Online lime comparison calculator
A useful tool for calculating and comparing the cost effectiveness of agricultural limes is the Lime Comparison Calculator on the Soil Quality website (see Figure 2).
To allow comparison of the total cost per hectare for the equivalent of 100% NV of lime, the Lime Comparison Calculator takes into account:
- cost of the lime
- cost of transport
- cost of spreading
- particle size distribution of the lime
- neutralising value of each particle size.
The neutralising values (NV) of larger particle sizes are discounted using the values of Cregan et al. (1989) to account for the reduced capacity to change soil pH in the short term:
- the NV of particles under 0.5mm is not discounted
- the NV of 0.5-1mm particles is discounted by 50%
- the NV of particles greater than 1mm is discounted by 80%.
The online lime comparison calculator is the easiest way to compare the cost effectiveness of limes. Lime suppliers should provide recent product test results detailing the information required for the calculations. Figure 2 shows lime X compared to lime Y, a coarser lime with lower overall neutralising value. Even though lime Y is 100km closer to the farm, it is still more cost effective to purchase lime X.