2013 Annual Report
1a.Objectives (from AD-416):
1. Detection of spray droplets using lidar technologies combined with micrometeorological methods under a range of atmospheric conditions. 2. Evaluation of spray drift for a range of atmospheric conditions. 3. Estimation of the potential for spray drift interception by biobuffers.
1b.Approach (from AD-416):
Data collection will be conducted over soybean canopies at different stages of growth and atmospheric conditions to create a range of potential spray drift patterns from the point of application. Experiments will be conducted in production fields using field scale application equipment with a range of nozzle sizes to create different spray droplet sizes. Measurements will be made with lidar to measure the movement of droplets from the application system and combined with micrometeorological techniques to quantify atmospheric stability. These data will be combined to estimate the horizontal and vertical movement from the release point and then use these data to estimate the potential for interception by biobuffers during the period of application.
Field experiments were conducted with a ground-based spray applicator over typical conditions in Midwest soybean production. Spray drift was measured with the lidar system to quantify the particulate size and the movement patterns coupled with micrometeorological measurements. Spray drift was affected by a combination of the micrometeorological conditions and the wake generated by the spray application equipment. Spray drift moved across the field more quickly and to greater heights than expected because of the additional lifting force generated by the wake effect. These experiments have identified a set of factors which have previously been undiscovered and need to be evaluated in future experiments in order to refine estimates of spray drift across production fields.