Assessment of Different Quantification Approaches and Application of Multiple Practices for a Single Farm Unit Dennis Haak, Agriculture & Agri-Food Canada October 30, 2008.

Outline 1.Methods for Quantifying Soil Carbon 2.Approaches for Quantifying N 2 O related to Soil Nutrient Management 3.Stacking Multiple Practices on a Single Farm

Methods for Quantifying Soil Carbon Measurement Modelling Methods of Soil Carbon Quantification

Direct Measurement of Soil Carbon 1.Challenges - low sequestration rates - high spatial variability - account for both C concentration and soil bulk density 2.Conclusion - # of samples required proves cost prohibitive for offset projects

Models for Quantifying Soil Carbon 1.Century 4.0 Model at Ecozone / region scale (5) - GHG inventory reporting from no till, fallow reduction, and conversion of annual crop to perennial forage - no till protocol for GHG carbon offsets 2. Scaling down models to work for smaller regions or possibly individual farms -additional point measurements to validate

Scaling Down Soil Carbon Models 1.C-Lock, Zimmerman, South Dakota - regional scale for historical baseline practices - individual farm for new practices 2.Alberta Specified Gas Emitters Regulation - guidance document for developing model based custom coefficients - criteria: peer reviewed, 3 rd party assessment, validated with long term site data sensitivity and uncertainty analysis model initialization & multiple runs

Soil Nutrient Management (Focus on N) 1.Principles - optimize source, rate, timing, placement - maximize crop utilization - minimize environmental losses, including N 2 O 2. GHG Inventory Process for Soil N 2 O - driven primarily by rate of N application - spring thaw, landscape position - fallow, irrigation, tillage system 3. No quantification methodology for most practices

Specific Nutrient Management Practices 1.Timing- fall versus spring - single versus split 2. Slow Release Forms of N 3.Increased legumes and pulses in rotation 4.Variable rate nutrient application 5.GPS controlled tracking to eliminate overlap 6.Green manure and cover crops 7.In Field Livestock Winter Grazing and Feeding

Options for N 2 O Offset Quantification 1. Simplified Approach – based on N rate reduction - use existing GHG inventory coefficient - assume N 2 O reduction leads to N rate reduction 2. Advantages - easy to monitor and verify - not necessary to understand N 2 O mechanism 3. Examples - N reduction in corn production (SMTWG, 2006) - Nitrous Oxide Emission Reduction protocol (Alberta, 2008)

Stacking Multiple Protocols / Practices for One Farm Rationale 1. Many practices contribute to GHG reductions 2.Benefit for most single practices is small 3. However, cost of adding a practice may be very small - monitoring and verification already in place

Stacking Multiple Protocols / Practices for One Farm Process So Far 1. Initial focus on no till – largest GHG benefit 2. Consider other practices that compliment no till - nutrient management practices - summerfallow reduction - increasing frequency of perennial forages in rotation with annual crops

Stacking Multiple Protocols / Practices for One Farm Challenges 1. Additional GHG reductions must be unique 2.Types of Issues - practice interactions - mixed quantification approaches

Practice Interactions 1. Example: No Till and Land Application of Nutrients 2.No Till protocol allows but does not distinguish - nutrient application with low disturbance placement or no incorporation. - timing of application 3.Nutrient Application Protocol - could consider change in timing - could consider low disturbance placement versus no incorporation - could not consider change from high to low disturbance placement without a change in timing

Mixed Quantification Approaches 1.Example: No Till and Fallow Reduction 2.No Till protocol uses regional baseline - discount applied equally to all land regardless of past management 3.Fallow protocol may use individual baseline - easy to verify historical practice of individual land parcels through remote sensing, crop insurance, etc. 4. May be acceptable, but rationalization required

The Potential for Integrated Farm Models 1.Current Examples - Comet-VR (USDA, Colorado State University) - Holos (AAFC, NLWIS) (previously GHGFarm) 2.Whole Farm Approach 3.Issue - original design as an awareness / extension tool needs more work to meet more rigorous requirements of offset system (eg. ISO 14064)

Thank you Questions and Discussion