The flow of phosphorus in Sweden (a typical western system)
Linear flows causes the HEAP-effects

Put the cursor over the different parts of the picture.
Click and see the explanation.


Hence, the linear flow causes a heap effect on at least two (structural) places: In the secondary agriculture and in the urban sites.

The only way to avoid this problem is to construct balanced sites.
In them, balanced agriculture is integrated with human settlement, in order to recycle nutrients even in situations with high energy prices and transportation problems.