The partnership between the Federation of City Farms & Community Gardens, Scottish Allotments & Gardens Society and the National Society of Allotment & Leisure Gardeners (now the National Allotments Society) has now "reached its natural conclusion", said coordinator Di Appleyard.
The Esmee Fairbairn Foundation granted £1,070,968 to the project, while the Big Lottery Fund's Local Food programme, the Tudor Trust, the Fund for the Environment & Urban Life and Department for Communities & Local Government made further grants.
The ARI's original purpose - to encourage the regeneration and uptake of allotments - "has we believe largely been fulfilled", said Appleyard, with allotment waiting lists at an all-time high.
The initiative's key services will be transferred to the Federation of City Farms & Community Gardens and the National Allotments Society, with seven regional volunteer mentors now working alongside Appleyard.
The ARI has produced Good Sites Guide (2004), Growing in the Community (2008), its appendix A Place to Grow (2010), Allotments: A Plotholder's Guide (2007) and Allotments: A Scottish Plotholder's Guide (2010).
Seven ARI pilot projects shared £252,836 from Esmee Fairburn, while 102 other projects received small grants totalling £136,000.
A final round of grants saw a total of £263,190 shared by 23 flagship projects. Requests were for £2,783,597.