Can preventive weed management help increase herbicide use efficiency? Evidence from maize fields in Germany

Due to the multiple negative environmental effects of the overuse of chemical pesticides, the European Union (EU) aims to reduce pesticide use – including herbicides – by 50%, by 2030. Preventive weed management (PWM), using among others in-version tillage and diverse crop rotations, is considered perhaps the most suitable strategy to reduce on-farm herbicide use. Whether and how these practices relate to herbicide reduction potential and crop yields is, however, not well understood. This paper addresses this gap by investigating the impact of PWM on maize yields and herbicide use. Using field-level data for 530 maize fields in eastern Germany, we apply a directional distance function approach in a data envelopment framework and estimate directional and simultaneous improvement potentials for herbicide use and maize yields. Our preliminary results indicate a similar performance with holistic PWM and without PWM in terms of both yields and herbicide use, whereas a partial implementation of PWM seems to increase herbicide use. We also find herbicide reduction potentials of 36-37% irrespective of the PWM suggesting notable improvement potentials by implementing best practices.