We must read Torah twice on Shabat. Maybe Talmud has debate what is “Shabat” here? Because there is Minhag Erets-Yisrael to read Torah twice in 7 years, “Shmitah”-reading, when 7 Jews read Torah by three verses each on every Shabat-reading. Though now we cannot fulfill Shmitah-Mitsvah, but Jews are living in Erets-Yisrael, may we now read Torah just twice in 7 years?
Answer:
There seems to be some unclarity. There is a mitzvah to read the Torah every Shabbos according to all opinions. At one point in history there were different customs as to how much was read on each occasion. While some finished the entire Torah every year, others took a number of years, as they read less each week.
This has no correlation to the mitzvah of Shmittah which requires us once in 7 years to rest from working the land of Israel for that entire year. The mitzvah of Shmittah has no bearing on the Torah portion read on Shabbat.
