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Gaseous emission from agricultural fields

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Gaseous emission from agricultural fields, its effects and mitigation - with scientific data and review of articles.

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Gaseous emission from agricultural fields

  1. 1. GASEOUS EMISSION FROM AGRICULTURAL FIELDS, ITS EFFECTS AND MITIGATION Student INIYALAKSHIMI.B.R 13-515-902 Chairman Dr. M.BASKAR Asst. Prof.(SS&AC). Members Dr. P.BALASUBRAMANIAM Prof. & Head (SS&AC) Dr. T.RAMESH Asst. Prof. (AGR)
  2. 2. INTRODUCTION o Ambient air - nitrogen (78%), oxygen (21%), Carbondioxide (0.03%) and other inert gases. o Every day, we breathe - 23,000 times, inhaling about 2000 litres of air along with wide variety of pollutants released into the air by automobiles, factories, power plants and other sources. o Number of harmful gases are being added to atmosphere which adversely affect air quality and make it unfit for living organisms. o Rise in concentration of green house gases has led to enhanced greenhouse effect resulting in global warming and global climate change.
  3. 3. • Agricultural fields also contributes majorly in the emission of these gases. •Soil contains air, which differs from atmospheric air concentration. • The percentage of carbondioxide which is 10 times higher (0.3%) than the atmospheric carbondioxide.
  4. 4. METHANE NITROUS OXIDE CARBONDIOXIDE AMMONIA HYDROGEN SULPHIDE & REDUCED S GASES GASES EMITTED FROM SO
  5. 5. CONTRIBUTION OF AGRICULTURAL SECTOR IN GREEN HOUSE GAS EMISSIONS
  6. 6. Annual emissions - 500 Tg.  23-times greater - than CO2. USEPA- 37.8 Tg/yr – rice fields. Entisols, Inceptisols, Alfisols, Vertisols and Mollisols. Bacterial decomposition of organic matter under anaerobic conditions as exist in lakes, ponds, marshes, rice fields and swamps. METHANE
  7. 7. METHANE FORMATION
  8. 8. MICROBES INVOLVED The methanogenic bacteria are anaerobes belonging to the genera Methanosarcina, Methanobacillus, Methanobacterium, Methanospirillum and Methanococcus. Some other methanogenic bacteria reduce carbon monoxide to methane, while some metabolize methyl mercaptan and dimethyl sulphide to CO2 and CH4.
  9. 9. Methane fluxes in rice fields
  10. 10. Methane emission from termites:
  11. 11. Typical termite densities per ecological regions and methane emission Termite Species (Ecological Region) 106 Termites per Acre Methane Emissions (lb CH4/1000 lb termite/hr) Tropical forest 18.01 4.2 Temperate forest 2.43 1.8 Savanna 17.81 8.0 Temperate grassland 8.66 1.8 Cultivated land 11.38 1.8 Desert scrub 0.93 1.0
  12. 12. Methane emission from permafrost soils  The new species Methanoflorens stordalenmirensis and a new family : Methanoflorentaceae. A release of 50 gigatons of this hard-hitting greenhouse gas (a gigaton is equal to a billion metric tons) between 2015 and 2025. 50 gigatons is 10 times as much methane as currently exists in the atmosphere
  13. 13. FACTORS AFFECTING METHANE FORMATION Carbondioxide Increase in carbondioxide decreases methane emission Type of soil Redox potential Soil carbon content Types of crops Organic matter Type of fertilizer Ammonium sulphate favours activity of other microbes over methanogens.
  14. 14. 0 50 100 150 200 250 300 350 400 450 Baseline SOC-max SOC-min Clay-max Clay-min BD-max BD-min Fe-max Fe-min FWC-max FWC-min CH4 Flux (10-6 Gg C ha-1 yr-1) SOILFACTORS continous flooding Conventional water regimes Source: Hayano et al. (2013) EFFECT OF SOIL FACTORS ON METHANE EMISSION
  15. 15. N treatment (kg N / ha) Methane g m-2 FN150 (150 kg N ha-1) 17.3 FN300 (300 kg N ha-1) 7.3 FN450 (450 kg N ha-1) 4.2 Source: Jianwen et al. (2005) N Application on methane emission
  16. 16. Crop species Soil temperature ( degree celcius) Total methane flux (kg C ha) Fallow (2010) 16.18 0.09 (2011) 15.57 0.01 Spring wheat(2010) 14.74 0.24 (2011) 14.51 -0.01 pea(2010) 15.27 0.11 (2011) 14.41 0.02 Source: Barsotti et al. (2013) Soil temperature and crop on methane emission
  17. 17. Water regime Methane g m-2 F 8.5 FDF 3.0 F – Continous flooding FDF - Flooding-Drainage- Frequent Source: Jianwen et al. (2005) Soil moisture
  18. 18. IMPACTS OF METHANE EMISSION ON ENVIRONMENT AND VEGETATION
  19. 19. 1.Water management. Hayano et al. (2013) 0 50 100 150 200 250 rapid moderate poor CH4 Flux (10-6 Gg C ha-1 yr-1) Drainagerate MITIGATION
  20. 20. Cultivation method of rice affect methane emission Source: Fazli et al.(2012)
  21. 21. 0 20 40 60 80 100 120 140 0 1 2 3 4 Totalmethaneemission Transplanting dates 1 30 days before RTD 2 15 days before RTD 3 OnRTD 4 15 days after RTD Effect of Transplanting dates on methane emission Kim et al. (2013)
  22. 22. Treatment Treatment details Cumulative CH4 emission Kg C ha-1 CK Control 1.90 Urea 100% urea 1.41 UM1 Urea and manure N at 5:5 1.93 UM2 Urea and manure N at 7:3 2.27 UB1 Biochar + urea(20 Mg ha-1) 0.57 UB2 Biochar + urea(40 Mg ha-1) 0.77 UM1B Biochar (30 Mg ha-1)+UM1 1.04 UM2B Biochar (30 Mg ha-1)+UM2 1.29 Application of BIOCHAR Source : J.Jia et al. (2012
  23. 23. Rice cultivars. Fertilization and other cultivation Ricebased cropping systems
  24. 24. Treatments Total emission (g N2O-N ha-1) Control 34.3 Urea 59.9 Urea plus DCD 49.0 Nimin coated urea 57.0 Neam coated urea 53.2 Deepanjan et al. (2000) EFFECT OF NITRIFICATION INHIBITORS ON METHANE EMISSION
  25. 25. No. Mitigation strategy Reduction % of methane emission References 1 Midseason drainage 40 Wassmann et al. (2009) 2 Fertilizer management (Switch from Urea to Ammonium sulfate) 55 EEAA (1999) 10–67 Wassmann et al. (2000) 3 Crop management (short duration varieties) 25 EEAA (1999) Percentage of reduction by various managements
  26. 26. NITROUS OXIDE AND NITROGEN OXIDES Source: IPCC Fourth Assessment Report: Climate Change 2007, Intergovernmental Panel on Climate Change
  27. 27. NITRIFICATION Nitrification is a oxidation process which involves oxidation of ammonium ions to nitrate by nitrifying microorganisms. DENITRIFICATION Denitrification is the reduction process of NO3 - to N2, mediated by facultative anaerobic bacteria, which correspond to 0.1-5.0% of the total bacteria population in the soil (Moreira & Siqueira 2006). Production of nitrogen gases
  28. 28. The denitrifiers are facultative aerobes such as Pseudomonas denitrificans, Paracoccus denitrificans and Thiobacillus denitrificans. N2O is also formed by the oxidation of ammonium by the autotrophic nitrifier, Nitrosomonas europea, by the reduction of nitrate by heterotrophic bacteria such as B.subtilis, E.coli and Aerobacter aerogens and By the reduction of nitrite by soil fungi such as Aspergillus flavus, Penicillium atrovelltum, Fusarium oxysporum and F.solani. Microbes involved
  29. 29.  Chemical decomposition of nitrite (chemidenitrification) and hydroxylamine oxidation (NH2OH).  Chemidenitrification - decomposition of NO2 - - neutral and acidic soils, causing volatilization and fixation of NO2 - in the soil organic matter. The amount of N2O produced this way is almost negligible.  Hydroxylamine - intermediate compound in the oxidation of NH4 + to NO3 - that can produce much more N2O than the chemidenitrification process.  In neutral and acidic soils, N2O is the main product of the NH2OH oxidation, due to its reaction with Mn and Fe, while in calcareous soils (pH from 7.8 to 8.2) the NH2OH reacts with CaCO3 and the main product is N2. Source: Bremner et al. 1980 Gas emitted from Non-biological process
  30. 30. Factors affecting emission: 1) N application 0 10 20 30 40 50 Before irrigation After irrigation N2Oflux(µg/m2/hr) Unfertilized Fertilized Source: Su et al. (1995)
  31. 31. Source: Jianwen et al. (2005) Water regime Nitrous oxide mg m-2 F 6 FDF 155 F – Continous flooding FDF - Flooding-Drainage-Frequent Soil moisture on nitrous oxide emission
  32. 32. Wetting Soil pH Gas diffusion and Oxygen – compaction, fine texture, surface sealing- limit gas diffusion- denitrification - reconsuming. Limited oxygen- nitrification – produces nitrous oxide. Relief position Soil characteristics
  33. 33. Influence of Available carbon 0 100 200 300 400 0 100 200 300 400 Denitrification(ppm N2O+N2) Organic C(ppm) Sainz Rozas et al. (2001)
  34. 34. AGRICULTURAL MANAGEMENT FACTORS Crop type Mosquera et al. (1992) 0 1 2 3 4 5 6 7 8 Maize Grass land N2OemissionKgha-1 Control Mineral fertilizer Cattle slurry, surface spreading Cattle slurry, Narrow-band application
  35. 35. Fertilizer management Soil and crop management – uncultivated soil Residues quality – C:N
  36. 36. IMPACTS ON ENVIRONMENT i) Global warming: ii)Formation of Acidrain
  37. 37. iii) Formation of secondary pollutant ozone:
  38. 38. Prioritizing the use of low N2O emission fertilizers Managing the N-fertilizer application – deep placement, split application. Managing the soil chemistry and microbiology – lime in acid soil Slow release fertilizers Site specific nutrient management techniques Tillage management – no till, reduced tillage Water management- drip, sprinkler, soil moisture sensors MITIGATION
  39. 39. Treatments Cumulative N2O emission (mg N2O m-2) Chemical Fertilizer (CF) 30.2 Lime Nitrogen (LN) 10.7 CF with Dicyanamide (CFD) 24.3 Yamamoto et al. (2013) TABLE: Cumulative nitrous oxide emission over 63 days in each of the plots fertilized with CF, LN, CFD Form a nitrification inhibitor (dicyanamide, DCD) during the decomposition process of lime-nitrogen Lime-nitrogen application
  40. 40. Treatment Treatment details Cumulative N2O emission Kg N ha-1 CK Control 0.4 Urea 100% urea 13.2 UM1 Urea and manure N at 5:5 10.4 UM2 Urea and manure N at 7:3 10.9 UB1 Biochar + urea(20 Mg ha-1) 2.4 UB2 Biochar + urea(40 Mg ha-1) 3.1 UM1B Biochar (30 Mg ha-1)+UM1 2.1 UM2B Biochar (30 Mg ha-1)+UM2 1.9 Jia et al. (2012) Application of Biochar
  41. 41. CARBONDIOXIDE
  42. 42. Source: IPCC Fourth Assessment Report: Climate Change 2007, Intergovernmental Panel on Climate Change.
  43. 43. SOURCES OF CARBONDIOXIDE FROM SOIL: Fermentation Tricarboxylic acid (TCA) cycle Root respiration Rhizosphere respiration Soil animals
  44. 44. Biome Below ground mortmass decomposition Litter decompositi on SOM decompositi on Root respiratio n Polar desert 0.2 0.2 0.1 0.2 Tundra 194.4 119.8 18.1 108.6 Forest tundra 248.2 340 17.0 210.8 Taiga 476 996 42.0 672.7 Mixed- decidious 168 246.4 11.2 243.0 Forest-steppe 341 233.2 11.0 221.7 Steppe 549 182.5 9.4 232.1 Subtropical woodland 2.6 2.2 0.1 2.3 Desert and semi desert 487 182.7 5.2 215.8 Carbondioxide emission from different biomes Kolchugin et al. (1995)
  45. 45. Effect of soil moisture on carbondioxide emission David Risk et al. (2002)
  46. 46. Effect of soil temperature on carbondioxide production David Risk et al. (2002)
  47. 47. a d bcdab d bcd abc cd d 0 1 2 3 4 5 A G F cumulativeCO2production gCO2kg-1d.s.12week N0 N30 N150 Influence of N application Kong et al. 2013
  48. 48. IMPACTS Tropospheric ozone formation Global warming
  49. 49. Sequestration of C in soil •Reduced tillage and no tillage practices •Promoting agro-forestry, Afforetration. •Increasing the passive or inert fraction of soil organic pool •Organic farming •Precision farming
  50. 50. Establishment methods CO2 CH4 N2O TS FS MS TS FS MS TS FS MS Coimbatore TPR 480 2644 1522 13.12 16.11 10.11 1.74 0.58 2.44 DSR 274 3012 2162 9.46 12.42 8.12 1.1 2.12 0.35 SRI 102 2894 2088 11.11 13.11 9.66 1.88 1.96 0.60 Aduthurai TPR 493 3164 1794 5.93 8.28 4.7 1.13 0.62 2.89 DSR 287 3963 3338 2.42 7.27 4.98 0.91 3.43 0.48 SRI 121 3340 2592 4.41 6.38 2.97 1.68 2.25 0.8 GASEOUS EMISSION FROM PADDY FIELDS Tamil Nadu TS – Tillering Stage FS – Flowering Stage MS – Maturity Stage TPR – Transplanted Rice DSR – Direct Seeded Rice SRI – System of Rice Intensification
  51. 51. AMMONIA
  52. 52.  Soil pH Increase in pH increases volatalization. Upto about pH 9, ammonia concentration increases by a factor of 10 per unit increase of pH.  Wind velocity Higher the wind velocity , higher the volatalization  Salinity  Fertilizer application – broadcast – band application and deep placement  Use of nitrification inhibitors FACTORS AFFECTING AMMONIA VOLATALIZATION
  53. 53. 0 10 20 30 40 1 2 3 4 5 6 7 8 9 10 NH3loss(%)ofappliedN soil solution pH Field Capacity Air dry kanani et al., 1991 Influence of soil moisture on cumulative NH3 loss from surfaced applied urea.
  54. 54. 0 500 1000 1500 2000 2500 3000 3500 Spring Summer Fall Winter Kgammonia Season Emissions from soil Emissions from lagoons Roelle et al. (2002) Diurnal and seasonal variability
  55. 55. kanani et al., 1991
  56. 56. Effect of soil temperature on ammonia emission Roelle et al. (2002)
  57. 57. Effect of over grazing on ammonia volatilization Yunhai Zhang et al
  58. 58. Impacts  Eutrophication  Soil acidification  Fertilization of vegetation
  59. 59. IMPACTS ON VEGETATION Plants, trees and crops - water. large release of ammonia occurs the vapor will likely burn the leaves of nearby downwind vegetation. Excess exposure leads to death of sensitive plants. Especially lichens, mosses,etc Shift in dominance from mosses, lichens and ericoids (heath species) towards grasses like Deschampsia flexuosa, Molinia caerulea and ruderal species, e.g. Chamerion angustifolium, Rumex acetosella, Rubus idaeus.
  60. 60. MITIGATION Slow release N fertilizers, Urease and nitrification inhibitors : Slow release fertilizers such as urea super granules (USG), sulphur coated urea, neem cake coated urea, neem oil coated urea, etc can be used to minimize the ammonia volatilization. Method and time of fertilizer application Site-specific N management Fertigation and foliar application Types of fertilizers
  61. 61. Emission factors based on fertilizer application (kg-NH3 / Mg-N) Fertilizer Group I soils Group II soils Group III Soils Anhydrous ammonia 48 48 48 Nitrogen solutions (urea & AN) 97 97 97 Urea 242 182 182 Diammonium phosphate 61 61 61 Ammonium nitrate (AN) 36 24 12 Liquidammonium polyphosphate 61 61 61 Aqueous ammonia 97 97 97 Ammonium thiosulfate 30 30 30 Calcium ammonium nitrate 36 24 12 Potassium nitrate 12 12 12 Monoammonium phosphate 61 61 61 Ammonium sulfate 182 121 61 AMMONIA EMISSION FROM DIFFERENT FERTILIZER APPLICATION Source: William Battye et al. (2004)
  62. 62. SULPHIDE AND SULPHUR GASES The annual rate of sulfur emission associates with human activities has been estimated of about 80 Tg S . Aerated soils the emissions were between 0.8 and 27 μg m−2 h−1 H2S
  63. 63. REDUCED S GASES FROM SOIL  Hydrogen sulfide (H2S)  Carbonyl sulfide (COS)  Carbon disulfide (CS2)  Methyl mercaptan (CH3SH)  Dimethyl sulfide (DMS)and  Dimethyl disulfide (DMDS)  Sulphur dioxide – In ASS –only trace amount.
  64. 64. ORGANISMS INVOLVED IN SULPHATE REDUCTION  Desulfotomaculatum (3species),  Desulfovibrio (5 species),  Desulfobacterium,  Desulfococcus,  Desulfosarcina,  Desulforomonas, and  Desulfomonas. Other heterotropic organisms include some bacteria actinomycetes, fungi, algae (Clostridium nitrificans, Aspergillus niger, A.nidulans, Pencilium chyrsogenum, chlorella pyrenecidosa, etc.)
  65. 65. FACTORS FAVOURING SULPHATE REDUCTION Organic matter – heterotropic microbes C:S ratio Presence of nitrogen and sulphur source Presence of iron and manganese Application of fertilizers and manures Redox potential Reaction Redox potential O2-H2O +380 to +320 NO3-N2. Mn4+-Mn2+ +280 to +220 Fe3+-Fe2+ +180 to +150 SO4 2—S2- -120 to -180 CO2-CH4 -200to -280
  66. 66. Gas During cropping After harvest N0-N Mineral Straw N0-N Mineral Straw DMS 3.9 5.7 5.4 0.6 1.1 0.7 COS -0.2 -0.5 -0.2 0.5 0.3 2.1 CS2 0.4 0.4 0.3 0.4 0.7 1.7 Total 4.1 5.7 5.5 1.5 2.7 4.5 Source: K.Kanda et al. (1992). Emission of reduced sulphur gases under mineral fertilizer without nitrogen(N0-N), mineral fertilizer(mineral), mineral fertilizer with rice straw application(straw). Influence of mineral fertilizer on sulphide gas emission
  67. 67. IMPACTS H2S at low levels can increase plant growth “fertilizer” effect
  68. 68. concentration and time of exposure increased there is a decrease in shoot height and root length ,  Decrease in fresh and dry weight,  Decrease in chlorophyll a,  Decrease in carbohydrase ,  Reduced activity of nitrate reductase and glutamate dehydrogenase,  Increase in peroxidase activity,  Increase in cysteine,  Decrease in serine ,  Increase in amino-N.
  69. 69. Occurrence of rotten egg smell and root discoloration have been observed. Soil and water samples containing high sulphur contents of 25 and 65 ppm in Thiruvaiaru and 23 and 60 ppm in Kumbakonam blocks respectively. The H2S symptoms are normally noticed in Cauvery Old Delta (Thanjavur,Thiruvarur and Nagapattinam) in kuruvai season during the years of poor rainfall coupled with delayed receipt of canal water. H2S injury in Cauvery Delta Zone Source: ARW for Rice (2013)
  70. 70. MITIGATION • AWD for soil aeration • Inter cultivation with cono weeder, • Summer ploughing • Split application and use of high MOP @ 43 kg/ha. • Avoid the use of high sulphate containing water for irrigation. • Drain the water fully and apply 10kg urea+10 kg potash evenly. After 2 days irrigate the field with small amount of water. And repeat the same in 7-10 days interval. • Apply iron containing fertilizers – sulphur precipitates as ferrous sulphate. • If the canal water contains high amount of sulphur compounds, store it in ponds and then irrigate through furrows, so that some amount of sulphur will evaporate
  71. 71. NOBLE GASES? THEY TOO EMITTED FROM SOIL……………………. SOUL OF INFINITE LIFE CONCLUSION

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