The following uses are permitted as of right in the AG zone:

    1. Agriculture, subject to all city and state laws and regulations including regulations of the department of health, and including the raising of field crops, horticulture, and animal husbandry, including feed lots, poultry farms and kennels and the necessary or usual ranch and farm dwellings;

    2. Parks and recreation areas operated by the city;

    3. Riding academies;

    4. Public utility buildings and installations necessary to the operation of a public utility other than offices, material yards or repair shops;

    5. Greenhouses and nurseries;

    6. Railroad through and spur tracks, but no sidings or other terminal-type facilities and no service, repair or administrative facilities;

    7. Carnivals and similar exhibitions, subject to the provisions and standards of Chapter 4.14 of this code;

    8. Single-family detached dwellings subject to the following standards:

        a. For all building permits issued after July 31, 1984, the principal structure shall have a floor area of not less than six hundred forty square feet; and a minimum width for any building elevation of not less than twenty feet, and

        b. All principal structures shall be roofed with a nonmetal type of roofing material, and

        c. All principal structures shall be sided with material other than flat or corrugated sheet metal.

    9. Extraction or landfilling, except as related to an approved subdivision plat or building permit, subject to the following conditions:

        a. The requirements for a grading permit pursuant to Chapter 20.30 must be satisfied.

        b. The extraction or landfilling site must be at least 300 feet from any residentially used property.

        c. The extraction or landfilling process must be completed within one construction season.

        d. Access to and from the site must be directly to an arterial street or on a route approved by the Public Works Department.

        e. Trucks and other machinery shall be operated only between 7 a.m. and 7 p.m., Monday through Friday and 8 a.m. and 3 p.m. on Saturday.

        f. Nuisance complaints related to dust, traffic, noise, or other impacts of the extraction or landfilling operation must be resolved in a timely mannerby cooperative efforts of the grading permit holder.

         g. The extraction or landfilling site does not occur in the Loes Hills within that area visible from the Loess Hills National Scenic Byway located on Highway 12 and Interstate Highway 29 as defined in Section 20.30.040.