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Ã山ǿ¼é's Faculty of Agricultural and Environmental Sciences is pleased to host Mitigating Agricultural Greenhouse Gases and Increasing Carbon Sequestration in a Circular Economy--an international symposium held under the auspices of the Agriculture and Agri-Food Canada Agricultural Greenhouse Gases Program II.

The AGGP II Project, An Integrated Socio-economic and Biophysical Framework for Mitigating Greenhouse Gas Emissions under Agricultural Water Management Systems in Eastern Canada, aimed to identify, develop and disseminate information for beneficial water management practices which simultaneously reduces GHG emissions, increases agricultural productivity and produces environmental co-benefits.

Some Findings

This project set out to develop 8 new BMPs and innovative methodologies and developed 12. The project successfully demonstrated 9 technologies/information products to crop growers. Over 200 agricultural producers participated in technology transfer events. Some 55 journal publications were produced by the researchers and at least 20 presentations were made to stakeholders.
Some specific results from this project are:

a) Controlled drainage (CD) produces profit via yield increases at the farm level. CD can be classified as a climate smart technology and decision makers should continue to work with the research community and crop growers to further promote adoption. We showed that CD & optimum fertilizer application reduced N2O emissions by over 45% compared to conventional drainage, and CD alone reduced CO2 emissions by 6% compared to conventional drainage.

b) Soil Organic Carbon (SOC) sequestration rates are projected to be −1.0 Mg ha−1 each year from 2038 to 2070 under CD, which was 22% lower than baseline. The removal of carbon from atmospheric CO2 into SOC pools by C sequestration through crop growth is an important process that reduces the net global warming potential.

c) A method was developed to label root exudates of ryegrass (Lolium multiflorum) with both 13C and 15N. This method is being applied to understand which microorganisms are metabolizing these substrates, producing greenhouse gases, and increase our understanding of soil C and N dynamics.

d) Fertilizer management: Fertilizer application is recommended 4 weeks after planting rather than 6 weeks (the traditional practice). Also, there should be a lag of 2 – 3 days after precipitation before applying fertilizer to reduce GHG emissions.

e) A two-node, low-cost prototype wireless sensor network for measuring CO2 flux was developed and tested, and is now being scaled up for large scale commercial farms.

f) Corn-soybean rotation reduced CO2 and N2O emission by 18.8% and 20.7% when compared with continuous cropping of corn. Corn-soybean rotation improves crop yields and sequesters carbon compared to continuous corn cropping.

g) Six shallow data-driven Machine learning (ML) algorithms were developed and tested for predicting CO2 and N2O emissions. The ML models were compared to biophysical models, RZWQM2 and DNDC . The predictive performances of ML models proved to be an effective and efficient alternative to mechanistic models. It is promising modelling framework to scale up emissions from farm level to regional scale.

h) An economic analysis showed that CD produced over 3% higher crop yields compared to conventional tile drainage (TD). The Net Present Value (NPV) of CD was C $546 ha-1 and C $968 ha-1 (2015) at a 5% discount rate over 20 years in Quebec and Ontario respectively. Additionally, CD has substantial social benefits because it reduces GHG emissions and nitrate leaching. Hence, there is a need for public financial assistance to encourage adoption.