Precision Agriculture and Crop Protection = (Precisielandbouw en Gewasbescherming) : Definitions and the relation between precision-applications and the authorisation procedure of PPPs

Summary

Precision agriculture is earning its place in the Dutch agricultural sector, with crop protection as one of the main points of attention for many farmers. Precision-application of plant protection products (PPPs) can, besides reduction in the amount applied, result in a lower exposure of different protection-targets to PPPs. Taking these effects into consideration, precision-applications for crop protection could play a role in the exposure assessment of PPPs in the authorisation procedures. The term precision agriculture is used in multiple, different ways and clear definitions lack. This report aims to define the terminology regarding crop protection through precision application of PPPs. Precision agriculture is defined as “Exactly meeting the needs of plants or animals within space and time while respecting economic and social boundaries and taking into account environmental aspects”. In the proposed terminology, an application is only a precision-application if site-specific measurements are done and a site-specific decision is made and this decision is subsequently carried out site-specifically. For precision-applications, two methods of operation are defined. In on-the-go precision-applications, measuring, decision-making and application are all done in real-time. In chained precision-applications, measurement, decision-making and application need not happen at the same time. Specifically for crop protection, three types of precision-application can be identified. In a variable rate application, the whole field is treated while the dose is varied to meet the conditions in each location. In a spot-spraying application, for each location the decision is made whether application is required before doing so. Finally, a hybrid form exists where variable rate and spot-spraying are combined: For each location the decision is made whether application is required and only if application is required, subsequently the appropriate dose is determined. As the term dose plays an important role, it is split into: • Advised dose, depicting the dose advised by the producer of the PPP • User dose, depicting the dose chosen by the user based on knowledge and experience • Minimal effective dose, depicting the dose which (in theory) is just high enough to reach the desired goal of the application, taking into account the local conditions at the moment of and on the position of application • Application dose, depicting the dose sent to the sprayer as required application-rate • Applied dose, depicting the dose as actually applied by the sprayer Multiple precision-applications for crop protection are illustrated using examples from practice. For every example, the methods used to site-specifically measure, decide and apply are described in detail. Additionally, a discussion on how different application-technologies can contribute to a higher efficiency during application is included. Precision agriculture and the assessment methodologies for the authorisation of PPPs are then discussed together. Variable rate applications mainly influence the applied dose per location; spot-spraying applications mainly influence the locations where application takes place; hybrid applications influence both these aspects. The proposed definitions and presented examples from current agricultural practice offer leads for the exposure assessment methodologies of PPPs in the authorisation procedure. Multiple challenges and opportunities within this procedure, such as left-over spraying fluid, influence of variability within a field and data-exchange, are discussed in the discussion-chapter. It is concluded that multiple opportunities exist to make steps towards inclusion of precision-techniques into the assessment methodologies for the authorisation of PPPs.