The formula for calculating the Effective Calcium Carbonate Equivalent (ECCE) for agricultural limestone is:
Fineness Factor (Iowa Limestone Law) is calculated from:
+ _______ % material passing an 8-mesh screen x 0.3 = _________
+ _______ % material passing a 60-mesh screen x 0.6 = _________
TOTAL Fineness Factor = _________
+ __80___ % material passing an 8-mesh screen x 0.3 = ____24___
+ __70___ % material passing a 60-mesh screen x 0.6 = ____42___
TOTAL Fineness Factor = ____76__
How much of this material would you need to apply to supply 2500 lbs of ECCE/ac?
100 / 2 = 50 mg/meq
2 meq acidity will require 2 meq of lime
Therefore, 2 meq of lime (pure CaCO3) = 100 mg CaCO3 required per 100 g soil,
or 1000 mg CaCO3 required per 1000 g (kg) of soil (this is 1 g CaCO3 per kg of soil)
56 / 2 = 28 mg/meq
Therefore, 2 meq of CaO = 56 mg CaO required per 100 g soil
or 560 mg CaO required per 1000 g (kg) of soil (this is a little more than 1/2 g CaO per kg of soil)
74 / 2 = 37 mg/meq
Therefore, 2 meq of Ca(OH)2 = 74 mg Ca(OH)2 required per 100 g soil
Conversion of mg per 100 g x 20 = lbs/2,000,000 lbs soil (acre furrow slice) (NOTE: As discussed in lecture, this factor converts mg per 100 g soil to lbs per acre.)
74 x 20 = 1480 lbs of Ca(OH)2 required per acre
50 / 37 x 100 (to get %) = 135%
6/8 = 1900/X; X = 2533 lbs of ECCE
7. Your local quarry has a liming material that is 87% ECCE and costs $13.00/ton ECCE delivered and spread on your field. Your soil test report calls for 3400 lbs/ac of ECCE. a) If you are applying lime to 20 acres, how much should you pay for the lime? b) How many tons of limestone must the quarry deliver to your field to meet this requirement?
a) As is often the case, the liming material from the quarry is not 100% effective. In this instance where the material is only 87% effective, more that 3400 lbs/ac must be applied.
3400/0.87 = 3908 lbs of this liming material is required to equal 3400 lbs of ECCE (but Iowa Limestone Law requires that the quarry price their material based on ECCE). Thus the cost of lime per acre is 3400/2000 = 1.7 tons/ac X $13.00/ton = $22.10/acre
This is applied to a 20-ac field.
20 ac X $22.10/ac = $442.00
b) To get the correct amount of lime applied, 3908 lbs must be applied per acre (which gives 3200 lbs ECCE becasue it is only 87% effective).
3908 lbs/ac X 20 ac = 78160 lbs limestone from this quarry
78160 lbs/2000 = 39.08 tons