• Authors:
    • Sanchez-Monedero,M. A.
    • Cayuela,M. L.
    • Roig,A.
  • Source: Acta Horticulturae
  • Volume: 1076
  • Issue: 1076
  • Year: 2015
  • Summary: The agricultural recycling of olive mill and winery wastes through composting and land application is reviewed in this manuscript in terms of the impact on greenhouse gas (GHG) emissions and the potential for soil C sequestration. The rich lignocellulosic composition and the low N availability of olive mill wastes have been revealed as the driving factors of the low degradation rate of these wastes during composting and after soil application. These peculiar characteristics minimise the emission of CH 4 and N 2O during composting and lead to an efficient and long-term C stabilisation when applied to the soil. These findings confirm the interest of the use of olive mill wastes in agriculture as a strategy to tackle the increasing CO 2 concentrations in the atmosphere, which is further supported by the well-known favourable agronomical properties of these wastes. The suitability of this strategy is also examined for winery wastes, which share some similar physicochemical characteristics with olive mill wastes. The agricultural use of these organic wastes could have important environmental benefits in Mediterranean agroecosystems.
  • Authors:
    • Scotti-Campos,P.
    • Semedo,J. N.
    • Pais,I. P.
    • Oliveira,M.
    • Passarinho,J.
    • Santos,M.
    • Almeida,A. S.
    • Costa,A. R.
    • Pinheiro,N.
    • Bagorro,C.
    • Coco,J.
    • Costa,A.
    • Coutinho,J.
    • Macas,B.
  • Source: Emirates Journal of Food and Agriculture
  • Volume: 27
  • Issue: 2
  • Year: 2015
  • Summary: Restricted water availability and yield reductions derived from climate changes have become a strong concern as regards fundamental crops, such as wheat. There is an increasing need to characterize germplasm diversity in order to highlight drought tolerant genotypes and to assist Portuguese wheat breeding programs. Bread wheat ( Triticum aestivum) varieties were selected from four different evolutive and/or breeding groups: ancient landraces, traditional varieties, modern currently used and advanced lines. The aim of this work was to identify physiological traits that contribute to drought tolerance during grain filling period. Plants were cultivated in pots, under semi-controlled greenhouse conditions. Drought was imposed by withholding irrigation after anthesis. Well irrigated and water stressed plants were compared as regards leaf gas exchanges (net photosynthetic rate, Pn; leaf stomatal conductance, gs; transpiration, E), instantaneous water use efficiency (iWUE), membrane electrolyte leakage, osmotic potential and leaf pigments. Subsequently, plants were maintained under a controlled irrigation (droughted plants: 50% of the water given to fully irrigated controls) until harvest, to quantify yield. Pn and gs were significantly reduced by drought in all varieties. As regards membrane integrity ancient and traditional varieties presented lower membrane injury, what may reflect a higher protoplasmic tolerance to drought. More evolved varieties (modern and advanced) showed higher spike weight per plant and number of grains per spike, disregard the water regime. Under water deficit 1000 kernel weight was reduced in all varieties except in traditional Pirana, which also showed an increase in the number of spikes per plant. Higher membrane stability, increased pigments and lower osmotic potential under drought may underly such improved response to drought, pointing this variety as an interesting genetic resource for breeding purposes.
  • Authors:
    • Agostini,Alessandro
    • Battini,Ferdinando
    • Giuntoli,Jacopo
    • Tabaglio,Vincenzo
    • Padella,Monica
    • Baxter,David
    • Marelli,Luisa
    • Amaducci,Stefano
  • Source: Desarrollo Tecnológico - Institut De Reconeixement Molecular I Desenvolupament Tecnològic
  • Volume: 8
  • Issue: 6
  • Year: 2015
  • Summary: We analysed the environmental impacts of three biogas systems based on dairy manure, sorghum and maize. The geographical scope of the analysis is the Po valley, in Italy. The anaerobic digestion of manure guarantees high GHG (Green House Gases) savings thanks to the avoided emissions from the traditional storage and management of raw manure as organic fertiliser. GHG emissions for maize and sorghum-based systems, on the other hand, are similar to those of the Italian electricity mix. In crop-based systems, the plants with open-tank storage of digestate emit 50% more GHG than those with gas-tight tanks. In all the environmental impact categories analysed (acidification, particulate matter emissions, and eutrophication), energy crops based systems have much higher impacts than the Italian electricity mix. Maize-based systems cause higher impacts than sorghum, due to more intensive cultivation. Manure-based pathways have always lower impacts than the energy crops based pathways, however, all biogas systems cause much higher impacts than the current Italian electricity mix. We conclude that manure digestion is the most efficient way to reduce GHG emissions; although there are trade-offs with other local environmental impacts. Biogas production from crops; although not providing environmental benefits per se; may be regarded as an option to facilitate the deployment of manure digestion.
  • Authors:
    • Cayambe,J.
    • Iglesias,A.
    • de Jalón,S. G.
    • Chuquillanqui,C.
    • Riga,P.
  • Source: ITEA
  • Volume: 111
  • Issue: 2
  • Year: 2015
  • Summary: The temperature rise of the planet associated with anthropogenic greenhouse gas emissions promotes interest for strategies to mitigate them. Since agriculture is a sector responsible for nearly a fifth of global emissions, it is necessary to identify measures to be applied, what is their mitigation potential and the estimated cost of implementing each measure. Our study addresses these questions by comparing the production of potato in two distinct production systems and with actual field data. In a first step, this paper calculates in a modern agricultural system the carbon footprint of mechanization and energy use for irrigation (located in Spain) and in less productive systems that integrate less technologies (located in Peru) . The results show that in the case studies in both countries the nitrogen cycle represents the primary source of greenhouse gas emissions, followed by energy fuel for irrigation and mechanization. Subsequently this study evaluates economically the mitigation actions through Marginal Abatement Cost Curves. These results demonstrate that the management of nitrogen fertilizer is the best alternative to reduce the carbon footprint because of their greater potential to reduce greenhouse gas emissions and their lower equivalent mitigation costs. Finally, the study provides a methodological framework that can be easily applied to other crops. © 2015, Asociacion Interprofesional para el Desarrollo Agrario. All rights reserved.
  • Authors:
    • Ingrao,Carlo
    • Rana,Roberto
    • Tricase,Caterina
    • Lombardi,Mariarosaria
  • Source: Applied Energy
  • Volume: 149
  • Year: 2015
  • Summary: Over the last few years, agro-biogas has been receiving great attention since it enables replacement of natural gas, thereby representing a tool which reduces greenhouse gas emissions and other environmental impacts. In this context, this paper is aimed at the application of the Carbon Footprint (CF) to an agro-biogas supply chain (SC) in Southern Italy, according to ISO/TS 14067:2013, so as to calculate the related 100-year Global Warming Potential (GWP(100)). The topic was addressed because agro-biogas SCs, though being acknowledged worldwide as sustainable ways to produce both electricity and heat, can be source of GHG emissions and therefore environmental assessments and improvements are needed. Additionally, the performed literature review highlighted deficiencies in PCF assessments, so this study could contribute to enriching the international knowledge on the environmental burdens associated with agro-biogas SCs. The analysis was conducted using a life-cycle approach, thus including in the assessment: functional unit choice, system border definition and inventory analysis development. The primary data needed was provided by a farm located in the province of Foggia (Apulia region in Southern Italy), already equipped with anaerobic digestion and cogeneration plant for biogas production and utilisation. Results from this study are in agreement with those found by some of the most relevant studies in the sector. Indeed, it was possible to observe that GWP100 was almost entirely due to cropland farming and, in particular, to the production of ammonium nitrate in the amount required for fertilisation. Furthermore, environmental credits were observed thanks to: carbon sequestration enabled by no-tillage practice; and avoided production of chemical fertiliser thanks to 50% organic farming. Based upon the results obtained, a sensitivity analysis was carried out, thus highlighting reduced environmental impacts if ammonium nitrate was replaced with urea. Finally, thanks to this study, all the target stakeholders will learn more about the input/output flows involved in the system analysed, the related environmental impacts and the improvements needed to reduce them. In this way, it could be possible to compare the analysed agro-biogas SC with others of equal functionality, and so to enable considerations to be made on the resulting similarities and differences in terms of methodological approach, inventory flows and environmental impact. (C) 2015 Elsevier Ltd. All rights
  • Authors:
    • Monteleone,M.
    • Garofalo,P.
    • Cammerino,A. R. B.
    • Libutti,A.
  • Source: Italian Journal of Agronomy
  • Volume: 10
  • Issue: 2
  • Year: 2015
  • Summary: Climate change mitigation is the most important driving force for bioenergy development. Consequently, the environmental design of bioenergy value chains should address the actual savings of both primary energy demand and greenhouse gases (GHG) emissions. According to the EU Renewable Energy Directive (2009/28/EC), no direct impacts and no GHG emissions should be attributed to crop residues (like cereal straws) when they are removed from agricultural land for the purpose of bioenergy utilisation. The carbon neutral assumption applied to crop residues is, however, a rough simplification. Crop residues, indeed, should not be viewed simply as a waste to be disposed, because they play a critical role in sustaining soil organic matter and therefore have an inherent C-capturing value. Moreover, considering straws as an energy feedstock, its status of co-product is clearly recognised and its availability could be obtained according to different cropping systems, corresponding to different primary energy costs and GHG emissions. This paper highlights some hidden features in the assessment of agricultural energy and carbon balance, still very difficult to be detected and accounted for. Although they are frequently disregarded, these features (such as long term dynamic trend of soil organic carbon and annual nitrous oxide emissions from the soil) should be carefully considered in assembling the energy and emission balance. By using a crop simulation model, the long-term soil organic matter and annual N2O soil emissions were estimated. Consequently, a comprehensive energy and GHG balance was determined in accordance with the life cycle assessment methodology. Contrasting methods of straw management and wheat cultivation were compared: straw retention vs removal from the soil; conventional vs conservation tillage; wheat cropping system as a single-crop or in rotation. The resulting carbon footprint of straws has different magnitudes with respect to the several experimental conditions. By selecting the best agricultural practices, energy from straw can be optimally coupled with grain productions, without detrimental effects on soil fertility. An improved and specifically tailored cropping system is designed to obtain an optimal trade-off. © M. Monteleone et al., 2015.
  • Authors:
    • Viger,M.
    • Hancock,R. D.
    • Miglietta,F.
    • Taylor,G.
  • Source: GCB Bioenergy
  • Volume: 7
  • Issue: 4
  • Year: 2015
  • Summary: Biochar is a carbon (C)-rich solid formed when biomass is used to produce bioenergy. This 'black carbon' has been suggested as a solution to climate change, potentially reducing global anthropogenic emissions of greenhouse gases by 12%, as well as promoting increased crop growth. How biochar application to soil leads to better crop yields remains open to speculation. Using the model plant Arabidopsis and the crop plant lettuce (Lactuca sativa L.), we found increased plant growth in both species following biochar application. Statistically significant increases for Arabidopsis in leaf area (130%), rosette diameter (61%) and root length (100%) were observed with similar findings in lettuce, where biochar application also increased leaf cell expansion. For the first time, global gene expression arrays were used on biochar-treated plants, enabling us to identify the growth-promoting plant hormones, brassinosteroid and auxin, and their signalling molecules, as key to this growth stimulation, with limited impacts on genes controlling photosynthesis. In addition, genes for cell wall loosening were promoted as were those for increased activity in membrane transporters for sugar, nutrients and aquaporins for better water and nutrient uptake and movement of sugars for metabolism in the plant. Positive growth effects were accompanied by down-regulation of a large suite of plant defence genes, including the jasmonic acid biosynthetic pathway, defensins and most categories of secondary metabolites. Such genes are critical for plant protection against insect and pathogen attack, as well as defence against stresses including drought. We propose a conceptual model to explain these effects in this biochar type, hypothesizing a role for additional K+ supply in biochar amended soils, leading to Ca2+ and Reactive Oxygen Species (ROS) -mediated signalling underpinning growth and defence signalling responses. © 2014 John Wiley & Sons Ltd.
  • Authors:
    • Fumagalli,Mattia
  • Source: Italian Journal of Agrometeorology
  • Volume: 20
  • Issue: 1
  • Year: 2015
  • Summary: Intensive maize production in Lombardy region (northern Italy) is widespread and requires big amounts of input, especially nitrogen (N), thus leading to potential environmental risks. Starting from farm survey data the current work aims to evaluate how alternative N management options for reducing losses can be effective in climate change mitigation. Under current management (ACT) of typical continuous maize cropping systems across the region, the greenhouse gases (GHG) emissions from the production of inorganic fertilisers and from direct and indirect N2O released after N application accounted for, on average, 67% of the total GHG emissions. The adoption of the best N management plans (FERT scenario), reduced GHG emissions and C-footprint (expressed per unit of agricultural product) by 27 and 26%, respectively. Furthermore, the double cropping system (two crops harvested in 12 months - ROT scenario) strongly increased GHG emissions in comparison with the only cultivation of a summer crop. However, the high productivity of this system, led to a C-footprint lower than the ACT one and still higher than the FERT one. The current work highlights the opportunities for carbon mitigation offered by changes on field N management, without significantly impact the yield.
  • Authors:
    • Machado,S.
    • Pritchett,L.
    • Petrie,S.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 5
  • Year: 2015
  • Summary: Winter wheat ( Triticum aestivum L.)-summer fallow (WW-SF) using conventional tillage (CT), the predominant cropping system in eastern Oregon, has increased soil erosion and depleted soil organic carbon (SOC). This research evaluates no-tillage (NT) systems designed to reduce these negative impacts on soil. In this long-term experiment (2004-2010), WW-SF using CT was compared with annual winter wheat (WW-WW), annual spring wheat (SW-SW), annual spring barley ( Hordeum vulgare L.) (SB-SB), winter wheat-chemical fallow (WW-CF), winter wheat-winter pea ( Pisum sativum L.) (WW-WP), and winter wheat-spring barley-chemical fallow rotation (WW-SB-CF), using NT. Measurements included, phenology, plant population, grain yield and yield components, residues, SOC, soil moisture, and precipitation. Water-use efficiency (WUE) was derived from precipitation and yield data. Under annual cropping, WW-WP and SB-SB produced higher yields than WW-WW and SW-SW. Grain yields in rotations with fallow (WW-SF, WW-CF, and WW-SB-CF) were not significantly different. On an annual basis, SB-SB and WW-WP produced the highest and lowest yields, respectively. The WUEs of fallow rotations, SB-SB, and SW-SW, were not different but were higher than WUEs of WW-WP and WW-WW. Residue cover and SOC were highest under annual cropping systems and lowest following peas in WW-WP and SF in WW-SF. We conclude that rotations with fallow using NT (WW-CF and WW-SB-CF) can replace the traditional WW-SF system without yield penalty.
  • Authors:
    • Panettieri,M.
    • Berns,A. E.
    • Knicker,H.
    • Murillo,J. M.
    • Madejon,E.
  • Source: Soil & Tillage Research
  • Volume: 151
  • Year: 2015
  • Summary: An augment of soil organic matter (SOM) in agricultural lands is mandatory to improve soil quality and fertility and to limit greenhouse gases emissions. A better protection of SOM from degradation is seconded to its inclusion in aggregates and to the formation of organo-mineral interactions with the clay fraction within the soil matrix. Under Mediterranean conditions, conservation agriculture (CA) has been widely related with macro-aggregates formation, SOM protection, and to an improvement of soil fertility and crop yields. The objective of this work was to evaluate the biogeochemical properties of five aggregate-size fractions obtained by dry sieving of a Calcic Fluvisol of an experimental farm managed under three different tillages. Soil aggregates distribution, total organic carbon (TOC), labile carbon pools, and enzymatic activities were measured in 2 different periods of the same agricultural campaign. CPMAS 13C NMR analyses were also performed to elucidate the structure of preserved SOM. The results evidenced seasonal variability in aggregate distribution, labile carbon pools and dehydrogenase activity (DHA), whereas TOC, permanganate oxidizable carbon (POxC), and beta- glucosidase activity demonstrated to be reliable soil quality indices for soil fractions. The NMR analyses showed a better SOM preservation under conservation tillages, due to higher plant litter inputs and/or higher amount of necromass derived compounds if compared with traditional tillage. Particularly interesting are the results of the O 0.5-1 mm fraction, in which different trends were found for beta-Glu and several organic compound classes if compared with the other fractions. Possibly, in this fraction are concentrated most of the products from cellulose depolymerization stabilized by organo-mineral interactions.