Why by-plant resolutions will be necessary in precision agriculture

1. Why by-plant resolutions will be necessary in precision agriculture

2. 1992, At What Resolution are there real biological differences

3. Target plant acquired over 70% of the total depleted 15N fertilizer that was taken up data revealed an individual corn plant acquires most of its N from within a radius of less than 0.5 m. Timely emergence impacts a plant's potential to achieve maximum yield. Plants lose yield potential by emerging as little as three days after their neighbors. Large doses of N fertilizer could not increase the yield of late emerging corn plants. Small spatial resolution N management techniques should be focused on determining the N demand of the early emerging plants. Paul Hodgen, Univ. Nebraska, Dissertation AA13271926, Jan 1, 2007

4. Plant-to-plant variation, avg. 45 bu/acNebraska, Iowa, Virginia, Oklahoma, Argentina, Mexico, Ohio OKLAHOMA IOWA

5. Variable Rate TechnologyTreat Temporal and Spatial Variability Wheat, 0.4m2 Corn, by plant

6. Causes for Delayed and uneven emergence • •variable depth of planting • •double seed drops • •wheel compaction • •seed geometry within the furrow • •surface crusting • •random soil clods • •soil texture differences • •variable distance between seeds • •variable soil compaction around the seed • •insect damage • •moisture availability • •variable surface residue • •variable seed furrow closure • •volunteerearly season root pruning (disease, insect) • The impact of uneven stands takes place prior to the time that irrigation is employed whether using surface/furrow or center pivot systems.

7. 34 ± 5.3 bu/ac 37 ± 9 bu/ac

8. Methods • A GreenSeeker Sensor was mounted on a bicycle • A shaft encoder was used to assign distance to each sensor reading • Readings were taken once per centimeter

9. No magic/transparent algorithm, methods Embedded technology Farmer fields in the USA, Argentina, and Mexico showed that over all sites, plant-to-plant variation in corn grain yield averaged 2765 kg ha-1 or 44.1 bu ac-1 (Martin et al., 2005). Hodgen et al. (2007) showed that if corn plants are delayed by as little as four days, the yield depression of that individual delayed plant was as much as 15 percent Summary

11. Norman, NE, 1995-2008Avg. Range = 61 bu/ac 2010, 1.54 billion bushels, Nebraska 2009, 159 bu/ac

12. Results

14. NDVI, V8 to V10 = CORN INSEY Days from planting to sensing

15. •variable depth of planting •double seed drops •wheel compaction •seed geometry within the furrow •surface crusting •random soil clods •soil texture differences •variable distance between seeds •variable soil compaction around the seed •insect damage •moisture availability •variable surface residue •variable seed furrow closure •volunteer early season root pruning (disease, insect) Causes for Delayed and uneven emergence

16. What is the fear of putting out an N Rich Strip? 2002

17. Fertilizing individual plants will require: • Sensing capability to locate plants, the proximity of neighboring plants, and yield potential of all plants • Calculating the desired fertilizer rate • Applying the desired amount of fertilizer within some (to be determined) constrained distance from the plant. By-Plant Fertilizer Applicator

18. Seed Placement and Leaf Orientation Yield increase up to 27.1% and 30.6% (prostrate and erect hybrids respectively at pop 74,100 plants/ha) when compared to random placement

19. Previous Work • OSU developed and demonstrated a pressure based binary control system to apply nitrogen fertilizer at a sub meter scale. • 1x, 2x, and 4x nozzles are opened quickly in combinations to provide 7 distinct rates.

20. Drop Nozzles in Corn • The pressure based binary system was used in corn by dropping nozzles into the canopy. • TeeJet SJ-3 fertilizer nozzles were oriented parallel with the row at a 45 degree angle.

21. Moving to Individual Plants • This same concept can be used when fertilizing individual plants. • Since the system will maintain a near constant pressure, rate will be based on speed, orifice size, and pulse

22. Comprehensive work from transects sampled all over the world have shown that the average difference in corn grain yield when determined by plant, averaged 44 bu/ac.   This included corn hybrid data from farmer fields in Nebraska, Ohio, Virginia, Iowa, Mexico, and Argentina (http://nue.okstate.edu/Index_Publications/Plant_toPlant.htm).  This exact same result was encountered in high and low yielding environments.  Because plant to plant differences in yield are common and incredibly large, there is significant room for improving nutrient management, especially since N demands by plant are equally as variable.   Because variable plant to plant N demands can be managed on-the-go using GreenSeeker sensing technology and advanced spraying systems, research programs like that at Oklahoma State University must deliver improved N management practices.  This has become more important when considering that nitrogen use efficiencies are so low, all over the world.

23. Predicting Mid-Season Yield Potential (YP0)  Predicting the Potential Response to Applied N Yield Potential Achievable with Added N Fertilization (YPN) Generating a Fertilizer N Rate Recommendation Current approach of determine sensor-based in-season N fertilization

24. Why they work Why they have weaknesses in certain regions Why is the algorithm based on yield potential Why predicting yield potential is going to be critical for N and other elements Understanding the Algorithm

25. How N recommendations are made

26. Benefits of sensor-based N fertilization

27. Spatial Variability of N, what is the scale?

28. Spectral Data Based on Reflectance Leaf Pigments Cell Structure Water Content Water Absorption Healthy Lignin and Tannins Water Absorption Damaged Cellulose Peak 970 Short Wave Infrared (1000-2500 nm) Visible Spectrum (400-700 nm) Near Infrared (700-1000 nm) Source: www.forestwatch.sr.unh.edu

29. Fundamental principles Expression of Variability By-Plant Variability Errors Associated with By-Plant Yield Corn Grain Yields Averaged over Larger Scales Errors in Corn Grain Yields from Larger Scales Why by-plant resolutions will be necessary in precision agriculture

30. VRT By-plant N fertilization strategy

31. Causes for Delayed and uneven emergence variable depth of planting double seed drops wheel compaction seed geometry within the furrow surface crusting random soil clods soil texture differences variable distance between seeds variable soil compaction around the seed insect damage moisture availability variable surface residue variable seed furrow closure volunteerearly season root pruning (disease, insect) The impact of uneven stands takes place prior to the time that irrigation is employed whether using surface/furrow or center pivot systems. Causes for the Large Differences in By-Plant Corn Grain Yields

32. By-plant ongoing research

33. Leaf orientation affected by seed position

35. Independence of YP0 and RI

36. 34 million ha’s Hand Planter

37. Of the 159,531,007 hectares of maize in 2009, there were approximately 34,409,010 hectares in the developing world. Of that total, around 60% was planted by hand, representing just over 20,645,000 hectares or 13% of the total maize area in the world (www.faostat.org. Web 24 Sept. 2010).

38. If single seeds could be planted 14-17 cm apart, much like conventional planters accomplish in the developed world, production levels could easily increase 25%. Despite the fact that third world maize yields are generally less than 2.0 Mg/ha (Dowswell et al., 1996), this 25% yield increase on 60% of the hand planted maize area in the third world would be worth more than 3 billion dollars/year (corn price at $0.3/kg) 20,000,000 has * 2.0 Mg/ha *0.25 (% increase) *0.3

39. Thank You!Questions?

42. Ramp Calibration Strip • Walk it off • Or use Hand-Held Sensor 0 N 195 N

43. VARI-TARGET variable rate nozzle bodies, most widely used metering orifice used with GreenSeeker

45. Argentina Australia Canada ChinaEcuador IndiaItaly Mexico Turkey Uzbekistan Zimbabwe 1992-present67 Graduate Students + Faculty1 week to 4 month study abroad

46. Ciudad Obregon, Mexico Modipuram, India

47. April 16, 2007Dr. Norman BorlaugCiudad Obregon, MX

48. Because yield and N responsiveness were consistently found to be independent of one another, and since both influence the demand for fertilizer N, estimates of both should be combined to calculate realistic in-season N rates. 

49. Strategy: Have to have experience seeing the different responses from one year to the next • Year OSU Dealer/Producer • 2005 80 >400 • 2006 586 Ramps • 2007 512 Ramps > 2000 • 2008 15 • 2009 20 3500 • 2010 20 3800 • 2011 60 4000 (includes canola)