Ecological future for robotic weeders

The head of the BHU Future Farming Centre at Lincoln is questioning the long term ecological impact of robotic weeders.

] by Kent Caddick

Dr Charles Merfield has recently published a paper in the international weed science journal ‘Weed Research’ which looks into robotic weeders and ecological weed management.

Dr Merfield said robotic weeders emulate current herbicide and mechanical weeding systems which aim to produce fields of only crop plants – monocultures.

“However, ecological and weed science is increasingly clear that monocultures have multiple negative outcomes, including increased pest and pathogen levels, reduced biodiversity, reduced ecosystem services, lower soil health, more competitive weeds dominating and less stable yields.

“Ecological weed management considers that not all non-crop plants cause harm, and that non-harmful species should be retained to provide multiple positive benefits.”

The paper describes three current levels of robotic weeders and a potential fourth: Level 1: follows crop rows; Level 2: identifies all crop plants and weeds all the soil around them; Level 3: identifies all plants, determines which are crop and then individually eliminates all other plants (currently considered state of the art).

“While current Level 3 robotic weeders are revolutionary in terms of the technical achievements of the robots themselves, what would be truly revolutionary in terms of addressing the deep sustainability of agriculture is Level 4 ecological weeding robots,” Merfield said.

“Level 4 weeders could achieve ecological weed management by identifying all plants as Level 3 weeders currently do, but then, only eliminating ‘true weeds’ leaving noncrop plants that are not harmful alive.”

Future farming: New research suggests the future of robotic weeders could include the ability to determine harmful weeds from benign thereby improving soil sustainability.