WASHINGTON – Scientists at the USDA’s Agricultural Research Service have uncovered ways to maximize the uptake of nutrients from animal waste by forage plants grown for hay.
Farmers apply livestock wastes because they’re effective, low-cost fertilizers. But when these nutrients accumulate in soils, they can cause environmental problems in certain situations.
The researchers have found that more than half of all the animal waste nutrients taken up by forage plants – like annual ryegrass, red clover and bermudagrass – concentrates in their stems or runners. By maximizing stem production, growers can optimize the uptake of a nutrient such as phosphorus from the soil.
Managing for hay production.
Managing the forage for hay production not only removes excess nutrients from the soil but provides the farmer with another source of income when the hay is sold off the farm.
While making forage into silage also removes nutrients from the soil, the product is more difficult to transport.
The scientists found that the species of forage plant influences the levels of nutrient concentration and retention. And the amount of nutrients also increases with the age of the plant until it is fully mature.
These findings suggest that managing forage plants for growth and maturity and then harvesting them as hay for selling off-farm would maximize nutrient removal and lessen the impact that excess nutrients have on the environment.
Further information from ARS is available at: www.ars.usda.gov/is/AR/archive/may01/hayst0501.htm.