UNIT 8

• Estimating and Monitoring Non-CO2 Greenhouse Gas Emissions from Field Burning of Crop Residues

  
• Jose Hermis P. Patricio, Professor, CMU-CFES
• Outline

  • Overview of agricultural residue burning
  • Importance of addressing the issue
  • Environmental and health impacts
  • Estimating greenhouse gas emissions from burning of agricultural wastes
  • Monitoring techniques
  • Management strategies

  
• Land Area for Agriculture
• Leading Crops in PH
• Given this, the country's agriculture sector is expectedly generating every year significant amount of wastes called crop residues (rice, corn and sugarcane)

  
• Sugarcane residues constitute about 11% of the world's agricultural waste (Crutzen and Andreae, 1990)

  
• Wetland rice cultivated in the Phils. under a moderate level of management produced between 0.6 and 0.9 tonnes of straw per tonne of grain (Ponnamperuma, 1984)

  
• Corn residues in the Philippines is produced at a rate of 4,731.92 kg ha-1 (DAP, nd)

  
• Burning of Agri Residues


  Common agricultural practice in the Philippines, particularly after harvest seasons

  
• Burning of Agri Residues


  • Primarily conducted to clear fields quickly for the next planting cycle
  • Main crops associated with residue burning include rice, sugarcane, corn, and other crops
  • Typically occurs in rural areas where agriculture is a major livelihood
  • Regulatory efforts exist to control burning, but enforcement can be challenging due to socioeconomic factors and limited resources

  
• Burning of Agri Residues

  • Causes significant air pollution, emitting pollutants such as particulate matter, carbon monoxide, and volatile organic compounds
  • Leads to health issues, including respiratory problems, particularly among vulnerable populations such as children and the elderly
  • Contributes to environmental degradation, soil erosion, loss of biodiversity, and greenhouse gas emissions

  
• However, the practice of field burning crop residues leads to the production not only of CO2 but also non-CO2 GHG and their precursors such as carbon monoxide (CO), methane (CH4), nitrous oxide (N2O) and nitrogen oxide (NOx)

  
• Estimating GHG Emissions from Burning of Agricultural Residues

  • Step 1: Total Carbon Released from Burning Agricultural Residues
  • Step 2: Calculate GHG emissions

  
• Total Carbon Released


  Data required: Amount of crops produced with residues that are commonly burned, Ratio of residue to crop product, Fraction of residue burned, Dry matter content of residue, Fraction oxidized in burning, and Carbon content of the residue

  
• Emission ratios
• Crop Residue Default Values

  
• Example from Patricio, 2018
• Objectives: 1) determine the "hot spot" regions/provinces in the Philippines in terms of crop residue burning, 2) propose practical measures or options to "cool" these identified hot spots and to recommend policy options to address such problem
• Data Sourcing: Primary data: C fractions and C-N ratio of crop residues, Secondary data: a) 1990-2015 volume of rice, corn and sugarcane production (Philippine Statistics Authority), b) default values on emissions factors and other related data (IPCC, 1996 & 2006; Crutzen, & Andreae, 1990)

  
• Calculation of Emissions: Total C released, CH4, CO, N2O and NOx emissions using the IPCC Tier 1 method

  
• GIS Mapping: Identification of "hotspot" regions and provinces in the Phils
• Statistical Analysis
• Findings


  • Mean annual volume of rice production= 13.6 M mt, 94.8% increase between 1990-2015, Most notable in Isabela, Pangasinan, Nueva Ecija & Iloilo
  • Corn subsector mean yield is about 5.5 M mt, 35.4% increase between 1990-2015, Prominent increase is observed in North and South Cotabato, Isabela, and Bukidnon
  • Sugarcane prdn annually is 22.7 M mt, 35.4% increase between 1990-2015, Prominent increase is observed in Negros Occidental & Oriental, Bukidnon & Batangas

  
• Findings


  • Residue generated and burned in fields: Sugarcane- 16,400 Gg & 4,100 Gg, respectively, Rice- 7,600 Gg & 4,500 Gg, Corn- 2,200 Gg & 550 Gg
  • Annually, around 550 Gg of CO, 21 Gg of CH4, 15 Gg of NOx, and 0.4 Gg of N2O are produced in the country due to crop residue burning

  
• Percentage distribution of non-CO2 emissions from crop residue burning: CH4 3.57%, CO 93.81%, N2O 0.07%, NOx 2.55%

  
• Regional percentage contribution to non-CO2 emissions from crop residue burning, 1990-2015

  
• Methane emissions, Gg: Surged by about 54% between 1990 (16 Gg) and 2015 (24.6 Gg), Notable in WV, NM, CL, Cag Val & SOCCSKSARGEN

  
• Carbon monoxide emissions, Gg: Increased by about 54% between 1990-2015 at 550 Gg yr-1, Notable in WV, CL, NM & SOCCSKSARGEN

  
• Nitrous oxide emissions, Gg: Posted an increase of 67% bet. 1990-2015 at 0.41 Gg yr-1, Notable in WV, CL, & Cag Val

  
• Nitrogen oxide emissions, Gg: Surged by >60% bet. 1990-2015, Notable in WV, CL, & Cag Val
• Conclusions


  • There is an upward trend in the volume of crop residue generated and burned in the Philippines from 1990 to 2015 due to increased volume of production of rice, sugarcane and corn
  • Sugarcane generated about 63% of the total volume of crop residue produced annually while rice and corn contributed 29% and 8%, respectively
  • There is an observed upward trend in the mean annual emissions of CH4, CO, N2O and NOx in the Philippines from crop residue burning from 1990 to 2015 which are estimated at 21 Gg, 550 Gg, 0.4 Gg and 15 Gg, respectively with CO constituting 94% of the total emissions
  • Western Visayas, Central Luzon, Northern Mindanao and Cagayan Valley are considered "hotspot" regions primarily the provinces of Negros Occidental, Antique, Aklan, Capiz, Iloilo, Bukidnon, Isabela, Pangasinan, Nueva Ecija, and North and South Cotabato

  
• Methods used for monitoring GHG emissions from agri residue burning

  • Direct Measurement Techniques: Field measurements, Flux chambers, Emission factor approach
  • Remote Sensing Technologies: Satellite Imagery, Infrared (IR) Sensors
  • Modeling Approaches: Emission Inventories, Atmospheric Dispersion Models
  • Carbon Accounting Tools: Carbon Footprint Calculators, Life Cycle Assessment (LCA)

  
• Management Strategies


  • Alternatives to Burning: Composting, Mulching, Bioenergy Production
  • Policy Interventions and Incentives
• Methane (CH4)


  Methane is a potent GHG with a much higher global warming potential (GWP) than carbon dioxide (CO2) over a 20-year timeframe. It is generated during the anaerobic decomposition of organic waste in landfills, where organic materials break down in the absence of oxygen.
• Carbon Dioxide (CO2)


  Carbon dioxide is emitted throughout various stages of solid waste management, including waste collection, transportation, treatment, and disposal. CO2 is released during the combustion of fossil fuels in waste collection vehicles, incinerators, and other waste treatment facilities. Landfills also emit CO2 through the aerobic decomposition of organic waste and the oxidation of landfill gas constituents.
• Nitrous Oxide (N2O)


  Nitrous oxide is produced through biological processes, such as nitrification and denitrification, occurring in waste treatment facilities, particularly during composting and anaerobic digestion processes.
• Other Trace Gases


  • Volatile organic compounds (VOCs)
  • Sulfur dioxide (SO2)
  • Ammonia (NH3)
• Sources of GHG Emissions in Solid Waste Management

  • Waste Generation
  • Collection and Transportation
  • Landfilling
  • Waste Treatment and Disposal
• Waste Generation


  Quantity and composition of waste generated, including organic, paper, plastics, and other materials.