Research shows changing pigs' food may reduce phosphorus in the soil.

This is the VOA Special English Agriculture Report. 

Hogs at an Ohio farm

Soil scientist Brian Wienhold said most of the phosphorus in traditional corn fed to pigs is in the substance phytate. Pigs lack a chemical in their bodies to break down phytate. Most of the phosphorus in traditional corn feed passes through the animal without processing. It is expelled in the manure.

Placing the usual swine manure in the fields can increase the phosphorus content of the ground. And when rains cause the phosphorus to wash away, it can harm the environment.

But science may be able to solve the problem. A report on the subject recently appeared in the publication Soil Science Society of America Journal. The researchers are from the Agricultural Research Service of the United States Department of Agriculture and the University of Nebraska at Lincoln. They tested fields not far from the Nebraska cities of Lincoln and Hastings. They put three different substances on the fields: chemical fertilizer, manure from swine fed traditional corn diets and manure from swine fed low-phytate corn diets.

The scientists then compared how much nitrogen and phosphorus were available in the soil. They found that using slurry from swine fed low-phytate corn diets resulted in slower build-up of phosphorus in the soil. At the same time, it did not reduce the availability of the phosphorus to the crops.

Other scientists also have worked with low-phytate feed in recent years. For example, in research reported in two thousand four, University of Kentucky researchers gave pigs and chicks low-phytate feed. The substance phytase was added to the feed. The researchers said it helped break down the phytates.

And that's the VOA Special English Agriculture Report, written by Jerilyn Watson. To learn more about agriculture, go to voaspecialenglish.com for transcripts and MP3 archives of our reports.