Category:801 Lime and Fertilizer: Difference between revisions

Refer to Sec 801 for MoDOT’s specifications.

For Laboratory testing and sample reporting procedures, refer to 801.2 Laboratory Testing Guidelines for Sec 801.

801.1 Construction Inspection Guidance for Sec 801

Description (Sec 801.1)

Roadside Development, where related to living plants, can only be defined in general terms. Successful inspection of seeding, fertilizing, sodding, mulch and planting largely depends on two conditions:

• Strict adherence to specifications, and
• Quality inspection based on experience, practical knowledge, and good judgment applied within the intent of specifications.

Material (Sec 801.2)

Fertilizing furnishes basic nutrients essential for plant growth and increases availability of other nutrients. Soil neutralization neutralizes soil acidity. The area to be limed and fertilized will be the area specified within the limits of construction. The contractor shall provide certification as per specification for lime and fertilizer.

Commercial Fertilizer

Commercial fertilizer must supply specified amounts of total nitrogen (N), available phosphoric acid (P₂O₅), and soluble potash (K₂O).

Components may be furnished individually, or as a mixture. Bagged commercial fertilizer may be accepted on the basis of bag label. When furnished in bulk, either mixed or as individual components, fertilizer is accepted by supplier certification.

When acceptance is by bag label analysis, the label should be removed from a sack for each type furnished, (i.e. 12-12-12 or 10-20-10). These figures represent the percent of each component in the total. This label should be retained in permanent records with proper notation in the inspector's diary. Label analysis may be used to determine proper application rate.

If acceptance is by supplier certification, the project file should have a copy of this certification to include certified analysis, which, in turn, may be used to determine application rates. A field inspection report should be issued showing quantity so accepted, the analysis and basis of acceptance.

Equipment (Sec 801.3)

No additional guidance

Construction Requirements (Sec 801.4)

Roadside Development, where related to living plants, can only be defined in general terms. Successful inspection of seeding, fertilizing, sodding, mulch, and planting largely depends on two conditions:

• Strict adherence to specifications, and
• Quality inspection based on experience, practical knowledge, and good judgment applied within the intent of specifications.

Depending on what type of a grading job is contracted (light grading-shallow cuts and light fills or major grading - deep cuts and high fills), the contract rates are based on soil samples that may or may not be representative of the actual material that will be seeded; therefore the fertilization rates provided in the contract are the minimum quantities to be applied.

It is the contractor’s responsibility to determine whether or not additional fertilizer and/or lime may be required. No direct payment will be made for any additional fertilizer required to meet this specification. The performance standard shall be met before acceptance of the work. (See Sec 805.4 of the Missouri Standard Specifications.)

The following examples illustrate methods that may be used to determine rate of application to provide specified quantities of nitrogen, phosphoric acid and potash.

Assume Contract requirements:

• nitrogen (N), 100 lbs. per acre,
• phosphoric acid (P₂O_5,), 200 lbs. per acre,
• potash (K₂O), 100 lbs. per acre.

The first case to be considered is for material furnished as a mixture with certified or acceptable test analysis for 10-20-10, (10% nitrogen, 20% phosphoric acid, and 10% potash). To compute weight of mixture to be placed per acre the following method is suggested.

Case 1
${\displaystyle Nitrogen:\,(Total\,weight,\,in\,lbs.,\,of\,mixture\,to\,be\,applied\,per\,acre)}$ ${\displaystyle ={\frac {Required\,wt.\,(in\,lbs.)\,Nitrogen\,per\,acre}{\%\,Nitrogen\,in\,mix\,(expressed\,as\,a\,decimal)}}}$ ${\displaystyle Total\,weight\,mixture\,per\,acre={\frac {100}{0.10}}=1000\,lbs.}$
${\displaystyle Phosphoric\,Acid:\,(Total\,weight,\,in\,lbs.,\,of\,mixture\,to\,be\,applied\,per\,acre)}$ ${\displaystyle ={\frac {Required\,wt.\,(in\,lbs.)\,Phosphoric\,Acid\,per\,acre}{\%\,Phosphoric\,Acid\,in\,mix\,(expressed\,as\,a\,decimal)}}}$ ${\displaystyle Total\,weight\,mixture\,per\,acre={\frac {200}{0.20}}=1000\,lbs.}$
${\displaystyle Potash:\,(Totalvweight,\,in\,lbs.,\,of\,mixture\,to\,be\,applied\,per\,acre)}$ ${\displaystyle ={\frac {Required\,wt.\,(in\,lbs.)\,Potash\,per\,acre}{\%\,Potash\,in\,mix\,(expressed\,as\,a\,decimal)}}}$ ${\displaystyle Total\,weight\,mixture\,per\,acre={\frac {100}{0.10}}=1000\,lbs.}$

Application of 1,000 lbs. of mixed commercial fertilizer will, therefore, furnish the specified amount of each required component.

The contractor may sometimes ask to use a mixed commercial fertilizer that will supply more of at least one required component than specified. For example, assume contract requirements are, as in the previous example, nitrogen 100 lbs. per acre, phosphoric acid 200 lbs. per acre, potash 100 lbs. per acre, and the contractor asks to use a 12-12-12 fertilizer. Following the methods in the above example:

This shows that 1667 lbs. of the mixture must be applied to obtain the required phosphoric acid; however, this amount will furnish twice the required nitrogen and potash. This could be an undesirable application and must be reviewed by the district office before permitting its use.

The next example assures the supplier furnishes three separate fertilizers to the project. The material will thus supply the required nitrogen, phosphoric acid, and potash as individual components. Assume specified amounts of 100 lbs. per acre of nitrogen, 200 lbs. per acre of phosphoric acid, and 100 lbs. per acre of potash as in the previous examples. Material furnished to supply nitrogen is certified and/or tested to be 33.5-0-0 fertilizer. Material furnished to supply phosphoric acid is certified and/or inspected as 0-46-0. Material furnished to supply potash is tested and/or certified as 0-0-62.

Case 3
${\displaystyle Nitrogen:\,Weight\,in\,lbs.\,of\,Nitrogen\,bearing\,material\,required\,per\,acre)}$ ${\displaystyle ={\frac {Required\,wt.\,(in\,lbs.)\,Nitrogen\,per\,acre}{\%\,Nitrogen\,in\,mix\,(expressed\,as\,a\,decimal)}}}$ ${\displaystyle Total\,weight\,mixture\,per\,acre={\frac {100}{0.335}}=229\,lbs.\,per\,acre}$
${\displaystyle Phosphoric\,Acid:\,Weight\,in\,lbs.\,of\,Phosphoric\,Acid\,bearing\,material\,required\,per\,acre)}$ ${\displaystyle ={\frac {Required\,wt.\,(in\,lbs.)\,Phosphoric\,Acid\,per\,acre}{\%\,Phosphoric\,Acid\,in\,mix\,(expressed\,as\,a\,decimal)}}}$ ${\displaystyle Total\,weight\,mixture\,per\,acre={\frac {200}{0.46}}=435\,lbs.\,per\,acre}$
${\displaystyle Potash:\,Weight\,in\,lbs.\,of\,Potash\,bearing\,material\,required\,per\,acre)}$ ${\displaystyle ={\frac {Required\,wt.\,(in\,lbs.)\,Potash\,per\,acre}{\%\,Potash\,in\,mix\,(expressed\,as\,a\,decimal)}}}$ ${\displaystyle Total\,weight\,mixture\,per\,acre={\frac {100}{0.62}}=161\,lbs.\,per\,acre}$

Using weights determined above, the contractor could apply components individually or could mix them in proper proportions by weight to be placed in one application.

Mixture to provide required nutrients:

• nitrogen (N)bearing material= 299 lbs.
• phosphoric acid (P₂O_5,) bearing material= 435 lbs.
• potash (K₂O) bearing material= 161 lbs.
• Total mixture per acre= 896 lbs.

If the contractor elects to mix materials the inspector should observe the operation since "hot spots" could result if mixing is not carefully done to assure a homogeneous mixture. Improper proportions or improper mixing could lead to an excess of one component and deficiencies of others, detrimental to establishment of vegetation.

As previously stated, the inspector must have a certification stating mix components. State law regulates tolerances of any commercial fertilizer. The supplier's certification is a statement that these regulatory tolerances have been met. The supplier's certification for bulk fertilizer should contain the following information with each lot or shipment:

• Name, brand, and trademark under which fertilizer is sold.
• Name, and address of person guaranteeing the fertilizer.
• Guaranteed chemical composition of the fertilizer expressed in the following terms:

• (a) Percent total nitrogen
• (b) Percent available phosphoric acid
• (c) Percent of soluble potash

• Project, Route, County, Contractor's name.

Bag label analysis should have items (1) and (3). The resident engineer should prepare a field acceptance report showing the quantity, the analysis and the basis of acceptance.

Method of Measurement (Sec 801.5)

Earth shoulders, medians, and the entire roadway outside the roadbed limits, excluding rock or surfaced areas, are fertilized and limed.

Basis of Payment (Sec 801.6)

Separate payment is not made for fertilizing and liming areas to be sodded or seeded by contract.