kernel.sysrq is defined in /etc/sysctl.conf owned by rc-scripts.
having it here as well, will print notice:

# /lib/systemd/systemd-sysctl
Overwriting earlier assignment of kernel/sysrq in file '/etc/sysctl.d/99-sysctl.conf'.

--- systemd-221/sysctl.d/50-default.conf~	2015-02-28 18:38:38.000000000 +0200
+++ systemd-221/sysctl.d/50-default.conf	2015-08-01 22:43:16.307974188 +0300
@@ -11,12 +11,6 @@
 # (e.g. /etc/sysctl.d/90-override.conf), and put any assignments
 # there.
 
-# System Request functionality of the kernel (SYNC)
-#
-# Use kernel.sysrq = 1 to allow all keys.
-# See http://fedoraproject.org/wiki/QA/Sysrq for a list of values and keys.
-kernel.sysrq = 16
-
 # Append the PID to the core filename
 kernel.core_uses_pid = 1