This netherworld domain is, in essence, an expansive and exaggeratedly large "sterile storage room" with a constant temperature.
Theoretically, if left undisturbed, any food discarded in this domain could be preserved far longer than in the normal environment of the Mortal World.
Moreover, since the Undead Army does not consume food meant for the living, he originally had high hopes for the state of provisions here.
But alas, he hadn't anticipated that even though the enemy consisted of a horde of mindless undead, they would still possess the foresight to thwart a living army, going so far as to burn the supplies clean beforehand.