Is zakat on agricultural produce (Ushr) obligatory upon a brother for his business project after the passing of a full year (hawl), and how is it calculated after deducting the debt amount, knowing that he did not repay his debt due to renovating and expanding the shop?

Zakat on trade goods becomes obligatory at the end of every lunar year if their value reaches the nisab (the equivalent of 85 grams of gold or 595 grams of silver). The amount of zakat is one-quarter of one-tenth (2.5%) of the total capital and profits. If a brother's debt consumes his wealth or reduces it below the nisab, then no zakat is due on him. However, if his wealth reaches the nisab after deducting the debt, then zakat becomes obligatory after subtracting the debt's value from the total wealth.