Last week, there were many news reports of waterlines freezing cities and towns around the area. Farmers and rural residents are not immune to this either. Waterlines and tiles buried 4 feet or shallower are prone to freezing this winter. The effect of this unusually cold winter will likely be around for a few more weeks.
You often hear the words “frost line” to describe the depth to which the soil is frozen. More specifically, it is the water within the soil that freezes. As the temperature begins to drop in the fall, the ground begins to freeze near the surface, and that frozen layer creeps deeper over the course of the winter. Generally, the colder the winter, and the longer the duration of the cold air, the deeper the ground will be frozen.
Air temperatures swing wildly compared to soil temperatures, so a single cold day does not have a great impact on the frost line depth. For example, at Purdue’s Northeast Purdue Ag Center, the air temperatures between Jan. 1 and Feb. 23 ranged between minus 15 to 50 degrees Fahrenheit, while soil temperatures ranged from 28 to 33 degrees on average at a 4-inch depth under bare soil. At deeper depths, the temperature is even more stable.
What that means to homeowners, farmers and gardeners is that soils that have reached the freezing point at 4 or 5 feet in depth are going to stay like that for a long time. Keeping some water flowing through the pipes might help to keep pipes from completely freezing.
On the positive side, the soil surface temperatures will begin to rise as we approach spring. Sooner than you would think, the planting season will be here. And as strange as it may seem, in a few weeks, we may be planting into soils that are still close to freezing point 5 feet below the surface.
Jeff Burbrink is an Extension educator in agriculture and natural resources. Write to him at 17746 E. C.R. 34, Goshen, IN 46528; call 533-0554; or fax 533-0254.