Landwehr-Feldartillerie-Abteilung

LFAR 1 Landwehr-Feldartillerie-Regiment Nr. 1
LFAR 2 Landwehr-Feldartillerie-Regiment Nr. 2
etc.

See:

http://www.altearmee.de/formationen/truppen_art.html

The Artillerie Ersetz-Abteilungen [of two batteries each] were, at some point, formed into Landwehr-Feldartillerie-Regimenten. The date is not clear to me.