Is the tenant entitled to demand the chemical (fertilizer) agreed upon with the landlord, which the landlord took for himself and did not give any of it to the tenant?

If you stipulated in the lease agreement that the fertilizer designated for the land should be obtained from the agricultural cooperative, then you have the right to do so, and the lessor is obligated to fulfill this condition. This is based on the Almighty's saying: "O you who have believed, fulfill [all] contracts," and on the Prophet's (peace be upon him) saying: "Muslims are bound by their stipulations."