(Mishnah): If as sharecropper received a field from his friend, at a fee of 700 dinars for 7 years, he must work 7 years, excluding the Shemita year.

If he arranged to work for one Shemita cycle for 700 dinars, the Shemita is included in this (even though he cannot work during that year).

(Gemara) - Beraisa: If a sharecropper received a field from his friend, if he planted one year and it did not grow, the owner can force him to plant a second year,

If it did not grow a second year, the owner cannot force him to plant a second year.

Raish Lakish: This applies to a field that had grown produce in the past, but if it had not, the owner can force him to plant a third year.