Lettuce sprouts amid rows of plastic covering the ground at One Straw Farm, an organic operation north of Baltimore. Although conventional farmers also use plastic mulch, organic produce farms like One Straw rely on the material even more because they must avoid chemical weed killers, which are banned in organic farming.

Lettuce sprouts amid rows of plastic covering the ground at One Straw Farm, an organic operation north of Baltimore. Although conventional farmers also use plastic mulch, organic produce farms like One Straw rely on the material even more because they must avoid chemical weed killers, which are banned in organic farming.