 However, from the 1960s, vast quantities of lime (pulverised chalk or limestone) were poured on the soil to reduce acidity.The effort went on for decades; by the late 1990s, between 14 million and 16 million tonnes of lime were being spread on Brazilian fields each year.The quantity rose to 25 million tonnes in 2003 and 2004, equalling around five tonnes of lime per hectare.