From Penn State Live
UNIVERSITY PARK, Pa. — A unique set of circumstances that could lead to a heightened threat of deadly gas again is being created in silos across the Northeast, according to a farm-safety expert in Penn State’s College of Agricultural Sciences.
The phenomenon may have started with the scorching heat wave the region experienced in early July — which has some areas on the edge of drought conditions — according to Davis Hill, senior extension associate in agricultural and biological engineering. It could develop if the region receives normal amounts of rainfall through the rest of the summer.
“There is now a lot of drought-stressed corn, particularly on manured fields,” he said. “If this crop receives sufficient rainfall later in the season, there will be a potential for higher-than-average nitrates to build up in the corn plants just prior to harvest. This condition can lead to high gas levels in silos.”
During the fermentation process of silage, a number of gases are given off, Hill explained. Of particular concern is a family of gases called oxides of nitrogen — often referred to as “silo gas.”
“The formation of these gases peaks in one to two days after filling and can last for 10 days to two weeks after the fresh, green forage is chopped and blown into the silo,” he said. “This is a naturally occurring process and is necessary to ferment the forage so it is usable feed for livestock and for long-term storage.”
Hill said that sometimes gas production is so great that it is mistaken for a silo fire.