Which root system concentrates nutrient uptake in surface soil?

The fibrous root system is characterized by a network of thin, branching roots that spread out horizontally near the surface of the soil. This design allows for efficient nutrient and water uptake from the upper soil layers, where organic matter tends to accumulate and where nutrients are often more readily available.

In contrast, a taproot system features a single, dominant root that grows deep into the soil, effectively accessing moisture and nutrients from deeper layers but not as efficiently from the surface soil. Adventitious roots can arise from various parts of the plant and are less specialized for nutrient uptake, often serving different functions. Storage roots are specialized for storing food and nutrients rather than optimizing nutrient uptake from the soil.

Thus, the fibrous root system is the most effective for concentrating nutrient uptake in the surface soil, making it the appropriate answer to the question.