Dr Annika Haß and Professor Catrin Westphal at Göttingen University's Functional Agrobiodiversity & Agroecology Research Group add: "In addition to these measures, high connectivity between quarries and neighbouring calcareous grasslands is crucial. This makes it easier for bees to move between the two habitats. Preserving and restoring nutrient-poor grasslands and maintaining quarries are good ways to support and conserve wild bees."

"Tracking these nitrogen losses, and trying to mitigate them, requires an approach that links economics, agroecology and hydrology to ensure that actions at one point in the chain do not have unintended consequences at another point."

He said he believes promoting more local agriculture would help, along with adopting farming methods that work with nature, including the sustainable techniques of agroecology and permaculture.

Gliessman, a retired agroecology professor at UC Santa Cruz, said the lawsuit led residents who were previously supportive of the carrot companies to see them in a new light.

"All in all, there is large diversity in the quality of the crop residues that are added to the soil as part of the general cultivation practice," says Professor and Department head Jørgen E. Olesen from the Department of Agroecology at Aarhus University.