Toggle Logger Channels
This module allows you to enable or disable specific logging channels in Drupal, including those from core and contributed modules. It provides a configuration page where you can select which channels to disable, preventing them from generating log entries.
Toggle Channels module provides the possibility to toggle (enable/disable) some (or all) logger's channels thrown through Drupal and installed contrib/custom modules.
Sometimes, for several reasons, it is not possible to disable some modules' logs. In this way, the Toggle Channels module, come in handy.
How it works
First of all go to admin/config/development/logging/toggle_channels to access to module's configuration page.
The first checkbox will enable the altering of the used logger replacing it with Nullable Logger provided by this module. This way, all the channels below selected, will not generate any log.
In the above picture was been disabled both logger's channels cron and user.