1. OMAF Nitrogen Verification Project Crop Technology Team 200 sites across Ontario (70 Hort) 3 years - 4 samples per year 2,400 soil samples!

2. Nitrogen and Groundwater 23% of Ontario residents rely on groundwater 90% of rural residents 15% of rural wells above 10 ppm NO3-N nitrates are the main quality issue soils with high leaching potential are at most risk

3. 1992 Groundwater Survey - Nitrates 1296 Rural Wells % of wells with greater than 10 ppm nitrates

4. Calculated Regional N Balance - OECD MacDonald, 2000

5. Calculated N Balance - 1996 Source: Environmental Sustainability of Canadian Agriculture 69% of Ont farmland increased at least 5kg/ha between 1981 and 1996 % Ont Farmland 26% 22% 15% 37% 21 - 40

6. Risk Assessment Residual N isnt necessarily the most accurate measure of risk on a farm-by farm basis Non- Farmers will use this data, unless given something better

7. Measured Ontario Soil nitrate-N (kg/ha) 2001-2003

9. Residual soil N, Hort sites, Nov 2002 Co-operator 60kg/ha A soil 80kg/ha B soil

10. Next Steps Add 2004 data Add Survey information to the database Separate out specific production systems –identify efficiencies and leaks Target management systems to reduce risks

11. Related Projects Cover Crops/Catch Crops

12. Soil Nitrate Levels under Cover Crops (planted Aug.15, 2003 after cucumbers)

13. Related Projects Cover Crops/Catch Crops Sweet Corn Nitrogen on-Farm Demonstration Trials 40 Years of Field Corn Nitrogen Database

16. Related Projects Cover Crops/Catch Crops Sweet Corn Nitrogen on-Farm Demonstration Trials 40 Years of Field Corn Nitrogen Database Fertigation Scheduling in Melons & S.berries –Tissue/Petiole Recs vs. Weekly Program