• Authors:
    • Wilson,T. M.
    • McGowen,B.
    • Mullock,J.
    • Arnall,D. B.
    • Warren,J. G.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 5
  • Year: 2015
  • Summary: Fertilizer-induced N 2O-N emissions (the difference between fertilized and unfertilized soils) are estimated to be 0.01 kg N 2O-N kg -1 of applied N. One approach to limiting N 2O-N production in soils is by improving nitrogen use efficiency (NUE) in dryland agricultural systems. However, baseline data on the rate of emissions is needed to determine the potential impact that these efforts might have on N 2O-N concentrations in the atmosphere. A study was established in a long-term continuous winter wheat ( Triticum aestivum L.) fertility experiment in Stillwater, OK, to determine the effects of N rate on N 2O-N emissions from a dryland winter wheat-summer fallow system in the southern Great Plains of the United States to fill this knowledge gap. Cumulative emissions of N 2O-N varied from year to year and were influenced by environment and N rate. Emissions following N fertilizer application were typically highest following N application, as well as toward the end of the summer fallow period, when summer rainfall and temperatures were conducive for N 2O-N production chambers within plots historically receiving 134 kg N ha -1 annually went unfertilized for the 2012-2013 and 2013-2014 crop years and produced N 2O-N emissions equivalent to the 45 and 90 kg N ha -1 rate treatments. Annual cumulative emissions ranged from 0.009 to 0.024 kg N 2O-N kg -1 N applied with an average of 0.015 kg N 2O-N kg -1 N applied, illustrating the variability in N 2O-N emissions.
  • Authors:
    • Cichorowski,G.
    • Joa,B.
    • Hottenroth,H.
    • Schmidt,M.
  • Source: The International Journal of Life Cycle Assessment
  • Volume: 20
  • Issue: 4
  • Year: 2015
  • Summary: Purpose: Following water, tea is the second most consumed drink worldwide and has the peculiarity that not only its production but especially its preparation can be associated with considerable greenhouse gas (GHG) emissions. The aims of this study were to calculate the cradle-to-gate and cradle-to-grave product carbon footprint (PCF) of Darjeeling tea and to identify potentials to reduce GHG emissions along its life cycle. Therefore, various options for action and their impact on the PCF were modeled by using a scenario analysis. Methods: To assess the PCF of Darjeeling tea, the method based on ISO/TS 14067 was used with some limitations. Besides one base scenario, alternative cradle-to-gate scenarios and different use profiles were modeled. The results were split in a cradle-to-gate and a cradle-to-grave perspective. For the cradle-to-gate phase a functional unit of one kilogram loose black Darjeeling tea was chosen, whereas for the cradle-to-grave phase one liter black Darjeeling tea that is prepared and ready to drink in Germany was seen as appropriate functional unit. Primary data for the present study has been collected from local farmers, manufacturers, and agents in Darjeeling, Kolkata, and Rotterdam. For secondary data, the database ecoinvent 2.2 was mainly used. Results and discussion: The cradle-to-gate PCF of 1 kg Darjeeling tea is between 7.1 and 25.3 kg CO 2e depending on the cultivation method, energy sources used, or mode of transportation. The cradle-to-grave PCF for 1 l organic Darjeeling tea is about 0.15 kg CO 2e. The largest share, 51%, makes up the use phase, which is clearly dominated by the boiling of water. The variety of possible use profiles yields results of great breadth. It shows that the life cycle of organic Darjeeling tea transported by ship, depending on the preparation variants can cause emissions from 0.12 to 0.51 kg CO 2e/l tea. Conclusions: The main reduction potentials for GHG emissions were identified in the process of water boiling, the intercontinental transport mode, and the cultivation method. Since the climate impact of tea strongly depends on the way in which it is prepared, the consumer has a decisive influence on the PCF. Therefore, in order to make a reliable statement about the climate performance of consumer goods such as tea, the whole life cycle must be considered.
  • Authors:
    • Dang,Y. P.
    • Seymour,N. P.
    • Walker,S. R.
    • Bell,M. J.
    • Freebairn,D. M.
  • Source: Soil & Tillage Research
  • Volume: 152
  • Year: 2015
  • Summary: Development of no-tillage (NT) farming has revolutionized agricultural systems by allowing growers to manage greater areas of land with reduced energy, labour and machinery inputs to control erosion, improve soil health and reduce greenhouse gas emission. However, NT farming systems have resulted in a build-up of herbicide-resistant weeds, an increased incidence of soil- and stubble-borne diseases and enrichment of nutrients and carbon near the soil surface. Consequently, there is an increased interest in the use of an occasional tillage (termed strategic tillage, ST) to address such emerging constraints in otherwise-NT farming systems. Decisions around ST uses will depend upon the specific issues present on the individual field or farm, and profitability and effectiveness of available options for management. This paper explores some of the issues with the implementation of ST in NT farming systems. The impact of contrasting soil properties, the timing of the tillage and the prevailing climate exert a strong influence on the success of ST. Decisions around timing of tillage are very complex and depend on the interactions between soil water content and the purpose for which the ST is intended. The soil needs to be at the right water content before executing any tillage, while the objective of the ST will influence the frequency and type of tillage implement used. The use of ST in long-term NT systems will depend on factors associated with system costs and profitability, soil health and environmental impacts. For many farmers maintaining farm profitability is a priority, so economic considerations are likely to be a primary factor dictating adoption. However, impacts on soil health and environment, especially the risk of erosion and the loss of soil carbon, will also influence a grower's choice to adopt ST, as will the impact on soil moisture reserves in rainfed cropping systems. (C) 2015 Elsevier B.V. All rights reserved.
  • Authors:
    • Ghini,Raquel
    • Torre-Neto,Andre
    • Dentzien,Anamaria F. M.
    • Guerreiro-Filho,Oliveiro
    • Iost,Regiane
    • Patricio,Flavia R. A.
    • Prado,Jeanne S. M.
    • Thomaziello,Roberto A.
    • Bettiol,Wagner
    • DaMatta,Fabio M.
  • Source: Climatic Change
  • Volume: 132
  • Issue: 2
  • Year: 2015
  • Summary: Despite the importance of coffee as a globally traded commodity and increasing concerns about risks associated with climate change, there is virtually no information about the effects of rising atmospheric [CO2] on field-grown coffee trees. This study shows the results of the first 2 years of an innovative experiment. Two commercial coffee cultivars (Catuai and Obat) were grown using the first free-air CO2 enrichment (FACE) facility in Latin America (ClimapestFACE). Plants of both cultivars maintained relatively high photosynthetic rates, water-use efficiency, increased growth and yield under elevated [CO2]. Harvestable crop yields increased 14.6 % for Catuai and 12.0 % for Obat. Leaf N content was lower in Obat (5.2 %) grown under elevated [CO2] than under ambient [CO2]; N content was unresponsive to elevated [CO2] in Catuai. Under elevated [CO2] reduced incidence of leaf miners (Leucoptera coffeella) occurred on both coffee cultivars during periods of high infestation. The percentage of leaves with parasitized and predated mines increased when leaf miner infestation was high, but there was no effect of elevated [CO2] on the incidence of natural enemies. The incidence of rust (Hemileia vastatrix) and Cercospora leaf spot (Cercospora coffeicola) was low during the trial, with maximum values of 5.8 and 1 %, respectively, and there was no significant effect of [CO2] treatments on disease incidence. The fungal community associated with mycotoxins was not affected by the treatments.
  • Authors:
    • Stegelin,F. E.
  • Source: Acta Horticulturae
  • Volume: 1090
  • Year: 2015
  • Summary: Agribusinesses with the purpose of growing and supplying horticultural crops to the end-user often realize there is power in numbers; in other words, using some form of organizational structure to provide economic gains (acquiring inputs cheaper, increasing distribution efficiencies, combining selling activities). Accomplishing these growth or survival strategies often involves collaborative purchasing and marketing with supply chain partners. The horticultural industry, among others, is abuzz with sustainability, emphasizing it as the original green industry. Sustainability encompasses three components: societal or community well-being, economics and profitability, and environmental quality. Hence, adopting a strategic alliance among industry partners should enhance the horticulture supply chain sustainability and profitability; but does it? The formation of horticultural crops producer strategic alliances, evaluating the supply chain participation within each of the alliances, and conducting a life cycle assessment to determine the carbon neutrality and sustainability of the supply chain was the impetus of this study. Net results of five transportation alliances established among small- to mid-sized greenhouse (floriculture) and container nurseries (annuals and perennials) in Georgia indicated a 12% average annual total cost savings to participating firms in each alliance, a 23% average annual total miles driven reduction and savings, an 18% average annual vehicle ownership expense savings to the alliance partners, a 31% average annual savings in driver labor and hours of drive time, and a 19% overall (system-wide) reduction in total carbon dioxide equivalent (CO 2e) emissions-reducing the carbon footprint, but not reaching carbon neutrality.
  • Authors:
    • Wang Zhan-biao
    • Wen Xin-ya
    • Zhang Hai-lin
    • Lu Xiao-hong
    • Chen Fu
  • Source: Journal of Integrative Agriculture
  • Volume: 14
  • Issue: 8
  • Year: 2015
  • Summary: Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon (C) emissions. This study was conducted to determine optimized N fertilizer application for high grain yield and lower C emissions in summer corn (Zea mays L.). Afield experiment, including 0 (NO), 75(N75), 150 (N150), 225 (N225), and 300 (N300) kg N ha(-1) treatments, was carried out during 2010-2012 in the North China Plain (NCP). The results showed that grain yield, input energy, greenhouse gas (GHG) emissions, and carbon footprint (CF) were all increased with the increase of N rate, except net energy yield (NEY). The treatment of N225 had the highest grain yield (10364.7 kg ha(-1)) and NEY (6.8%), but the CF (0.25) was lower than that of N300, which indicates that a rate of 225 kg N ha(-1) can be optimal for summer corn in NCR Comparing GHG emision compontents, N fertilizer (0-51.1%) was the highest and followed by electricity for irrigation (19.73-49.35%). We conclude that optimazing N fertilizer application rate and reducing electricity for irrigation are the two key measures to increase crop yield, improve energy efficiency and decrease GHG emissions in corn production.
  • Authors:
    • Xu,X.
  • Source: Acta Scientiae Circumstantiae
  • Volume: 35
  • Issue: 8
  • Year: 2015
  • Summary: Farmland releases greenhouse gases, therefore is of great importance to climate change. Carbon footprint is an ideal method to evaluate comprehensive greenhouse gas emissions of crops through the entire life cycle. This study took Jinzhong City, Shanxi Province, a typical winter wheat planting area as an example. Carbon footprint of wheat production was calculated using life cycle assessment. Furthermore, carbon footprint was optimized based on nonlinear programming aiming at reducing carbon emission as well as increasing crop unit yield. Results showed that, after energy-based allocating, carbon footprint for 1000 kg wheat production was 1357.28 kg CO2 equivalent under traditional farm management. Two major phrases of carbon footprint generation were N2O emission from farmland and urea manufacture. Through altering the fertilizer amount and adjusting the ratio of urea and mature, carbon footprint of 1000 kg wheat production could be reduced to 469.99 kg CO2 equivalent, with 9.13% increase in unit yield. Carbon footprint of wheat production in Jinzhong City showed great difference with results from previous studies in China, which was most likely due to various fertilizer amounts and N2O emission coefficients in different studies. This study provides important information in integrated greenhouse gas emissions of wheat production and quantitative methods to decrease carbon emission and increase crop yield. ©, 2015, Science Press. All right reserved.
  • Authors:
    • Jones, L. E.
    • Maddison, A. L.
    • Castle, M.
    • Barraclough, T. J. P.
    • Purdy, S. J.
    • Cunniff, J.
    • Shield, I. F.
    • Gregory, A. S.
    • Karp, A.
  • Source: Science Article
  • Volume: 80
  • Year: 2015
  • Summary: Willows ( Salix spp.) grown as short rotation coppice (SRC) are viewed as a sustainable source of biomass with a positive greenhouse gas (GHG) balance due to their potential to fix and accumulate carbon (C) below ground. However, exploiting this potential has been limited by the paucity of data available on below ground biomass allocation and the extent to which it varies between genotypes. Furthermore, it is likely that allocation can be altered considerably by environment. To investigate the role of genotype and environment on allocation, four willow genotypes were grown at two replicated field sites in southeast England and west Wales, UK. Above and below ground biomass was intensively measured over two two-year rotations. Significant genotypic differences in biomass allocation were identified, with below ground allocation differing by up to 10% between genotypes. Importantly, the genotype with the highest below ground biomass also had the highest above ground yield. Furthermore, leaf area was found to be a good predictor of below ground biomass. Growth environment significantly impacted allocation; the willow genotypes grown in west Wales had up to 94% more biomass below ground by the end of the second rotation. A single investigation into fine roots showed the same pattern with double the volume of fine roots present. This greater below ground allocation may be attributed primarily to higher wind speeds, plus differences in humidity and soil characteristics. These results demonstrate that the capacity exists to breed plants with both high yields and high potential for C accumulation.
  • Authors:
    • Gao,Wei
    • Yang,Jun
    • Ren,Shun-rong
    • Liu Hailong
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 103
  • Issue: 1
  • Year: 2015
  • Summary: Evaluating the effects of management practices on the soil organic carbon (SOC), total nitrogen (TN) and grain yields would be valuable to explain field-level variability in crop production. A 33-year field experiment on the fluvo-aquic soil of North China with six treatments in a wheat (Triticum aestivium L.)-maize (Zea mays L.) rotation was evaluated. The six treatments were: non-fertilization (CK), nitrogen (N), nitrogen-phosphorus fertilization (NP), nitrogen-phosphorus-potassium fertilization (NPK), manure and nitrogen fertilization (NM), and straw returned with nitrogen fertilizers (NS). The results showed that the content of SOC and TN significantly increased in NM treatment. Application of inorganic fertilizers had small influence on SOC, but SOC and TN increased significantly in NM treatment over the long-term experiment. Compared to control, grain yield of wheat and maize increased two times under all treatments. The highest grain yield was detected in NM and NPK treatments. However, wheat yield was not significantly different (P > 0.05) between control and N treatment. Grain yields were more than doubled under fertilization for both wheat and maize, with the highest yield under the NM and NPK treatments and the lowest under CK treatment for maize and N treatment for wheat. The NP fertilization had little effect on maize yield in long-term, suggesting that potassium was not the primary limiting nutrients in the study site. Statistical analysis indicated that maize yield was significantly correlated with SOC and TN, and wheat yield was significantly correlated with SOC only. However, the relationships were stronger with TN (r = 0.26-0.42) than SOC (r = 0.12-0.37), indicating the importance of maintaining TN in agricultural soils. There was a strong positive linear correlation between carbon sequestered and carbon input (r = 0.828, P < 0.01) in the study site, indicating that the conversion rate of carbon input to SOC was 8.5 %. SOC did not reach the saturation in fluvo-aquic soil and have the potential to sequester more carbon.
  • Authors:
    • Hossain,M. K.
    • Strezov,V.
    • Nelson,P. F.
  • Source: Pedosphere
  • Volume: 25
  • Issue: 5
  • Year: 2015
  • Summary: To investigate the potential effects of wastewater sludge and sludge biochar on growth, yield and metal bioaccumulation of cherry tomato ( Lycopersicon esculentum L.), a pot experiment was carried out under greenhouse environment with three different treatments, control soil (CP), soil with wastewater sludge (SS) and soil with sludge biochar (SB), to reveal the comparative effect between the amendments of wastewater sludge and sludge biochar. The soil used for pot experiment was Chromosol. Wastewater sludge and sludge biochar produced through pyrolysis process at 550°C were applied at 10 t ha -1. No significant difference was found in growth and production of cherry tomatoes between wastewater sludge and sludge biochar applications to the soil. The accumulation rates of metals in the fruits were lower in the treatment with sludge biochar than in the treatment with wastewater sludge. The study highlights the benefits of risk mitigation from toxic metal accumulation in fruits using wastewater sludge and sludge biochar as soil conditioners.