Autonomous farm robots guided by GPS can plant and harvest multiple crops in close proximity, enabling beneficial interactions between different plants and potentially boosting biodiversity.
Strip cropping, which involves partitioning fields into narrow bands containing different plants, is a common farming practice. Now, robotic technology is making it possible to space crops closer together than ever before.
Kit Franklin at Harper Adams University, UK, who is working on trials of this method, says one can think of it as taking the diverse planting approach that an allotment gardener might and scaling it up massively with autonomous machinery. This could enable commercial farms to stop planting vast, non-biodiverse fields and reap the benefits of mingling plants with different needs and mutually beneficial habits, he says.
At New Scientist Live in London on 8 October, Franklin presented preliminary results from the latest experiments conducted on the Hands Free Farm at the Harper Adams University campus in Shropshire.
The robots are equipped with a seed drill that deposits crops in 2-metre-wide rows and a combine harvester that collects the plants once they reach maturity. This year, the university ran a trial with half a hectare of repeating rows of wheat, barley and beans.
“We’ve been able to plant those crops as separate strips and then tend them as separate crops, and then come back and harvest them as separate crops,” says Franklin. “With conventional farm machinery and conventional operational practices it’s very hard to do that. But with these small, very precise, autonomous machines… we can now actually maybe divide our fields up differently and start farming in a different geometry, which might be beneficial for crop growth, and also wider biodiversity and carbon capture and all those sorts of things.”
Franklin says the crops have a beneficial impact on each other, with beans drawing nitrogen, which wheat and barley require to grow, down into the soil and storing it. “The one is potentially feeding the other,” he says.
Feeding the plants in this natural way reduces the need to spray artificial fertilisers, potentially reducing the carbon footprint and complexity of farming. Planting crops of varying heights, which are harvested at different times of year, can also increase the amount of sunlight each row receives, boosting growth, says Franklin.
Weeds were a problem in the trial crop because of a summer with variable weather, but the technology still proved successful. In the coming year, Franklin and his colleagues plan to plant winter crops, as well as the spring crops of beans, wheat and barley they tried this year. They aim to get an even wider range of plants from the same field and maximise the area’s the diversity and efficiency.
Felicity Crotty at the Royal Agricultural University in the UK, who is not involved in the project, says the approach could be beneficial for farmers and the environment. “You’re actually increasing your biodiversity on the farm, and also that potentially reduces pest pressure, because pests usually detect crops by certain smells or volatiles. So when they’re looking for something to eat they might miss it, because it will be hidden amongst the other crops,” she says.
But relatively small-scale experiments may not translate into industrial farming, says Crotty. “Whether it would be scalable across a 10-hectare field or a 100-hectare farm, I’m not totally convinced,” she says.