Nasser owns agricultural land and has agreed with Ahmed to exploit his agricultural land, with the value of the crop being shared equally, $50\%$ for each partner.

The crop yield was $2000$ sacks of wheat.

The cost of farming was $40,000$ riyals.

The cost of irrigating the land was $20,000$ riyals.

The value of one sack is $100$ riyals.

Required: Calculate the zakat base and the amount of zakat.