Direct and indirect drift assessment means. Part 3: field drift experiments

Area of Science:

• Agricultural Engineering
• Environmental Science
• Agronomy

Background:

• Spray drift is a significant environmental concern in agriculture.
• Understanding factors influencing spray drift is crucial for developing mitigation strategies.

Purpose of the Study:

• To investigate the effect of nozzle type and size on sedimenting spray drift.
• To quantify the impact of atmospheric conditions on near-field spray drift.
• To develop and validate a drift prediction equation.

Main Methods:

• Field drift experiments using fluorescent tracers and horizontal drift collectors.
• Sampling at 24 downwind positions up to 20m.
• Continuous monitoring of meteorological conditions.
• Calculation of total drift reduction potential (DRPt).

Main Results:

• Atmospheric conditions significantly affect near-field sedimenting spray drift.
• Air inclusion nozzles demonstrated the highest drift reduction potential (up to 89.8%), followed by low-drift and flat fan nozzles.
• Nozzle type's effect on drift was most pronounced with smaller nozzle sizes.
• A validated non-linear drift prediction equation was developed.

Conclusions:

• Spray nozzle selection is critical for minimizing spray drift.
• Air inclusion and low-drift nozzles offer substantial drift reduction benefits.
• The developed drift prediction model and database contribute to better understanding and management of spray drift.