• Authors:
    • Lehmann, J.
    • Lamers, J.
    • Bationo, A.
  • Source: Article
  • Volume: 102
  • Issue: 1
  • Year: 2015
  • Authors:
    • Buerkert, Andreas
    • Bruentrup, Michael
    • Lamers, John P. A.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 102
  • Issue: 1
  • Year: 2015
  • Summary: Low concentrations of phosphorus (P) also limit crop production on the acid, sandy soils in Sudano-Sahelian West Africa (SSWA). An increased P-use is thus a key leverage for enhancing food security and alleviating poverty. Therefore, P-imports into the predominating agro-pastoral farming systems are indispensable, but most smallholders are cash-poor and risk averse, face labor-constraints, and P-fertiliser responses are site-specific. Key to the adoption of any new technology is a high financial performance with low risk levels of failure, low demands of labor and cash, and adaptation to the prevailing farming systems. Financial performances were assessed from nine, annually applied fertilising practices during 4 years in five SSWA zones. Information about the farming systems, labor demands, and input-output prices stem from secondary sources. The profitability largely depended on rainfall and location-specific soil conditions, but those of annually repeated mineral and organic P-strategies increased over time. Several P-fertilisations were profitable on a per land unit basis, but could not compete with farmers' practices on a per labor unit basis. Mulching with and without P (13 kg P ha(-1)) were not financially superior, but the broadcast application of 13 kg P ha(-1) became profitable over time. Hill-placed P (4 kg P ha(-1)), also known as micro-dosing, was a profitable alternative to farmers' practices particularly in the intermediate rainfall zone. The results showed the importance of recommendations following rainfall zones, which are of interest across a spectrum of users including policy makers, land use practitioners, private firms, NGOs and research for development implementers.
  • Authors:
    • Miglierina,A. M.
    • Iglesias,J. O.
    • Laurent,G. C.
    • Rodriguez,R. A.
    • Ayastuy,M. E.
    • Lobartini,J. C.
  • Source: Acta Horticulturae
  • Volume: 1076
  • Issue: 1076
  • Year: 2015
  • Summary: The application of composted organic wastes to soil can be used for conserving soil organic matter, reclaiming degraded soils and supplying plants with nutrients. Two greenhouse experiments were carried out to evaluate the addition of compost on chemical and physical properties of soils. Four different texture soils were used: Sandy soil (S1), Silty loam soil (S2), Clay loam soil (S3) (33.2 O.C. g.kg -1) and Clay loam soil (S4) (14.8 O.C. g.kg -1) cultivated with lettuce ( Lactuca sativa L.) in the Bahia Blanca region, Argentina. The application of compost had a significant effect on lettuce productivity and nutrient uptake by the crop in three of the four soil types; showing a positive effect on the dry weight, number, length and width of the leaves. The applied dose (40 Mg ha -1) modified the chemical composition of the plants: those grown in soil with added compost showed higher concentrations of nutrients than those grown in control soils. In clay loam soil (S3) no difference were found in plant productivity between treatments with and without application of compost. With respect to soil properties changes, the application of compost affected the soil pH in variable way; increased organic carbon, total nitrogen and available phosphorus. The addition of compost lowered bulk density in soils S2 and S4; increased the percentage of macropores and mesopores in S2; diminished content of mesopores and increased content of micropores at S3 and S4. The variations on chemical and physical soil properties demonstrate the benefits of compost addition, even in a short period of time.
  • Authors:
    • Migliorati,M. de A.
    • Bell,M.
    • Grace,P. R.
    • Scheer,C.
    • Rowlings,D. W.
    • Liu Shen
  • Source: Agriculture, Ecosystems and Environment
  • Volume: 204
  • Issue: 1
  • Year: 2015
  • Summary: Alternative sources of N are required to bolster subtropical cereal production without increasing N 2O emissions from these agro-ecosystems. The reintroduction of legumes in cereal cropping systems is a possible strategy to reduce synthetic N inputs but elevated N 2O losses have sometimes been observed after the incorporation of legume residues. However, the magnitude of these losses is highly dependent on local conditions and very little data are available for subtropical regions. The aim of this study was to assess whether, under subtropical conditions, the N mineralised from legume residues can substantially decrease the synthetic N input required by the subsequent cereal crop and reduce overall N 2O emissions during the cereal cropping phase. Using a fully automated measuring system, N 2O emissions were monitored in a cereal crop (sorghum) following a legume pasture and compared to the same crop in rotation with a grass pasture. Each crop rotation included a nil and a fertilised treatment to assess the N availability of the residues. The incorporation of legumes provided enough readily available N to effectively support crop development but the low labile C left by these residues is likely to have limited denitrification and therefore N 2O emissions. As a result, N 2O emissions intensities (kg N 2O-N yield -1 ha -1) were considerably lower in the legume histories than in the grass. Overall, these findings indicate that the C supplied by the crop residue can be more important than the soil NO 3- content in stimulating denitrification and that introducing a legume pasture in a subtropical cereal cropping system is a sustainable practice from both environmental and agronomic perspectives.
  • 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:
    • Deng,Q.
    • Hui,D. F.
    • Wang,J. M.
    • Iwuozo,S.
    • Yu,C. L.
    • Jima,T.
    • Smart,D.
    • Reddy,C.
    • Dennis,S.
  • Source: Web Of Knowledge
  • Volume: 10
  • Issue: 4
  • Year: 2015
  • Summary: Background: A three-year field experiment was conducted to examine the responses of corn yield and soil nitrous oxide (N 2O) emission to various management practices in middle Tennessee. Methodology/Principal Findings: The management practices include no-tillage + regular applications of urea ammonium nitrate (NT-URAN); no-tillage + regular applications of URAN + denitrification inhibitor (NT-inhibitor); no-tillage + regular applications of URAN + biochar (NT-biochar); no-tillage + 20% applications of URAN + chicken litter (NT-litter), no-tillage + split applications of URAN (NT-split); and conventional tillage + regular applications of URAN as a control (CT-URAN). Fertilizer equivalent to 217 kg N ha -1 was applied to each of the experimental plots. Results showed that no-tillage (NT-URAN) significantly increased corn yield by 28% over the conventional tillage (CT-URAN) due to soil water conservation. The management practices significantly altered soil N 2O emission, with the highest in the CT-URAN (0.48 mg N 2O m -2 h -1) and the lowest in the NT-inhibitor (0.20 mg N 2O m -2 h -1) and NT-biochar (0.16 mg N 2O m -2 h -1) treatments. Significant exponential relationships between soil N 2O emission and water filled pore space were revealed in all treatments. However, variations in soil N 2O emission among the treatments were positively correlated with the moisture sensitivity of soil N 2O emission that likely reflects an interactive effect between soil properties and WFPS. Conclusion/Significance: Our results indicated that improved fertilizer and soil management have the potential to maintain highly productive corn yield while reducing greenhouse gas emissions.
  • 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:
    • Kibue,Grace Wanjiru
    • Pan,Genxing
    • Zheng,Jufeng
    • Li Zhengdong
    • Mao,Li
  • Source: Environment, Development and Sustainability
  • Volume: 17
  • Issue: 3
  • Year: 2015
  • Summary: Agricultural production is a complex interaction between human and natural environment, making agriculture both significantly responsible and vulnerable to climate change. China, whose socioeconomy is fundamentally dependent on agriculture, is already experiencing climate-change-related issues that threaten food security and sustainable development. Climate change mitigation and adaptation are of great concern to ensure food security for the growing population and improve the livelihoods of poor smallholder producers. A questionnaire survey was conducted in Henan Province, China to assess agronomic practices of smallholder farmers, adaptation strategies and how climate change awareness and perceptions influence the farmers' choice of agronomic practices. The results showed that the vast majority of farmers owned < 10 Chinese Mu (0.7 ha) and nearly all farmers' relied on intensive use of chemical fertilizers and pesticides to increase yield at the detriment of environment. However, farmers who were aware of climate change had adopted agronomic practices that reduce impacts of climate change. Information about climate change, lack of incentives, lack of credit facilities and small farm sizes were major hindrance to adaptation and adoption of farming practices that can reduce impacts of climate change. This study recommends that research findings should be disseminated to farmers in timely and appropriate ways. The central government should formulate policies to include subsidies and incentives for farmers to motivate adoption of eco-friendly agronomic practices.
  • Authors:
    • Liu ShuWei
    • Zhao Chun
    • Zhang YaoJun
    • Hu ZhiQiang
    • Wang Cong
    • Zong YaJie
    • Zhang Ling
    • Zou JianWen
  • Source: GCB Bioenergy
  • Volume: 7
  • Issue: 4
  • Year: 2015
  • Summary: A full accounting of net greenhouse gas balance (NGHGB) and greenhouse gas intensity (GHGI) was examined in an annual coastal reclaimed saline Jerusalem artichoke-fallow cropping system under various soil practices including soil tillage, soil ameliorant, and crop residue amendments. Seasonal fluxes of soil carbon dioxide (CO 2), methane (CH 4), and nitrous oxide (N 2O) were measured using static chamber method, and the net ecosystem exchange of CO 2 (NEE) was determined by the difference between soil heterotrophic respiration ( RH) and net primary production (NPP). Relative to no-tillage, rotary tillage significantly decreased the NPP of Jerusalem artichoke while it had no significant effects on the annual RH. Rotary tillage increased CH 4 emissions, while seasonal or annual soil N 2O emissions did not statistically differ between the two tillage treatments. Compared with the control plots, soil ameliorant or straw amendment enhanced RH, soil CH 4, and N 2O emissions under the both tillage regimes. Annual NGHGB was negative for all the field treatments, as a consequence of net ecosystem CO 2 sequestration exceeding the CO 2-equivalents released as CH 4 and N 2O emissions, which indicates that Jerusalem artichoke-fallow cropping system served as a net sink of GHGs. The annual net NGHGB and GHGI were estimated to be 11-21% and 4-8% lower in the NT than in RT cropping systems, respectively. Soil ameliorant and straw amendments greatly increased NPP and thus significantly decreased the negative annual net NGHGB. Overall, higher NPP but lower climatic impacts of coastal saline bioenergy production would be simultaneously achieved by Jerusalem artichoke cultivation under no-tillage with improved saline soil conditions in southeast China.
  • Authors:
    • Martinez-Luscher,J.
    • Morales,F.
    • Sanchez-Diaz,M.
    • Delrot,S.
    • Aguirreolea,J.
    • Gomes,E.
    • Pascual,I.
  • Source: Plant Science
  • Volume: 236
  • Year: 2015
  • Summary: The increase in grape berry ripening rates associated to climate change is a growing concern for wine makers as it rises the alcohol content of the wine. The present work studied the combined effects of elevated CO 2, temperature and UV-B radiation on leaf physiology and berry ripening rates. Three doses of UV-B: 0, 5.98, 9.66 kJ m -2 d -1, and two CO 2-temperature regimes: ambient CO 2-24/14°C (day/night) (current situation) and 700 ppm CO 2-28/18°C (climate change) were imposed to grapevine fruit-bearing cuttings from fruit set to maturity under greenhouse-controlled conditions. Photosynthetic performance was always higher under climate change conditions. High levels of UV-B radiation down regulated carbon fixation rates. A transient recovery took place at veraison, through the accumulation of flavonols and the increase of antioxidant enzyme activities. Interacting effects between UV-B and CO 2-temperature regimes were observed for the lipid peroxidation, which suggests that UV-B may contribute to palliate the signs of oxidative damage induced under elevated CO 2-temperature. Photosynthetic and ripening rates were correlated. Thereby, the hastening effect of climate change conditions on ripening, associated to higher rates of carbon fixation, was attenuated by UV-B radiation.