1. Managing N using The Illinois Soil Nitrogen Test Tim Smith Cropsmith Inc. Nitrogen Testing, Consulting

2. Don’t be mislead focus on what is important

5. How much N do you need? Yield 126 Yield 227 0 N Rate 210lb N On-Farm trial Champaign County Illinois 2003

6. How little N do you need? Yield 177 Yield 193 On-Farm trial Champaign County Illinois 2003 0 N Rate 210lb PY Rate 192 lbs N At today's NH3 prices each bushel gain cost $5.16 in N

7. Corn yield at the zero-N rate as a percent of yield at EONR. 80 75 Wisconsin 76 60 Minnesota 75 45 Iowa 64 54 Illinois ---------- % ----------- Soybean Corn State Previous Crop

9. Example of Nitrogen Response Trial 200 80 120 40 0 0 160 200 120 80 120 40 80 160 0 160 40 200

10. The Closer to the Economic N Rate the more money you make Within $8 of best N rate $26.70 from best N rate Cropsmith Recommendation University Recommendations

13. What kind of nitrogen release do your soils have? IPNI-Crop Nutrient response tool EON 130 lbs N EON 180 lbs N Both fields yielded 200 bushels

14. Is the Economic N Rate Stabile Year to Year? Jack Meisinger InfoAg presentation 2007

15. ISNT Soil Test Map

16. Cropsmith Variable Rate Application Map

17. Results from 2007 ISNT 175-225 ISNT 270-304 Corn $3.35 Fert. N $.50 MRTN Recommendation 147lbs N

18. 2007 ISNT Values

19. 2007 ISNT Nitrogen Recommendations

20. 2007 Results ISNT 175-225 ISNT 270-304 Corn $3.35 Fert. N $.50 MRTN Recommendation 147lbs N

21. How much N do you need? Soil Test ISNT 192 PPM Experimental Best N Rate 180 lbs Yield 126 Yield 227 0 N Rate 210lb N Rate Cropsmith Recommendation 169 lbs N On-Farm trial Champaign County Illinois 2003

22. How little N do you need? Yield 177 Yield 193 On-Farm trial Champaign County Illinois 2003 Soil Test ISNT 225 PPM Experimental Best N Rate 126 Cropsmith Recommendation 147 lbs N

25. Or maybe old ones

26. Sources of N to Plants Fertilizer N – Less Efficient Organic Soil N – More Efficient 200 bu Corn 150 bu Corn

29. N cycle 50-90% 10-50%

31. 17 Sites Indiana Purdue (Camberato, Nielsen)

32. Corn after Soybeans 2005 190 Acre field in McLean County (C.U. Williams Farm) Average yield 189 bu. Ave.135 lbs of N Yield 189 Bushel

34. Average N Rate 146# N

35. Soil is more efficient at delivering N to plants U of I C.U. Williams Field 2006 Ave yield 191.3 bu.

40. Fall 2007 results

41. 175 N 192

42. 155 N 225

43. What kind of nitrogen response does your soils have? Southern Illinois Economic N Rate 192 ISNT 95 Central Illinois Economic N Rate 124 ISNT 265

44. Nafziger 2006 MRTN 3 Outliers Removed one each , Rotation, Variability, Flooded field CC North CSB North CC Central CSB South CSB Central