As part of your equipment have something to dig with, and when you relieve yourself, dig a hole and cover up your excrement. (NIV)
And you shall have a paddle or shovel among your weapons, and when you sit down outside [to relieve yourself], you shall dig a hole with it and turn back and cover up what has come from you. (AMP)
And thou shalt have a paddle upon thy weapon; and it shall be, when thou wilt ease thyself abroad, thou shalt dig therewith, and shalt turn back and cover that which cometh from thee: (KJV)