Alan Hudson, the farmer at the center of a environmental law case that could shake up the Eastern Shore chicken business, took the stand in federal court Wednesday to tell his side of the story.

Hudson testified that as a 19-year-old, he built the chicken houses at issue in the case, on the Berlin-area farm that has been in his family for at least a century.

"That was going to be my contribution to getting my foot in the door farming with them," the 37-year-old Hudson said, adding that the farm needed a new stream of revenue after its dairy closed down a few years before.

In 2010 Hudson and his wife, Kristin, were sued over allegations that pollution from those chicken houses had drained into a stream that ultimately flows to the Chesapeake Bay. The suit by the Waterkeeper Alliance, an environmental group, also named Salisbury-based poultry firm Perdue, alleging that the company controlled the way Hudson raised the chickens as a contractor and should held liable for any waste they produce.

The trial is being watched closely. Farmers worry that a ruling in the Waterkeepers' favor would threaten their way of doing business, while environmentalists hope that it would let them hold large agricultural companies accountable for pollution.

The Waterkeepers, represented by the University of Maryland environmental law clinic, rested their case Tuesday.

Defense attorneys asked Judge William M. Nickerson on Wednesday morning to throw out the case before they called their first witnesses. Following a line of attack they have taken throughout the case, they argued that the alliance has no real evidence that pollution in the water came from the chicken houses.

James L. Shea, one of Perdue's attorneys, suggested his opponents have tried to fit the circumstantial evidence they have from water samples into a preconceived idea about pollution on the Eastern Shore, calling them "advocates in search of reform."

Since before the trial started, attorneys for Perdue and the Hudsons have attempted to characterize the environmental group as uncaring campaigners, willing to trample a family farm to achieve their objectives.

"They believe in a cause, and they believe the end justifies the means," Shea said Wednesday.

George F. Ritchie, Hudson's lawyer, sought to paint a sympathetic portrait of the man at the heart of the case. Hudson took the stand dressed in a navy blazer, khakis, a white Oxford shirt and gold tie, and stroked his neatly trimmed mustache as he answered Ritchie's questions.

Hudson acknowledged that he was nervous, and when he spoke too quickly for the court reporter to keep up, he apologized, saying, "I'm always in a hurry, there's always more to do."

Hudson will wrap up his testimony Thursday morning, and he faces cross-examination from the environmentalists' lawyers.

The farmer's testimony came on the heels of a week's worth of witnesses seeking to prove the farm's chicken waste fouled a ditch draining the farm.

A key witness for the Waterkeeper Alliance was Bruce A. Bell, an environmental engineer from Monroe, N.Y., who has frequently testified as an expert, including in several high-profile water pollution cases.

Bell told the judge that after examining a variety of data and visiting the farm, he found the chicken-rearing operation was a "contributor" and "most likely the major contributor" to the bacteria and nutrient pollution found in the drainage ditch, while waste from cows on the farm and possibly wildlife also may have contributed.

Bell said dried particles of chicken manure could be seen clinging to large fans venting the chicken houses and on the ground outside, where rainfall would wash it into the ditch through a swale and a pipe installed to drain the area between the chicken houses.

But in his testimony Wednesday, Hudson said his cows produce between 500 and 600 tons of manure a year, much of which falls around the drainage ditch. Federal law does not regulate runoff from pastures. He also said that the matter on the fans was too lightly colored to be chicken litter.

Baltimore Sun reporter Timothy B. Wheeler contributed to this article.

iduncan@baltsun.com