What effect does porous soil high in organic matter have on pesticide application?

Porous soil that is high in organic matter can influence pesticide application significantly. When pesticides are applied to this type of soil, the organic matter can enhance the soil's adsorption capacity. This means that the organic particles bind to the pesticide molecules, effectively reducing their bioavailability and limiting the active ingredient's effectiveness in controlling pests.

Therefore, the high organic content causes the pesticides to be less available for uptake by plants or target organisms, reducing their overall efficacy. This highlights the importance of considering soil composition and characteristics when applying pesticides, as it can directly affect pest management outcomes.

The other options do not accurately reflect the relationship between porous, organic-rich soil and pesticide availability; they either suggest no impact or an increase in available active ingredients, which contradicts the known effects of organic matter on pesticide retention in soil.