4169.03 FERTILIZER.
Fertilizer shall be of the grade, type, and form specified and shall comply with rules of the Iowa Department of Agriculture and the following requirements:

The grade of fertilizer will be identified according to the percent nitrogen (N), percent available phosphoric acid, (P₂O₅), and percent water soluble potassium, (K₂O), in that order, and approval will be based on that identification.

All fertilizer shall be furnished from an established fertilizer dealer and guaranteed analysis shall be provided through mechanically printed commercial fertilizer bags or a manufacturer's (not a distributor's) bill of lading.

Inspection and acceptance of fertilizer will be in accordance with Materials I.M. 469.03.

Fertilizer shall be of a type that can be uniformly distributed by the application equipment. Fertilizer may be chemically combined or may be furnished as separate ingredients. Fertilizer supplied as chemically combined shall have each unit of fertilizer chemically combined, and the manufacturer's guarantee shall indicate compliance with this requirement. Fertilizer supplied as separate ingredients shall be of uniform size, and the analysis shall be guaranteed by the manufacturer. Fertilizer supplied as separate ingredients shall be mixed using a drum mixer, grinder mixer, or other approved mechanical mixers. Fertilizer shall be mixed only the the fertilizer dealer.

When a 6-24-24 chemically combined commercial fertilizer has been specified, a combination of ammoniated phosphate, muriate of potash (granular form), and urea (granular form) may be used.

When a 13-13-13 chemically combined commercial fertilizer has been specified, a combination of ammoniated phosphate, muriate of potash (granular form) may be used.

Ammoniated phosphate shall consist of either monoammonium phosphate (11-52-0) or diammonium phosphate (18-46-0).

Fertilizer may be furnished in a dry or liquid form.

The Contractor shall furnish a list of the number of containers and a corresponding scale ticket from an approved scale for the fertilizer to be used in the work.

Official samples taken by the Contracting Authority may be tested. A tolerance of minus 1.0 percentage point from the guaranteed analysis for each nutrient will be considered substantial compliance.

Ground limestone shall be of the type known as No. 1 fine (70% passing No. 200 (75 µm) sieve) with an analysis of elemental calcium of not less than 37% nor more than 40%.

4169.04 INOCULANT FOR LEGUMES.
An inoculant is a culture of bacteria specifically formulated for legume seeds (alfalfa, clovers, lespedeza, birdsfoot trefoil, hairy vetch, and crownvetch). The manufacturer's container shall indicate the specific legume seed to be inoculated and the expiration date. All inoculant shall meet requirements of the Iowa Seed Law. Safety precautions specified on the product label shall be followed.

4169.05 RESERVED.

4169.06 STICKING AGENT.
A sticking agent shall be a commercial material recommended by the manufacturer to improve adhesion of inoculant to the seed. For quantities less than 50 pounds (25 kg), the sticking agent need not be a commercial agent, but shall be approved by the Engineer and shall be applied separately prior to application of inoculant. Safety precautions specified on the product label shall be followed. A sticking agent is not required if a liquid formulation of inoculant is used.

4169.07 SOD.
Sod shall consist of approximately 1 inch (25 mm) of well established turf consisting of live Kentucky bluegrass, unless otherwise specified. Sod shall be free from roots of trees or brush, stones, and other objectionable materials. Sod shall be free from all noxious weeds and reasonably free of all other weeds.

Sod shall be cut in strips of uniform width and thickness with ends square. The Engineer may order the thickness adjusted to meet the sod conditions. Sod shall be cut to the length specified for the use intended. If not specified, the minimum length shall be 3 feet (1 m). All sod areas shall be mowed to a height of approximately 1 1/2 inches (40 mm) to 2 inches (50 mm) prior to cutting.

Sod shall have been regularly maintained prior to cutting. The Contractor shall be responsible for the application of pre-emergence weed control chemicals and weed control chemicals for broadleaf weeds.

Within 1 hour after being cut, sod shall be rolled or stacked. Other methods of handling sod may be approved by the Engineer. Precautions shall be taken to prevent drying or heating. Sod damaged by heat or dry conditions, or sod cut more than 18 hours before being incorporated into the work, shall not be used.

Sod will be subject to inspection by the Engineer at the job site, and approval of the work constitutes approval of the material.

4169.08 MULCH.
Material used as mulch may consist of threshed or unthreshed prairie hay, threshed cereal straw, wood excelsior, wood cellulose, or other material, as specified. All material used as mulch shall be free from noxious weeds.

The Contractor shall furnish a list of the number of bales and corresponding ticket from an approved scale for the mulch material to be used on the project.

Wood excelsior shall be composed of wood fibers, a minimum of 8 inches (200 mm) long, based on an average of 100 fibers, and approximately 0.024 inch (600 µm) thick and 0.031 inch (800 µm) wide. The fibers shall be cut from green wood and shall be reasonably free of seeds or other viable plant material. Wood excelsior shall be baled and the weight (mass) determined. The weight (mass) of the material shall be furnished by the manufacturer and shall be used for determining the rate of application.

4169.09 STAKES FOR HOLDING SOD.
Stakes for holding sod shall be either wood or metal, except that wood stakes shall be used in sandy soils or when required by the Engineer.

Wood stakes for holding sod shall be 1 inch (25 mm) to 1 1/2 inches (40 mm) in width, 1/4 inch (6 mm) to 1/2 inch (13 mm) in thickness, and 12 inches (300 mm) long. Where this length of stake does not provide firm bearing, the Engineer may require stakes of sufficient length to secure firm bearing.

Wire stakes shall be in the form of staples made from No. 11 (3.06 mm diameter) wire or heavier and shall have a minimum 2 inch (50 mm) flat spread on the top of the sod. The legs shall be at least 6 inches (150 mm) in length. The Engineer may require wire legs longer than 6 inches (150 mm).

4169.10 SPECIAL DITCH CONTROL AND SLOPE PROTECTION.
Jute mesh, plastic netting, wood excelsior mat, and wire staples shall comply with the following:

A. Jute Mesh Over Sod.
Jute mesh over sod shall be a uniform, open, plain weave, of single jute yarn. The yarn shall be of loosely twisted construction and shall not vary in thickness by more than 50% its normal diameter. Jute mesh shall be furnished in rolled strips and shall meet the following minimum requirements:

Jute mesh shall be nontoxic to the growth of plants and germination of seeds and shall be identified by tag.

Width - minimum 48 inches ± 1 inch (1.2 m ± 25 mm) from manufacturer's rated width.

78 warp ends per 4 feet (1.2 m) of width.

45 weft ends per yard (meter).

Weight (mass) to average 1.22 pounds per linear yard (0.6 kg per meter) (based on 48 inch (1.2 m) width) with a minus tolerance of 5%.

All material must be new and unused.

At the Contractor's option, plastic netting (polypropylene) may be substituted for jute mesh. It shall meet the following requirements:

Color - black or green, with UV additives

Mesh size - approximately 0.6" x 0.7" (15 mm x 18 mm)

Weight (Mass) - approximately 9 pounds per 1,000 square feet (44 g/m²)

Width - 48 inches (1.2 m) minimum

B. Wire Staples.
Wire staples for holding special ditch control wood excelsior mat and special ditch control jute mesh over sod shall meet the following requirements:

• Wire staples shall be U-shaped.
  
• Length of each leg shall be 6 inches (150 mm) minimum.
  
• Wire diameter shall be No. 11 (3.06 mm) wire.
  
• Staples shall be of sufficient hardness to facilitate installation without bending. In sandy soil conditions, wire staples with a minimum length of 12 inches (0.3 m) will be required when directed by the Engineer.

C. Wood Excelsior Mat.
Wood excelsior mat shall meet the requirements of Materials I.M. 469.10.

Wood excelsior mat shall be a mat of interlocking wood fibers with a plastic netting applied to both sides for holding the excelsior in place. The mat shall be nontoxic to growth of plants and germination of seeds. The netting applied to both sides shall have a mesh size of approximately 5/8 inch by 3/4 inch (16 mm by 19 mm). The mat shall be furnished in rolls with a minimum length of 180 feet (55 m) and a uniform, minimum width of 48 inches (1.2 m), within a tolerance of minus 1 inch (25 mm) and plus 3 inches (75 mm). As furnished, the mat shall have a minimum weight (mass) of 0.88 pound per square yard (480 g/m²). The mat shall be furnished in plastic bags or otherwise protected to prevent damage from weather or handling.

At the Contractor's option, coconut fiber mat may be substituted for wood excelsior mat for special ditch control, and straw mat, straw-coconut fiber mat or coconut fiber mat may be substituted for wood excelsior mat for slope protection. These mats shall meet the following requirements:

The mat shall be of consistent thickness with the straw, straw-coconut fiber or coconut fiber evenly distributed over the entire area of the mat. The top side of the mat shall be covered with a polypropylene netting with a 1/2 inch by 1/2 inch (12.5 mm by 12.5 mm) mesh attached with cotton thread. The mat shall be furnished in rolls with a minimum width of 47 inches (1190 mm) and a minimum length of 80 feet (24 m). As furnished, the mat shall have a minimum weight (mass) of 0.50 pound per square yard (270 g/m²). The mat shall be furnished in plastic bags or otherwise protected to prevent damage from weather or handling.