Contact Dr. Bill Deen: bdeen@uoguelph.ca
Presentation Video:
- Over the past two decades there has been a steady decline in rotation complexity
- In Ontario, as well as surrounding states, corn and soybean now dominate rotations
- Long term trials at Elora (shown in slide above) and Ridgetown indicate the problems associated with simple corn:soybean rotations
- Economic and environmental reasons exist for increasing diversity
- In Ontario wheat represents the main opportunity to increase diversity
- Corn yield is increasing in Ontario
- Relationship between corn transpiration and yield is linear…more yield requires more water
- Analysis of corn yield and precipitation data from 32 counties over 60 demonstrates that corn is increasingly being constrained by water limitations.
- A simple corn soybean rotation will accentuate this problem
- Climate change, increasing yield potential, residue removal will accentuate this problem
- Predicting corn N requirement will become more difficult as uncertainty of water effect increases
- A long term nitrogen trial at Elora demonstrates effect of year to year variation in precipitation on EONR (Economic Optimum rate of Nitrogen) (2013 a “wet” year …high N requirement, 2012 a “dry” year…low N requirement)
- Effect of precipitation on yield and N requirement, may occur after N is typically applied
- Applications in excess of EONR increases risk of N loss to environment
- Future N recommendations systems may need to explicitly consider interactions with precipitation and plant water availability
Environmental Sustainability in Agriculture- Knowledge to Action KTT 