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Developing Infrastructure for Implementing Adaptive Management Practices for Corn on a Large Scale in Iowa. Tracy Blackmer Peter Kyveryga. Advancing Agricultural Performance ®. www.isafarmnet.com. Precision Ag Tools. 2008 Aerial Image. .
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Developing Infrastructure for Implementing Adaptive Management Practices for Corn on a Large Scale in Iowa Tracy Blackmer Peter Kyveryga Advancing Agricultural Performance® www.isafarmnet.com Iowa Soybean Association On-Farm Network®
Precision Ag Tools 2008 Aerial Image . The high price of nitrogen fertilizer/grain combined with the complexity of N dynamics makes it desirable to improve N management.
Precision Ag Tools 2008 Aerial Image
Precision Ag Tools Started as a variable rate project to identify areas needing more or less N. The results were such that improvements are needed at a whole field level before we target a subfield level.
Precision Ag Tools Precision ag tools help collect an unprecedented amount of data.
Replicated Strip Trials Replicated strip trial example. N-50 refers to “normal” rate and 50 lbs N/a less.
Replicated Strip Trial Report Replicated strip trial example. Page 1 Aerial image
Replicated Strip Trial Report Replicated strip trial example. Page 2 Grain yield map
Replicated Strip Trial Report Replicated strip trial example. Page 3 Treatment position map
Replicated Strip Trial Report Replicated strip trial example. Page 4 Summary statistics
Case Study: Grower Evaluation • Fertilizer N Grain Yield • --------lb N/acre-------- -----------------bu/acre------------------- • 2001 C-SB 80 130 176.8 175.6 -1.2 • 2002 C-SB 70 120 192.5 195.4 2.9 • 2003 C-C 130 180 166.6 166.2 -0.4 • 2004 C-SB 60 110 199.7 206.1 6.4 • C-C 110 160 172.0 178.3 6.3 • 2005 C-SB 60 110 191.8 197.6 5.8 • C-C 110 160 182.1 193.9 11.9 • C-C 120 150 188.4 192.5 4.1 • C-C 125 150 177.1 182.1 5.0 Year Rotation Low Rate High Rate Low Rate High Rate Diff.
Additional Analysis Yield increase from an additional 50 lbs N/a as affected by rainfall Rainfall has a big impact on N management. This should be factored into the evaluations.
Nitrogen Evaluations Over 1,000 guided stalk sample fields. Over 150 N replicated strip trials.
End of Season Stalk Nitrate Test Stalk samples collected from 6-14 inches above ground after physiological maturity.
End of Season Stalk Nitrate Test Stalk samples collected from 6-14 inches above ground after physiological maturity.
Replicated Strip Trials • Data collected • Aerial Imagery • Grain yield • Stalk nitrate
Stalk Testing the Strip Tests Calibration data is consistent with recommendations.
Guided Stalk Sampling How do you represent this field?
Guided Stalk Sampling • Four stalk nitrate samples • Three by soil map units • One sample based on image “deficiency”
Statewide Analysis • Applying adaptive management results in feedback data. One outcome is a “benchmark” • The benchmark can: • provide a status of management to the public • track impact of programming • Impact regulations The distribution of stalk nitrate samples across Iowa in 2007 Excess Optimal Marginal Deficient
Guided Stalk Sampling The benefit is multiplied by focusing on results in a group – not just an individual.
Guided Stalk Sampling Group Summary of stalk nitrate samples Differences between management practices are often observed at a group level. Sample percentage Management practice
Statewide Analysis The distribution of N forms is fairly well distributed.
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