• Authors:
    • Ramirez,T.
    • Meas,Y.
    • Dannehl,D.
    • Schuch,I.
    • Miranda,L.
    • Rocksch,T.
    • Schmidt,U.
  • Source: Journal of Cleaner Production
  • Volume: 104
  • Year: 2015
  • Summary: The water and carbon footprint of the presented dried tomato value chain is compared to the conventional process. The coupling of pre- and post-harvest processes, namely growing and drying respectively, is analyzed for resource consumption optimization. The growing system of tomatoes ( Solanum lycopersicon L. cv, Pannovy) in an energy efficient greenhouse (operating as a solar thermal collector) is databased; while the post-harvest process consists of a model-based solar drying system. The thermodynamic operation zones (temperature, humidity and enthalpy) are detailed to apply energy interaction between both processes. The results of the monthly record of a season show that the water footprint was reduced from 91 to 51.1 L kg -1 with a standard deviation from 53.2 to 12.4 L kg -1. The carbon footprint was reduced from 40.2 to 11 kg kg -1 with a standard deviation from 23.9 to 11.4 kg carbon dioxide kg -1. From the observed variation from monthly values, the relevance of the seasonal effect on resources needed for implementing process improvements is highlighted. The use of renewable energy and energy efficiency concepts is shown to have a positive impact when applied at industrial level in 'compound industries' that share sub-processes in the value chains.
  • Authors:
    • Reicosky,Don C.
  • Source: Journal of Soil and Water Conservation
  • Volume: 70
  • Issue: 5
  • Year: 2015
  • Authors:
    • Solaiman,Zakaria M.
    • Anawar,Hossain M.
  • Source: Pedosphere
  • Volume: 25
  • Issue: 5
  • Year: 2015
  • Summary: Biochar addition to soil is currently being considered as a means to sequester carbon while simultaneously improving soil health, soil fertility and agronomic benefits. The focus of this special issue is on current research on the effects of biochar application to soil for overcoming diverse soil constraints and recommending further research relating to biochar application to soil. The biochar research has progressed considerably with important key findings on agronomic benefits, carbon sequestration, greenhouse gas emissions, soil acidity, soil fertility, soil health, soil salinity, etc., but more research is required before definitive recommendations can be made to end-users regarding the effects of biochar application across a range of soils, climates and land management practices.
  • Authors:
    • Tran,T.
    • Da,G.
    • Moreno-Santander,M. A.
    • Velez-Hernandez,G. A.
    • Giraldo-Toro,A.
    • Piyachomkwan,K.
    • Sriroth,K.
    • Dufour,D.
  • Source: Resources, Conservation & Recycling
  • Volume: 100
  • Year: 2015
  • Summary: Energy use, water use and greenhouse gas (GHG) emissions were assessed for the transformation of cassava roots into starch by two small-scale (ST1, ST2: 1-2 t starch per day) and one large-scale (VLT: 100-200 t starch per day) technologies. The goal of the study was to identify hotspots of energy use and GHG emissions, as well as sustainable practices, with a view to uncover opportunities to improve the environmental performance of cassava starch production. VLT required 2527 MJ/t starch, mainly (77%) from biogas used to dry starch, but was the most efficient in terms of water use (10 m 3/t starch) due to the practice of water recycling between unit operations. ST1 and ST2 were similar in terms of electricity use (212 MJ/t starch), and were able to rely on solar energy to dry starch, due to the small volumes of production. In contrast, water use varied from 21 to 62 m 3/t starch due to differences in the design of the rasping and starch recovery (extraction) operations. GHG emissions were 149, 93 and 105 kg CO 2eq/t starch for VLT, ST1 and ST2 respectively. For ST1 and ST2, methane emissions from untreated wastewater were the main contribution to GHG emissions. For VLT, methane was captured to produce biogas and to dry starch, and the main contribution to GHG emissions was the use of non-renewable grid electricity. Biogas technology was adopted in the past 12 years in the case of VLT. Previously fuel oil was used instead of biogas, which resulted in GHG emissions of 539 kg CO 2eq/t starch. VLT used markedly more electricity than ST1 and ST2, which was necessary to ensure the high output and consistent starch quality. Strategies to reduce the impacts of cassava starch production could focus on (1) increasing the energy efficiency of the drying operation, in order to make more biogas available for other uses such as production of renewable electricity; (2) improving the design of some unit operations with regards to water and energy efficiency; and (3) promoting the transfer and adoption of water recycling practices.
  • Authors:
    • Ahlstrom,Anders
    • Raupach,Michael R.
    • Schurgers,Guy
    • Smith,Benjamin
    • Arneth,Almut
    • Jung,Martin
    • Reichstein,Markus
    • Canadell,Josep G.
    • Friedlingstein,Pierre
    • Jain,Atul K.
    • Kato,Etsushi
    • Poulter,Benjamin
    • Sitch,Stephen
    • Stocker,Benjamin D.
    • Viovy,Nicolas
    • Wang,Ying Ping
    • Wiltshire,Andy
    • Zaehle,Soenke
    • Zeng,Ning
  • Source: Science
  • Volume: 348
  • Issue: 6237
  • Year: 2015
  • Summary: The growth rate of atmospheric carbon dioxide (CO2) concentrations since industrialization is characterized by large interannual variability, mostly resulting from variability in CO2 uptake by terrestrial ecosystems (typically termed carbon sink). However, the contributions of regional ecosystems to that variability are not well known. Using an ensemble of ecosystem and land-surface models and an empirical observation-based product of global gross primary production, we show that the mean sink, trend, and interannual variability in CO2 uptake by terrestrial ecosystems are dominated by distinct biogeographic regions. Whereas the mean sink is dominated by highly productive lands (mainly tropical forests), the trend and interannual variability of the sink are dominated by semi- arid ecosystems whose carbon balance is strongly associated with circulation- driven variations in both precipitation and temperature.
  • Authors:
    • Navarro, J.
    • Li, J.
    • Nolan, M.
    • Crossman, N. D.
    • Bryan, B. A.
    • Connor, J. D.
  • Source: Primary Research Article
  • Volume: 21
  • Issue: 11
  • Year: 2015
  • Summary: Competition for land is increasing, and policy needs to ensure the efficient supply of multiple ecosystem services from land systems. We modelled the spatially explicit potential future supply of ecosystem services in Australia's intensive agricultural land in response to carbon markets under four global outlooks from 2013 to 2050. We assessed the productive efficiency of greenhouse gas emissions abatement, agricultural production, water resources, and biodiversity services and compared these to production possibility frontiers (PPFs). While interacting commodity markets and carbon markets produced efficient outcomes for agricultural production and emissions abatement, more efficient outcomes were possible for water resources and biodiversity services due to weak price signals. However, when only two objectives were considered as per typical efficiency assessments, efficiency improvements involved significant unintended trade-offs for the other objectives and incurred substantial opportunity costs. Considering multiple objectives simultaneously enabled the identification of land use arrangements that were efficient over multiple ecosystem services. Efficient land use arrangements could be selected that meet society's preferences for ecosystem service provision from land by adjusting the metric used to combine multiple services. To effectively manage competition for land via land use efficiency, market incentives are needed that effectively price multiple ecosystem services.
  • Authors:
    • Lupwayi, N.
    • Blackshaw, R.
    • Li, L
    • Pearson, D.
    • Larney, F.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 6
  • Year: 2015
  • Summary: Dry bean ( Phaseolus vulgaris L.) production on the Canadian prairies has traditionally used wide rows, inter-row cultivation, and undercutting at harvest. Recent breeding efforts have produced cultivars with more upright growth which are better suited to solid-seeded narrow-row production systems. A 12 yr (2000-2011) study compared conservation (CONS) and conventional (CONV) management for dry bean in 3- to 6-yr rotations. The CONS rotations included reduced tillage, cover crops, feedlot manure compost, and solid-seeded narrow-row dry bean. Effects of CONS management on plant density were inconsistent with some years showing lower density when seeded into high-residue conditions. On average, there was a 3 d maturity advantage with CONS (103 d) vs. CONV (106 d) management. The CONS rotations showed significantly higher mean incidence (19%) of white mold [ Sclerotinia sclerotiorum (Lib.) de Bary] than CONV rotations (6%). Averaging across 12 yr, there was no significant rotation effect on yield ( P=0.19) showing that CONS production performed as good as CONV production. In the last 2 yr (2010-2011) of the study, in an attempt to reduce harvest losses, CONS dry bean was undercut rather than direct combined. This led to significantly higher (25%) yield with CONS (3311 kg ha -1) vs. CONV management (2651 kg ha -1). Our results provide incentive for more rapid adoption of conservation-oriented soil and crop management practices for dry bean production on the Canadian prairies, including narrow rows, reduced tillage, cover crops, and feedlot manure compost addition.
  • Authors:
    • Braden, J. B.
    • Cai, X.
    • Eheart, J. W.
    • Ng, T. L.
    • Czapar, G. F.
  • Source: Journal of Water Resources Planning and Management
  • Volume: 140
  • Issue: 1
  • Year: 2014
  • Summary: Excessive nitrate loads in surface waters are a major cause of hypoxia and eutrophication. In many places, agriculture is the single largest source of nitrogen entering receiving waters. Perennial energy grass crops have the potential to reduce nitrogen loads from agricultural areas, while sequestering carbon and offering new economic opportunities for farmers. This study analyzes farm system-scale cropping and fertilizer application decisions, and resulting nitrate loads, as driven by prices for the bioenergy crop miscanthus, as well as investigates reductions of carbon and other greenhouse gas emissions and nitrogen fertilizer use. An economic model of farm-system-scale decisions is coupled to a hydrologic-agronomic model of the physical stream system to obtain nitrate loading and crop yield results for varying combinations of prices and policies for a typical Midwestern agricultural watershed. For the scenarios examined, a large reduction in stream nitrate load depends on a high price for miscanthus relative to competing crops. A price for miscanthus that exceeds 50% of the average of corn and soybean prices, per unit weight, is estimated to lead to nitrate load reductions of 25% or more. Though significant, these reductions are still less than the recommended 45% reduction in stream nitrogen flux entering the Gulf of Mexico needed to mitigate the hypoxia problem in the gulf. Miscanthus prices are unlikely ever to reach such levels. However, nitrate load reductions could still be achieved by implementing a nitrogen fertilizer reduction subsidy alongside a miscanthus market. The results also show that carbon trading is unlikely to result in any significant reduction in nitrate load. The results are useful for improving understanding of the potential of these incentives, individually and concurrently, to reduce pollution from Midwestern crop agriculture.
  • Authors:
    • McDonald, A. J.
    • Bishnoi, D. K.
    • Kumar, A.
    • Jat, M. L.
    • Majumdar, K.
    • Sapkota, T. B.
    • Pampolino, M.
  • Source: Field Crops Research
  • Volume: 155
  • Year: 2014
  • Summary: In the high-yielding wheat production systems in Northwest (NW) Indo-Gangetic Plains of India, intensive tillage operations and blanket fertilizer recommendations have led to high production costs, decreased nutrient use efficiency, lower profits and significant environmental externalities. No-tillage (NT) has been increasingly adopted in this region to reduce costs and increase input use efficiency. But, optimal nutrient management practices for NT based wheat production are still poorly understood. Opportunities exist to further enhance the yield, profitability, and resource use efficiency of NT wheat through site-specific nutrient management (SSNM). On-farm trials were conducted in seven districts of Haryana, India for two consecutive years (2010-11 and 2011-12) to evaluate three different approaches to SSNM based on recommendations from the Nutrient Expert (R) (NE) decision support system in NT and conventional tillage (CT) based wheat production systems. Performance of NE based recommendations was evaluated against current state recommendations and farmers' practices for nutrient management. Three SSNM treatments based on NE based recommendation were (1) 'NE80:20' with 80% N applied at planting and 20% at second irrigation (2) 'NE33:33:33' with N split as 33% basal, 33% at Crown Root Initiation (CRI) and 33% at second irrigation; and (3) 'NE80:GS' with N split as 80% basal and further application of N based on optical sensor (Green Seeker (TM))-guided recommendations. Yield, nutrient use efficiency and economic profitability were determined following standard agronomic and economic measurements and calculations. Cool Farm Tool (CET), an empirical model to estimate greenhouse gases (GHGs) from agriculture production, was used to estimate GHG emissions under different treatments. Wheat grain and biomass yield were higher under NT in 2010-11 but no difference was observed in 2011-12. The three NE-based nutrient management strategies increased yield, nutrient use efficiency as well as net return as compared to state recommendation and farmers' fertilization practice. Global warming potential (GWP) of wheat production was also lower with NT system as compared to CT system and NE-based nutrient managements as compared to farmers' fertilization practice. State recommended nutrient management had similar GWP as NE-based nutrient managements except NE80:GS in which GWP was the lowest. Results suggest that no-tillage system along with site-specific approaches for nutrient management can increase yield, nutrient use efficiency and profitability while decreasing GHG from wheat production in NW India.
  • Authors:
    • Utomo,M.
  • Source: Sustainable Living with Environmental Risks
  • Volume: 9784431548041
  • Year: 2014
  • Summary: Global warming due to greenhouse gas emissions is currently receiving considerable attention worldwide. Agricultural systems contribute up to 20 % of this global warming. However, agriculture can reduce its own emissions while increasing carbon sequestration through use of recommended management practices, such as consernvation tillage (CT). The objective of this paper is to review the role of long-term CT in mitigating greenhouse gas emissions during corn production in rainfed tropical agro-ecosystems. The types of conservation tillage were no-tillage (NT) and minimum tillage (MT). In a long-term plot study, CO2 emission from CT throughout the corn season was consistently lower than that from intensive tillage (IT). The cumulative CO2 emissions of NT, MT, and IT in corn crops were 1.0, 1.5, and 2.0 Mg CO2-C ha-1season-1, respectively. Soil carbon storage at 0-20 cm depth after 23 years of NT cropping was 36.4 Mg C ha-1, or 43 % and 20 % higher than the soil carbon strorage of IT and MT, respectively. Thus, NT had sequestered some 4.4 Mg C ha-1of carbon amounting to carbon sequestration rate of 0.2 Mg C ha-1 year-1. IT, on the other hand, had depleted soil carbon by as much as 6.6 Mg C ha-1, yielding a carbon depletion rate of 0.3 Mg C ha-1 year-1. Assessment of the farmer's corn fields confirmed these findings. CO2 emission from CT corn farming was similar to that of rubber agroforest and lower than IT corn farming. Based on carbon balance analysis, it can be concluded that corn crops in tropical rainfed agro-ecosystems were not in fact net emitters, and that NT was a better net sinker than other tillage methods. © 2014 The Editor(s) (if applicable) and the Author(s). All rights reserved.