Insecticide Half-Life: Is Soil Safe for Edibles After Orthene Use?

Orthene (acephate) is a mobile insecticide that washes out of soil rather than binding to particles, with a half-life of only three days. Half-life means the pesticide amount halves every three days: 1 → ½ → ¼ → ⅛, etc. After several half-lives, residue is negligible. Soil in half-barrels previously treated with Orthene for fire ants is safe for planting turnip greens or other edibles.