【生態】イネ科牧草の雑種が洪水リスクを吸収する

A hybrid forage grass that could help to reduce the risk of flooding is reported in the journal Scientific Reports. The new hybrid - a cross between a perennial ryegrass, the grass species of choice for most temperate grassland farmers, and a meadow fescue, a more stress-resistant grass species - was shown to reduce runoff during rainfall events compared to its parent cultivars.

Kit Macleod and colleagues conducted a two-year field experiment to show that the novel grass Festulolium hybrid, also known as Prior, reduced runoff by 51% compared to perennial ryegrass (Lolium perenne) and 43% compared to its other parent cultivar, the meadow fescue (Festulolium pratensis). They show that after six months, Prior produced a larger and more extensively distributed root system compared to its parent species, but after two years Prior retained a lower number of roots, with new root growth confined to the surface soil. The authors suggest that the rapid initial growth and the senescence of the root system may explain the reduced runoff demonstrated in Prior. Hybrid grasses of this type show potential for reducing the likelihood of flood generation, while maintaining food production, they conclude.

Further studies are required to assess the long-term and larger scale effects of the hybrid grass on runoff generation to fully understand any potential benefits for land management and flood control.