麦-玉轮作系统实施测土施肥减排GHG碳贸易量核算

According to the basic requirement of CDM methodology, this study sets up greenhouse gas(GHG) mitigation methodology for carbon trading by applying soil testing and fertilizer recommendation in wheat-corn system, based on the analysis on application rate of fertilizer of wheat-corn system in China's intensive regions and the mitigation potential of application of soil testing and fertilizer recommendation.Then completes verifying and modifying the DNDC model through the experiment datas and sets up the regional database of fertilizer application,fraction of above-ground residue and excrements incorporated in soil,field management,soil and meteorology acquired by field survey and statistics supporting the operation of DNDC model.Finally, taking Huantai county of Shandong Province as an example, calculates the amount of carbon trading of GHG mitigation by applying soil testing and fertilizer recommendation in wheat-corn system, and additionally, estimates the feasibility of implementing the carbon trading project on the county area choosing towns as basic geographic unit.This research is critical for establishing the metering method of GHG mitigation and quantifying the regional GHG mitigation by applying soil testing and fertilizer recommendation.

本研究在分析我国农业生产集约区小麦玉米轮作系统化肥施用量及实施测土配方施肥减排潜力的基础上，按照碳贸易项目方法学的基本要求，提出以DNDC模型为主要工具的小麦玉米轮作系统实施测土施肥减排GHG的碳贸易计量方法。依据田间试验数据，完成DNDC模型的验证与修正；基于实地调查和统计资料，获取农户施肥、畜禽粪便与秸秆还田、田间管理、气象条件等数据，建立支持DNDC模型运转的区域GIS数据库。以山东省桓台县为典型案例，运用提出的计量方法，模拟常规施肥和测土配方施肥两种情境下温室气体排放量，综合考虑化肥生产耗能，计算桓台县小麦玉米轮作系统实施测土配方施肥减排GHG的碳贸易量，进而评估以县域为基本单元实施碳贸易项目的可行性。该研究对于确立小麦玉米轮作系统实施测土配方施肥减排碳贸易计量方法，科学计量区域农田实施测土配方施肥GHG减排量具有重要意义。

农田N2O是重要的温室气体排放源，农田N2O减排是农业减排的重要组成部分，农业碳贸易是推进农业减排的有效途径。本研究提出了以DNDC模型为主要计量工具，包含项目边界、基准线、项目排放、额外性分析、泄露、监测等内容的测土配方施肥GHG减排碳贸易方法学。以山东省桓台县为例，通过实地调研和田间试验，建立了以乡镇为单元的施肥、农田管理、气象数据、种植作物及轮作方式等区域GIS数据库，结合化肥生产耗能调研，核算了桓台县不同模拟单元小麦-玉米轮作系统测土配方施肥减排GHG碳贸易量。计算结果表明，桓台县麦-玉轮作系统实施测土配方施肥温室气体减排2.47万t CO2，其中农田减量施肥减排0.86万t CO2，减少氮、磷肥所引起的化肥生产企业节约能耗1.63万t CO2，钾肥增加排放40 t CO2，符合小型碳交易项目要求，证明了以县域或更大区域农田系统实施测土配方施肥碳交易是可行的。本研究完善了农田碳贸易的方法学体系，为区域农田实施测土配方施肥温室气体减排计量及碳交易实施提供了可靠计量方法。