Use of ammoniacal N in continuous corn production results in greater acidification of the surface soil layer under conservation tillage. Moldboard plowing results in dilution of acid inputs to greater depth. The objective of this work was to observe soil reaction after a lime application made to a continuous corn experiment initiated in 1970. Four fertilizer N rates (0. 84. 168. and 336 kg N ha‐1) and two primary tillage systems (no‐tillage and moldboard plowing) were used. Lime application was made to half of each plot in 1983. Control of developed acidity was achieved the first year on the plowed soil. This was not the case on the most acid no‐till soil, where both corn dry matter production and leaf Mn concentration also indicated persistence of acidity. Surface lime application resulted in soil pH changes limited to the upper 10 cm of no‐till soil. Shallow incorporation of lime may be needed to more quickly control strongly developed acidity in no‐till soils.