Comparative Life Cycle Assessment of intra-row and inter-row weeding practices using autonomous robot systems in French vineyards

Abstract

Viticulture, as well as other crops, is facing obligation to reduce the use of herbicides and to develop alternatives solutions to chemical weed control. These alternatives can be achieved by mechanical weeding either using tractors or weeding robots. This paper provides a quantitative environmental impact assessment using Life Cycle Assessment of intra-row and inter-row weeding practices using autonomous robot systems in three French vineyards. Twenty-seven scenarios were built to assess chemical, mechanical or a combination of the two for intra-row weeding management combined with mechanical weeding or mowing as inter-row management. Results shows that scenarios using weeding robots for the intra-row management have greater impacts than conventional ones on mineral resources, human toxicity, freshwater ecotoxicity and marine eutrophication due to the manufacture, the lifetime (when assumed short) and the functionality of robots. However, these same scenarios have fewer impacts than conventional ones on climate change, fossil resources, ozone depletion, acidification and particle formation, especially when robots are used on plots closed to the winery. This study had shed some light on the relative impacts of a robotic machine intended to replace tractors and vine straddles tractors in certain tillage operations. In particular, it may allow the implementation of an eco-design approach for the use of robots, making it possible to find the operating point that could minimize the overall impact of robotic solutions.

Keywords: Agricultural robot; Chemical weeding; French vineyards; Life Cycle Assessment; Mechanical weeding.