Agronomy Degree Practice Exam

What is the growth habit of alfalfa that allows it to remain productive after regrowth?

1. Perennial

2. Annual

3. Biennial

4. Deciduous

The correct answer is: Perennial

The growth habit of alfalfa being perennial is significant because it means that the plant can live for multiple years, allowing it to regrow each season after being harvested. Perennial plants have deep and extensive root systems, which enable them to access moisture and nutrients from the soil, thereby supporting regrowth after cutting. This adaptive trait is essential in agricultural practices, particularly in forage systems where continual production is desired. In contrast, annual plants complete their life cycle within one year, dying after producing seeds, which does not allow for regrowth after harvest. Biennial plants have a life cycle spanning two years, during which they typically produce vegetative growth in the first year and flowers and seeds in the second year, but they don't provide the same consistent regrowth benefits as perennials do. Deciduous plants shed their leaves seasonally, but this trait does not apply to the regrowth capability that is vital to the productivity of alfalfa. Therefore, the perennial nature of alfalfa is what allows it to remain productive and thrive for years after being cut back.