Manure-DNDC: Building a Process-Based Biogeochemical Tool for Estimating Ammonia and GHG Emissions from California Dairies

Transcription

1 Manure-DNDC: Building a Process-Based Biogeochemical Tool for Estimating Ammonia and GHG Emissions from California Dairies William Salas*, Applied Geosolutions, LLC Changsheng Li, University of New Hampshire, Durham Frank Mitloehner, University of California, Davis Charles Krauter, California State University, Fresno John Pisano, University of California, Riverside * wsalas@ags .com, ph:

2 1999 California CH 4 Emissions MMTCO 2 eq Waste 47% Energy 13% Agriculture 40% Manure Management 41% Rice Paddies 4% Burning Ag. Residues ~0% Enteric Fermentation 55% Source: CEC 2002 GHG Inventory

3 1999 California N 2 O Emissions MMTCO 2 eq Waste 5% Industrial Processes 1% Energy 29% Manure Management 5% Burning Ag. Residues 1% Agriculture 65% Manure applied soils 32% Agricultural Soils 62% Source: CEC 2002 GHG Inventory

4 Project Goals Modify an existing process-based biogeochemical model (DNDC) for estimating CH4, NH3, NO, N2O emissions from dairy systems in California. Collect field data to calibrate and validate this model Build GIS databases on soils, climate, dairy locations, and manure management. Apply the model to estimate emissions across California. Note: model is designed for both regional and single farm simulations.

5 What are Process-based Models? Process-based modeling refers to biochemical and geochemical reactions or processes Process modeling, in this case, does not refer to AFO practices or components (e.g. dairy drylots or manure lagoons) per se, but Biogeochemical processes like decomposition, hydrolysis, nitrification, denitrification, etc True process-based models do not rely on constant emission factors. They simulate and track the impact on emissions of varying conditions within components of the dairies (e.g., climate, flush lanes, storage facility, soils).

6 Nitrogen Biogeochemistry of Manure Manure production Manure organic pools N tranformation in manure Atmospheric N deposit or fertilization Fresh manure Very labile litter N NO N2O N2 N2 NH3 Labile litter N Dung Resistant litter N N2O NO Bedding Labile microbial N NO2- Resistant microbial N Urine Labile humad N NO3- Resistant humad N Nitrification Passive humus N NH4+ NH3 Denitrification Assimilation Decomposition Chemical equilibrium Hydrolysis Litter fall Urea Atmospheric deposition and fertilization Gas emission Chemodenitrification Clay- NH4+ Leaching

7 Why DNDC Model? Contains algorithms for both anaerobic and aerobic soil environments Simulates full range of biogeochemical processes: decomposition, hydrolysis, nitrification, denitrification, ammonium adsorption, chemical equilibriums of ammonium/ammonia, fermentation, and gas diffusion Well validated across a wide range of agroecosystems and is currently being used for national GHG emission inventories and mitigation studies worldwide.

8 DNDC has been tested against a wide range of datasets of CO2, CH4, N2O, Observed and DNDC-Modeled N2O Fluxes from Agricultural Soils in the U.S., Canada, the NO U.K., and Germany, NH3 emissions New Zealand, observed China, Japan, worldwide and Costa Rica 1000 R 2 = 0.84 Modeled N2O flux, kg N/ha/year Observed N2O flux, kg N/ha/year

9 Biogeochemical Model is a Mathematical Expression of Biogeochemical Field Biogeochemical processes controlling C and N transformation in soil organic matter have been developed in DNDC Biochemical & geochemical reactions Environmental factors Ecological drivers Mechanical movement Gravity Transformation & transport of chemical elements Dissolution / crystallization Combination / decomposition Oxidation / reduction Adsorption / desorption Complexation / decomplexation Radiation Temperature Moisture Eh ph Climate Soil properties Vegetation Anthropogenic activities Assimilation / dissimilation Substrates

10 Soil Trace Gas Evolution Driven by Redox Potential (Eh) DNDC quantifies trace gas emissions by tracking microbial activity in soil organic matter

11 Create Manure-DNDC by linking farm components to DNDC Feeding Housing Storage Treatment Field application DNDC

12 Manure-DNDC utilizes the existing biogeochemical processes to track manure turnover in the farm components Manure production Housing Storage Field application Milk or meat production Intake of C, N and water Temperature, moisture, ph, bedding and ventilation Decomposition, hydrolysis, nitrification, denitrification, fermentation Aerobic storage or compost, lagoon, slurry tank, digester Decomposition, hydrolysis, nitrification, denitrification, fermentation Climate, soil, farming management Decomposition, hydrolysis, nitrification, denitrification, fermentation Quantity and quality of fresh manure: dung and urine Emissions of CO 2, NH 3, CH 4, N 2 O, NO Quantity and quality of manure Emissions of CO 2, NH 3, CH 4, N 2 O, NO Quantity and quality of residue manure Emissions of CO 2, NH 3, CH 4, N 2 O, NO Soil C and N storage

13 Input parameters: - Daily climate data; - Animal type and population; milk/meat production; Intake protein and feed quality; - Housing: ventilation; floor surface and bedding; cleaning method; - Compost size, density, storage time, litter addition; - Lagoon capacity, surface area, coverage, draining frequency; - Slurry tank capacity, coverage, storage time; - Anaerobic digester capacity, CH4 production; - Manure field application: amount, C/N, timing, depth.

14 Output parameters: - Production of urine and feces; - Enteric CH4, N2O and CO2; - Emissions of CH4, N2O, NH3, NO, N2 and CO2 from feeding lot, compost, lagoon, slurry tank and field; - N leaching and uptake in field; - Crop growth and yield; - Soil C sequestration.

15 Manure-DNDC will be validated with datasets observed in housing, storage, treatment and field application. Sampling and measurement are conducted at feed-lot, housing, storage, lagoon and field in 6 dairy farms in CA in

16 Sweep Air - Minimum of 5 chamber volumes of Ultra Zero Air (80% N2 and 20% O2) prior to any sampling US-EPA Isolation flux chamber Summa Canister sampling for GC-MS analysis INNOV A multigas analyzer Six gases NH3 N2O CO2 H2O Ethanol Methanol Filter trap (denuder) for ammonia Exercise corral receives 25% - 40% of the manure, depending on

17 Sampling ethanol, methanol, ammonia, N2O and ROG s from Total Mixed Ration (TMR) using flux chambers at Dairy A.

18 Flux Chamber monitoring of flush lane at Dairy B

19 GIS databases have been constructed to support regional simulations for CA dairies Climate, soil, livestock and management information have been collected.

20 Example Results Manure-DNDC for a dairy farm: -500 cows with milk production 10 kg/head and weight gain 0.8 kg/head per day; -Feeding rate 6.8 kg DM with protein 0.43 kg/head per day; -Dung and urine separated for compost and lagoon, respectively; -Compost litter addition 2000 kg DM, C/N ratio 45; -Lagoon capacity 2000 cubic meter, surface area 200 m 2 ; -No slurry tank or anaerobic digester utilized; -Lagoon manure application depth 20 cm.

21 Manure-DNDC tracks N transport and transformation at farm scale

22 Emissions of CH 4, NH 3, N 2 O and N 2 are dominated by different farm components CH 4 : >80% from enteric emission NH 3 : 70% from field application N 2 O: 60% from field application N 2 : 99% from lagoon emission

23 Modeled daily CH 4, NH 3 and N 2 O emissions from a dairy. CH 4 NH 3 N 2 O

24 Impact of change in diet (protein intake ) on gas emissions CH 4 NH 3 N 2 O N 2

25 Expected Project Outcomes: Biogeochemical process modeling tool for estimating air emissions (CH 4, NH 3, N 2 O, NO) and N leaching from California dairies; GIS databases on dairies (location, types, herd sizes, manure management, local soils, climate, etc); Regional estimates of NH 3 and GHG emissions from California dairies; Emission inventory tool for emission inventories ranging from project or facility level up to air-district and state level

26 Thank you!