Which herbicide is strongly adsorbed to soil, readily degraded by soil microorganisms, has little to no leaching, and is nonselective?

• A. Glyphosate (Roundup)
• B. Bromacil
• C. 2,4-D
• D. Imazapyr

Answer: (A)

The key idea is how a herbicide behaves in the soil: it stays put, is broken down by soil microbes, doesn’t move much with water, and it kills most plants it contacts. Glyphosate fits this profile well. It binds strongly to soil particles and organic matter, which limits its leaching through the soil profile. Microorganisms in the soil readily degrade glyphosate, so it doesn’t persist for long. As a nonselective herbicide, it affects a wide range of plant species, not just a narrow group.

In contrast, bromacil tends to be more mobile and can leach in certain soils because it doesn’t bind as tightly. 2,4-D is more prone to movement in some soils and is considered selective, mainly affecting broadleaf plants rather than grasses. Imazapyr can be persistent and may show some mobility in coarse soils, making its fate less consistent with “little to no leaching.”