Sparing, a.
Spare; saving; frugal; merciful. Bacon. -- Spar"ing*ly, adv. -- Spar"ing*ness, n.
Shades of meaning
Fernald has no entry of its own for sparing; he lists it under frugality.
Where he writes about it:
Economy is a wise and careful administration of the means at one's disposal; frugality is a withholding of expenditure, or sparing of supplies or provision, to a noticeable and often to a painful degree; parsimony is excessive and unreasonable saving for the sake of saving. — from frugality