and parameter values. A greater proportion of the uncertainty in climate change impact projections was due to variations among crop models than to variations among downscaled general circulation models. Uncertainties in simulated impacts increased with CO2 concentrations and associated warming. These impact uncertainties can be reduced by improving temperature and CO2 relationships in models and better quantified through use of multi-model ensembles. Less uncertainty in describing how climate change may affect agricultural productivity will aid adaptation strategy development and policy making.
  • Authors:
    • Dymond, J. R.
    • McNeill, S.
    • Andrew, R. M.
    • Kirschbaum, M. U. F.
    • Ausseil, A. G. E.
    • Carswell, F.
    • Mason, N. W. H.
  • Source: Ecosystem services in New Zealand: conditions and trends
  • Year: 2013
  • Summary: This chapter reviews all stocks and fluxes of carbon in New Zealand, and reviews biophysical regulation through surface albedo. The terrestrial environment provides a climate-regulation service by assimilating, transforming, and adjusting to emissions of greenhouse gases that could otherwise lead to undesirable changes in global climate. Quantifying this service requires accounting for both stocks and flows. While greenhouse gas emissions and removals are reported in the national inventory, this inventory accounts only for human-induced changes in greenhouse gases, and omits some natural processes and ecosystems; for example, indigenous forest and scrub are not included but represent the largest biomass carbon pool in New Zealand. Emissions are mainly attributed to the energy and agricultural sectors, while removals come from exotic forestry and natural shrubland regeneration. Erosion plays a role as a carbon sink through natural regeneration of soil carbon on slopes. Biophysical regulation occurs through absorption or reflection of solar radiation (albedo). Forests tend to absorb more radiation than crops or pasture, thus contributing to a lesser extent to global warming. Government currently provides some mechanisms to incentivise sustainable land management in favour of increased forest area on lands unsuitable for agriculture. However, carbon stocks are also at risk of being lost through degradation of natural ecosystems, and this requires active management and mitigation strategies.
  • Authors:
    • Zhou, D.
    • Wang, J.
    • Chen, Z.. L.
    • Bi, C. J.
  • Source: Pedosphere
  • Volume: 23
  • Issue: 2
  • Year: 2013
  • Summary: Soil health assessment is an important step toward understanding the potential effects of agricultural practices on crop yield, quality and human health. The objectives of this study were to select a minimum data set for soil health evaluation from the physical, chemical and biological properties and environmental pollution characteristics of agricultural soil and to develop a soil health diagnosis model for determining the soil health status under different planting patterns and soil types in Chongming Island of Shanghai, China. The results showed that the majority of the farmland soils in Chongming Island were in poor soil health condition, accounting for 48.9% of the survey samples, followed by the medium healthy soil, accounting for 32.2% of the survey samples and mainly distributed in the central and mid-eastern regions of the island. The indicators of pH, total organic carbon, microbial biomass carbon and Cd exerted less influence on soil health, while the soil salinization and nitrate accumulation under a greenhouse cropping pattern and phosphate fertilizer shortage in the paddy field had limited the development of soil health. Dichlorodiphenyltrichloroethanes, hexachlorocyclohexanes and Hg contributed less to soil health index (SHI) and showed no significant difference among paddy field, greenhouse and open-air vegetable/watermelon fields. The difference of the SHI of the three soil types was significant at P = 0.05. The paddy soil had the highest SHI values, followed by the gray alluvial soil, and the coastal saline soil was in a poor soil health condition, indicating a need to plant some salt-tolerant crops to effectively improve soil quality.
  • Authors:
    • Blanke, M. M.
  • Source: Acta Horticulturae International Society for Horticultural Science
  • Issue: 998
  • Year: 2013
  • Summary: Thinning is a prerequisite in worldwide fruit production. The question arose as to its contribution to the carbon footprint in different production schemes. Carbon footprinting of thinning in fruit orchards is based on fossil fuel consumption, converted into greenhouse gas emission (GHG) and expressed as CO 2 equivalents, which comprises carbon dioxide (CO 2; factor 1), methane (CH 4; factor 25) and nitrous oxides (N 2O; factor 298), according to PAS 2050: Oct 2011 and PAS 2050-1 (hort). Flower thinning with ATS foliar nitrogen fertiliser emitted 25-37 kg CO 2e/ha per treatment (without associated N 2O emissions), while fruitlet thinning with 6-BA emitted ca. 13 kg CO 2e/ha, Brevis 18.5 (single application) or 34 (double application) kg CO 2e/ha and lime sulfur in organic orchards 27-42 kg CO 2e/ha. Mechanical thinning with the Bonner machine at 6 km/h at 360 rpm produced 27.9 kg CO 2e/ha emissions, while manual fruitlet thinning after June drop had a carbon footprint of only 3.1 kg CO 2e/ha, since manual labour does not utilize fossil fuel.
  • Authors:
    • Adami, M.
    • Aguiar, D. A.
    • de Figueiredo, E. B.
    • Bordonal, R. de O.
    • Rudorff, B. F. T.
    • La Scala, N.
  • Source: Biomass and Bioenergy
  • Volume: 59
  • Year: 2013
  • Summary: Brazil is a major sugarcane producer and Sao Paulo State cultivates 5.5 million hectares, close to 50% of Brazil's sugarcane area. The rapid increase in production has brought into question the sustainability of biofuels, especially considering the greenhouse gas (GHG) emissions associated to the agricultural sector. Despite the significant progress towards the green harvest practices, 1.67 million hectares were still burned in Sao Paulo State during the 2011 harvest season. Here an emissions inventory for the life cycle of sugarcane agricultural production is estimated using IPCC methodologies, according to the agriculture survey data and remote sensing database. Our hypothesis is that 1.67 million hectares shall be converted from burned to green harvest scenarios up to years 2021 (rate 1), 2014 (rate 2) or 2029 (rate 3). Those conversions would represent a significant GHG mitigation, ranging from 50.5 to 70.9 megatons of carbon dioxide equivalent (Mt CO(2)eq) up to 2050, depending on the conversion rate and the green harvest systems adopted: conventional (scenario 51) or conservationist management (scenario S2). We show that a green harvest scenario where crop rotation and reduced soil tillage are practiced has a higher mitigation potential (70.9 Mt CO(2)eq), which is already practiced in some of the sugarcane areas. Here we support the decision to not just stop burning prior to harvest, but also to consider other better practices in sugarcane areas to have a more sustainable sugarcane based ethanol production in the most dense cultivated sugarcane region in Brazil. (C) 2013 Elsevier Ltd. All rights reserved.
  • Authors:
    • Chapman, S. C.
    • James, A. T.
    • Dreccer, M. F.
    • Bourgault, M.
  • Source: Functional Plant Biology
  • Volume: 40
  • Issue: 2
  • Year: 2013
  • Summary: Atmospheric CO2 levels have increased from similar to 280 ppm in the pre-industrial era to 391 ppm in 2012. High CO2 concentrations stimulate photosynthesis in C-3 plants such as wheat, but large variations have been reported in the literature in the response of yield and other traits to elevated CO2 (eCO(2)). Few studies have investigated genotypic variation within a species to address issues related to breeding for specific adaptation to eCO(2). The objective of this study was to determine the response to eCO(2) of 20 wheat lines which were chosen for their contrasting expression in tillering propensity, water soluble carbohydrate (WSC) accumulation in the stem, early vigour and transpiration efficiency. Experiments were performed in control environment chambers and in a glasshouse with CO2 levels controlled at either 420 ppm (local ambient) or 700 ppm (elevated). The results showed no indication of a differential response to eCO(2) for any of these lines and adaptive traits were expressed in a consistent manner in ambient and elevated CO2 environments. This implies that for these traits, breeders could expect consistent rankings in the future, assuming these results are validated under field conditions. Additional climate change impacts related to drought and high temperature are also expected to interact with these traits such that genotype rankings may differ from the unstressed condition.
  • Authors:
    • Castanheira, E. G.
    • Freire, F.
  • Source: Journal of Cleaner Production
  • Volume: 54
  • Year: 2013
  • Summary: The increase in soybean production as a source of protein and oil is being stimulated by the growing demand for livestock feed, food and numerous other applications. Significant greenhouse gas (GHG) emissions can result from land use change due to the expansion and cultivation of soybean. However, this is complex to assess and the results can vary widely. The main goal of this article is to investigate the life-cycle GHG balance for soybean produced in Latin America, assessing the implications of direct land use change emissions and different cultivation systems. A life-cycle model, including inventories for soybean produced in three different climate regions, was developed, addressing land use change, cultivation and transport to Europe. A comprehensive evaluation of alternative land use change scenarios (conversion of tropical forest, forest plantations, perennial crop plantations, savannah and grasslands), cultivation (tillage, reduced tillage and no-tillage) and soybean transportation systems was undertaken. The main results show the importance of land use change in soybean GHG emissions, but significant differences were observed for the alternative scenarios, namely 0.1-17.8 kg CO(2)eq kg(-1) soybean. The original land choice is a critical issue in ensuring the lowest soybean GHG balance and degraded grassland should preferably be used for soybean cultivation. The highest GHG emissions were calculated for tropical moist regions when rainforest is converted into soybean plantations (tillage system). When land use change is not considered, the GHG intensity varies from 0.3 to 0.6 kg CO(2)eq kg(-1) soybean. It was calculated that all tillage systems have higher GHG emissions than the corresponding no-tillage and reduced tillage systems. The results also show that N2O emissions play a major role in the GHG emissions from cultivation, although N2O emission calculations are very sensitive to the parameters and emission factors adopted.
  • Authors:
    • Zhang, Y.
    • Wu, L.
    • Wang, H.
    • Liu, L.
    • Huang, L.
    • Niu, Y.
    • Chai, R.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 96
  • Issue: 1
  • Year: 2013
  • Summary: Proper management of synthetic nitrogen (N) fertilizer can reduce direct N2O emission from soil and indirect CO2 emission from production and transportation of synthetic N. In the late 1990s, the average application rates of synthetic N were 212, 207 and 207 kg ha(-1), respectively, for rice, wheat, and maize in China's croplands. But research suggests that the optimal synthetic N application rates for the main grain crops in China should be in the range of 110-150 kg ha(-1). Excessive application of synthetic N has undoubtedly resulted in massive emission of greenhouse gases. Therefore, optimizing N application rates for grain crops in China has a great potential for mitigating the emission of greenhouse gases. Nevertheless, this mitigation potential (MP) has not yet been well quantified. This study aimed at estimating the MP of N2O and CO2 emissions associated with synthetic N production and transportation in China based on the provincial level statistical data. Our research indicates that the total consumption of synthetic N on grain crops in China can be reduced by 5.0-8.4 Tg yr(-1) (28-47 % of the total consumption) if the synthetic N application rate is controlled at 110-150 kg ha(-1). The estimated total MP of greenhouse gases, including direct N2O emission from croplands and indirect CO2 emission from production and transportation of synthetic N, ranges from 41.7 to 70.1 Tg CO2_eq. yr(-1). It was concluded that reducing synthetic N application rate for grain crops in China to a reasonable level of 110-150 kg ha(-1) can greatly reduce the emission of greenhouse gases, especially in the major grain-crop production provinces such as Shandong, Henan, Jiangsu, Hebei, Anhui and Liaoning.