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- Evaluation of Tomato-Based Packing Material for Retention of Ammonia, Nitrous Oxide, Carbon Dioxide and Methane in Gas Phase Biofilters: A Laboratory StudyPublication . Pereira, José L.S.; Perdigão, Adelaide; Marques, Francisco; Coelho, Catarina; Mota, Mariana; Fangueiro, DavidBiofilters are an effective air pollution control technology to break down gaseous contaminants and produce innocuous end products. This laboratory study aimed to evaluate a biofilter media, mainly composed by tomato waste, as packing material to reduce NH3, N2O, CO2 and CH4 losses from stored pig slurry. Three mixtures of packing materials, with and without oxalic acid, were arranged in treatments, namely: mixture of tomato waste, pine bark and agricultural compost; mixture of tomato waste and rice husk; tomato waste only. A control treatment (no biofilter) was also included. The experiments were conducted using a system of laboratory scale biofilters connected to jars filled with pig slurry and under a constant airflow rate. The gas concentrations were measured for 14 days and the physicochemical of the packing materials were assessed. Results showed that biofilter media mixtures had a potential for NH3 retention ranging from 51 to 77% and the addition of oxalic acid to these biofilters increased NH3 retention to 72–79%. Additionally, the biofilter media mixtures with and without oxalic acid showed a potential retention for CH4 (29–69%) but not for N2O, yet with no impact on the global warming potential. It can be concluded that tomato based biofilters had the potential to reduce gaseous emissions from slurry.
- Effect of Biochar on Emission of Greenhouse Gases and Productivity of Cardoon Crop (Cynara cardunculus L.)Publication . Barracosa, Paulo; Cardoso, Isabel; Marques, Francisco; Pinto, António; Oliveira, Jorge; Trindade, Henrique; Rodrigues, P.; Pereira, José L.S.Cardoon could be cropped for agro-environmental, industrial, and pharmaceutical purposes. The aim of this study was to assess the effects of biochar on emissions of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4), and productivity of cardoon crop. A pot experiment was run outdoors from April to August 2018, with a cardoon plant per pot. The following four treatments, with four replicates each, were applied: control, soil only; mineral, soil amended with mineral fertilizer (2.5 g N m−2); biochar, soil amended with biochar (1 kg m−2); and mineral+biochar, soil amended with mineral fertilizer (2.5 g N m−2) and biochar (1 kg m−2). The morphological characteristics and biomass production of cardoon plants were evaluated, and the fluxes of N2O, CO2 and CH4 were measured by using the closed chamber technique. The application of biochar combined with mineral reduced N2O emissions by 36% and global warming potential (GWP) by 26% relative to mineral. However, the cumulative CO2 and CH4 emissions as well as yield-scaled GWP were not significantly different among amended soil treatments. Furthermore, the biomass production was increased by 50% by the application of biochar combined with mineral fertilizer relative to mineral. It was concluded that biochar combined with mineral fertilizer is recommended as a pathway mitigation for agro-environmental purposes, because it reduces the global warming potential and could increase the biomass production of cardoon plants.
- Mitigating Ammonia and Greenhouse Gas Emissions from Stored Pig Slurry Using Chemical Additives and BiocharsPublication . Pereira, José L.S.; Perdigão, Adelaide; Marques, Francisco; Ferreira Wessel, Dulcineia; Trindade, Henrique; Fangueiro, DavidSlurry storage is a significant source of NH3 and greenhouse gas (GHG) emissions. The aim of this laboratory study was to assess the effects of different chemical additives and biochars on the emissions of NH3, N2O, CO2, and CH4 during the short-term storage of pig slurry. The experiment was performed using Kilner jars filled with raw slurry as control and six treatment additives (5% w/w): acidified slurry, alkalinized slurry, neutralized slurry, agroforestry biochar, cardoon biochar, and elderberry biochar. The gas emissions were measured for 30 days, and the composition of the slurries was determined. During short-term storage, the results of this laboratory study indicated that the NH3 emissions were reduced by 58% by acidification and by 20% by the biochars (Agroforestry, Cardoon, and Elderberry treatments), while neutralization reduced this loss by only 12%. Nitrous oxide emissions were not reduced by the chemical additives (Acidified, Alkalinized, and Neutralized treatments), while this loss was increased by 12% by the biochars. Carbon dioxide, CH4, and global warming potential emissions were not affected by the chemical additives and biochars. Furthermore, the absence of differences between the biochars may be related to their similar composition. Regarding the influence of the studied additives on NH3 losses, it can be concluded that acidification was the best mitigation measure and the biochars were quite similar due to their composition. Furthermore, neutralization had the advantage of sanitizing the slurry, but only had a mild impact on NH3 preservation.
- Influence of Nitrogen Application and Drip Irrigation on Greenhouse Gas Emissions and Yield of Cardoon Crop (Cynara cardunculus L.)Publication . Barracosa, Paulo; Antunes, Manuela; Marques, Francisco; Pinto, António; Oliveira, Jorge; Trindade, Henrique; Pereira, José L.S.Background: Cardoon is a multi-purpose crop with a wide spectrum of potential applications. Objective: The aim of this study was to assess the effects of nitrogen (N) application and drip irrigation practices on emissions of nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) and morphological characterization and biomass production of cardoon crop. Methods: The experiment was run under field conditions from April to August 2018. The field experiment was a randomized complete block design with three replications and four treatments: (i) non-amended soil as control (CONTR); (ii) mineral N fertilizer and non-irrigated (NITRO); (iii) non-fertilized and drip irrigation (IRRIG); and (iv) mineral N fertilizer and drip irrigation by fertigation (FERTI). The fluxes of N2O, CO2 and CH4 were measured by the closed chamber technique and the morphological characteristics and yield of cardoon plants were evaluated per treatment. Results: Results showed that the N2O emissions and global warming potential were not significantly different among the application of mineral N fertilizer itself or by drip fertigation with an emission rate of 0.5% of N applied and -6,8 t CO2-eq. ha-1. The characteristics related to biomass production did not differ significantly (p>0.05) between amended treatments although numerically higher in IRRIG treatment. Conclusion: It was concluded that the application of mineral N fertilizer itself or drip fertigation had no significant effect on N2O emissions and global warming potential. Additionally, the plant growth, including biomass production, increased due to drip irrigation, but not significantly.
- Effect of Different Tannery Sludge Composts on the Production of Ryegrass: A Pot ExperimentPublication . Perdigão, Adelaide; Marques, Francisco; Pereira, José L.S.Background: Tannery industry produces high amounts of nutrient rich sludges that can be used as organic fertilizers. Objective: The aim of this study was to evaluate the fertilizing potential of composted tannery sludge. Methods: A pot experiment was carried out with ryegrass (Lolium perenne L.) to test two different composts: 2.0 kg dry matter (DM) tannery fatty sludge + 1.5 kg DM sheep manure + 1.5 kg DM wheat straw (Compost 1) and 2.0 kg DM tannery sludge + 1.5 kg DM sheep manure + 1.5 kg DM wheat straw (Compost 2). Five treatments, with three replicates each, were assigned: Control (C); Compost 1 at 6 t (C1-6) and 12 t (C1-12) DM ha-1; Compost 2 at 6 t (C2-6) and 12 t (C2-12) DM ha-1. Each treatment was applied in a pot and mixed with 5 kg of sieved soil (<2 mm). Results: Results showed that production of DM ranged between 1.2 t DM ha-1 for C1-6 and 2.4 t DM ha-1 for C2-12. The highest B, Na and N levels in ryegrass was observed in C2-12, with 175 mg kg-1 DM, 9 g kg-1 DM and 30 g kg-1 DM, respectively. At the end of the experiment no differences were observed between treatments for C, N, P2O5, and K2O levels. Differences were observed at Zn level ranged between 101 mg kg-1 DM for C1-6 and 71 mg kg-1 DM for C2-12. Conclusion: The C2-12 treatment was the best because induces higher DM production and nutrients in ryegrass and without dangerous concentration of heavy metals in soil. Composted waste from the tannery industry is a good source of nutrients for agriculture.
- Greenhouse Gas Emissions and Ryegrass Yield after Application of Solid-Liquid Pig Slurry and Biochar to an Agricultural SoilPublication . Pereira, José Luís da Silva; Perdigão, Adelaide; Bonifácio, Gabriel; Figueiredo, Vitor; Marques, Francisco; Trindade, Henrique; Ferreira Wessel, DulcineiaBackground: The application of animal slurry to the soil improves its quality, as manure contains many nutrients for plants. However, this could negatively impact the environment. Objective: This field study investigated the effects of the addition of biochar after the mechanical separation of Whole pig Slurry (WS) into Solid (SF) and Liquid Fractions (LF) on Greenhouse Gases (GHG) emissions (N2O, CO2, and CH4) and ryegrass (Lolium multiflorum Lam. cv magnum) yield. Methods: Biochar (1.0 kg m-2) was applied in plots alone or together with each of the three slurries (80 kg N ha-1) in a total of eight treatments with three replications, including just soil with and without biochar as controls. Soil properties, Greenhouse Gas (GHG) fluxes, and yield were measured during theautumn/winter growing season. Results: The results showed that the addition of biochar to these three slurries significantly increased the soil pH and showed no impact on the other physicochemical properties. The GHG emissions were not significantly different between treatments with and without biochar. The N use efficiency increased significantly in SF > WS > LF, whereas no differences were observed among these three slurries with and without biochar. Conclusion: It can be concluded that the addition of biochar combined with WS or SF/LF to sandy-loam soil appears to have no impact on GHG emissions and ryegrass yield during the autumn/winter season. Overall, this finding suggests that amounts higher than 1.0 kg m-2 of biochar combined with SF may need to be applied to soil to reduce GHG emissions and nitrate leaching and increase N use efficiency and crop yield