Agland and residential real estate have increased since 2005 - BUT they have not increased 10-20%. Agland is calculated on a 5 year rolling average according to Kathy Croker (BV County Assessor). Residential real estate is based on actual sales in 2006. The importance of comparable properties and the criteria for those properties when you sell or purchase a home are noted in a previous post. CMA Post Link
Both Ag and Residential will be subject to equalization by the State of Iowa but start preparing now. Contact a Realtor or an Appraiser if you think you assessment is incorrect (you will have it by April 15th). A Realtor can do a CMA (Competitive Market Analysis) and an Appraiser will appraise your property - both can show what the fair market value of your property actually is. This is very important because this amount is the one you should be taxed on.
The assessors will notify you by April 15, and you will have until May 5 to appeal the new assessment. To appeal you will need to be armed with facts that show your home has been assessed higher than the actual fair market value to get the taxes reduced.
Pay your fair share, but don't you work too hard to give your money away?