A qualitative study of the nodulating ability of legumes of Pakistan

Abstract

Legume-Rhizobium symbiosis accumulates substantial amounts of mineralizable nitrogen which help in ecological rehabilitation of degraded soils and increase the soil fertility in agricultural ecosystem. Nodulation was studied in 72 legume species from various parts of Pakistan. All the species of Papilionoideae and Mimosoideae were nodulated whereas all the species examined in Caesalpinioideae were non-nodulated. Attempts to elicit nodulation in Caesalpinioid species by rhizobial inoculation were not successful and they were accepted as lacking nodulating ability. Nodulation is reported for the first time in 6 species within 3 genera of Mimosoideae and 9 species within 5 genera of Papilionoideae. Majority of the species were abundantly nodulated under natural soil conditions or when grown in uninoculated garden soil indicating distribution of wide range of naturalized rhizobia. The study shows that the wild legumes hold great promise for inclusion in revegetation of denuded and derelict ecosystems.