On-The-Go Grain Protein Monitors

1. On-The-Go Grain Protein Monitors Dan Long USDA-ARS Pendleton, OR

2. Questions • What kinds of sensors are there? • How do they work? • How well do they work? • What can I do with the information?

3. Near Infrared Analysis • Typical molecules include CH, OH and NH and their related chemistries regarding constituents (protein, fat, oil, glycerin, water, methanol).

4. Principle of OperationTransmittance Detector NIR Radiation Light Source Sample Cell

5. Principle of OperationReflectance NIR Radiation Light Source Grain Stream Detector

6. Mode of OperationOn-Line grain stream sensor

7. Mode of OperationIn-Line grain stream sensor

8. Handheld Computer Zeltex AccuHarvest Inlet Sampling Device Outlet

9. Zeltex AccuHarvest

10. NIR Technology Cropscan 2000G fiber optic cable spectrometer

11. inlet sampling device fiber optic cable outlet

12. inlet sampling device fiber optic cable outlet

13. Dsquared Development ProSpectra™

15. AccuHarvest Field Tests

16. SEP=0.49% AccuHarvest Vs. Reference Protein

17. Map Comparison

18. Cropscan 2000G

19. Cropscan Vs. Reference Protein SEP=0.66% R2 = 0.99 SEP = 0.19%

20. Map Comparison

21. Overall Precision R2 = 0.9 SEP=0.9 y = 1.07x - 1.25 R2 = 0.71 SEP=0.9%

22. ProSpectra™

30. Continuous Wheat No-Till Wheat-Fallow Wheat-Fallow Pea-Wheat-Fallow No-Till Volunteer Wheat

32. Nutrient Management Opportunities • Verify protein response to applied N • Identify N management zones • Evaluate N sufficiency for yield • Estimate N removed in grain • Estimate N required to reach protein level • Estimate straw yield

33. Verify Protein Response

34. ZONE 1999 H MH M ML L Identify Management Zones

35. Ave. Protein (1997) & Soil N (1999)

36. 1997 1999 Map Comparison of Differing Years

37. Evaluate N Sufficiency For Yield

38. 30 bu/a 14% protein 60 bu/a 11% protein knoll bottom Where Was N Deficient for Yield?

39. Yield Map Interpretation deficient sufficient

40. N Management Strategy • N Removed = (YieldProtein)(1005.7) • N Deficit = (Target Level - Current Level)  N Unit Equivalent • Site Specific Management Guideline#24 (http://www.ppi-far.org/ssmg)

41. Precision N Management

42. 90 70 50 30 5 Spatially Variable Vs. Uniform

43. Grain Protein Response

44. Water-N-Genotype Gradient 3 years – HR Spring Wheat 7.3” 11.5” 16.6” 18 bu/ac 39 bu/ac 65 bu/ac

46. 20 19 18 Y = 0.081 + 12.98(X) 17 16 Grain Protein (%) 15 14 13 Low Moisture (7.3 in) 12 Normal Moisture (11.5 in) High Moisture (16.5 in) 15% Protein Level 11 10 0 20 40 60 80 100 120 140 160 180 200 220 -1 Applied N (kg ha ) Fertilizer N Equivalent 12-22 lb N Grain Protein (%) Applied N (lb ac-1)

47. 6000 Y = 0.783 X + 776 5000 Std error pred = 364 4000 Predicted straw yield, lb/ac 3000 2000 Model factors grain yield 1000 grain protein 0 0 1000 2000 3000 4000 5000 6000 Observed straw yield, lb/ac Straw Yield Prediction

48. Limitations of Technology • Precision and bias • Vibration • Foreign material • Wear and build up • Field to field differences in grain • Transfer of calibration • Each instrument is slightly different • Thermal stability • Harvested grain differs from that used for calibration

49. Protein Indices are Imperfect • Climate: may not be suited for rainfall regimes where yield potential exceeds 60 bu/ac • Genotype: some cultivars do not experience yield loss when protein is below the critical level (Fowler, 2003) • Weather-soil interactions: • Influences mineralizable N and plant N uptake • Excess N leads to yield reductions under severe drought • Protein is abnormally elevated under severe drought (Seles and Zentner, 2001)

50. Towards Improved PNM • Previous season • Grain yield and protein sensing • Assess N sufficiency • Identify management zones • Retrospective assessment