Firstly: The Ruling of Charity on Crops
Charity is payable on crops if its conditions are met. Consensus has been quoted on charity on crops being holistically wajib by: al-Mawardi, Ibn Hazm, al-Kasani, and al-Nawawi.
Secondly: Other Payable Portion other than Charity
There is no other amount or portion of wealth that is legally payable on crops other than the charity at harvest. This is the position of the vast majority of scholars.