The Collaborative International Dictionary of English v.0.48:

nonproductive \nonproductive\ adj.
   not directly productive; as, nonproductive labor.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

nonproductive
    adj 1: not directly productive; "nonproductive labor"

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "nonproductive":
   acarpous, arid, barren, celibate, childless, desert, desolate,
   drained, dried-up, dry, exhausted, fallow, fruitless, gaunt,
   gelded, impotent, ineffectual, infecund, infertile, issueless,
   jejune, leached, menopausal, nonfertile, nonproducing, nonprolific,
   sine prole, sterile, sucked dry, teemless, uncultivated, unfertile,
   unfruitful, unplowed, unproductive, unprolific, unsown, untilled,
   virgin, waste, wasted, without issue