What is the ruling of Islam regarding estimating the compensation (ghurm) against the brother who did not participate in the cultivation of his deceased mother's land, which was cultivated by his deceased brother, knowing that the cost of cultivation was in 1993, and does he have the right to claim his share of the land?

If the father improved his mother's land without it being a donation, he is considered a partner with her in the land to the extent that his improvement increased its value. He or his heirs are entitled to the value of the improvement. As for the other brother, he has his share of the original value of the land. So, if the land was worth twenty before the improvement and thirty after it, the improver is a partner by one-third, and the one who did not improve it gets two-thirds of the land's value.