Gardeners at a National Trust property have asked their male staff to pee outside.

Employees at Wimpole Hall in Cambridgeshire have installed a "pee bale", BBC News reports.

Head gardener Philip Waites said that he asked his staff to urinate on the three-metre long bale to help activate the composting process.

However, he added that the bale is only in use outside of visiting hours as he does not want to "scare" the public.

"For eight weeks now, male members of our garden and estate teams have been using the outdoor straw bale when nature calls," Waites said. "There are obvious logistical benefits to limiting it to male members of the team, but also male pee is preferable to women's, as the male stuff is apparently less acidic."

The estate claimed that staff will eventually make about 1,000 visits to the bale, saving about 30% of water because of fewer toilet flushes.

The Hall's head composter Rosemary Hooper also praised the idea, adding that members of the public could put it into practice at home.

"Peeing on a compost heap activates the composting process and helps to produce a ready supply of lovely organic matter to add back to the garden," she said.

"Adding a little pee just helps get it all going. It's totally safe and a bit of fun, too."