Healthy soils provide essential ecosystem services (e.g. nutrient recycling, carbon sequestration, climate regulation, and water filtration) that sustain plants, animals, and humans. The growing trend towards simplifying systems in Ontario and the northern corn-belt (i.e., corn-soy rotations) may risk soil health degradation and resiliency against stress; one strategy thought to improve soil health and ecosystem services is to establish a diverse crop rotation which includes cover crops and/or intercrops in the rotation. To ensure uptake of sustainable agricultural practices in Ontario, the economic and environmental benefits and trade-offs of soil ecosystem services under different management and environmental stressors must be elucidated. Diverse rotations with integrated cover/intercrops might lead to competition for water and nutrients between intercrop and the cash crop, which could negatively impact cash crop yields and profitability, and therefore limit the likelihood of farmers adopting the practice. Two important questions must be answered for farmers: i) will diverse cropping systems actually result in productive and profitable cash crops over time? (ii) what are the trade-offs between environmental and economic benefits of implementing a diverse cropping rotation?
This project will address these research gaps by measuring (i) crop productivity and profitability (ii) crop nutrient and water supply and use efficiency, and (iii) socio-economic value of a diverse crop rotation vs a conventional rotation over a 5 yr period. It is very challenging to study nutrient leaching and soil water movement in the field under realistic soil moisture regimes. Typical studies employ small-scale lysimeters (e.g., 0.1 m2) which have no control over environmental conditions, often produce experimental artifacts, and do not encompass soil’s inherent variability, thereby representing a gap in our understanding of soil water and nutrient movement. We are excited to announce that a new high-tech soil lysimeter system is being installed at Elora, ON, which enables us to study soil processes in 2 m3 undisturbed soil columns under realistic conditions in the field. Our lysimeters enable detailed quantification of soil nutrient and water status as affected by changes in management (i.e., adopting more diverse crop rotations which include cover crops/intercrops) and changes in climate (i.e., occurrence of severe weather events).