surfaceapplied

Surfaceapplied refers to substances that are applied to the surface of a substrate rather than being mixed into it. In agriculture and horticulture, surface-applied products include fertilizers, pesticides, lime or gypsum, and soil amendments that are spread or sprayed on the soil surface or on plant tissue and may or may not subsequently infiltrate into the topsoil. The term contrasts with incorporated, injected, or banded methods that place material below or within the soil profile.

Common applications include surface-applied fertilizers such as urea granules, nitrate-based fertilizers, and slow-release formulations applied to soil surfaces; surface-applied pesticides and herbicides applied as sprays or granules; and lime or gypsum applied on the surface to adjust soil pH and then dissolved by rainfall.

Advantages of surface-applied approaches include simplicity, reduced soil disturbance, suitability for no-till systems, and rapid surface coverage. Limitations include potential volatilization losses for nitrogen compounds, runoff or erosion losses, uneven distribution on uneven ground, and dependence on rainfall or irrigation for incorporation and movement into the root zone.

Effectiveness depends on product properties, soil moisture, rainfall, temperature, and crop stage. Regulatory and environmental considerations cover label directions, drift minimization, timing relative to rainfall, and potential non-target impacts.

Surface-applied strategies are often evaluated in field experiments to optimize rates, timing, and formulations for specific crops and soils.