August
18, 2010 – Reducing the runoff from plant nutrients that can eventually wash
into the Chesapeake Bay could someday be as easy as checking the weather
forecast, thanks in part to work by U.S. Department of Agriculture (USDA)
scientists.
August
18, 2010 – Reducing the runoff from plant nutrients that can eventually wash
into the Chesapeake Bay could someday be as easy as checking the weather
forecast, thanks in part to work by U.S. Department of Agriculture (USDA)
scientists.
One
way farmers manage manure from their livestock is by applying it to crop
fields, which increases soil levels of nitrogen and phosphorus. But when it
rains, the nitrogen and phosphorus in freshly applied manure is much more
likely to run off and pollute nearby water sources, which can end up degrading
water quality throughout the watershed.
Hydrologist
Tony Buda and soil scientist Peter Kleinman with USDA’s Agricultural Research
Service (ARS) are contributing to the development of a web-based “fertilizer
forecast.” The scientists want to create a tool that produces 24-hour and
five-day runoff forecasts that are as user-friendly as weather forecasts.
The
scientists are based at the ARS Pasture Systems and Watershed Management
Research Unit in University Park, PA. ARS is USDA’s primary intramural
scientific research agency.
The
researchers are using National Weather Service (NWS) predictions of
precipitation, soil moisture, and other data to design a simple hydrologic
model that indicates the probability of field runoff occurrence. As part of
this work, they are analyzing how runoff measurements in different Pennsylvania
regions correlate with different NWS data sets for the same areas.
For
instance, the scientists have found that soil moisture forecasts are a strong
indicator of nutrient runoff potential in fields underlain by fragipans, which
are dense subsurface soil layers that can block water movement through soil.
But at sites with other soil characteristics, runoff potential is much more
strongly associated with other variables, such as forecasts of rainfall
amounts.
The
team hopes that when their “forecast” is ready, it will give farmers a
user-friendly tool that can be used to optimize fertilizer runoff management
and enhance water quality.
