When crops and livestock are spatially disconnected the agroenvironmental problems associated with nitrogen (N) use can be multiplied. On the crop side, the lack of manure availability results in a constant need for new nitrogen synthetic fertiliser. On the livestock side, large amounts of manure cannot be efficiently reused as a fertiliser and it is applied on small closer croplands at excessive rates or directly discharged to rivers. Indeed, some livestock systems that are very efficient when analysed at the farm scale lose a great deal of efficiency when externalities are considered. Crop and livestock reconnection has been recognised as an outstanding strategy to proceed from problem to solution. We propose this special issue within the framework of the XXI International Nitrogen Workshop (Madrid October 2022) welcoming original and high-quality contributions dealing with different dimensions of crop-livestock reconnection as a strategy to reduce N waste, accepting contributions from the workshop as well as from outside. We can consider studies dealing with strategies to 1) reduce feed imports, thus relocating feed production, 2) improve local and regional optimal allocation of manure, and 3) improve NUE system efficiency through better crop and livestock spatial planning. All the contributions should include an evaluation of the contribution of any change to N waste reduction.