A narrowly averted farm tragedy in September has a farm safety expert in Penn State's College of Agricultural Sciences renewing his warning about the dangers of toxic gases emanating from manure-storage facilities. Davis Hill, senior extension associate in the University's Agricultural Safety and Health Program, notes four predominant toxic gases that are produced during manure storage and released during agitation. The most serious of these, from a health standpoint, is hydrogen sulfide. Federal and state agriculture officials have raised concerns about the possibility of higher-than-usual levels of hydrogen sulfide gas being emitted from manure pits containing gypsum-based animal bedding.
When people think about the sources of greenhouse gas emissions, they think of oil refineries, smokestacks, and trucks spewing out thick black smoke. They don't usually think of cows.
But recently, the idea that cattle could be a source of greenhouse gas has been attracting attention. It turns out that the belches of cows, sheep, and other livestock animals contain substantial amounts of methane, a particularly potent greenhouse gas that has about 25 times the global warming potential of carbon dioxide.
By its nature, a national conference on manure tends to generate more dung jokes than ecological perspective. But at Penn State's 2010 Manure Expo on July 15, humor will give way to insights on principles of environmental balance and nutrient utilization.