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Dairy heifers in
experimental corrals on cornfields before spring planting. Aluminum masks
surrounding corrals capture ammonia emitted from the soil surface. Click
the image for more information about it.
Looking to Africa for Lessons in Dairy Farming
Peabody September 1, 2005
An Agricultural Research
Service scientist has found an innovative way to manage the tons of animal
waste that are produced each year on dairy farms. But the idea isn't entirely
his; African herdsmen have been practicing it for hundreds of years.
Powell, an agroecologist at the agency's
Dairy Forage Research Center in Madison, Wis., studies how nutrients are
cycled on dairy farms. He's knows that whatever goes into an agricultural
system-the forage and supplements fed to cows-must come out.
According to Powell, just one dairy cow excretes about eight gallons
of urine and the same amount of manure every day. This waste contains natural
fertilizers like nitrogen and phosphorus that can be applied to fields to give
forage crops a boost. But if they're not spread strategically, the nutrients
can build up in soils and could leach into waterways.
Now, after 15 years spent in West Africa watching traditional pastoral
societies herd their animals, Powell thinks he's discovered an approach that
optimizes the waste's potential, while being easy on the environment.
According to Powell, manure is African herdsmen's only fertilizer, so
they don't waste a bit of it. They situate their animals directly onto
croplands being prepared for the next season's plantings. Eventually, the
animals are shifted from one section of the field to another, their hooves
tilling the manure and urine right into the soil.
In contrast, most U.S. dairy farmers keep their cows indoors and truck
the manure daily out to fields. In his studies with this system, which he calls
"corralling," Powell has found that farmers who let their cows gather directly
onto fields can watch their crop production nearly double, while saving on
fertilizer costs. Consumers can also be content knowing that livestock are
getting a breath of fresh outdoor air.
about this research in the September 2005 issue of Agricultural Research
magazine. ARS is the U.S. Department of
Agriculture's chief scientific research agency.