In the 1970s, research on agroforestry in the UK and Ireland occurred in a piecemeal manner. Due to difficulties in applying conclusions from isolated experiments across the countries, it was decided to establish experimental sites to carry out research on silvopastoral agroforestry based on experiments with common protocols. This was the Silvopastoral National Network Experiment.
In the UK, a network of sites was set up to carry out a planned series of experiments on poplar grown in a normal UK cereal rotation in 3 different geographical locations. This was the National Network Silvoarable Agroforestry Experiment. Protocols were such that treatments imposed were the same at each site, to allow comparison of performance of different poplar cultivars in different climatic zones of England. The basic design was to allow comparison with extensive plantings in southern England by Bryant and May of poplar for matches in 8 m x 8 m layouts.
There are six sites in the Network: