According to Mainichi, NHK has announced to postpone the airing of Moshidora
due to the extended news programs on the earthquake. It had been scheduled to be aired from March 14th - 25th. The new schedule hasn't been fixed yet.
Update March 20th
According to NHK, Moshidora will start on April 8th. It will be aired weekly.
Update March 24th
According to NHK, the new airing schedule of Moshidora was announced.
Episodes 1 -5: Apr 25th - 29th
Episodes 6 - 10: May 2nd - May 6th
Every Friday from Apr 29th