Illinois 2018 Farmland Affidavit is a legal document used by agricultural landowners to declare their land as agricultural property for the purpose of lower property taxes. There are two types of Illinois 2018 Farmland Affidavit, the Illinois Farmland Assessment Affidavit and the Illinois Agricultural Use Value Assessment Affidavit. The Illinois Farmland Assessment Affidavit is used to qualify for a lower assessed value of land to be used for agricultural production. The Illinois Agricultural Use Value Assessment Affidavit is used to qualify for a lower assessed value of land that is used for other agricultural purposes such as habitat conservation or natural resource management. Both affidavits require the landowner to provide proof of ownership, proof of agricultural use, and a plan for the use of the land. The affidavits must be filled out and signed by the landowner and submitted to the local county assessor.