The rally, from Kathmandu to Delhi, which stopped over at Saifai here, aims to create awareness for environment protection and women empowerment.
Speaking on the occasion, Akhilesh blamed the "state of Delhi" for increased pollution in Yamuna and said that it was "their responsibility to clean it".
Earlier on Saturday, the Mahotsava had got off with fanfare but Akhilesh was conspicuous by his absence on the inaugural day, triggering speculation.
Though there was no official word from Samajwadi Party or the government, sources in the ruling party said the Chief Minister, who is also the state president of SP, was upset over sacking of his two close associates -- Sunil Yadav alias Sajan and Anand Bhadauria.
Another SP leader Subodh Yadav, son of party MLA from Etah Rameshwar Yadav, was also expelled on charges of indulging in anti-party activities.
All members of the Yadav family usually attend the inaugural session of the Mahotsav. Last year too, Akhilesh was present, along with his MP wife Dimple Yadav and their children.