Banded Drift - Precision Ag Drift Method

Michael Bird and David Patterson

Purpose

Explore the possibility of using existing regulatory drift curves to create new curves based off banded pesticide applications. This idea is potentially of use to precision agriculture.

Motiviating Idea

Imagine a ditch that is one meter downwind of a field of wheat. For now, assume the field is long and wide and that the water body runs along the entire edge of the field.

If a boom sprayer sprays up to the edge of the wheat, we can use FOCUS SW drift curves to calculate:

• The deposition curve over the ditch
• The total deposition in the water body assuming we know the ditch width and the PPP application rate

If a boom sprayer moved itself 1m into the field (i.e) a 1 m crop buffer, we could similarly calculate deposition curve. The idea is that if you subtracted the 1 m curve from the edge of field curve, you would be left with the drift that resulted from spraying the 1 m wide strip from field edge into the field.

There is the potential to use this idea to refine drift depositions for banded applications where bands run parallel to the ditch

What's Here

• In EU_preciusion_Ag_drift you'll find the R shiny app source code
• scripts include R scripts that created the contour plots found in plots
• docs include:
  • Bayer's Piacenza presentation (inspiration)
  • Copies of the original regression parameters for FOCUS SW
  • Rautmann paper
  • A powerpoint file with some visuals
  • A copy of the powerpoint David and Michael presented at the GB Fate Modelling forum explaining the method.
• data contains csvs on:
• focus water body dimensions
• focus sw drift curve regression parameters
• focus sw crop geometry data (for distance to bank)
• field_images contains pngs generated by the plotting functions for visual reference

Method Assumptions

• That it's possible to accurately spray a band of a desired width (this ignores the realities of nozzle distribution over the boom)
• That the drift curve from a non-edge-of-field band will be equivalent to the drift curve from an edge-of-field band. This will not be true as drift from inner bands (especially from vertical crops) will have additional canopy effects, reducing drift. This means this assumption is a conservative one for RA

Todo

• Implement R functions that allow for calculating deposition curves aligning with FOCUS SW.
• Explore the impact of row dimensions in gradient plots
• Implement methods into a shiny apps for accessibility reasons
• Investigate likely values for band and inter-band width for various crops and countries.