Pit Silos

A college professor I may be, but I know a hole in the ground when I see one.  In fact I claim to know quite a bit about certain holes in the ground common to farm life in this part of the country, especially the ones you can fill with silage.

Silos connote particular things in the historic culture of the plains.  They represent old-fashioned diversified farming, wherein a major part of field agriculture went toward production of forage for beef and dairy cattle.  They represent, too, the hopes and dreams of a more confident generation that built these works in the expectation of permanence and left them as inadvertent monuments.

Whereas the popular image of silos is one of verticality, it has always also been common to put silage into the ground.  Trench silos were common from the 1930s on, but until then, farmers dug pit silos-cylindrical holes deep into the ground.  They were filled from silage cutters, and the silage later hauled up for cattle with a block and tackle.  Pit silos were constructed at least as far south as Kansas and to the north into Saskatchewan.

Reading old extension agent reports from North Dakota west of the Missouri River, I learn that the county agents were encouraging farmers to dig pits.  There were two schemes for finishing them.

In the first method, once the hole was done, chicken wire was tacked to the sides of it, and plaster applied.  This worked reasonably well, but was not so good for the long term.  It was asking a lot of soil stability for the walls to remain intact.

In the second method, concrete walls were poured.  This required the construction of forms.  The forms consisted of vertical staves some three feet long, held together in a circle by two-inch lumber on the inside.  The forms were lowered into the hole and concrete poured four inches thick outside them.  After a couple of days the forms were raised and another segment poured, until the surface of the ground was reached.  Then the builders poured a circular curb, perhaps three feet high, atop the ground.

County agent J.C. Russell of Golden Valley County, of whom I have written before, was a great believer in pit silos.  In 1921 he built a set of forms, which year after year he loaned to farmers desiring to pour their own silos.

Russell also reported an ingenious method of raising dirt devised by a fellow named P.O. Peterson of Beach.  The worst part of constructing a pit silo was getting the dirt out of the hole.  Peterson made a bucket out of an oil drum with the home-made bail affixed more than halfway down the bucket.  The poor devil down in the hole filled this bucket, after which his partner above ground drew it up a sort of plank runway, using a team.  The bucket was pulled ten feet above ground with a block and tackle mounted on a derrick, and when it cleared the plank runway, it tipped-because of how the bail was placed-dumping the earth on the ground.

County agent R.C. Newcomer, in Grant County, had farmers building pit silos, as did G.C. Poe in Mercer County.  Poe calculated that the value of forage saved from spoilage in pit silos he got built in 1924 would pay for the whole county extension program.

You can imagine the difficulties with pit silos.  Hauling silage up in winter would have been wearisome.  Gas accumulating in the pit could even be dangerous.  On the other hand, pit silos were easy to fill, and easy to tamp, and the silage kept well.

There are probably more of these antique silos around the country than we know, because of course, you won’t see them from the road.  They were dug up to 20 feet deep, but the ones I have seen are filled near to the top with junk. They are trash middens.