What mechanism causes plant ion-uptake to acidify soil? Solution Answer= The mechanisms that causes plant ion uptake to acidify soil= soil acidification is a natural process in high rainfall environments major nutrient fertilizers such as nitrogen is major nutrient affecting soil pH there are 3 mechanisms 1] root interception = it is physical contact resulted by root growth 2] Mass flow= involves the transport of nutrients to the root as a result of transpiration 3] diffusion movement= caused by differences in concentration nutrients are taken up by roots which dominant in nutrition or by leaves is only additional in nutrition.