In the 1950s, they started using variable-rate application of lime and other materials. When it comes to precision farming, the limelight seldom shines on lime. Nitrogen, phosphorus, seed and chemicals receive most of the attention. That's nothing new-lime has long been overlooked. However, it deserves to be the star of the show.
Lime improves yields by making many other nutrients more available to plants.
It may be impossible to benefit from the variable application of phosphorus, potassium, nitrogen and other nutrients until lime brings soil pH levels into line. The map on the right shows soil pH levels after the field was resampled in 1995. The field was sampled, and lime was applied three times between the two maps shown. By 1995, the soil pH picture had changed dramatically. That's what Olson found when he compared variable rate and conventional application methods with Indiana farmer John Pickering.