Under acidic conditions a farmer treats the soil of his field with quicklime or slaked lime or chalk.
The nature of the compounds, quicklime$\left(\mathit{CaO}\right)$, slaked lime $\left[\mathit{Ca}\right(\mathit{OH}{)}_2]$ and chalk $\left[\mathit{CaC}{O}_3\right]$ is basic in nature. 

So, the use of these basic fertilizers is common only when the soil is very acidic in nature and it is not suitable for agriculture. Bases work as a neutralizing agent which neutralizes the acidic content in the soil.